Merge #2472

2472: Split up ty tests a bit r=matklad a=flodiebold

`simple` is a bit of a kitchen sink (and not all of them are really about 'simple' features), suggestions for further divisions there are welcome :smile: 

Co-authored-by: Florian Diebold <[email protected]>

6 files changed, 4876 insertions, 0 deletions

diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
new file mode 100644
index 000000000..0d9a35ce0
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -0,0 +1,268 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn cfg_impl_block() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo cfg:test
+use foo::S as T;
+struct S;
+
+#[cfg(test)]
+impl S {
+    fn foo1(&self) -> i32 { 0 }
+}
+
+#[cfg(not(test))]
+impl S {
+    fn foo2(&self) -> i32 { 0 }
+}
+
+fn test() {
+    let t = (S.foo1(), S.foo2(), T.foo3(), T.foo4());
+    t<|>;
+}
+
+//- /foo.rs crate:foo
+struct S;
+
+#[cfg(not(test))]
+impl S {
+    fn foo3(&self) -> i32 { 0 }
+}
+
+#[cfg(test)]
+impl S {
+    fn foo4(&self) -> i32 { 0 }
+}
+"#,
+    );
+    assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo(Vec<i32>);
+
+macro_rules! foo {
+    ($($item:expr),*) => {
+            {
+                Foo(vec![$($item,)*])
+            }
+    };
+}
+
+fn main() {
+    let x = foo!(1,2);
+}
+"#),
+        @r###"
+    ![0; 17) '{Foo(v...,2,])}': Foo
+    ![1; 4) 'Foo': Foo({unknown}) -> Foo
+    ![1; 16) 'Foo(vec![1,2,])': Foo
+    ![5; 15) 'vec![1,2,]': {unknown}
+    [156; 182) '{     ...,2); }': ()
+    [166; 167) 'x': Foo
+    "###
+    );
+}
+
+#[test]
+fn infer_legacy_textual_scoped_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo(Vec<i32>);
+
+#[macro_use]
+mod m {
+    macro_rules! foo {
+        ($($item:expr),*) => {
+            {
+                Foo(vec![$($item,)*])
+            }
+        };
+    }
+}
+
+fn main() {
+    let x = foo!(1,2);
+    let y = crate::foo!(1,2);
+}
+"#),
+        @r###"
+    ![0; 17) '{Foo(v...,2,])}': Foo
+    ![1; 4) 'Foo': Foo({unknown}) -> Foo
+    ![1; 16) 'Foo(vec![1,2,])': Foo
+    ![5; 15) 'vec![1,2,]': {unknown}
+    [195; 251) '{     ...,2); }': ()
+    [205; 206) 'x': Foo
+    [228; 229) 'y': {unknown}
+    [232; 248) 'crate:...!(1,2)': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_path_qualified_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+#[macro_export]
+macro_rules! foo {
+    () => { 42i32 }
+}
+
+mod m {
+    pub use super::foo as bar;
+}
+
+fn main() {
+    let x = crate::foo!();
+    let y = m::bar!();
+}
+"#),
+        @r###"
+    ![0; 5) '42i32': i32
+    ![0; 5) '42i32': i32
+    [111; 164) '{     ...!(); }': ()
+    [121; 122) 'x': i32
+    [148; 149) 'y': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_type_value_macro_having_same_name() {
+    assert_snapshot!(
+        infer(r#"
+#[macro_export]
+macro_rules! foo {
+    () => {
+        mod foo {
+            pub use super::foo;
+        }
+    };
+    ($x:tt) => {
+        $x
+    };
+}
+
+foo!();
+
+fn foo() {
+    let foo = foo::foo!(42i32);
+}
+"#),
+        @r###"
+    ![0; 5) '42i32': i32
+    [171; 206) '{     ...32); }': ()
+    [181; 184) 'foo': i32
+    "###
+    );
+}
+
+#[test]
+fn processes_impls_generated_by_macros() {
+    let t = type_at(
+        r#"
+//- /main.rs
+macro_rules! m {
+    ($ident:ident) => (impl Trait for $ident {})
+}
+trait Trait { fn foo(self) -> u128 {} }
+struct S;
+m!(S);
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn infer_macro_with_dollar_crate_is_correct_in_expr() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo
+fn test() {
+    let x = (foo::foo!(1), foo::foo!(2));
+    x<|>;
+}
+
+//- /lib.rs crate:foo
+#[macro_export]
+macro_rules! foo {
+    (1) => { $crate::bar!() };
+    (2) => { 1 + $crate::baz() };
+}
+
+#[macro_export]
+macro_rules! bar {
+    () => { 42 }
+}
+
+pub fn baz() -> usize { 31usize }
+"#,
+    );
+    assert_eq!("(i32, usize)", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_builtin_macros_line() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! line {() => {}}
+
+fn main() {
+    let x = line!();
+}
+"#),
+        @r###"
+    ![0; 1) '6': i32
+    [64; 88) '{     ...!(); }': ()
+    [74; 75) 'x': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_file() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! file {() => {}}
+
+fn main() {
+    let x = file!();
+}
+"#),
+        @r###"
+    ![0; 2) '""': &str
+    [64; 88) '{     ...!(); }': ()
+    [74; 75) 'x': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_column() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! column {() => {}}
+
+fn main() {
+    let x = column!();
+}
+"#),
+        @r###"
+    ![0; 2) '13': i32
+    [66; 92) '{     ...!(); }': ()
+    [76; 77) 'x': i32
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
new file mode 100644
index 000000000..45164c9e9
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -0,0 +1,1005 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn infer_slice_method() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "slice"]
+impl<T> [T] {
+    fn foo(&self) -> T {
+        loop {}
+    }
+}
+
+#[lang = "slice_alloc"]
+impl<T> [T] {}
+
+fn test() {
+    <[_]>::foo(b"foo");
+}
+"#),
+        @r###"
+    [45; 49) 'self': &[T]
+    [56; 79) '{     ...     }': T
+    [66; 73) 'loop {}': !
+    [71; 73) '{}': ()
+    [133; 160) '{     ...o"); }': ()
+    [139; 149) '<[_]>::foo': fn foo<u8>(&[T]) -> T
+    [139; 157) '<[_]>:..."foo")': u8
+    [150; 156) 'b"foo"': &[u8]
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_struct() {
+    assert_snapshot!(
+        infer(r#"
+struct A { x: u32 }
+
+impl A {
+    fn new() -> A {
+        A { x: 0 }
+    }
+}
+fn test() {
+    let a = A::new();
+    a.x;
+}
+"#),
+        @r###"
+    [49; 75) '{     ...     }': A
+    [59; 69) 'A { x: 0 }': A
+    [66; 67) '0': u32
+    [88; 122) '{     ...a.x; }': ()
+    [98; 99) 'a': A
+    [102; 108) 'A::new': fn new() -> A
+    [102; 110) 'A::new()': A
+    [116; 117) 'a': A
+    [116; 119) 'a.x': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum A { B, C }
+
+impl A {
+    pub fn b() -> A {
+        A::B
+    }
+    pub fn c() -> A {
+        A::C
+    }
+}
+fn test() {
+    let a = A::b();
+    a;
+    let c = A::c();
+    c;
+}
+"#),
+        @r###"
+    [47; 67) '{     ...     }': A
+    [57; 61) 'A::B': A
+    [88; 108) '{     ...     }': A
+    [98; 102) 'A::C': A
+    [121; 178) '{     ...  c; }': ()
+    [131; 132) 'a': A
+    [135; 139) 'A::b': fn b() -> A
+    [135; 141) 'A::b()': A
+    [147; 148) 'a': A
+    [158; 159) 'c': A
+    [162; 166) 'A::c': fn c() -> A
+    [162; 168) 'A::c()': A
+    [174; 175) 'c': A
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_with_modules() {
+    assert_snapshot!(
+        infer(r#"
+mod a {
+    struct A;
+    impl A { pub fn thing() -> A { A {} }}
+}
+
+mod b {
+    struct B;
+    impl B { pub fn thing() -> u32 { 99 }}
+
+    mod c {
+        struct C;
+        impl C { pub fn thing() -> C { C {} }}
+    }
+}
+use b::c;
+
+fn test() {
+    let x = a::A::thing();
+    let y = b::B::thing();
+    let z = c::C::thing();
+}
+"#),
+        @r###"
+    [56; 64) '{ A {} }': A
+    [58; 62) 'A {}': A
+    [126; 132) '{ 99 }': u32
+    [128; 130) '99': u32
+    [202; 210) '{ C {} }': C
+    [204; 208) 'C {}': C
+    [241; 325) '{     ...g(); }': ()
+    [251; 252) 'x': A
+    [255; 266) 'a::A::thing': fn thing() -> A
+    [255; 268) 'a::A::thing()': A
+    [278; 279) 'y': u32
+    [282; 293) 'b::B::thing': fn thing() -> u32
+    [282; 295) 'b::B::thing()': u32
+    [305; 306) 'z': C
+    [309; 320) 'c::C::thing': fn thing() -> C
+    [309; 322) 'c::C::thing()': C
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make(val: T) -> Gen<T> {
+        Gen { val }
+    }
+}
+
+fn test() {
+    let a = Gen::make(0u32);
+}
+"#),
+        @r###"
+    [64; 67) 'val': T
+    [82; 109) '{     ...     }': Gen<T>
+    [92; 103) 'Gen { val }': Gen<T>
+    [98; 101) 'val': T
+    [123; 155) '{     ...32); }': ()
+    [133; 134) 'a': Gen<u32>
+    [137; 146) 'Gen::make': fn make<u32>(T) -> Gen<T>
+    [137; 152) 'Gen::make(0u32)': Gen<u32>
+    [147; 151) '0u32': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_with_default_param() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T=u32> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::make();
+}
+"#),
+        @r###"
+    [80; 104) '{     ...     }': Gen<T>
+    [90; 98) 'loop { }': !
+    [95; 98) '{ }': ()
+    [118; 146) '{     ...e(); }': ()
+    [128; 129) 'a': Gen<u32>
+    [132; 141) 'Gen::make': fn make<u32>() -> Gen<T>
+    [132; 143) 'Gen::make()': Gen<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_with_default_tuple_param() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct Gen<T=()> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::make();
+    a.val<|>;
+}
+"#,
+    );
+    assert_eq!(t, "()");
+}
+
+#[test]
+fn infer_associated_method_generics_without_args() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::<u32>::make();
+}
+"#),
+        @r###"
+    [76; 100) '{     ...     }': Gen<T>
+    [86; 94) 'loop { }': !
+    [91; 94) '{ }': ()
+    [114; 149) '{     ...e(); }': ()
+    [124; 125) 'a': Gen<u32>
+    [128; 144) 'Gen::<...::make': fn make<u32>() -> Gen<T>
+    [128; 146) 'Gen::<...make()': Gen<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_2_type_params_without_args() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T, U> {
+    val: T,
+    val2: U,
+}
+
+impl<T> Gen<u32, T> {
+    pub fn make() -> Gen<u32,T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::<u32, u64>::make();
+}
+"#),
+        @r###"
+    [102; 126) '{     ...     }': Gen<u32, T>
+    [112; 120) 'loop { }': !
