use std::fmt::Write;
use std::sync::Arc;

use insta::assert_snapshot;

use ra_db::{salsa::Database, FilePosition, SourceDatabase};
use ra_syntax::{
    algo,
    ast::{self, AstNode},
    SyntaxKind::*,
};
use test_utils::covers;

use crate::{
    expr::BodySourceMap, mock::MockDatabase, ty::display::HirDisplay, ty::InferenceResult,
    SourceAnalyzer,
};

// These tests compare the inference results for all expressions in a file
// against snapshots of the expected results using insta. Use cargo-insta to
// update the snapshots.

#[test]
fn infer_await() {
    let (mut db, pos) = MockDatabase::with_position(
        r#"
//- /main.rs

struct IntFuture;

impl Future for IntFuture {
    type Output = u64;
}

fn test() {
    let r = IntFuture;
    let v = r.await;
    v<|>;
}

//- /std.rs
#[prelude_import] use future::*;
mod future {
    trait Future {
        type Output;
    }
}

"#,
    );
    db.set_crate_graph_from_fixture(crate_graph! {
        "main": ("/main.rs", ["std"]),
        "std": ("/std.rs", []),
    });
    assert_eq!("u64", type_at_pos(&db, pos));
}

#[test]
fn infer_box() {
    let (mut db, pos) = MockDatabase::with_position(
        r#"
//- /main.rs

fn test() {
    let x = box 1;
    let t = (x, box x, box &1, box [1]);
    t<|>;
}

//- /std.rs
#[prelude_import] use prelude::*;
mod prelude {}

mod boxed {
    pub struct Box<T: ?Sized> {
        inner: *mut T,
    }
}

"#,
    );
    db.set_crate_graph_from_fixture(crate_graph! {
        "main": ("/main.rs", ["std"]),
        "std": ("/std.rs", []),
    });
    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
}

#[test]
fn infer_try() {
    let (mut db, pos) = MockDatabase::with_position(
        r#"
//- /main.rs

fn test() {
    let r: Result<i32, u64> = Result::Ok(1);
    let v = r?;
    v<|>;
}

//- /std.rs

#[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;
    }
}

"#,
    );
    db.set_crate_graph_from_fixture(crate_graph! {
        "main": ("/main.rs", ["std"]),
        "std": ("/std.rs", []),
    });
    assert_eq!("i32", type_at_pos(&db, pos));
}

#[test]
fn infer_for_loop() {
    let (mut db, pos) = MockDatabase::with_position(
        r#"
//- /main.rs

use std::collections::Vec;

fn test() {
    let v = Vec::new();
    v.push("foo");
    for x in v {
        x<|>;
    }
}

//- /std.rs

#[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;
    }
}
"#,
    );
    db.set_crate_graph_from_fixture(crate_graph! {
        "main": ("/main.rs", ["std"]),
        "std": ("/std.rs", []),
    });
    assert_eq!("&str", type_at_pos(&db, pos));
}

#[test]
fn infer_while_let() {
    covers!(infer_while_let);
    let (db, pos) = MockDatabase::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;
}
"#),
        @r###"

    [11; 71) '{     ...= b; }': ()
    [21; 22) 'a': isize
    [25; 31) '1isize': isize
    [41; 42) 'b': usize
    [52; 53) '1': usize
    [63; 64) 'c': usize
    [67; 68) 'b': usize
    "###
    );
}

#[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_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) '{     ...     }': !
    [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_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 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 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_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] = [];
    let z: &[u8] = &[1, 2, 3];
}
"#),
        @r###"

    [9; 10) 'x': &str
    [18; 19) 'y': isize
    [28; 324) '{     ... 3]; }': ()
    [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;_]
    [300; 301) 'z': &[u8;_]
    [311; 321) '&[1, 2, 3]': &[u8;_]
    [312; 321) '[1, 2, 3]': [u8;_]
    [313; 314) '1': u8
    [316; 317) '2': u8
    [319; 320) '3': u8
    "###
    );
}

#[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_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_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
    "###
    );
}

#[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': {unknown}
    [291; 304) 'TraitTest::ID': {unknown}
    "###
    );
}

#[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) '{     ...     }': !
    [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_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) '{     ...     }': !
    [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) '{     ...     }': !
    [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 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]
#[should_panic] // we currently can't handle this
fn recursive_type_alias() {
    assert_snapshot!(
        infer(r#"
struct A<X> {}
type Foo = Foo;
type Bar = A<Bar>;
fn test(x: Foo) {}
"#),
        @""
    )
}

#[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_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; 65) '{     x }': &T
    [62; 63) 'x': &T
    [77; 157) '{     ...(1); }': ()
    [87; 88) 'y': u32
    [91; 96) '10u32': u32
    [102; 104) 'id': fn id<u32>(T) -> T
    [102; 107) 'id(y)': u32
    [105; 106) 'y': u32
    [117; 118) 'x': bool
    [127; 132) 'clone': fn clone<bool>(&T) -> T
    [127; 135) 'clone(z)': bool
    [133; 134) 'z': &bool
    [141; 151) 'id::<i128>': fn id<i128>(T) -> T
    [141; 154) 'id::<i128>(1)': i128
    [152; 153) '1': i128
    "###
    );
}

