1 files changed, 523 insertions, 0 deletions

diff --git a/crates/ide_db/src/call_info/tests.rs b/crates/ide_db/src/call_info/tests.rs
new file mode 100644
index 000000000..9335aeaa5
--- /dev/null
+++ b/crates/ide_db/src/call_info/tests.rs
@@ -0,0 +1,523 @@
+use crate::RootDatabase;
+use base_db::{fixture::ChangeFixture, FilePosition};
+use expect_test::{expect, Expect};
+use test_utils::{mark, RangeOrOffset};
+
+/// Creates analysis from a multi-file fixture, returns positions marked with <|>.
+pub(crate) fn position(ra_fixture: &str) -> (RootDatabase, FilePosition) {
+    let change_fixture = ChangeFixture::parse(ra_fixture);
+    let mut database = RootDatabase::default();
+    database.apply_change(change_fixture.change);
+    let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker (<|>)");
+    let offset = match range_or_offset {
+        RangeOrOffset::Range(_) => panic!(),
+        RangeOrOffset::Offset(it) => it,
+    };
+    (database, FilePosition { file_id, offset })
+}
+
+fn check(ra_fixture: &str, expect: Expect) {
+    let (db, position) = position(ra_fixture);
+    let call_info = crate::call_info::call_info(&db, position);
+    let actual = match call_info {
+        Some(call_info) => {
+            let docs = match &call_info.doc {
+                None => "".to_string(),
+                Some(docs) => format!("{}\n------\n", docs.as_str()),
+            };
+            let params = call_info
+                .parameter_labels()
+                .enumerate()
+                .map(|(i, param)| {
+                    if Some(i) == call_info.active_parameter {
+                        format!("<{}>", param)
+                    } else {
+                        param.to_string()
+                    }
+                })
+                .collect::<Vec<_>>()
+                .join(", ");
+            format!("{}{}\n({})\n", docs, call_info.signature, params)
+        }
+        None => String::new(),
+    };
+    expect.assert_eq(&actual);
+}
+
+#[test]
+fn test_fn_signature_two_args() {
+    check(
+        r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>3, ); }
+"#,
+        expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+    );
+    check(
+        r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3<|>, ); }
+"#,
+        expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+    );
+    check(
+        r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3,<|> ); }
+"#,
+        expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
+    );
+    check(
+        r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3, <|>); }
+"#,
+        expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_two_args_empty() {
+    check(
+        r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>); }
+"#,
+        expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_two_args_first_generics() {
+    check(
+        r#"
+fn foo<T, U: Copy + Display>(x: T, y: U) -> u32
+    where T: Copy + Display, U: Debug
+{ x + y }
+
+fn bar() { foo(<|>3, ); }
+"#,
+        expect![[r#"
+                fn foo(x: i32, y: {unknown}) -> u32
+                (<x: i32>, y: {unknown})
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_no_params() {
+    check(
+        r#"
+fn foo<T>() -> T where T: Copy + Display {}
+fn bar() { foo(<|>); }
+"#,
+        expect![[r#"
+                fn foo() -> {unknown}
+                ()
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_for_impl() {
+    check(
+        r#"
+struct F;
+impl F { pub fn new() { } }
+fn bar() {
+    let _ : F = F::new(<|>);
+}
+"#,
+        expect![[r#"
+                fn new()
+                ()
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_for_method_self() {
+    check(
+        r#"
+struct S;
+impl S { pub fn do_it(&self) {} }
+
+fn bar() {
+    let s: S = S;
+    s.do_it(<|>);
+}
+"#,
+        expect![[r#"
+                fn do_it(&self)
+                ()
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_for_method_with_arg() {
+    check(
+        r#"
+struct S;
+impl S {
+    fn foo(&self, x: i32) {}
+}
+
+fn main() { S.foo(<|>); }
+"#,
+        expect![[r#"
+                fn foo(&self, x: i32)
+                (<x: i32>)
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_for_method_with_arg_as_assoc_fn() {
+    check(
+        r#"
+struct S;
+impl S {
+    fn foo(&self, x: i32) {}
+}
+
+fn main() { S::foo(<|>); }
+"#,
+        expect![[r#"
+                fn foo(self: &S, x: i32)
+                (<self: &S>, x: i32)
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_with_docs_simple() {
+    check(
+        r#"
+/// test
+// non-doc-comment
+fn foo(j: u32) -> u32 {
+    j
+}
+
+fn bar() {
+    let _ = foo(<|>);
+}
+"#,
+        expect![[r#"
+                test
+                ------
+                fn foo(j: u32) -> u32
+                (<j: u32>)
+            "#]],
+    );
+}
+
+#[test]
+fn test_fn_signature_with_docs() {
+    check(
+        r#"
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```
+/// let five = 5;
+///
+/// assert_eq!(6, my_crate::add_one(5));
+/// ```
+pub fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+pub fn do() {
+    add_one(<|>
+}"#,
+        expect![[r##"
+                Adds one to the number given.