+    [117; 120) '{ }': ()
+    [140; 180) '{     ...e(); }': ()
+    [150; 151) 'a': Gen<u32, u64>
+    [154; 175) 'Gen::<...::make': fn make<u64>() -> Gen<u32, T>
+    [154; 177) 'Gen::<...make()': Gen<u32, u64>
+    "###
+    );
+}
+
+#[test]
+fn cross_crate_associated_method_call() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:other_crate
+fn test() {
+    let x = other_crate::foo::S::thing();
+    x<|>;
+}
+
+//- /lib.rs crate:other_crate
+mod foo {
+    struct S;
+    impl S {
+        fn thing() -> i128 {}
+    }
+}
+"#,
+    );
+    assert_eq!("i128", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_trait_method_simple() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait1 {
+    fn method(&self) -> u32;
+}
+struct S1;
+impl Trait1 for S1 {}
+trait Trait2 {
+    fn method(&self) -> i128;
+}
+struct S2;
+impl Trait2 for S2 {}
+fn test() {
+    S1.method(); // -> u32
+    S2.method(); // -> i128
+}
+"#),
+        @r###"
+    [31; 35) 'self': &Self
+    [110; 114) 'self': &Self
+    [170; 228) '{     ...i128 }': ()
+    [176; 178) 'S1': S1
+    [176; 187) 'S1.method()': u32
+    [203; 205) 'S2': S2
+    [203; 214) 'S2.method()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_scoped() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+struct S;
+mod foo {
+    pub trait Trait1 {
+        fn method(&self) -> u32;
+    }
+    impl Trait1 for super::S {}
+}
+mod bar {
+    pub trait Trait2 {
+        fn method(&self) -> i128;
+    }
+    impl Trait2 for super::S {}
+}
+
+mod foo_test {
+    use super::S;
+    use super::foo::Trait1;
+    fn test() {
+        S.method(); // -> u32
+    }
+}
+
+mod bar_test {
+    use super::S;
+    use super::bar::Trait2;
+    fn test() {
+        S.method(); // -> i128
+    }
+}
+"#),
+        @r###"
+    [63; 67) 'self': &Self
+    [169; 173) 'self': &Self
+    [300; 337) '{     ...     }': ()
+    [310; 311) 'S': S
+    [310; 320) 'S.method()': u32
+    [416; 454) '{     ...     }': ()
+    [426; 427) 'S': S
+    [426; 436) 'S.method()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_1() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+struct S;
+impl Trait<u32> for S {}
+fn test() {
+    S.method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [92; 111) '{     ...d(); }': ()
+    [98; 99) 'S': S
+    [98; 108) 'S.method()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_more_params() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T1, T2, T3> {
+    fn method1(&self) -> (T1, T2, T3);
+    fn method2(&self) -> (T3, T2, T1);
+}
+struct S1;
+impl Trait<u8, u16, u32> for S1 {}
+struct S2;
+impl<T> Trait<i8, i16, T> for S2 {}
+fn test() {
+    S1.method1(); // u8, u16, u32
+    S1.method2(); // u32, u16, u8
+    S2.method1(); // i8, i16, {unknown}
+    S2.method2(); // {unknown}, i16, i8
+}
+"#),
+        @r###"
+    [43; 47) 'self': &Self
+    [82; 86) 'self': &Self
+    [210; 361) '{     ..., i8 }': ()
+    [216; 218) 'S1': S1
+    [216; 228) 'S1.method1()': (u8, u16, u32)
+    [250; 252) 'S1': S1
+    [250; 262) 'S1.method2()': (u32, u16, u8)
+    [284; 286) 'S2': S2
+    [284; 296) 'S2.method1()': (i8, i16, {unknown})
+    [324; 326) 'S2': S2
+    [324; 336) 'S2.method2()': ({unknown}, i16, i8)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_2() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn test() {
+    S(1u32).method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [102; 127) '{     ...d(); }': ()
+    [108; 109) 'S': S<u32>(T) -> S<T>
+    [108; 115) 'S(1u32)': S<u32>
+    [108; 124) 'S(1u32...thod()': u32
+    [110; 114) '1u32': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method() {
+    assert_snapshot!(
+        infer(r#"
+trait Default {
+    fn default() -> Self;
+}
+struct S;
+impl Default for S {}
+fn test() {
+    let s1: S = Default::default();
+    let s2 = S::default();
+    let s3 = <S as Default>::default();
+}
+"#),
+        @r###"
+    [87; 193) '{     ...t(); }': ()
+    [97; 99) 's1': S
+    [105; 121) 'Defaul...efault': fn default<S>() -> Self
+    [105; 123) 'Defaul...ault()': S
+    [133; 135) 's2': S
+    [138; 148) 'S::default': fn default<S>() -> Self
+    [138; 150) 'S::default()': S
+    [160; 162) 's3': S
+    [165; 188) '<S as ...efault': fn default<S>() -> Self
+    [165; 190) '<S as ...ault()': S
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> T;
+}
+struct S;
+impl Trait<u32> for S {}
+struct G<T>;
+impl<T> Trait<T> for G<T> {}
+fn test() {
+    let a = S::make();
+    let b = G::<u64>::make();
+    let c: f64 = G::make();
+}
+"#),
+        @r###"
+    [127; 211) '{     ...e(); }': ()
+    [137; 138) 'a': u32
+    [141; 148) 'S::make': fn make<S, u32>() -> T
+    [141; 150) 'S::make()': u32
+    [160; 161) 'b': u64
+    [164; 178) 'G::<u64>::make': fn make<G<u64>, u64>() -> T
+    [164; 180) 'G::<u6...make()': u64
+    [190; 191) 'c': f64
+    [199; 206) 'G::make': fn make<G<f64>, f64>() -> T
+    [199; 208) 'G::make()': f64
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make<U>() -> (T, U);
+}
+struct S;
+impl Trait<u32> for S {}
+struct G<T>;
+impl<T> Trait<T> for G<T> {}
+fn test() {
+    let a = S::make::<i64>();
+    let b: (_, i64) = S::make();
+    let c = G::<u32>::make::<i64>();
+    let d: (u32, _) = G::make::<i64>();
+    let e: (u32, i64) = G::make();
+}
+"#),
+        @r###"
+    [135; 313) '{     ...e(); }': ()
+    [145; 146) 'a': (u32, i64)
+    [149; 163) 'S::make::<i64>': fn make<S, u32, i64>() -> (T, U)
+    [149; 165) 'S::mak...i64>()': (u32, i64)
+    [175; 176) 'b': (u32, i64)
+    [189; 196) 'S::make': fn make<S, u32, i64>() -> (T, U)
+    [189; 198) 'S::make()': (u32, i64)
+    [208; 209) 'c': (u32, i64)
+    [212; 233) 'G::<u3...:<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
+    [212; 235) 'G::<u3...i64>()': (u32, i64)
+    [245; 246) 'd': (u32, i64)
+    [259; 273) 'G::make::<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
+    [259; 275) 'G::mak...i64>()': (u32, i64)
+    [285; 286) 'e': (u32, i64)
+    [301; 308) 'G::make': fn make<G<u32>, u32, i64>() -> (T, U)
+    [301; 310) 'G::make()': (u32, i64)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_3() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> (Self, T);
+}
+struct S<T>;
+impl Trait<i64> for S<i32> {}
+fn test() {
+    let a = S::make();
+}
+"#),
+        @r###"
+    [101; 127) '{     ...e(); }': ()
+    [111; 112) 'a': (S<i32>, i64)
+    [115; 122) 'S::make': fn make<S<i32>, i64>() -> (Self, T)
+    [115; 124) 'S::make()': (S<i32>, i64)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_4() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> (Self, T);
+}
+struct S<T>;
+impl Trait<i64> for S<u64> {}
+impl Trait<i32> for S<u32> {}
+fn test() {
+    let a: (S<u64>, _) = S::make();
+    let b: (_, i32) = S::make();
+}
+"#),
+        @r###"
+    [131; 203) '{     ...e(); }': ()
+    [141; 142) 'a': (S<u64>, i64)
+    [158; 165) 'S::make': fn make<S<u64>, i64>() -> (Self, T)
+    [158; 167) 'S::make()': (S<u64>, i64)
+    [177; 178) 'b': (S<u32>, i32)
+    [191; 198) 'S::make': fn make<S<u32>, i32>() -> (Self, T)
+    [191; 200) 'S::make()': (S<u32>, i32)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_5() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make<U>() -> (Self, T, U);
+}
+struct S<T>;
+impl Trait<i64> for S<u64> {}
+fn test() {
+    let a = <S as Trait<i64>>::make::<u8>();
+    let b: (S<u64>, _, _) = Trait::<i64>::make::<u8>();
+}
+"#),
+        @r###"
+    [107; 211) '{     ...>(); }': ()
+    [117; 118) 'a': (S<u64>, i64, u8)
+    [121; 150) '<S as ...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
+    [121; 152) '<S as ...<u8>()': (S<u64>, i64, u8)
+    [162; 163) 'b': (S<u64>, i64, u8)
+    [182; 206) 'Trait:...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
+    [182; 208) 'Trait:...<u8>()': (S<u64>, i64, u8)
+    "###
+    );
+}
+
+#[test]
+fn infer_call_trait_method_on_generic_param_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    fn method(&self) -> u32;
+}
+fn test<T: Trait>(t: T) {
+    t.method();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [64; 65) 't': T
+    [70; 89) '{     ...d(); }': ()
+    [76; 77) 't': T
+    [76; 86) 't.method()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_call_trait_method_on_generic_param_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+fn test<U, T: Trait<U>>(t: T) {
+    t.method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [71; 72) 't': T
+    [77; 96) '{     ...d(); }': ()
+    [83; 84) 't': T
+    [83; 93) 't.method()': [missing name]
+    "###
+    );
+}
+
+#[test]
+fn infer_with_multiple_trait_impls() {
+    assert_snapshot!(
+        infer(r#"
+trait Into<T> {
+    fn into(self) -> T;
+}
+struct S;
+impl Into<u32> for S {}
+impl Into<u64> for S {}
+fn test() {
+    let x: u32 = S.into();
+    let y: u64 = S.into();
+    let z = Into::<u64>::into(S);
+}
+"#),
+        @r###"
+    [29; 33) 'self': Self
+    [111; 202) '{     ...(S); }': ()
+    [121; 122) 'x': u32
+    [130; 131) 'S': S
+    [130; 138) 'S.into()': u32
+    [148; 149) 'y': u64
+    [157; 158) 'S': S
+    [157; 165) 'S.into()': u64
+    [175; 176) 'z': u64
+    [179; 196) 'Into::...::into': fn into<S, u64>(Self) -> T
+    [179; 199) 'Into::...nto(S)': u64
+    [197; 198) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn method_resolution_unify_impl_self_type() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S<T>;
+impl S<u32> { fn foo(&self) -> u8 {} }
+impl S<i32> { fn foo(&self) -> i8 {} }
+fn test() { (S::<u32>.foo(), S::<i32>.foo())<|>; }
+"#,
+    );
+    assert_eq!(t, "(u8, i8)");
+}
+
+#[test]
+fn method_resolution_trait_before_autoref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(&self) -> i8 { 0 } }
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_by_value_before_autoref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone { fn clone(&self) -> Self; }
+struct S;
+impl Clone for S {}
+impl Clone for &S {}
+fn test() { (S.clone(), (&S).clone(), (&&S).clone())<|>; }
+"#,
+    );
+    assert_eq!(t, "(S, S, &S)");
+}
+
+#[test]
+fn method_resolution_trait_before_autoderef() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(self) -> i8 { 0 } }
+impl Trait for &S { fn foo(self) -> u128 { 0 } }
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_impl_before_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(self) -> i8 { 0 } }
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "i8");
+}
+
+#[test]
+fn method_resolution_impl_ref_before_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(&self) -> i8 { 0 } }
+impl Trait for &S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "i8");
+}
+
+#[test]
+fn method_resolution_trait_autoderef() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_trait_from_prelude() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:other_crate
+struct S;
+impl Clone for S {}
+
+fn test() {
+    S.clone()<|>;
+}
+
+//- /lib.rs crate:other_crate
+#[prelude_import] use foo::*;
+
+mod foo {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+"#,
+    );
+    assert_eq!("S", type_at_pos(&db, pos));
+}
+
+#[test]
+fn method_resolution_where_clause_for_unknown_trait() {
+    // The blanket impl shouldn't apply because we can't even resolve UnknownTrait
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T> Trait for T where T: UnknownTrait {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_not_met() {
+    // The blanket impl shouldn't apply because we can't prove S: Clone
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T> Trait for T where T: Clone {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    // This is also to make sure that we don't resolve to the foo method just
+    // because that's the only method named foo we can find, which would make
+    // the below tests not work
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_inline_not_met() {
+    // The blanket impl shouldn't apply because we can't prove S: Clone
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T: Clone> Trait for T {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_where_clause_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Into<T> { fn into(self) -> T; }
+trait From<T> { fn from(other: T) -> Self; }
+struct S1;
+struct S2;
+impl From<S2> for S1 {}
+impl<T, U> Into<U> for T where U: From<T> {}
+fn test() { S2.into()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_inline() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Into<T> { fn into(self) -> T; }
+trait From<T> { fn from(other: T) -> Self; }
+struct S1;
+struct S2;
+impl From<S2> for S1 {}
+impl<T, U: From<T>> Into<U> for T {}
+fn test() { S2.into()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_encountering_fn_type() {
+    type_at(
+        r#"
+//- /main.rs
+fn foo() {}
+trait FnOnce { fn call(self); }
+fn test() { foo.call()<|>; }
+"#,
+    );
+}
+
+#[test]
+fn method_resolution_slow() {
+    // this can get quite slow if we set the solver size limit too high
+    let t = type_at(
+        r#"
+//- /main.rs
+trait SendX {}
+
+struct S1; impl SendX for S1 {}
+struct S2; impl SendX for S2 {}
+struct U1;
+
+trait Trait { fn method(self); }
+
+struct X1<A, B> {}
+impl<A, B> SendX for X1<A, B> where A: SendX, B: SendX {}
+
+struct S<B, C> {}
+
+trait FnX {}
+
+impl<B, C> Trait for S<B, C> where C: FnX, B: SendX {}
+
+fn test() { (S {}).method()<|>; }
+"#,
+    );
+    assert_eq!(t, "()");
+}
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
new file mode 100644
index 000000000..cb3890b42
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -0,0 +1,238 @@
+use super::infer;
+use insta::assert_snapshot;
+use test_utils::covers;
+
+#[test]
+fn infer_pattern() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &i32) {
+    let y = x;
+    let &z = x;
+    let a = z;
+    let (c, d) = (1, "hello");
+
+    for (e, f) in some_iter {
+        let g = e;
+    }
+
+    if let [val] = opt {
+        let h = val;
+    }
+
+    let lambda = |a: u64, b, c: i32| { a + b; c };
+
+    let ref ref_to_x = x;
+    let mut mut_x = x;
+    let ref mut mut_ref_to_x = x;
+    let k = mut_ref_to_x;
+}
+"#),
+        @r###"
+    [9; 10) 'x': &i32
+    [18; 369) '{     ...o_x; }': ()
+    [28; 29) 'y': &i32
+    [32; 33) 'x': &i32
+    [43; 45) '&z': &i32
+    [44; 45) 'z': i32
+    [48; 49) 'x': &i32
+    [59; 60) 'a': i32
+    [63; 64) 'z': i32
+    [74; 80) '(c, d)': (i32, &str)
+    [75; 76) 'c': i32
+    [78; 79) 'd': &str