#[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>
    "###
    );
}

#[test]
fn cross_crate_associated_method_call() {
    let (mut db, pos) = MockDatabase::with_position(
        r#"
//- /main.rs
fn test() {
    let x = other_crate::foo::S::thing();
    x<|>;
}

//- /lib.rs
mod foo {
    struct S;
    impl S {
        fn thing() -> i128 {}
    }
}
"#,
    );
    db.set_crate_graph_from_fixture(crate_graph! {
        "main": ("/main.rs", ["other_crate"]),
        "other_crate": ("/lib.rs", []),
    });
    assert_eq!("i128", type_at_pos(&db, pos));
}

#[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
    [126; 128) '99': 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
    [118; 120) '99': u32
    [161; 163) '99': u32
    "###
    );
}

#[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': {unknown}
    [138; 148) 'S::default': {unknown}
    [138; 150) 'S::default()': {unknown}
    [160; 162) 's3': S
    [165; 188) '<S as ...efault': fn default<S>() -> Self
    [165; 190) '<S as ...ault()': S
    "###
    );
}

#[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_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 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 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");
}

#[ignore]
#[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_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_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 (mut db, pos) = MockDatabase::with_position(
        r#"
//- /main.rs
struct S;
impl Clone for S {}

fn test() {
    S.clone()<|>;
}

//- /lib.rs
#[prelude_import] use foo::*;

mod foo {
    trait Clone {
        fn clone(&self) -> Self;
    }
}
"#,
    );
    db.set_crate_graph_from_fixture(crate_graph! {
        "main": ("/main.rs", ["other_crate"]),
        "other_crate": ("/lib.rs", []),
    });
    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() {
    covers!(trait_resolution_on_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, "()");
}

#[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 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: ?Sized> 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()': {unknown}
    [204; 205) 'y': &impl Trait<u64>
    [204; 211) 'y.foo()': {unknown}
    [217; 218) 'z': impl Trait<u64>
    [217; 224) 'z.foo()': {unknown}
    [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()': {unknown}
    [201; 202) 'y': &dyn Trait<u64>
    [201; 208) 'y.foo()': {unknown}
    [214; 215) 'z': dyn Trait<u64>
    [214; 221) 'z.foo()': {unknown}
    [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 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]
// FIXME this is currently a Salsa panic; it would be nicer if it just returned
// in Unknown, and we should be able to do that once Salsa allows us to handle
// the cycle. But at least it doesn't overflow for now.
#[should_panic]
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]
// FIXME this is currently a Salsa panic; it would be nicer if it just returned
// in Unknown, and we should be able to do that once Salsa allows us to handle
// the cycle. But at least it doesn't overflow for now.
#[should_panic]
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}");
}

fn type_at_pos(db: &MockDatabase, pos: FilePosition) -> String {
    let file = db.parse(pos.file_id).ok().unwrap();
    let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
    let analyzer = SourceAnalyzer::new(db, pos.file_id, expr.syntax(), Some(pos.offset));
    let ty = analyzer.type_of(db, &expr).unwrap();
    ty.display(db).to_string()
}

fn type_at(content: &str) -> String {
    let (db, file_pos) = MockDatabase::with_position(content);
    type_at_pos(&db, file_pos)
}

fn infer(content: &str) -> String {
    let (db, _, file_id) = MockDatabase::with_single_file(content);
    let source_file = db.parse(file_id).ok().unwrap();

    let mut acc = String::new();

    let mut infer_def = |inference_result: Arc<InferenceResult>,
                         body_source_map: Arc<BodySourceMap>| {
        let mut types = Vec::new();

        for (pat, ty) in inference_result.type_of_pat.iter() {
            let syntax_ptr = match body_source_map.pat_syntax(pat) {
                Some(sp) => {
                    sp.map(|ast| ast.either(|it| it.syntax_node_ptr(), |it| it.syntax_node_ptr()))
                }
                None => continue,
            };
            types.push((syntax_ptr, ty));
        }

        for (expr, ty) in inference_result.type_of_expr.iter() {
            let syntax_ptr = match body_source_map.expr_syntax(expr) {
                Some(sp) => {
                    sp.map(|ast| ast.either(|it| it.syntax_node_ptr(), |it| it.syntax_node_ptr()))
                }
                None => continue,
            };
            types.push((syntax_ptr, ty));
        }

        // sort ranges for consistency
        types.sort_by_key(|(src_ptr, _)| (src_ptr.ast.range().start(), src_ptr.ast.range().end()));
        for (src_ptr, ty) in &types {
            let node = src_ptr.ast.to_node(&src_ptr.file_syntax(&db));