+
+                # Examples
+
+                ```
+                let five = 5;
+
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
+    );
+}
+
+#[test]
+fn test_fn_signature_with_docs_impl() {
+    check(
+        r#"
+struct addr;
+impl addr {
+    /// Adds one to the number given.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let five = 5;
+    ///
+    /// assert_eq!(6, my_crate::add_one(5));
+    /// ```
+    pub fn add_one(x: i32) -> i32 {
+        x + 1
+    }
+}
+
+pub fn do_it() {
+    addr {};
+    addr::add_one(<|>);
+}
+"#,
+        expect![[r##"
+                Adds one to the number given.
+
+                # Examples
+
+                ```
+                let five = 5;
+
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
+    );
+}
+
+#[test]
+fn test_fn_signature_with_docs_from_actix() {
+    check(
+        r#"
+struct WriteHandler<E>;
+
+impl<E> WriteHandler<E> {
+    /// Method is called when writer emits error.
+    ///
+    /// If this method returns `ErrorAction::Continue` writer processing
+    /// continues otherwise stream processing stops.
+    fn error(&mut self, err: E, ctx: &mut Self::Context) -> Running {
+        Running::Stop
+    }
+
+    /// Method is called when writer finishes.
+    ///
+    /// By default this method stops actor's `Context`.
+    fn finished(&mut self, ctx: &mut Self::Context) {
+        ctx.stop()
+    }
+}
+
+pub fn foo(mut r: WriteHandler<()>) {
+    r.finished(<|>);
+}
+"#,
+        expect![[r#"
+                Method is called when writer finishes.
+
+                By default this method stops actor's `Context`.
+                ------
+                fn finished(&mut self, ctx: &mut {unknown})
+                (<ctx: &mut {unknown}>)
+            "#]],
+    );
+}
+
+#[test]
+fn call_info_bad_offset() {
+    mark::check!(call_info_bad_offset);
+    check(
+        r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo <|> (3, ); }
+"#,
+        expect![[""]],
+    );
+}
+
+#[test]
+fn test_nested_method_in_lambda() {
+    check(
+        r#"
+struct Foo;
+impl Foo { fn bar(&self, _: u32) { } }
+
+fn bar(_: u32) { }
+
+fn main() {
+    let foo = Foo;
+    std::thread::spawn(move || foo.bar(<|>));
+}
+"#,
+        expect![[r#"
+                fn bar(&self, _: u32)
+                (<_: u32>)
+            "#]],
+    );
+}
+
+#[test]
+fn works_for_tuple_structs() {
+    check(
+        r#"
+/// A cool tuple struct
+struct S(u32, i32);
+fn main() {
+    let s = S(0, <|>);
+}
+"#,
+        expect![[r#"
+                A cool tuple struct
+                ------
+                struct S(u32, i32)
+                (u32, <i32>)
+            "#]],
+    );
+}
+
+#[test]
+fn generic_struct() {
+    check(
+        r#"
+struct S<T>(T);
+fn main() {
+    let s = S(<|>);
+}
+"#,
+        expect![[r#"
+                struct S({unknown})
+                (<{unknown}>)
+            "#]],
+    );
+}
+
+#[test]
+fn works_for_enum_variants() {
+    check(
+        r#"
+enum E {
+    /// A Variant
+    A(i32),
+    /// Another
+    B,
+    /// And C
+    C { a: i32, b: i32 }
+}
+
+fn main() {
+    let a = E::A(<|>);
+}
+"#,
+        expect![[r#"
+                A Variant
+                ------
+                enum E::A(i32)
+                (<i32>)
+            "#]],
+    );
+}
+
+#[test]
+fn cant_call_struct_record() {
+    check(
+        r#"
+struct S { x: u32, y: i32 }
+fn main() {
+    let s = S(<|>);
+}
+"#,
+        expect![[""]],
+    );
+}
+
+#[test]
+fn cant_call_enum_record() {
+    check(
+        r#"
+enum E {
+    /// A Variant
+    A(i32),
+    /// Another
+    B,
+    /// And C
+    C { a: i32, b: i32 }
+}
+
+fn main() {
+    let a = E::C(<|>);
+}
+"#,
+        expect![[""]],
+    );
+}
+
+#[test]
+fn fn_signature_for_call_in_macro() {
+    check(
+        r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo() { }
+id! {
+    fn bar() { foo(<|>); }
+}
+"#,
+        expect![[r#"
+                fn foo()
+                ()
+            "#]],
+    );
+}
+
+#[test]
+fn call_info_for_lambdas() {
+    check(
+        r#"
+struct S;
+fn foo(s: S) -> i32 { 92 }
+fn main() {
+    (|s| foo(s))(<|>)
+}
+        "#,
+        expect![[r#"
+                (S) -> i32
+                (<S>)
+            "#]],
+    )
+}
+
+#[test]
+fn call_info_for_fn_ptr() {
+    check(
+        r#"
+fn main(f: fn(i32, f64) -> char) {
+    f(0, <|>)
+}
+        "#,
+        expect![[r#"
+                (i32, f64) -> char
+                (i32, <f64>)
+            "#]],
+    )
+}