+    [83; 95) '(1, "hello")': (i32, &str)
+    [84; 85) '1': i32
+    [87; 94) '"hello"': &str
+    [102; 152) 'for (e...     }': ()
+    [106; 112) '(e, f)': ({unknown}, {unknown})
+    [107; 108) 'e': {unknown}
+    [110; 111) 'f': {unknown}
+    [116; 125) 'some_iter': {unknown}
+    [126; 152) '{     ...     }': ()
+    [140; 141) 'g': {unknown}
+    [144; 145) 'e': {unknown}
+    [158; 205) 'if let...     }': ()
+    [165; 170) '[val]': {unknown}
+    [173; 176) 'opt': {unknown}
+    [177; 205) '{     ...     }': ()
+    [191; 192) 'h': {unknown}
+    [195; 198) 'val': {unknown}
+    [215; 221) 'lambda': |u64, u64, i32| -> i32
+    [224; 256) '|a: u6...b; c }': |u64, u64, i32| -> i32
+    [225; 226) 'a': u64
+    [233; 234) 'b': u64
+    [236; 237) 'c': i32
+    [244; 256) '{ a + b; c }': i32
+    [246; 247) 'a': u64
+    [246; 251) 'a + b': u64
+    [250; 251) 'b': u64
+    [253; 254) 'c': i32
+    [267; 279) 'ref ref_to_x': &&i32
+    [282; 283) 'x': &i32
+    [293; 302) 'mut mut_x': &i32
+    [305; 306) 'x': &i32
+    [316; 336) 'ref mu...f_to_x': &mut &i32
+    [339; 340) 'x': &i32
+    [350; 351) 'k': &mut &i32
+    [354; 366) 'mut_ref_to_x': &mut &i32
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_ergonomics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T>(T);
+
+fn test() {
+    let A(n) = &A(1);
+    let A(n) = &mut A(1);
+}
+"#),
+    @r###"
+    [28; 79) '{     ...(1); }': ()
+    [38; 42) 'A(n)': A<i32>
+    [40; 41) 'n': &i32
+    [45; 50) '&A(1)': &A<i32>
+    [46; 47) 'A': A<i32>(T) -> A<T>
+    [46; 50) 'A(1)': A<i32>
+    [48; 49) '1': i32
+    [60; 64) 'A(n)': A<i32>
+    [62; 63) 'n': &mut i32
+    [67; 76) '&mut A(1)': &mut A<i32>
+    [72; 73) 'A': A<i32>(T) -> A<T>
+    [72; 76) 'A(1)': A<i32>
+    [74; 75) '1': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_ergonomics_ref() {
+    covers!(match_ergonomics_ref);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let v = &(1, &2);
+    let (_, &w) = v;
+}
+"#),
+    @r###"
+    [11; 57) '{     ...= v; }': ()
+    [21; 22) 'v': &(i32, &i32)
+    [25; 33) '&(1, &2)': &(i32, &i32)
+    [26; 33) '(1, &2)': (i32, &i32)
+    [27; 28) '1': i32
+    [30; 32) '&2': &i32
+    [31; 32) '2': i32
+    [43; 50) '(_, &w)': (i32, &i32)
+    [44; 45) '_': i32
+    [47; 49) '&w': &i32
+    [48; 49) 'w': i32
+    [53; 54) 'v': &(i32, &i32)
+    "###
+    );
+}
+
+#[test]
+fn infer_adt_pattern() {
+    assert_snapshot!(
+        infer(r#"
+enum E {
+    A { x: usize },
+    B
+}
+
+struct S(u32, E);
+
+fn test() {
+    let e = E::A { x: 3 };
+
+    let S(y, z) = foo;
+    let E::A { x: new_var } = e;
+
+    match e {
+        E::A { x } => x,
+        E::B if foo => 1,
+        E::B => 10,
+    };
+
+    let ref d @ E::A { .. } = e;
+    d;
+}
+"#),
+        @r###"
+    [68; 289) '{     ...  d; }': ()
+    [78; 79) 'e': E
+    [82; 95) 'E::A { x: 3 }': E
+    [92; 93) '3': usize
+    [106; 113) 'S(y, z)': S
+    [108; 109) 'y': u32
+    [111; 112) 'z': E
+    [116; 119) 'foo': S
+    [129; 148) 'E::A {..._var }': E
+    [139; 146) 'new_var': usize
+    [151; 152) 'e': E
+    [159; 245) 'match ...     }': usize
+    [165; 166) 'e': E
+    [177; 187) 'E::A { x }': E
+    [184; 185) 'x': usize
+    [191; 192) 'x': usize
+    [202; 206) 'E::B': E
+    [210; 213) 'foo': bool
+    [217; 218) '1': usize
+    [228; 232) 'E::B': E
+    [236; 238) '10': usize
+    [256; 275) 'ref d ...{ .. }': &E
+    [264; 275) 'E::A { .. }': E
+    [278; 279) 'e': E
+    [285; 286) 'd': &E
+    "###
+    );
+}
+
+#[test]
+fn infer_generics_in_patterns() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+
+enum Option<T> {
+    Some(T),
+    None,
+}
+
+fn test(a1: A<u32>, o: Option<u64>) {
+    let A { x: x2 } = a1;
+    let A::<i64> { x: x3 } = A { x: 1 };
+    match o {
+        Option::Some(t) => t,
+        _ => 1,
+    };
+}
+"#),
+        @r###"
+    [79; 81) 'a1': A<u32>
+    [91; 92) 'o': Option<u64>
+    [107; 244) '{     ...  }; }': ()
+    [117; 128) 'A { x: x2 }': A<u32>
+    [124; 126) 'x2': u32
+    [131; 133) 'a1': A<u32>
+    [143; 161) 'A::<i6...: x3 }': A<i64>
+    [157; 159) 'x3': i64
+    [164; 174) 'A { x: 1 }': A<i64>
+    [171; 172) '1': i64
+    [180; 241) 'match ...     }': u64
+    [186; 187) 'o': Option<u64>
+    [198; 213) 'Option::Some(t)': Option<u64>
+    [211; 212) 't': u64
+    [217; 218) 't': u64
+    [228; 229) '_': Option<u64>
+    [233; 234) '1': u64
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
new file mode 100644
index 000000000..09d684ac2
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -0,0 +1,333 @@
+use super::infer;
+use insta::assert_snapshot;
+use test_utils::covers;
+
+#[test]
+fn bug_484() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+   let x = if true {};
+}
+"#),
+        @r###"
+    [11; 37) '{    l... {}; }': ()
+    [20; 21) 'x': ()
+    [24; 34) 'if true {}': ()
+    [27; 31) 'true': bool
+    [32; 34) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn no_panic_on_field_of_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum X {}
+
+fn test(x: X) {
+    x.some_field;
+}
+"#),
+        @r###"
+    [20; 21) 'x': X
+    [26; 47) '{     ...eld; }': ()
+    [32; 33) 'x': X
+    [32; 44) 'x.some_field': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn bug_585() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    X {};
+    match x {
+        A::B {} => (),
+        A::Y() => (),
+    }
+}
+"#),
+        @r###"
+    [11; 89) '{     ...   } }': ()
+    [17; 21) 'X {}': {unknown}
+    [27; 87) 'match ...     }': ()
+    [33; 34) 'x': {unknown}
+    [45; 52) 'A::B {}': {unknown}
+    [56; 58) '()': ()
+    [68; 74) 'A::Y()': {unknown}
+    [78; 80) '()': ()
+    "###
+    );
+}
+
+#[test]
+fn bug_651() {
+    assert_snapshot!(
+        infer(r#"
+fn quux() {
+    let y = 92;
+    1 + y;
+}
+"#),
+        @r###"
+    [11; 41) '{     ...+ y; }': ()
+    [21; 22) 'y': i32
+    [25; 27) '92': i32
+    [33; 34) '1': i32
+    [33; 38) '1 + y': i32
+    [37; 38) 'y': i32
+    "###
+    );
+}
+
+#[test]
+fn recursive_vars() {
+    covers!(type_var_cycles_resolve_completely);
+    covers!(type_var_cycles_resolve_as_possible);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let y = unknown;
+    [y, &y];
+}
+"#),
+        @r###"
+    [11; 48) '{     ...&y]; }': ()
+    [21; 22) 'y': &{unknown}
+    [25; 32) 'unknown': &{unknown}
+    [38; 45) '[y, &y]': [&&{unknown};_]
+    [39; 40) 'y': &{unknown}
+    [42; 44) '&y': &&{unknown}
+    [43; 44) 'y': &{unknown}
+    "###
+    );
+}
+
+#[test]
+fn recursive_vars_2() {
+    covers!(type_var_cycles_resolve_completely);
+    covers!(type_var_cycles_resolve_as_possible);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let x = unknown;
+    let y = unknown;
+    [(x, y), (&y, &x)];
+}
+"#),
+        @r###"
+    [11; 80) '{     ...x)]; }': ()
+    [21; 22) 'x': &&{unknown}
+    [25; 32) 'unknown': &&{unknown}
+    [42; 43) 'y': &&{unknown}
+    [46; 53) 'unknown': &&{unknown}
+    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown});_]
+    [60; 66) '(x, y)': (&&&{unknown}, &&&{unknown})
+    [61; 62) 'x': &&{unknown}
+    [64; 65) 'y': &&{unknown}
+    [68; 76) '(&y, &x)': (&&&{unknown}, &&&{unknown})
+    [69; 71) '&y': &&&{unknown}
+    [70; 71) 'y': &&{unknown}
+    [73; 75) '&x': &&&{unknown}
+    [74; 75) 'x': &&{unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_1() {
+    // caused stack overflow, taken from std
+    assert_snapshot!(
+        infer(r#"
+enum Maybe<T> {
+    Real(T),
+    Fake,
+}
+
+fn write() {
+    match something_unknown {
+        Maybe::Real(ref mut something) => (),
+    }
+}
+"#),
+        @r###"
+    [54; 139) '{     ...   } }': ()
+    [60; 137) 'match ...     }': ()
+    [66; 83) 'someth...nknown': Maybe<{unknown}>
+    [94; 124) 'Maybe:...thing)': Maybe<{unknown}>
+    [106; 123) 'ref mu...ething': &mut {unknown}
+    [128; 130) '()': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_2() {
+    covers!(type_var_resolves_to_int_var);
+    // caused "equating two type variables, ...", taken from std
+    assert_snapshot!(
+        infer(r#"
+fn test_line_buffer() {
+    &[0, b'\n', 1, b'\n'];
+}
+"#),
+        @r###"
+    [23; 53) '{     ...n']; }': ()
+    [29; 50) '&[0, b...b'\n']': &[u8;_]
+    [30; 50) '[0, b'...b'\n']': [u8;_]
+    [31; 32) '0': u8
+    [34; 39) 'b'\n'': u8
+    [41; 42) '1': u8
+    [44; 49) 'b'\n'': u8
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_3() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+pub fn compute() {
+    match nope!() {
+        SizeSkeleton::Pointer { non_zero: true, tail } => {}
+    }
+}
+"#),
+        @r###"
+    [18; 108) '{     ...   } }': ()
+    [24; 106) 'match ...     }': ()
+    [30; 37) 'nope!()': {unknown}
+    [48; 94) 'SizeSk...tail }': {unknown}
+    [82; 86) 'true': {unknown}
+    [88; 92) 'tail': {unknown}
+    [98; 100) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_4() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+pub fn primitive_type() {
+    match *self {
+        BorrowedRef { type_: Primitive(p), ..} => {},
+    }
+}
+"#),
+        @r###"
+    [25; 106) '{     ...   } }': ()
+    [31; 104) 'match ...     }': ()
+    [37; 42) '*self': {unknown}
+    [38; 42) 'self': {unknown}
+    [53; 91) 'Borrow...), ..}': {unknown}
+    [74; 86) 'Primitive(p)': {unknown}
+    [84; 85) 'p': {unknown}
+    [95; 97) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_5() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+fn extra_compiler_flags() {
+    for content in doesnt_matter {
+        let name = if doesnt_matter {
+            first
+        } else {
+            &content
+        };
+
+        let content = if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) {
+            name
+        } else {
+            content
+        };
+    }
+}
+"#),
+        @r###"
+    [27; 323) '{     ...   } }': ()
+    [33; 321) 'for co...     }': ()
+    [37; 44) 'content': &{unknown}
+    [48; 61) 'doesnt_matter': {unknown}
+    [62; 321) '{     ...     }': ()
+    [76; 80) 'name': &&{unknown}
+    [83; 167) 'if doe...     }': &&{unknown}
+    [86; 99) 'doesnt_matter': bool
+    [100; 129) '{     ...     }': &&{unknown}
+    [114; 119) 'first': &&{unknown}
+    [135; 167) '{     ...     }': &&{unknown}
+    [149; 157) '&content': &&{unknown}
+    [150; 157) 'content': &{unknown}
+    [182; 189) 'content': &{unknown}
+    [192; 314) 'if ICE...     }': &{unknown}
+    [195; 232) 'ICE_RE..._VALUE': {unknown}
+    [195; 248) 'ICE_RE...&name)': bool
+    [242; 247) '&name': &&&{unknown}
+    [243; 247) 'name': &&{unknown}
+    [249; 277) '{     ...     }': &&{unknown}
+    [263; 267) 'name': &&{unknown}
+    [283; 314) '{     ...     }': &{unknown}
+    [297; 304) 'content': &{unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_nested_generics_crash() {
+    // another crash found typechecking rustc
+    assert_snapshot!(
+        infer(r#"
+struct Canonical<V> {
+    value: V,
+}
+struct QueryResponse<V> {
+    value: V,
+}
+fn test<R>(query_response: Canonical<QueryResponse<R>>) {
+    &query_response.value;
+}
+"#),
+        @r###"
+    [92; 106) 'query_response': Canonical<QueryResponse<R>>
+    [137; 167) '{     ...lue; }': ()
+    [143; 164) '&query....value': &QueryResponse<R>
+    [144; 158) 'query_response': Canonical<QueryResponse<R>>
+    [144; 164) 'query_....value': QueryResponse<R>
+    "###
+    );
+}
+
+#[test]
+fn bug_1030() {
+    assert_snapshot!(infer(r#"
+struct HashSet<T, H>;
+struct FxHasher;
+type FxHashSet<T> = HashSet<T, FxHasher>;
+
+impl<T, H> HashSet<T, H> {
+    fn default() -> HashSet<T, H> {}
+}
+
+pub fn main_loop() {
+    FxHashSet::default();
+}
+"#),
+    @r###"
+    [144; 146) '{}': ()
+    [169; 198) '{     ...t(); }': ()
+    [175; 193) 'FxHash...efault': fn default<{unknown}, FxHasher>() -> HashSet<T, H>
+    [175; 195) 'FxHash...ault()': HashSet<{unknown}, FxHasher>
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
new file mode 100644
index 000000000..18976c9ae
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -0,0 +1,1608 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn infer_box() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+fn test() {
+    let x = box 1;
+    let t = (x, box x, box &1, box [1]);
+    t<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use prelude::*;
+mod prelude {}
+
+mod boxed {
+    pub struct Box<T: ?Sized> {
+        inner: *mut T,
+    }
+}
+
+"#,
+    );
+    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_adt_self() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs
+enum Nat { Succ(Self), Demo(Nat), Zero }
+
+fn test() {
+    let foo: Nat = Nat::Zero;
+    if let Nat::Succ(x) = foo {
+        x<|>
+    }
+}
+
+"#,
+    );
+    assert_eq!("Nat", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_ranges() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+fn test() {
+    let a = ..;
+    let b = 1..;
+    let c = ..2u32;
+    let d = 1..2usize;
+    let e = ..=10;
+    let f = 'a'..='z';
+
+    let t = (a, b, c, d, e, f);
+    t<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use prelude::*;
+mod prelude {}
+
+pub mod ops {
+    pub struct Range<Idx> {
+        pub start: Idx,
+        pub end: Idx,
+    }
+    pub struct RangeFrom<Idx> {
+        pub start: Idx,
+    }
+    struct RangeFull;
+    pub struct RangeInclusive<Idx> {
+        start: Idx,
+        end: Idx,
+        is_empty: u8,
+    }
+    pub struct RangeTo<Idx> {
+        pub end: Idx,
+    }
+    pub struct RangeToInclusive<Idx> {
+        pub end: Idx,
+    }
+}
+"#,
+    );
+    assert_eq!(
+        "(RangeFull, RangeFrom<i32>, RangeTo<u32>, Range<usize>, RangeToInclusive<i32>, RangeInclusive<char>)",
+        type_at_pos(&db, pos),
+    );
+}
+
+#[test]
+fn infer_while_let() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs
+enum Option<T> { Some(T), None }
+
+fn test() {
+    let foo: Option<f32> = None;
+    while let Option::Some(x) = foo {
+        <|>x
+    }
+}
+
+"#,
+    );
+    assert_eq!("f32", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_basics() {
+    assert_snapshot!(
+        infer(r#"
+fn test(a: u32, b: isize, c: !, d: &str) {
+    a;
+    b;
+    c;
+    d;
+    1usize;
+    1isize;
+    "test";
+    1.0f32;
+}"#),
+        @r###"
+    [9; 10) 'a': u32
+    [17; 18) 'b': isize
+    [27; 28) 'c': !
+    [33; 34) 'd': &str
+    [42; 121) '{     ...f32; }': !