            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.clone()) {
                (self_param.self_kw_token().text_range(), "self".to_string())
            } else {
                (src_ptr.ast.range(), node.text().to_string().replace("\n", " "))
            };
            let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
            write!(
                acc,
                "{}{} '{}': {}\n",
                macro_prefix,
                range,
                ellipsize(text, 15),
                ty.display(&db)
            )
            .unwrap();
        }
    };

    for node in source_file.syntax().descendants() {
        if node.kind() == FN_DEF || node.kind() == CONST_DEF || node.kind() == STATIC_DEF {
            let analyzer = SourceAnalyzer::new(&db, file_id, &node, None);
            infer_def(analyzer.inference_result(), analyzer.body_source_map());
        }
    }

    acc.truncate(acc.trim_end().len());
    acc
}

fn ellipsize(mut text: String, max_len: usize) -> String {
    if text.len() <= max_len {
        return text;
    }
    let ellipsis = "...";
    let e_len = ellipsis.len();
    let mut prefix_len = (max_len - e_len) / 2;
    while !text.is_char_boundary(prefix_len) {
        prefix_len += 1;
    }
    let mut suffix_len = max_len - e_len - prefix_len;
    while !text.is_char_boundary(text.len() - suffix_len) {
        suffix_len += 1;
    }
    text.replace_range(prefix_len..text.len() - suffix_len, ellipsis);
    text
}

#[test]
fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
    let (mut db, pos) = MockDatabase::with_position(
        "
        //- /lib.rs
        fn foo() -> i32 {
            <|>1 + 1
        }
    ",
    );
    {
        let file = db.parse(pos.file_id).ok().unwrap();
        let node = file.syntax().token_at_offset(pos.offset).right_biased().unwrap().parent();
        let events = db.log_executed(|| {
            SourceAnalyzer::new(&db, pos.file_id, &node, None);
        });
        assert!(format!("{:?}", events).contains("infer"))
    }

    let new_text = "
        fn foo() -> i32 {
            1
            +
            1
        }
    "
    .to_string();

    db.query_mut(ra_db::FileTextQuery).set(pos.file_id, Arc::new(new_text));

    {
        let file = db.parse(pos.file_id).ok().unwrap();
        let node = file.syntax().token_at_offset(pos.offset).right_biased().unwrap().parent();
        let events = db.log_executed(|| {
            SourceAnalyzer::new(&db, pos.file_id, &node, None);
        });
        assert!(!format!("{:?}", events).contains("infer"), "{:#?}", events)
    }
}

#[test]
fn no_such_field_diagnostics() {
    let diagnostics = MockDatabase::with_files(
        r"
        //- /lib.rs
        struct S { foo: i32, bar: () }
        impl S {
            fn new() -> S {
                S {
                    foo: 92,
                    baz: 62,
                }
            }
        }
        ",
    )
    .diagnostics();

    assert_snapshot!(diagnostics, @r###"
    "baz: 62": no such field
    "{\n            foo: 92,\n            baz: 62,\n        }": fill structure fields
    "###
    );
}

mod branching_with_never_tests {
    use super::type_at;

    #[test]
    fn if_never() {
        let t = type_at(
            r#"
//- /main.rs
fn test() {
    let i = if true {
        loop {}
    } else {
        3.0
    };
    i<|>
    ()
}
"#,
        );
        assert_eq!(t, "f64");
    }

    #[test]
    fn if_else_never() {
        let t = type_at(
            r#"
//- /main.rs
fn test(input: bool) {
    let i = if input {
        2.0
    } else {
        return
    };
    i<|>
    ()
}
"#,
        );
        assert_eq!(t, "f64");
    }

    #[test]
    fn match_first_arm_never() {
        let t = type_at(
            r#"
//- /main.rs
fn test(a: i32) {
    let i = match a {
        1 => return,
        2 => 2.0,
        3 => loop {},
        _ => 3.0,
    };
    i<|>
    ()
}
"#,
        );
        assert_eq!(t, "f64");
    }

    #[test]
    fn match_second_arm_never() {
        let t = type_at(
            r#"
//- /main.rs
fn test(a: i32) {
    let i = match a {
        1 => 3.0,
        2 => loop {},
        3 => 3.0,
        _ => return,
    };
    i<|>
    ()
}
"#,
        );
        assert_eq!(t, "f64");
    }

    #[test]
    fn match_all_arms_never() {
        let t = type_at(
            r#"
//- /main.rs
fn test(a: i32) {
    let i = match a {
        2 => return,
        _ => loop {},
    };
    i<|>
    ()
}
"#,
        );
        assert_eq!(t, "!");
    }

    #[test]
    fn match_no_never_arms() {
        let t = type_at(
            r#"
//- /main.rs
fn test(a: i32) {
    let i = match a {
        2 => 2.0,
        _ => 3.0,
    };
    i<|>
    ()
}
"#,
        );
        assert_eq!(t, "f64");
    }
}