+    [48; 49) 'a': u32
+    [55; 56) 'b': isize
+    [62; 63) 'c': !
+    [69; 70) 'd': &str
+    [76; 82) '1usize': usize
+    [88; 94) '1isize': isize
+    [100; 106) '"test"': &str
+    [112; 118) '1.0f32': f32
+    "###
+    );
+}
+
+#[test]
+fn infer_let() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let a = 1isize;
+    let b: usize = 1;
+    let c = b;
+    let d: u32;
+    let e;
+    let f: i32 = e;
+}
+"#),
+        @r###"
+    [11; 118) '{     ...= e; }': ()
+    [21; 22) 'a': isize
+    [25; 31) '1isize': isize
+    [41; 42) 'b': usize
+    [52; 53) '1': usize
+    [63; 64) 'c': usize
+    [67; 68) 'b': usize
+    [78; 79) 'd': u32
+    [94; 95) 'e': i32
+    [105; 106) 'f': i32
+    [114; 115) 'e': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_paths() {
+    assert_snapshot!(
+        infer(r#"
+fn a() -> u32 { 1 }
+
+mod b {
+    fn c() -> u32 { 1 }
+}
+
+fn test() {
+    a();
+    b::c();
+}
+"#),
+        @r###"
+    [15; 20) '{ 1 }': u32
+    [17; 18) '1': u32
+    [48; 53) '{ 1 }': u32
+    [50; 51) '1': u32
+    [67; 91) '{     ...c(); }': ()
+    [73; 74) 'a': fn a() -> u32
+    [73; 76) 'a()': u32
+    [82; 86) 'b::c': fn c() -> u32
+    [82; 88) 'b::c()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_path_type() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+
+impl S {
+    fn foo() -> i32 { 1 }
+}
+
+fn test() {
+    S::foo();
+    <S>::foo();
+}
+"#),
+        @r###"
+    [41; 46) '{ 1 }': i32
+    [43; 44) '1': i32
+    [60; 93) '{     ...o(); }': ()
+    [66; 72) 'S::foo': fn foo() -> i32
+    [66; 74) 'S::foo()': i32
+    [80; 88) '<S>::foo': fn foo() -> i32
+    [80; 90) '<S>::foo()': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_struct() {
+    assert_snapshot!(
+        infer(r#"
+struct A {
+    b: B,
+    c: C,
+}
+struct B;
+struct C(usize);
+
+fn test() {
+    let c = C(1);
+    B;
+    let a: A = A { b: B, c: C(1) };
+    a.b;
+    a.c;
+}
+"#),
+        @r###"
+    [72; 154) '{     ...a.c; }': ()
+    [82; 83) 'c': C
+    [86; 87) 'C': C(usize) -> C
+    [86; 90) 'C(1)': C
+    [88; 89) '1': usize
+    [96; 97) 'B': B
+    [107; 108) 'a': A
+    [114; 133) 'A { b:...C(1) }': A
+    [121; 122) 'B': B
+    [127; 128) 'C': C(usize) -> C
+    [127; 131) 'C(1)': C
+    [129; 130) '1': usize
+    [139; 140) 'a': A
+    [139; 142) 'a.b': B
+    [148; 149) 'a': A
+    [148; 151) 'a.c': C
+    "###
+    );
+}
+
+#[test]
+fn infer_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum E {
+  V1 { field: u32 },
+  V2
+}
+fn test() {
+  E::V1 { field: 1 };
+  E::V2;
+}"#),
+        @r###"
+    [48; 82) '{   E:...:V2; }': ()
+    [52; 70) 'E::V1 ...d: 1 }': E
+    [67; 68) '1': u32
+    [74; 79) 'E::V2': E
+    "###
+    );
+}
+
+#[test]
+fn infer_refs() {
+    assert_snapshot!(
+        infer(r#"
+fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
+    a;
+    *a;
+    &a;
+    &mut a;
+    b;
+    *b;
+    &b;
+    c;
+    *c;
+    d;
+    *d;
+}
+"#),
+        @r###"
+    [9; 10) 'a': &u32
+    [18; 19) 'b': &mut u32
+    [31; 32) 'c': *const u32
+    [46; 47) 'd': *mut u32
+    [59; 150) '{     ... *d; }': ()
+    [65; 66) 'a': &u32
+    [72; 74) '*a': u32
+    [73; 74) 'a': &u32
+    [80; 82) '&a': &&u32
+    [81; 82) 'a': &u32
+    [88; 94) '&mut a': &mut &u32
+    [93; 94) 'a': &u32
+    [100; 101) 'b': &mut u32
+    [107; 109) '*b': u32
+    [108; 109) 'b': &mut u32
+    [115; 117) '&b': &&mut u32
+    [116; 117) 'b': &mut u32
+    [123; 124) 'c': *const u32
+    [130; 132) '*c': u32
+    [131; 132) 'c': *const u32
+    [138; 139) 'd': *mut u32
+    [145; 147) '*d': u32
+    [146; 147) 'd': *mut u32
+    "###
+    );
+}
+
+#[test]
+fn infer_literals() {
+    assert_snapshot!(
+        infer(r##"
+fn test() {
+    5i32;
+    5f32;
+    5f64;
+    "hello";
+    b"bytes";
+    'c';
+    b'b';
+    3.14;
+    5000;
+    false;
+    true;
+    r#"
+        //! doc
+        // non-doc
+        mod foo {}
+        "#;
+    br#"yolo"#;
+}
+"##),
+        @r###"
+    [11; 221) '{     ...o"#; }': ()
+    [17; 21) '5i32': i32
+    [27; 31) '5f32': f32
+    [37; 41) '5f64': f64
+    [47; 54) '"hello"': &str
+    [60; 68) 'b"bytes"': &[u8]
+    [74; 77) ''c'': char
+    [83; 87) 'b'b'': u8
+    [93; 97) '3.14': f64
+    [103; 107) '5000': i32
+    [113; 118) 'false': bool
+    [124; 128) 'true': bool
+    [134; 202) 'r#"   ...    "#': &str
+    [208; 218) 'br#"yolo"#': &[u8]
+    "###
+    );
+}
+
+#[test]
+fn infer_unary_op() {
+    assert_snapshot!(
+        infer(r#"
+enum SomeType {}
+
+fn test(x: SomeType) {
+    let b = false;
+    let c = !b;
+    let a = 100;
+    let d: i128 = -a;
+    let e = -100;
+    let f = !!!true;
+    let g = !42;
+    let h = !10u32;
+    let j = !a;
+    -3.14;
+    !3;
+    -x;
+    !x;
+    -"hello";
+    !"hello";
+}
+"#),
+        @r###"
+    [27; 28) 'x': SomeType
+    [40; 272) '{     ...lo"; }': ()
+    [50; 51) 'b': bool
+    [54; 59) 'false': bool
+    [69; 70) 'c': bool
+    [73; 75) '!b': bool
+    [74; 75) 'b': bool
+    [85; 86) 'a': i128
+    [89; 92) '100': i128
+    [102; 103) 'd': i128
+    [112; 114) '-a': i128
+    [113; 114) 'a': i128
+    [124; 125) 'e': i32
+    [128; 132) '-100': i32
+    [129; 132) '100': i32
+    [142; 143) 'f': bool
+    [146; 153) '!!!true': bool
+    [147; 153) '!!true': bool
+    [148; 153) '!true': bool
+    [149; 153) 'true': bool
+    [163; 164) 'g': i32
+    [167; 170) '!42': i32
+    [168; 170) '42': i32
+    [180; 181) 'h': u32
+    [184; 190) '!10u32': u32
+    [185; 190) '10u32': u32
+    [200; 201) 'j': i128
+    [204; 206) '!a': i128
+    [205; 206) 'a': i128
+    [212; 217) '-3.14': f64
+    [213; 217) '3.14': f64
+    [223; 225) '!3': i32
+    [224; 225) '3': i32
+    [231; 233) '-x': {unknown}
+    [232; 233) 'x': SomeType
+    [239; 241) '!x': {unknown}
+    [240; 241) 'x': SomeType
+    [247; 255) '-"hello"': {unknown}
+    [248; 255) '"hello"': &str
+    [261; 269) '!"hello"': {unknown}
+    [262; 269) '"hello"': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_backwards() {
+    assert_snapshot!(
+        infer(r#"
+fn takes_u32(x: u32) {}
+
+struct S { i32_field: i32 }
+
+fn test() -> &mut &f64 {
+    let a = unknown_function();
+    takes_u32(a);
+    let b = unknown_function();
+    S { i32_field: b };
+    let c = unknown_function();
+    &mut &c
+}
+"#),
+        @r###"
+    [14; 15) 'x': u32
+    [22; 24) '{}': ()
+    [78; 231) '{     ...t &c }': &mut &f64
+    [88; 89) 'a': u32
+    [92; 108) 'unknow...nction': {unknown}
+    [92; 110) 'unknow...tion()': u32
+    [116; 125) 'takes_u32': fn takes_u32(u32) -> ()
+    [116; 128) 'takes_u32(a)': ()
+    [126; 127) 'a': u32
+    [138; 139) 'b': i32
+    [142; 158) 'unknow...nction': {unknown}
+    [142; 160) 'unknow...tion()': i32
+    [166; 184) 'S { i3...d: b }': S
+    [181; 182) 'b': i32
+    [194; 195) 'c': f64
+    [198; 214) 'unknow...nction': {unknown}
+    [198; 216) 'unknow...tion()': f64
+    [222; 229) '&mut &c': &mut &f64
+    [227; 229) '&c': &f64
+    [228; 229) 'c': f64
+    "###
+    );
+}
+
+#[test]
+fn infer_self() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+
+impl S {
+    fn test(&self) {
+        self;
+    }
+    fn test2(self: &Self) {
+        self;
+    }
+    fn test3() -> Self {
+        S {}
+    }
+    fn test4() -> Self {
+        Self {}
+    }
+}
+"#),
+        @r###"
+    [34; 38) 'self': &S
+    [40; 61) '{     ...     }': ()
+    [50; 54) 'self': &S
+    [75; 79) 'self': &S
+    [88; 109) '{     ...     }': ()
+    [98; 102) 'self': &S
+    [133; 153) '{     ...     }': S
+    [143; 147) 'S {}': S
+    [177; 200) '{     ...     }': S
+    [187; 194) 'Self {}': S
+    "###
+    );
+}
+
+#[test]
+fn infer_binary_op() {
+    assert_snapshot!(
+        infer(r#"
+fn f(x: bool) -> i32 {
+    0i32
+}
+
+fn test() -> bool {
+    let x = a && b;
+    let y = true || false;
+    let z = x == y;
+    let t = x != y;
+    let minus_forty: isize = -40isize;
+    let h = minus_forty <= CONST_2;
+    let c = f(z || y) + 5;
+    let d = b;
+    let g = minus_forty ^= i;
+    let ten: usize = 10;
+    let ten_is_eleven = ten == some_num;
+
+    ten < 3
+}
+"#),
+        @r###"
+    [6; 7) 'x': bool
+    [22; 34) '{     0i32 }': i32
+    [28; 32) '0i32': i32
+    [54; 370) '{     ... < 3 }': bool
+    [64; 65) 'x': bool
+    [68; 69) 'a': bool
+    [68; 74) 'a && b': bool
+    [73; 74) 'b': bool
+    [84; 85) 'y': bool
+    [88; 92) 'true': bool
+    [88; 101) 'true || false': bool
+    [96; 101) 'false': bool
+    [111; 112) 'z': bool
+    [115; 116) 'x': bool
+    [115; 121) 'x == y': bool
+    [120; 121) 'y': bool
+    [131; 132) 't': bool
+    [135; 136) 'x': bool
+    [135; 141) 'x != y': bool
+    [140; 141) 'y': bool
+    [151; 162) 'minus_forty': isize
+    [172; 180) '-40isize': isize
+    [173; 180) '40isize': isize
+    [190; 191) 'h': bool
+    [194; 205) 'minus_forty': isize
+    [194; 216) 'minus_...ONST_2': bool
+    [209; 216) 'CONST_2': isize
+    [226; 227) 'c': i32
+    [230; 231) 'f': fn f(bool) -> i32
+    [230; 239) 'f(z || y)': i32
+    [230; 243) 'f(z || y) + 5': i32
+    [232; 233) 'z': bool
+    [232; 238) 'z || y': bool
+    [237; 238) 'y': bool
+    [242; 243) '5': i32
+    [253; 254) 'd': {unknown}
+    [257; 258) 'b': {unknown}
+    [268; 269) 'g': ()
+    [272; 283) 'minus_forty': isize
+    [272; 288) 'minus_...y ^= i': ()
+    [287; 288) 'i': isize
+    [298; 301) 'ten': usize
+    [311; 313) '10': usize
+    [323; 336) 'ten_is_eleven': bool
+    [339; 342) 'ten': usize
+    [339; 354) 'ten == some_num': bool
+    [346; 354) 'some_num': usize
+    [361; 364) 'ten': usize
+    [361; 368) 'ten < 3': bool
+    [367; 368) '3': usize
+    "###
+    );
+}
+
+#[test]
+fn infer_field_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+struct A {
+    b: B,
+}
+struct B;
+
+fn test1(a: A) {
+    let a1 = a;
+    a1.b;
+    let a2 = &a;
+    a2.b;
+    let a3 = &mut a;
+    a3.b;
+    let a4 = &&&&&&&a;
+    a4.b;
+    let a5 = &mut &&mut &&mut a;
+    a5.b;
+}
+
+fn test2(a1: *const A, a2: *mut A) {
+    a1.b;
+    a2.b;
+}
+"#),
+        @r###"
+    [44; 45) 'a': A
+    [50; 213) '{     ...5.b; }': ()
+    [60; 62) 'a1': A
+    [65; 66) 'a': A
+    [72; 74) 'a1': A
+    [72; 76) 'a1.b': B
+    [86; 88) 'a2': &A
+    [91; 93) '&a': &A
+    [92; 93) 'a': A
+    [99; 101) 'a2': &A
+    [99; 103) 'a2.b': B
+    [113; 115) 'a3': &mut A
+    [118; 124) '&mut a': &mut A
+    [123; 124) 'a': A
+    [130; 132) 'a3': &mut A
+    [130; 134) 'a3.b': B
+    [144; 146) 'a4': &&&&&&&A
+    [149; 157) '&&&&&&&a': &&&&&&&A
+    [150; 157) '&&&&&&a': &&&&&&A
+    [151; 157) '&&&&&a': &&&&&A
+    [152; 157) '&&&&a': &&&&A
+    [153; 157) '&&&a': &&&A
+    [154; 157) '&&a': &&A
+    [155; 157) '&a': &A
+    [156; 157) 'a': A
+    [163; 165) 'a4': &&&&&&&A
+    [163; 167) 'a4.b': B
+    [177; 179) 'a5': &mut &&mut &&mut A
+    [182; 200) '&mut &...&mut a': &mut &&mut &&mut A
+    [187; 200) '&&mut &&mut a': &&mut &&mut A
+    [188; 200) '&mut &&mut a': &mut &&mut A
+    [193; 200) '&&mut a': &&mut A
+    [194; 200) '&mut a': &mut A
+    [199; 200) 'a': A
+    [206; 208) 'a5': &mut &&mut &&mut A
+    [206; 210) 'a5.b': B
+    [224; 226) 'a1': *const A
+    [238; 240) 'a2': *mut A
+    [250; 273) '{     ...2.b; }': ()
+    [256; 258) 'a1': *const A
+    [256; 260) 'a1.b': B
+    [266; 268) 'a2': *mut A
+    [266; 270) 'a2.b': B
+    "###
+    );
+}
+
+#[test]
+fn infer_argument_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "deref"]
+pub trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct A<T>(T);
+
+impl<T> A<T> {
+    fn foo(&self) -> &T {
+        &self.0
+    }
+}
+
+struct B<T>(T);
+
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+fn test() {
+    let t = A::foo(&&B(B(A(42))));
+}
+"#),
+        @r###"
+    [68; 72) 'self': &Self
+    [139; 143) 'self': &A<T>
+    [151; 174) '{     ...     }': &T
+    [161; 168) '&self.0': &T
+    [162; 166) 'self': &A<T>
+    [162; 168) 'self.0': T
+    [255; 259) 'self': &B<T>
+    [278; 301) '{     ...     }': &T
+    [288; 295) '&self.0': &T
+    [289; 293) 'self': &B<T>
+    [289; 295) 'self.0': T
+    [315; 353) '{     ...))); }': ()
+    [325; 326) 't': &i32
+    [329; 335) 'A::foo': fn foo<i32>(&A<T>) -> &T
+    [329; 350) 'A::foo...42))))': &i32
+    [336; 349) '&&B(B(A(42)))': &&B<B<A<i32>>>
+    [337; 349) '&B(B(A(42)))': &B<B<A<i32>>>
+    [338; 339) 'B': B<B<A<i32>>>(T) -> B<T>
+    [338; 349) 'B(B(A(42)))': B<B<A<i32>>>
+    [340; 341) 'B': B<A<i32>>(T) -> B<T>
+    [340; 348) 'B(A(42))': B<A<i32>>
+    [342; 343) 'A': A<i32>(T) -> A<T>
+    [342; 347) 'A(42)': A<i32>
+    [344; 346) '42': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_method_argument_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "deref"]
+pub trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct A<T>(*mut T);
+
+impl<T> A<T> {
+    fn foo(&self, x: &A<T>) -> &T {
+        &*x.0
+    }
+}
+
+struct B<T>(T);
+
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+fn test(a: A<i32>) {
+    let t = A(0 as *mut _).foo(&&B(B(a)));
+}
+"#),
+        @r###"
+    [68; 72) 'self': &Self
+    [144; 148) 'self': &A<T>
+    [150; 151) 'x': &A<T>
+    [166; 187) '{     ...     }': &T
+    [176; 181) '&*x.0': &T
+    [177; 181) '*x.0': T
+    [178; 179) 'x': &A<T>
+    [178; 181) 'x.0': *mut T
+    [268; 272) 'self': &B<T>
+    [291; 314) '{     ...     }': &T
+    [301; 308) '&self.0': &T
+    [302; 306) 'self': &B<T>
+    [302; 308) 'self.0': T
+    [326; 327) 'a': A<i32>
+    [337; 383) '{     ...))); }': ()
+    [347; 348) 't': &i32
+    [351; 352) 'A': A<i32>(*mut T) -> A<T>
+    [351; 365) 'A(0 as *mut _)': A<i32>
+    [351; 380) 'A(0 as...B(a)))': &i32
+    [353; 354) '0': i32
+    [353; 364) '0 as *mut _': *mut i32
+    [370; 379) '&&B(B(a))': &&B<B<A<i32>>>
+    [371; 379) '&B(B(a))': &B<B<A<i32>>>
+    [372; 373) 'B': B<B<A<i32>>>(T) -> B<T>
+    [372; 379) 'B(B(a))': B<B<A<i32>>>
+    [374; 375) 'B': B<A<i32>>(T) -> B<T>
+    [374; 378) 'B(a)': B<A<i32>>
+    [376; 377) 'a': A<i32>
+    "###
+    );
+}
+
+#[test]
+fn infer_in_elseif() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo { field: i32 }
+fn main(foo: Foo) {
+    if true {
+
+    } else if false {
+        foo.field
+    }
+}
+"#),
+        @r###"
+    [35; 38) 'foo': Foo
+    [45; 109) '{     ...   } }': ()
+    [51; 107) 'if tru...     }': ()
+    [54; 58) 'true': bool
+    [59; 67) '{      }': ()
+    [73; 107) 'if fal...     }': ()
+    [76; 81) 'false': bool
+    [82; 107) '{     ...     }': i32
+    [92; 95) 'foo': Foo
+    [92; 101) 'foo.field': i32
+    "###
+    )
+}
+
+#[test]
+fn infer_if_match_with_return() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() {
+    let _x1 = if true {
+        1
+    } else {
+        return;
+    };
+    let _x2 = if true {
+        2
+    } else {
+        return
+    };
+    let _x3 = match true {
+        true => 3,
+        _ => {
+            return;
+        }
+    };
+    let _x4 = match true {
+        true => 4,
+        _ => return
+    };
+}"#),
+        @r###"
+    [10; 323) '{     ...  }; }': ()
+    [20; 23) '_x1': i32
+    [26; 80) 'if tru...     }': i32
+    [29; 33) 'true': bool
+    [34; 51) '{     ...     }': i32
+    [44; 45) '1': i32
+    [57; 80) '{     ...     }': !
+    [67; 73) 'return': !
+    [90; 93) '_x2': i32
+    [96; 149) 'if tru...     }': i32
+    [99; 103) 'true': bool
+    [104; 121) '{     ...     }': i32
+    [114; 115) '2': i32
+    [127; 149) '{     ...     }': !
+    [137; 143) 'return': !
+    [159; 162) '_x3': i32
+    [165; 247) 'match ...     }': i32
+    [171; 175) 'true': bool
+    [186; 190) 'true': bool
+    [194; 195) '3': i32
+    [205; 206) '_': bool
+    [210; 241) '{     ...     }': !
+    [224; 230) 'return': !
+    [257; 260) '_x4': i32
+    [263; 320) 'match ...     }': i32
+    [269; 273) 'true': bool
+    [284; 288) 'true': bool
+    [292; 293) '4': i32
+    [303; 304) '_': bool
+    [308; 314) 'return': !
+    "###
+    )
+}
+
+#[test]
+fn infer_inherent_method() {
+    assert_snapshot!(
+        infer(r#"
+struct A;
+
+impl A {
+    fn foo(self, x: u32) -> i32 {}
+}
+
+mod b {
+    impl super::A {
+        fn bar(&self, x: u64) -> i64 {}
+    }
+}
+
+fn test(a: A) {
+    a.foo(1);
+    (&a).bar(1);
+    a.bar(1);
+}
+"#),
+        @r###"
+    [32; 36) 'self': A
+    [38; 39) 'x': u32
+    [53; 55) '{}': ()
+    [103; 107) 'self': &A
+    [109; 110) 'x': u64
+    [124; 126) '{}': ()
+    [144; 145) 'a': A
+    [150; 198) '{     ...(1); }': ()
+    [156; 157) 'a': A
+    [156; 164) 'a.foo(1)': i32
+    [162; 163) '1': u32
+    [170; 181) '(&a).bar(1)': i64
+    [171; 173) '&a': &A
+    [172; 173) 'a': A
+    [179; 180) '1': u64
+    [187; 188) 'a': A
+    [187; 195) 'a.bar(1)': i64
+    [193; 194) '1': u64
+    "###
+    );
+}
+
+#[test]
+fn infer_inherent_method_str() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "str"]
+impl str {
+    fn foo(&self) -> i32 {}
+}
+
+fn test() {
+    "foo".foo();
+}
+"#),
+        @r###"
+    [40; 44) 'self': &str
+    [53; 55) '{}': ()
+    [69; 89) '{     ...o(); }': ()
+    [75; 80) '"foo"': &str
+    [75; 86) '"foo".foo()': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_tuple() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &str, y: isize) {
+    let a: (u32, &str) = (1, "a");
+    let b = (a, x);
+    let c = (y, x);
+    let d = (c, x);
+    let e = (1, "e");
+    let f = (e, "d");
+}
+"#),
+        @r###"
+    [9; 10) 'x': &str
+    [18; 19) 'y': isize
+    [28; 170) '{     ...d"); }': ()
+    [38; 39) 'a': (u32, &str)
+    [55; 63) '(1, "a")': (u32, &str)
+    [56; 57) '1': u32
+    [59; 62) '"a"': &str
+    [73; 74) 'b': ((u32, &str), &str)
+    [77; 83) '(a, x)': ((u32, &str), &str)
+    [78; 79) 'a': (u32, &str)
+    [81; 82) 'x': &str
+    [93; 94) 'c': (isize, &str)
+    [97; 103) '(y, x)': (isize, &str)
+    [98; 99) 'y': isize
+    [101; 102) 'x': &str
+    [113; 114) 'd': ((isize, &str), &str)
+    [117; 123) '(c, x)': ((isize, &str), &str)
+    [118; 119) 'c': (isize, &str)
+    [121; 122) 'x': &str
+    [133; 134) 'e': (i32, &str)
+    [137; 145) '(1, "e")': (i32, &str)
+    [138; 139) '1': i32
+    [141; 144) '"e"': &str
+    [155; 156) 'f': ((i32, &str), &str)
+    [159; 167) '(e, "d")': ((i32, &str), &str)
+    [160; 161) 'e': (i32, &str)
+    [163; 166) '"d"': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_array() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &str, y: isize) {
+    let a = [x];
+    let b = [a, a];
+    let c = [b, b];
+
+    let d = [y, 1, 2, 3];
+    let d = [1, y, 2, 3];
+    let e = [y];
+    let f = [d, d];
+    let g = [e, e];
+
+    let h = [1, 2];
+    let i = ["a", "b"];
+
+    let b = [a, ["b"]];
+    let x: [u8; 0] = [];
+}
+"#),
+        @r###"
+    [9; 10) 'x': &str
+    [18; 19) 'y': isize
+    [28; 293) '{     ... []; }': ()
+    [38; 39) 'a': [&str;_]
+    [42; 45) '[x]': [&str;_]
+    [43; 44) 'x': &str
+    [55; 56) 'b': [[&str;_];_]
+    [59; 65) '[a, a]': [[&str;_];_]
+    [60; 61) 'a': [&str;_]
+    [63; 64) 'a': [&str;_]
+    [75; 76) 'c': [[[&str;_];_];_]
+    [79; 85) '[b, b]': [[[&str;_];_];_]
+    [80; 81) 'b': [[&str;_];_]
+    [83; 84) 'b': [[&str;_];_]
+    [96; 97) 'd': [isize;_]
+    [100; 112) '[y, 1, 2, 3]': [isize;_]
+    [101; 102) 'y': isize
+    [104; 105) '1': isize
+    [107; 108) '2': isize
+    [110; 111) '3': isize
+    [122; 123) 'd': [isize;_]
+    [126; 138) '[1, y, 2, 3]': [isize;_]
+    [127; 128) '1': isize
+    [130; 131) 'y': isize
+    [133; 134) '2': isize
+    [136; 137) '3': isize
+    [148; 149) 'e': [isize;_]
+    [152; 155) '[y]': [isize;_]
+    [153; 154) 'y': isize
+    [165; 166) 'f': [[isize;_];_]
+    [169; 175) '[d, d]': [[isize;_];_]
+    [170; 171) 'd': [isize;_]
+    [173; 174) 'd': [isize;_]
+    [185; 186) 'g': [[isize;_];_]
+    [189; 195) '[e, e]': [[isize;_];_]
+    [190; 191) 'e': [isize;_]
+    [193; 194) 'e': [isize;_]
+    [206; 207) 'h': [i32;_]
+    [210; 216) '[1, 2]': [i32;_]
+    [211; 212) '1': i32
+    [214; 215) '2': i32
+    [226; 227) 'i': [&str;_]
+    [230; 240) '["a", "b"]': [&str;_]
+    [231; 234) '"a"': &str
+    [236; 239) '"b"': &str
+    [251; 252) 'b': [[&str;_];_]
+    [255; 265) '[a, ["b"]]': [[&str;_];_]
+    [256; 257) 'a': [&str;_]
+    [259; 264) '["b"]': [&str;_]
+    [260; 263) '"b"': &str
+    [275; 276) 'x': [u8;_]
+    [288; 290) '[]': [u8;_]
+    "###
+    );
+}
+
+#[test]
+fn infer_struct_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+
+fn test(a1: A<u32>, i: i32) {
+    a1.x;
+    let a2 = A { x: i };
+    a2.x;
+    let a3 = A::<i128> { x: 1 };
+    a3.x;
+}
+"#),
+        @r###"
+    [36; 38) 'a1': A<u32>
+    [48; 49) 'i': i32
+    [56; 147) '{     ...3.x; }': ()
+    [62; 64) 'a1': A<u32>
+    [62; 66) 'a1.x': u32
+    [76; 78) 'a2': A<i32>
+    [81; 91) 'A { x: i }': A<i32>
+    [88; 89) 'i': i32
+    [97; 99) 'a2': A<i32>
+    [97; 101) 'a2.x': i32
+    [111; 113) 'a3': A<i128>
+    [116; 134) 'A::<i1...x: 1 }': A<i128>
+    [131; 132) '1': i128
+    [140; 142) 'a3': A<i128>
+    [140; 144) 'a3.x': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_tuple_struct_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T>(T);
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn test() {
+    A(42);
+    A(42u128);
+    Some("x");
+    Option::Some("x");
+    None;
+    let x: Option<i64> = None;
+}
+"#),
+        @r###"
+    [76; 184) '{     ...one; }': ()
+    [82; 83) 'A': A<i32>(T) -> A<T>
+    [82; 87) 'A(42)': A<i32>
+    [84; 86) '42': i32
+    [93; 94) 'A': A<u128>(T) -> A<T>
+    [93; 102) 'A(42u128)': A<u128>
+    [95; 101) '42u128': u128
+    [108; 112) 'Some': Some<&str>(T) -> Option<T>
+    [108; 117) 'Some("x")': Option<&str>
+    [113; 116) '"x"': &str
+    [123; 135) 'Option::Some': Some<&str>(T) -> Option<T>
+    [123; 140) 'Option...e("x")': Option<&str>
+    [136; 139) '"x"': &str
+    [146; 150) 'None': Option<{unknown}>
+    [160; 161) 'x': Option<i64>
+    [177; 181) 'None': Option<i64>
+    "###
+    );
+}
+
+#[test]
+fn infer_function_generics() {
+    assert_snapshot!(
+        infer(r#"
+fn id<T>(t: T) -> T { t }
+
+fn test() {
+    id(1u32);
+    id::<i128>(1);
+    let x: u64 = id(1);
+}
+"#),
+        @r###"
+    [10; 11) 't': T
+    [21; 26) '{ t }': T
+    [23; 24) 't': T
+    [38; 98) '{     ...(1); }': ()
+    [44; 46) 'id': fn id<u32>(T) -> T
+    [44; 52) 'id(1u32)': u32
+    [47; 51) '1u32': u32
+    [58; 68) 'id::<i128>': fn id<i128>(T) -> T
+    [58; 71) 'id::<i128>(1)': i128
+    [69; 70) '1': i128
+    [81; 82) 'x': u64
+    [90; 92) 'id': fn id<u64>(T) -> T
+    [90; 95) 'id(1)': u64
+    [93; 94) '1': u64
+    "###
+    );
+}
+
+#[test]
+fn infer_impl_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T1, T2> {
+    x: T1,
+    y: T2,
+}
+impl<Y, X> A<X, Y> {
+    fn x(self) -> X {
+        self.x
+    }
+    fn y(self) -> Y {
+        self.y
+    }
+    fn z<T>(self, t: T) -> (X, Y, T) {
+        (self.x, self.y, t)
+    }
+}
+
+fn test() -> i128 {
+    let a = A { x: 1u64, y: 1i64 };
+    a.x();
+    a.y();
+    a.z(1i128);
+    a.z::<u128>(1);
+}
+"#),
+        @r###"
+    [74; 78) 'self': A<X, Y>
+    [85; 107) '{     ...     }': X
+    [95; 99) 'self': A<X, Y>
+    [95; 101) 'self.x': X
+    [117; 121) 'self': A<X, Y>
+    [128; 150) '{     ...     }': Y
+    [138; 142) 'self': A<X, Y>
+    [138; 144) 'self.y': Y
+    [163; 167) 'self': A<X, Y>
+    [169; 170) 't': T
+    [188; 223) '{     ...     }': (X, Y, T)
+    [198; 217) '(self.....y, t)': (X, Y, T)
+    [199; 203) 'self': A<X, Y>
+    [199; 205) 'self.x': X
+    [207; 211) 'self': A<X, Y>
+    [207; 213) 'self.y': Y
+    [215; 216) 't': T
+    [245; 342) '{     ...(1); }': ()
+    [255; 256) 'a': A<u64, i64>
+    [259; 281) 'A { x:...1i64 }': A<u64, i64>
+    [266; 270) '1u64': u64
+    [275; 279) '1i64': i64
+    [287; 288) 'a': A<u64, i64>
+    [287; 292) 'a.x()': u64
+    [298; 299) 'a': A<u64, i64>
+    [298; 303) 'a.y()': i64
+    [309; 310) 'a': A<u64, i64>
+    [309; 319) 'a.z(1i128)': (u64, i64, i128)
+    [313; 318) '1i128': i128
+    [325; 326) 'a': A<u64, i64>
+    [325; 339) 'a.z::<u128>(1)': (u64, i64, u128)
+    [337; 338) '1': u128
+    "###
+    );
+}
+
+#[test]
+fn infer_impl_generics_with_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+enum Option<T> {
+    Some(T),
+    None,
+}
+impl<T> Option<T> {
+    fn as_ref(&self) -> Option<&T> {}
+}
+fn test(o: Option<u32>) {
+    (&o).as_ref();
+    o.as_ref();
+}
+"#),
+        @r###"
+    [78; 82) 'self': &Option<T>
+    [98; 100) '{}': ()
+    [111; 112) 'o': Option<u32>
+    [127; 165) '{     ...f(); }': ()
+    [133; 146) '(&o).as_ref()': Option<&u32>
+    [134; 136) '&o': &Option<u32>
+    [135; 136) 'o': Option<u32>
+    [152; 153) 'o': Option<u32>
+    [152; 162) 'o.as_ref()': Option<&u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_generic_chain() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+impl<T2> A<T2> {
+    fn x(self) -> T2 {
+        self.x
+    }
+}
+fn id<T>(t: T) -> T { t }
+
+fn test() -> i128 {
+     let x = 1;
+     let y = id(x);
+     let a = A { x: id(y) };
+     let z = id(a.x);
+     let b = A { x: z };
+     b.x()
+}
+"#),
+        @r###"
+    [53; 57) 'self': A<T2>
+    [65; 87) '{     ...     }': T2
+    [75; 79) 'self': A<T2>
+    [75; 81) 'self.x': T2
+    [99; 100) 't': T
+    [110; 115) '{ t }': T
+    [112; 113) 't': T
+    [135; 261) '{     ....x() }': i128
+    [146; 147) 'x': i128
+    [150; 151) '1': i128
+    [162; 163) 'y': i128
+    [166; 168) 'id': fn id<i128>(T) -> T
+    [166; 171) 'id(x)': i128
+    [169; 170) 'x': i128
+    [182; 183) 'a': A<i128>
+    [186; 200) 'A { x: id(y) }': A<i128>
+    [193; 195) 'id': fn id<i128>(T) -> T
+    [193; 198) 'id(y)': i128
+    [196; 197) 'y': i128
+    [211; 212) 'z': i128
+    [215; 217) 'id': fn id<i128>(T) -> T
+    [215; 222) 'id(a.x)': i128
+    [218; 219) 'a': A<i128>
+    [218; 221) 'a.x': i128
+    [233; 234) 'b': A<i128>
+    [237; 247) 'A { x: z }': A<i128>
+    [244; 245) 'z': i128
+    [254; 255) 'b': A<i128>
+    [254; 259) 'b.x()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_const() {
+    assert_snapshot!(
+        infer(r#"
+struct Struct;
+
+impl Struct {
+    const FOO: u32 = 1;
+}
+
+enum Enum {}
+
+impl Enum {
+    const BAR: u32 = 2;
+}
+
+trait Trait {
+    const ID: u32;
+}
+
+struct TraitTest;
+
+impl Trait for TraitTest {
+    const ID: u32 = 5;
+}
+
+fn test() {
+    let x = Struct::FOO;
+    let y = Enum::BAR;
+    let z = TraitTest::ID;
+}
+"#),
+        @r###"
+    [52; 53) '1': u32
+    [105; 106) '2': u32
+    [213; 214) '5': u32
+    [229; 307) '{     ...:ID; }': ()
+    [239; 240) 'x': u32
+    [243; 254) 'Struct::FOO': u32
+    [264; 265) 'y': u32
+    [268; 277) 'Enum::BAR': u32
+    [287; 288) 'z': u32
+    [291; 304) 'TraitTest::ID': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_type_alias() {
+    assert_snapshot!(
+        infer(r#"
+struct A<X, Y> { x: X, y: Y }
+type Foo = A<u32, i128>;
+type Bar<T> = A<T, u128>;
+type Baz<U, V> = A<V, U>;
+fn test(x: Foo, y: Bar<&str>, z: Baz<i8, u8>) {
+    x.x;
+    x.y;
+    y.x;
+    y.y;
+    z.x;
+    z.y;
+}
+"#),
+        @r###"
+    [116; 117) 'x': A<u32, i128>
+    [124; 125) 'y': A<&str, u128>
+    [138; 139) 'z': A<u8, i8>
+    [154; 211) '{     ...z.y; }': ()
+    [160; 161) 'x': A<u32, i128>
+    [160; 163) 'x.x': u32
+    [169; 170) 'x': A<u32, i128>
+    [169; 172) 'x.y': i128
+    [178; 179) 'y': A<&str, u128>
+    [178; 181) 'y.x': &str
+    [187; 188) 'y': A<&str, u128>
+    [187; 190) 'y.y': u128
+    [196; 197) 'z': A<u8, i8>
+    [196; 199) 'z.x': u8
+    [205; 206) 'z': A<u8, i8>
+    [205; 208) 'z.y': i8
+    "###
+    )
+}
+
+#[test]
+fn recursive_type_alias() {
+    assert_snapshot!(
+        infer(r#"
+struct A<X> {}
+type Foo = Foo;
+type Bar = A<Bar>;
+fn test(x: Foo) {}
+"#),
+        @r###"
+    [59; 60) 'x': {unknown}
+    [67; 69) '{}': ()
+    "###
+    )
+}
+
+#[test]
+fn infer_type_param() {
+    assert_snapshot!(
+        infer(r#"
+fn id<T>(x: T) -> T {
+    x
+}
+
+fn clone<T>(x: &T) -> T {
+    *x
+}
+
+fn test() {
+    let y = 10u32;
+    id(y);
+    let x: bool = clone(z);
+    id::<i128>(1);
+}
+"#),
+        @r###"
+    [10; 11) 'x': T
+    [21; 30) '{     x }': T
+    [27; 28) 'x': T
+    [44; 45) 'x': &T
+    [56; 66) '{     *x }': T
+    [62; 64) '*x': T
+    [63; 64) 'x': &T
+    [78; 158) '{     ...(1); }': ()
+    [88; 89) 'y': u32
+    [92; 97) '10u32': u32
+    [103; 105) 'id': fn id<u32>(T) -> T
+    [103; 108) 'id(y)': u32
+    [106; 107) 'y': u32
+    [118; 119) 'x': bool
+    [128; 133) 'clone': fn clone<bool>(&T) -> T
+    [128; 136) 'clone(z)': bool
+    [134; 135) 'z': &bool
+    [142; 152) 'id::<i128>': fn id<i128>(T) -> T
+    [142; 155) 'id::<i128>(1)': i128
+    [153; 154) '1': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_const() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo;
+impl Foo { const ASSOC_CONST: u32 = 0; }
+const GLOBAL_CONST: u32 = 101;
+fn test() {
+    const LOCAL_CONST: u32 = 99;
+    let x = LOCAL_CONST;
+    let z = GLOBAL_CONST;
+    let id = Foo::ASSOC_CONST;
+}
+"#),
+        @r###"
+    [49; 50) '0': u32
+    [80; 83) '101': u32
+    [95; 213) '{     ...NST; }': ()
+    [138; 139) 'x': {unknown}
+    [142; 153) 'LOCAL_CONST': {unknown}
+    [163; 164) 'z': u32
+    [167; 179) 'GLOBAL_CONST': u32
+    [189; 191) 'id': u32
+    [194; 210) 'Foo::A..._CONST': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_static() {
+    assert_snapshot!(
+        infer(r#"
+static GLOBAL_STATIC: u32 = 101;
+static mut GLOBAL_STATIC_MUT: u32 = 101;
+fn test() {
+    static LOCAL_STATIC: u32 = 99;
+    static mut LOCAL_STATIC_MUT: u32 = 99;
+    let x = LOCAL_STATIC;
+    let y = LOCAL_STATIC_MUT;
+    let z = GLOBAL_STATIC;
+    let w = GLOBAL_STATIC_MUT;
+}
+"#),
+        @r###"
+    [29; 32) '101': u32
+    [70; 73) '101': u32
+    [85; 280) '{     ...MUT; }': ()
+    [173; 174) 'x': {unknown}
+    [177; 189) 'LOCAL_STATIC': {unknown}
+    [199; 200) 'y': {unknown}
+    [203; 219) 'LOCAL_...IC_MUT': {unknown}
+    [229; 230) 'z': u32
+    [233; 246) 'GLOBAL_STATIC': u32
+    [256; 257) 'w': u32
+    [260; 277) 'GLOBAL...IC_MUT': u32
+    "###
+    );
+}
+
+#[test]
+fn shadowing_primitive() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct i32;
+struct Foo;
+
+impl i32 { fn foo(&self) -> Foo { Foo } }
+
+fn main() {
+    let x: i32 = i32;
+    x.foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "Foo");
+}
+
+#[test]
+fn not_shadowing_primitive_by_module() {
+    let t = type_at(
+        r#"
+//- /str.rs
+fn foo() {}
+
+//- /main.rs
+mod str;
+fn foo() -> &'static str { "" }
+
+fn main() {
+    foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "&str");
+}
+
+#[test]
+fn not_shadowing_module_by_primitive() {
+    let t = type_at(
+        r#"
+//- /str.rs
+fn foo() -> u32 {0}
+
+//- /main.rs
+mod str;
+fn foo() -> &'static str { "" }
+
+fn main() {
+    str::foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "u32");
+}
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
new file mode 100644
index 000000000..93c5f9a15
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -0,0 +1,1424 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn infer_await() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct IntFuture;
+
+impl Future for IntFuture {
+    type Output = u64;
+}
+
+fn test() {
+    let r = IntFuture;
+    let v = r.await;
+    v<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use future::*;
+mod future {
+    trait Future {
+        type Output;
+    }
+}
+
+"#,
+    );
+    assert_eq!("u64", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_try() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+fn test() {
+    let r: Result<i32, u64> = Result::Ok(1);
+    let v = r?;
+    v<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    trait Try {
+        type Ok;
+        type Error;
+    }
+}
+
+#[prelude_import] use result::*;
+mod result {
+    enum Result<O, E> {
+        Ok(O),
+        Err(E)
+    }
+
+    impl<O, E> crate::ops::Try for Result<O, E> {
+        type Ok = O;
+        type Error = E;
+    }
+}
+
+"#,
+    );
+    assert_eq!("i32", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_for_loop() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+use std::collections::Vec;
+
+fn test() {
+    let v = Vec::new();
+    v.push("foo");
+    for x in v {
+        x<|>;
+    }
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use iter::*;
+mod iter {
+    trait IntoIterator {
+        type Item;
+    }
+}
+
+mod collections {
+    struct Vec<T> {}
+    impl<T> Vec<T> {
+        fn new() -> Self { Vec {} }
+        fn push(&mut self, t: T) { }
+    }
+
+    impl<T> crate::iter::IntoIterator for Vec<T> {
+        type Item=T;
+    }
+}
+"#,
+    );
+    assert_eq!("&str", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_from_bound_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn foo<T: Trait<u32>>(t: T) {}
+fn test() {
+    let s = S(unknown);
+    foo(s);
+}
+"#),
+        @r###"
+    [86; 87) 't': T
+    [92; 94) '{}': ()
+    [105; 144) '{     ...(s); }': ()
+    [115; 116) 's': S<u32>
+    [119; 120) 'S': S<u32>(T) -> S<T>
+    [119; 129) 'S(unknown)': S<u32>
+    [121; 128) 'unknown': u32
+    [135; 138) 'foo': fn foo<S<u32>>(T) -> ()
+    [135; 141) 'foo(s)': ()
+    [139; 140) 's': S<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_from_bound_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn foo<U, T: Trait<U>>(t: T) -> U {}
+fn test() {
+    let s = S(unknown);
+    let x: u32 = foo(s);
+}
+"#),
+        @r###"
+    [87; 88) 't': T
+    [98; 100) '{}': ()
+    [111; 163) '{     ...(s); }': ()
+    [121; 122) 's': S<u32>
+    [125; 126) 'S': S<u32>(T) -> S<T>
+    [125; 135) 'S(unknown)': S<u32>
+    [127; 134) 'unknown': u32
+    [145; 146) 'x': u32
+    [154; 157) 'foo': fn foo<u32, S<u32>>(T) -> U
+    [154; 160) 'foo(s)': u32
+    [158; 159) 's': S<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_project_associated_type() {
+    // y, z, a don't yet work because of https://github.com/rust-lang/chalk/issues/234
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+struct S;
+impl Iterable for S { type Item = u32; }
+fn test<T: Iterable>() {
+    let x: <S as Iterable>::Item = 1;
+    let y: <T as Iterable>::Item = no_matter;
+    let z: T::Item = no_matter;
+    let a: <T>::Item = no_matter;
+}
+"#),
+        @r###"
+    [108; 261) '{     ...ter; }': ()
+    [118; 119) 'x': u32
+    [145; 146) '1': u32
+    [156; 157) 'y': {unknown}
+    [183; 192) 'no_matter': {unknown}
+    [202; 203) 'z': {unknown}
+    [215; 224) 'no_matter': {unknown}
+    [234; 235) 'a': {unknown}
+    [249; 258) 'no_matter': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_return_associated_type() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+struct S;
+impl Iterable for S { type Item = u32; }
+fn foo1<T: Iterable>(t: T) -> T::Item {}
+fn foo2<T: Iterable>(t: T) -> <T as Iterable>::Item {}
+fn foo3<T: Iterable>(t: T) -> <T>::Item {}
+fn test() {
+    let x = foo1(S);
+    let y = foo2(S);
+    let z = foo3(S);
+}
+"#),
+        @r###"
+    [106; 107) 't': T
+    [123; 125) '{}': ()
+    [147; 148) 't': T
+    [178; 180) '{}': ()
+    [202; 203) 't': T
+    [221; 223) '{}': ()
+    [234; 300) '{     ...(S); }': ()
+    [244; 245) 'x': u32
+    [248; 252) 'foo1': fn foo1<S>(T) -> <T as Iterable>::Item
+    [248; 255) 'foo1(S)': u32
+    [253; 254) 'S': S
+    [265; 266) 'y': u32
+    [269; 273) 'foo2': fn foo2<S>(T) -> <T as Iterable>::Item
+    [269; 276) 'foo2(S)': u32
+    [274; 275) 'S': S
+    [286; 287) 'z': u32
+    [290; 294) 'foo3': fn foo3<S>(T) -> <T as Iterable>::Item
+    [290; 297) 'foo3(S)': u32
+    [295; 296) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_type_bound() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+fn test<T: Iterable<Item=u32>>() {
+    let y: T::Item = unknown;
+}
+"#),
+        @r###"
+    [67; 100) '{     ...own; }': ()
+    [77; 78) 'y': {unknown}
+    [90; 97) 'unknown': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_const_body() {
+    assert_snapshot!(
+        infer(r#"
+const A: u32 = 1 + 1;
+static B: u64 = { let x = 1; x };
+"#),
+        @r###"
+    [16; 17) '1': u32
+    [16; 21) '1 + 1': u32
+    [20; 21) '1': u32
+    [39; 55) '{ let ...1; x }': u64
+    [45; 46) 'x': u64
+    [49; 50) '1': u64
+    [52; 53) 'x': u64
+    "###
+    );
+}
+
+#[test]
+fn tuple_struct_fields() {
+    assert_snapshot!(
+        infer(r#"
+struct S(i32, u64);
+fn test() -> u64 {
+    let a = S(4, 6);
+    let b = a.0;
+    a.1
+}
+"#),
+        @r###"
+    [38; 87) '{     ... a.1 }': u64
+    [48; 49) 'a': S
+    [52; 53) 'S': S(i32, u64) -> S
+    [52; 59) 'S(4, 6)': S
+    [54; 55) '4': i32
+    [57; 58) '6': u64
+    [69; 70) 'b': i32
+    [73; 74) 'a': S
+    [73; 76) 'a.0': i32
+    [82; 83) 'a': S
+    [82; 85) 'a.1': u64
+    "###
+    );
+}
+
+#[test]
+fn tuple_struct_with_fn() {
+    assert_snapshot!(
+        infer(r#"
+struct S(fn(u32) -> u64);
+fn test() -> u64 {
+    let a = S(|i| 2*i);
+    let b = a.0(4);
+    a.0(2)
+}
+"#),
+        @r###"
+    [44; 102) '{     ...0(2) }': u64
+    [54; 55) 'a': S
+    [58; 59) 'S': S(fn(u32) -> u64) -> S
+    [58; 68) 'S(|i| 2*i)': S
+    [60; 67) '|i| 2*i': |i32| -> i32
+    [61; 62) 'i': i32
+    [64; 65) '2': i32
+    [64; 67) '2*i': i32
+    [66; 67) 'i': i32
+    [78; 79) 'b': u64
+    [82; 83) 'a': S
+    [82; 85) 'a.0': fn(u32) -> u64
+    [82; 88) 'a.0(4)': u64
+    [86; 87) '4': u32
+    [94; 95) 'a': S
+    [94; 97) 'a.0': fn(u32) -> u64
+    [94; 100) 'a.0(2)': u64
+    [98; 99) '2': u32
+    "###
+    );
+}
+
+#[test]
+fn indexing_arrays() {
+    assert_snapshot!(
+        infer("fn main() { &mut [9][2]; }"),
+        @r###"
+    [10; 26) '{ &mut...[2]; }': ()
+    [12; 23) '&mut [9][2]': &mut {unknown}
+    [17; 20) '[9]': [i32;_]
+    [17; 23) '[9][2]': {unknown}
+    [18; 19) '9': i32
+    [21; 22) '2': i32
+    "###
+    )
+}
+
+#[test]
+fn deref_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+impl S {
+    fn foo(&self) -> u128 {}
+}
+
+fn test(s: Arc<S>) {
+    (*s, s.foo())<|>;
+}
+"#,
+    );
+    assert_eq!(t, "(S, u128)");
+}
+
+#[test]
+fn deref_trait_with_inference_var() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+fn new_arc<T>() -> Arc<T> {}
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+fn foo(a: Arc<S>) {}
+
+fn test() {
+    let a = new_arc();
+    let b = (*a)<|>;
+    foo(a);
+}
+"#,
+    );
+    assert_eq!(t, "S");
+}
+
+#[test]
+fn deref_trait_infinite_recursion() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct S;
+
+impl Deref for S {
+    type Target = S;
+}
+
+fn test(s: S) {
+    s.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn deref_trait_with_question_mark_size() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+impl S {
+    fn foo(&self) -> u128 {}
+}
+
+fn test(s: Arc<S>) {
+    (*s, s.foo())<|>;
+}
+"#,
+    );
+    assert_eq!(t, "(S, u128)");
+}
+
+#[test]
+fn obligation_from_function_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<u32> for S {}
+
+fn foo<T: Trait<U>, U>(t: T) -> U {}
+
+fn test(s: S) {
+    foo(s)<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn obligation_from_method_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<isize> for S {}
+
+struct O;
+impl O {
+    fn foo<T: Trait<U>, U>(&self, t: T) -> U {}
+}
+
+fn test() {
+    O.foo(S)<|>;
+}
+"#,
+    );
+    assert_eq!(t, "isize");
+}
+
+#[test]
+fn obligation_from_self_method_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<i64> for S {}
+
+impl S {
+    fn foo<U>(&self) -> U where Self: Trait<U> {}
+}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "i64");
+}
+
+#[test]
+fn obligation_from_impl_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<&str> for S {}
+
+struct O<T>;
+impl<U, T: Trait<U>> O<T> {
+    fn foo(&self) -> U {}
+}
+
+fn test(o: O<S>) {
+    o.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "&str");
+}
+
+#[test]
+fn generic_param_env_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test<T: Clone>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn generic_param_env_1_not_met() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test<T>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn generic_param_env_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S {}
+fn test<T: Trait>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn generic_param_env_2_not_met() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S {}
+fn test<T>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn generic_param_env_deref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+}
+trait Trait {}
+impl<T> Deref for T where T: Trait {
+    type Target = i128;
+}
+fn test<T: Trait>(t: T) { (*t)<|>; }
+"#,
+    );
+    assert_eq!(t, "i128");
+}
+
+#[test]
+fn associated_type_placeholder() {
+    let t = type_at(
+        r#"
+//- /main.rs
+pub trait ApplyL {
+    type Out;
+}
+
+pub struct RefMutL<T>;
+
+impl<T> ApplyL for RefMutL<T> {
+    type Out = <T as ApplyL>::Out;
+}
+
+fn test<T: ApplyL>() {
+    let y: <RefMutL<T> as ApplyL>::Out = no_matter;
+    y<|>;
+}
+"#,
+    );
+    // inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
+    // FIXME: fix type parameter names going missing when going through Chalk
+    assert_eq!(t, "ApplyL::Out<[missing name]>");
+}
+
+#[test]
+fn associated_type_placeholder_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+pub trait ApplyL {
+    type Out;
+}
+fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
+
+fn test<T: ApplyL>(t: T) {
+    let y = foo(t);
+    y<|>;
+}
+"#,
+    );
+    // FIXME here Chalk doesn't normalize the type to a placeholder. I think we
+    // need to add a rule like Normalize(<T as ApplyL>::Out -> ApplyL::Out<T>)
+    // to the trait env ourselves here; probably Chalk can't do this by itself.
+    // assert_eq!(t, "ApplyL::Out<[missing name]>");
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn impl_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+    fn foo2(&self) -> i64;
+}
+fn bar() -> impl Trait<u64> {}
+
+fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+    x.foo2();
+    y.foo2();
+    z.foo2();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [55; 59) 'self': &Self
+    [99; 101) '{}': ()
+    [111; 112) 'x': impl Trait<u64>
+    [131; 132) 'y': &impl Trait<u64>
+    [152; 269) '{     ...2(); }': ()
+    [158; 159) 'x': impl Trait<u64>
+    [165; 166) 'y': &impl Trait<u64>
+    [176; 177) 'z': impl Trait<u64>
+    [180; 183) 'bar': fn bar() -> impl Trait<u64>
+    [180; 185) 'bar()': impl Trait<u64>
+    [191; 192) 'x': impl Trait<u64>
+    [191; 198) 'x.foo()': u64
+    [204; 205) 'y': &impl Trait<u64>
+    [204; 211) 'y.foo()': u64
+    [217; 218) 'z': impl Trait<u64>
+    [217; 224) 'z.foo()': u64
+    [230; 231) 'x': impl Trait<u64>
+    [230; 238) 'x.foo2()': i64
+    [244; 245) 'y': &impl Trait<u64>
+    [244; 252) 'y.foo2()': i64
+    [258; 259) 'z': impl Trait<u64>
+    [258; 266) 'z.foo2()': i64
+    "###
+    );
+}
+
+#[test]
+fn dyn_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+    fn foo2(&self) -> i64;
+}
+fn bar() -> dyn Trait<u64> {}
+
+fn test(x: dyn Trait<u64>, y: &dyn Trait<u64>) {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+    x.foo2();
+    y.foo2();
+    z.foo2();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [55; 59) 'self': &Self
+    [98; 100) '{}': ()
+    [110; 111) 'x': dyn Trait<u64>
+    [129; 130) 'y': &dyn Trait<u64>
+    [149; 266) '{     ...2(); }': ()
+    [155; 156) 'x': dyn Trait<u64>
+    [162; 163) 'y': &dyn Trait<u64>
+    [173; 174) 'z': dyn Trait<u64>
+    [177; 180) 'bar': fn bar() -> dyn Trait<u64>
+    [177; 182) 'bar()': dyn Trait<u64>
+    [188; 189) 'x': dyn Trait<u64>
+    [188; 195) 'x.foo()': u64
+    [201; 202) 'y': &dyn Trait<u64>
+    [201; 208) 'y.foo()': u64
+    [214; 215) 'z': dyn Trait<u64>
+    [214; 221) 'z.foo()': u64
+    [227; 228) 'x': dyn Trait<u64>
+    [227; 235) 'x.foo2()': i64
+    [241; 242) 'y': &dyn Trait<u64>
+    [241; 249) 'y.foo2()': i64
+    [255; 256) 'z': dyn Trait<u64>
+    [255; 263) 'z.foo2()': i64
+    "###
+    );
+}
+
+#[test]
+fn dyn_trait_bare() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    fn foo(&self) -> u64;
+}
+fn bar() -> Trait {}
+
+fn test(x: Trait, y: &Trait) -> u64 {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+}
+"#),
+        @r###"
+    [27; 31) 'self': &Self
+    [61; 63) '{}': ()
+    [73; 74) 'x': dyn Trait
+    [83; 84) 'y': &dyn Trait
+    [101; 176) '{     ...o(); }': ()
+    [107; 108) 'x': dyn Trait
+    [114; 115) 'y': &dyn Trait
+    [125; 126) 'z': dyn Trait
+    [129; 132) 'bar': fn bar() -> dyn Trait
+    [129; 134) 'bar()': dyn Trait
+    [140; 141) 'x': dyn Trait
+    [140; 147) 'x.foo()': u64
+    [153; 154) 'y': &dyn Trait
+    [153; 160) 'y.foo()': u64
+    [166; 167) 'z': dyn Trait
+    [166; 173) 'z.foo()': u64
+    "###
+    );
+}
+
+#[test]
+fn weird_bounds() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {}
+fn test() {
+    let a: impl Trait + 'lifetime = foo;
+    let b: impl 'lifetime = foo;
+    let b: impl (Trait) = foo;
+    let b: impl ('lifetime) = foo;
+    let d: impl ?Sized = foo;
+    let e: impl Trait + ?Sized = foo;
+}
+"#),
+        @r###"
+    [26; 237) '{     ...foo; }': ()
+    [36; 37) 'a': impl Trait + {error}
+    [64; 67) 'foo': impl Trait + {error}
+    [77; 78) 'b': impl {error}
+    [97; 100) 'foo': impl {error}
+    [110; 111) 'b': impl Trait
+    [128; 131) 'foo': impl Trait
+    [141; 142) 'b': impl {error}
+    [163; 166) 'foo': impl {error}
+    [176; 177) 'd': impl {error}
+    [193; 196) 'foo': impl {error}
+    [206; 207) 'e': impl Trait + {error}
+    [231; 234) 'foo': impl Trait + {error}
+    "###
+    );
+}
+
+#[test]
+fn assoc_type_bindings() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    type Type;
+}
+
+fn get<T: Trait>(t: T) -> <T as Trait>::Type {}
+fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
+fn set<T: Trait<Type = u64>>(t: T) -> T {t}
+
+struct S<T>;
+impl<T> Trait for S<T> { type Type = T; }
+
+fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
+    get(x);
+    get2(x);
+    get(y);
+    get2(y);
+    get(set(S));
+    get2(set(S));
+    get2(S::<str>);
+}
+"#),
+        @r###"
+    [50; 51) 't': T
+    [78; 80) '{}': ()
+    [112; 113) 't': T
+    [123; 125) '{}': ()
+    [155; 156) 't': T
+    [166; 169) '{t}': T
+    [167; 168) 't': T
+    [257; 258) 'x': T
+    [263; 264) 'y': impl Trait<Type = i64>
+    [290; 398) '{     ...r>); }': ()
+    [296; 299) 'get': fn get<T>(T) -> <T as Trait>::Type
+    [296; 302) 'get(x)': {unknown}
+    [300; 301) 'x': T
+    [308; 312) 'get2': fn get2<{unknown}, T>(T) -> U
+    [308; 315) 'get2(x)': {unknown}
+    [313; 314) 'x': T
+    [321; 324) 'get': fn get<impl Trait<Type = i64>>(T) -> <T as Trait>::Type
+    [321; 327) 'get(y)': {unknown}
+    [325; 326) 'y': impl Trait<Type = i64>
+    [333; 337) 'get2': fn get2<{unknown}, impl Trait<Type = i64>>(T) -> U
+    [333; 340) 'get2(y)': {unknown}
+    [338; 339) 'y': impl Trait<Type = i64>
+    [346; 349) 'get': fn get<S<u64>>(T) -> <T as Trait>::Type
+    [346; 357) 'get(set(S))': u64
+    [350; 353) 'set': fn set<S<u64>>(T) -> T
+    [350; 356) 'set(S)': S<u64>
+    [354; 355) 'S': S<u64>
+    [363; 367) 'get2': fn get2<u64, S<u64>>(T) -> U
+    [363; 375) 'get2(set(S))': u64
+    [368; 371) 'set': fn set<S<u64>>(T) -> T
+    [368; 374) 'set(S)': S<u64>
+    [372; 373) 'S': S<u64>
+    [381; 385) 'get2': fn get2<str, S<str>>(T) -> U
+    [381; 395) 'get2(S::<str>)': str
+    [386; 394) 'S::<str>': S<str>
+    "###
+    );
+}
+
+#[test]
+fn impl_trait_assoc_binding_projection_bug() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+pub trait Language {
+    type Kind;
+}
+pub enum RustLanguage {}
+impl Language for RustLanguage {
+    type Kind = SyntaxKind;
+}
+struct SyntaxNode<L> {}
+fn foo() -> impl Iterator<Item = SyntaxNode<RustLanguage>> {}
+
+trait Clone {
+    fn clone(&self) -> Self;
+}
+
+fn api_walkthrough() {
+    for node in foo() {
+        node.clone()<|>;
+    }
+}
+
+//- /std.rs crate:std
+#[prelude_import] use iter::*;
+mod iter {
+    trait IntoIterator {
+        type Item;
+    }
+    trait Iterator {
+        type Item;
+    }
+    impl<T: Iterator> IntoIterator for T {
+        type Item = <T as Iterator>::Item;
+    }
+}
+"#,
+    );
+    assert_eq!("{unknown}", type_at_pos(&db, pos));
+}
+
+#[test]
+fn projection_eq_within_chalk() {
+    // std::env::set_var("CHALK_DEBUG", "1");
+    assert_snapshot!(
+        infer(r#"
+trait Trait1 {
+    type Type;
+}
+trait Trait2<T> {
+    fn foo(self) -> T;
+}
+impl<T, U> Trait2<T> for U where U: Trait1<Type = T> {}
+
+fn test<T: Trait1<Type = u32>>(x: T) {
+    x.foo();
+}
+"#),
+        @r###"
+    [62; 66) 'self': Self
+    [164; 165) 'x': T
+    [170; 186) '{     ...o(); }': ()
+    [176; 177) 'x': T
+    [176; 183) 'x.foo()': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn where_clause_trait_in_scope_for_method_resolution() {
+    let t = type_at(
+        r#"
+//- /main.rs
+mod foo {
+    trait Trait {
+        fn foo(&self) -> u32 {}
+    }
+}
+
+fn test<T: foo::Trait>(x: T) {
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn super_trait_method_resolution() {
+    assert_snapshot!(
+        infer(r#"
+mod foo {
+    trait SuperTrait {
+        fn foo(&self) -> u32 {}
+    }
+}
+trait Trait1: foo::SuperTrait {}
+trait Trait2 where Self: foo::SuperTrait {}
+
+fn test<T: Trait1, U: Trait2>(x: T, y: U) {
+    x.foo();
+    y.foo();
+}
+"#),
+        @r###"
+    [50; 54) 'self': &Self
+    [63; 65) '{}': ()
+    [182; 183) 'x': T
+    [188; 189) 'y': U
+    [194; 223) '{     ...o(); }': ()
+    [200; 201) 'x': T
+    [200; 207) 'x.foo()': u32
+    [213; 214) 'y': U
+    [213; 220) 'y.foo()': u32
+    "###
+    );
+}
+
+#[test]
+fn super_trait_cycle() {
+    // This just needs to not crash
+    assert_snapshot!(
+        infer(r#"
+trait A: B {}
+trait B: A {}
+
+fn test<T: A>(x: T) {
+    x.foo();
+}
+"#),
+        @r###"
+    [44; 45) 'x': T
+    [50; 66) '{     ...o(); }': ()
+    [56; 57) 'x': T
+    [56; 63) 'x.foo()': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn super_trait_assoc_type_bounds() {
+    assert_snapshot!(
+        infer(r#"
+trait SuperTrait { type Type; }
+trait Trait where Self: SuperTrait {}
+
+fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
+fn set<T: Trait<Type = u64>>(t: T) -> T {t}
+
+struct S<T>;
+impl<T> SuperTrait for S<T> { type Type = T; }
+impl<T> Trait for S<T> {}
+
+fn test() {
+    get2(set(S));
+}
+"#),
+        @r###"
+    [103; 104) 't': T
+    [114; 116) '{}': ()
+    [146; 147) 't': T
+    [157; 160) '{t}': T
+    [158; 159) 't': T
+    [259; 280) '{     ...S)); }': ()
+    [265; 269) 'get2': fn get2<u64, S<u64>>(T) -> U
+    [265; 277) 'get2(set(S))': u64
+    [270; 273) 'set': fn set<S<u64>>(T) -> T
+    [270; 276) 'set(S)': S<u64>
+    [274; 275) 'S': S<u64>
+    "###
+    );
+}
+
+#[test]
+fn fn_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait FnOnce<Args> {
+    type Output;
+
+    fn call_once(self, args: Args) -> <Self as FnOnce<Args>>::Output;
+}
+
+fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
+    f.call_once((1, 2));
+}
+"#),
+        @r###"
+    [57; 61) 'self': Self
+    [63; 67) 'args': Args
+    [150; 151) 'f': F
+    [156; 184) '{     ...2)); }': ()
+    [162; 163) 'f': F
+    [162; 181) 'f.call...1, 2))': {unknown}
+    [174; 180) '(1, 2)': (u32, u64)
+    [175; 176) '1': u32
+    [178; 179) '2': u64
+    "###
+    );
+}
+
+#[test]
+fn closure_1() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+    type Output;
+}
+
+enum Option<T> { Some(T), None }
+impl<T> Option<T> {
+    fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> {}
+}
+
+fn test() {
+    let x = Option::Some(1u32);
+    x.map(|v| v + 1);
+    x.map(|_v| 1u64);
+    let y: Option<i64> = x.map(|_v| 1);
+}
+"#),
+        @r###"
+    [148; 152) 'self': Option<T>
+    [154; 155) 'f': F
+    [173; 175) '{}': ()
+    [189; 308) '{     ... 1); }': ()
+    [199; 200) 'x': Option<u32>
+    [203; 215) 'Option::Some': Some<u32>(T) -> Option<T>
+    [203; 221) 'Option...(1u32)': Option<u32>
+    [216; 220) '1u32': u32
+    [227; 228) 'x': Option<u32>
+    [227; 243) 'x.map(...v + 1)': Option<u32>
+    [233; 242) '|v| v + 1': |u32| -> u32
+    [234; 235) 'v': u32
+    [237; 238) 'v': u32
+    [237; 242) 'v + 1': u32
+    [241; 242) '1': u32
+    [249; 250) 'x': Option<u32>
+    [249; 265) 'x.map(... 1u64)': Option<u64>
+    [255; 264) '|_v| 1u64': |u32| -> u64
+    [256; 258) '_v': u32
+    [260; 264) '1u64': u64
+    [275; 276) 'y': Option<i64>
+    [292; 293) 'x': Option<u32>
+    [292; 305) 'x.map(|_v| 1)': Option<i64>
+    [298; 304) '|_v| 1': |u32| -> i64
+    [299; 301) '_v': u32
+    [303; 304) '1': i64
+    "###
+    );
+}
+
+#[test]
+fn closure_2() {
+    assert_snapshot!(
+        infer(r#"
+trait FnOnce<Args> {
+    type Output;
+}
+
+fn test<F: FnOnce(u32) -> u64>(f: F) {
+    f(1);
+    let g = |v| v + 1;
+    g(1u64);
+    let h = |v| 1u128 + v;
+}
+"#),
+        @r###"
+    [73; 74) 'f': F
+    [79; 155) '{     ...+ v; }': ()
+    [85; 86) 'f': F
+    [85; 89) 'f(1)': {unknown}
+    [87; 88) '1': i32
+    [99; 100) 'g': |u64| -> i32
+    [103; 112) '|v| v + 1': |u64| -> i32
+    [104; 105) 'v': u64
+    [107; 108) 'v': u64
+    [107; 112) 'v + 1': i32
+    [111; 112) '1': i32
+    [118; 119) 'g': |u64| -> i32
+    [118; 125) 'g(1u64)': i32
+    [120; 124) '1u64': u64
+    [135; 136) 'h': |u128| -> u128
+    [139; 152) '|v| 1u128 + v': |u128| -> u128
+    [140; 141) 'v': u128
+    [143; 148) '1u128': u128
+    [143; 152) '1u128 + v': u128
+    [151; 152) 'v': u128
+    "###
+    );
+}
+
+#[test]
+fn closure_as_argument_inference_order() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+    type Output;
+}
+
+fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U {}
+fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U {}
+
+struct S;
+impl S {
+    fn method(self) -> u64;
+
+    fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U {}
+    fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U {}
+}
+
+fn test() {
+    let x1 = foo1(S, |s| s.method());
+    let x2 = foo2(|s| s.method(), S);
+    let x3 = S.foo1(S, |s| s.method());
+    let x4 = S.foo2(|s| s.method(), S);
+}
+"#),
+        @r###"
+    [95; 96) 'x': T
+    [101; 102) 'f': F
+    [112; 114) '{}': ()
+    [148; 149) 'f': F
+    [154; 155) 'x': T
+    [165; 167) '{}': ()
+    [202; 206) 'self': S
+    [254; 258) 'self': S
+    [260; 261) 'x': T
+    [266; 267) 'f': F
+    [277; 279) '{}': ()
+    [317; 321) 'self': S
+    [323; 324) 'f': F
+    [329; 330) 'x': T
+    [340; 342) '{}': ()
+    [356; 515) '{     ... S); }': ()
+    [366; 368) 'x1': u64
+    [371; 375) 'foo1': fn foo1<S, u64, |S| -> u64>(T, F) -> U
+    [371; 394) 'foo1(S...hod())': u64
+    [376; 377) 'S': S
+    [379; 393) '|s| s.method()': |S| -> u64
+    [380; 381) 's': S
+    [383; 384) 's': S
+    [383; 393) 's.method()': u64
+    [404; 406) 'x2': u64
+    [409; 413) 'foo2': fn foo2<S, u64, |S| -> u64>(F, T) -> U
+    [409; 432) 'foo2(|...(), S)': u64
+    [414; 428) '|s| s.method()': |S| -> u64
+    [415; 416) 's': S
+    [418; 419) 's': S
+    [418; 428) 's.method()': u64
+    [430; 431) 'S': S
+    [442; 444) 'x3': u64
+    [447; 448) 'S': S
+    [447; 472) 'S.foo1...hod())': u64
+    [454; 455) 'S': S
+    [457; 471) '|s| s.method()': |S| -> u64
+    [458; 459) 's': S
+    [461; 462) 's': S
+    [461; 471) 's.method()': u64
+    [482; 484) 'x4': u64
+    [487; 488) 'S': S
+    [487; 512) 'S.foo2...(), S)': u64
+    [494; 508) '|s| s.method()': |S| -> u64
+    [495; 496) 's': S
+    [498; 499) 's': S
+    [498; 508) 's.method()': u64
+    [510; 511) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn unselected_projection_in_trait_env_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+}
+
+trait Trait2 {
+    fn foo(&self) -> u32;
+}
+
+fn test<T: Trait>() where T::Item: Trait2 {
+    let x: T::Item = no_matter;
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+    type Item;
+}
+
+trait Trait2 {
+    fn foo(&self) -> u32;
+}
+
+fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
+    let x: T::Item = no_matter;
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn trait_impl_self_ty() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+   fn foo(&self);
+}
+
+struct S;
+
+impl Trait<Self> for S {}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "()");
+}
+
+#[test]
+fn trait_impl_self_ty_cycle() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+   fn foo(&self);
+}
+
+struct S<T>;
+
+impl Trait for S<Self> {}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_cycle_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+}
+
+trait Trait2<T> {}
+
+fn test<T: Trait>() where T: Trait2<T::Item> {
+    let x: T::Item = no_matter<|>;
+}
+"#,
+    );
+    // this is a legitimate cycle
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_cycle_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+    type Item;
+}
+
+fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
+    let x: T::Item = no_matter<|>;
+}
+"#,
+    );
+    // this is a legitimate cycle
+    assert_eq!(t, "{unknown}");
+}