1 files changed, 274 insertions, 0 deletions
diff --git a/src/tools/rust-analyzer/crates/ide-completion/src/tests/fn_param.rs b/src/tools/rust-analyzer/crates/ide-completion/src/tests/fn_param.rs
new file mode 100644
index 000000000..cce74604c
--- /dev/null
+++ b/src/tools/rust-analyzer/crates/ide-completion/src/tests/fn_param.rs
@@ -0,0 +1,274 @@
+use expect_test::{expect, Expect};
+
+use crate::tests::{completion_list, completion_list_with_trigger_character};
+
+fn check(ra_fixture: &str, expect: Expect) {
+    let actual = completion_list(ra_fixture);
+    expect.assert_eq(&actual);
+}
+
+fn check_with_trigger_character(ra_fixture: &str, trigger_character: char, expect: Expect) {
+    let actual = completion_list_with_trigger_character(ra_fixture, Some(trigger_character));
+    expect.assert_eq(&actual)
+}
+
+#[test]
+fn only_param() {
+    check(
+        r#"
+fn foo(file_id: usize) {}
+fn bar(file_id: usize) {}
+fn baz(file$0) {}
+"#,
+        expect![[r#"
+            bn file_id: usize
+            kw mut
+            kw ref
+        "#]],
+    );
+}
+
+#[test]
+fn last_param() {
+    check(
+        r#"
+fn foo(file_id: usize) {}
+fn bar(file_id: usize) {}
+fn baz(foo: (), file$0) {}
+"#,
+        expect![[r#"
+            bn file_id: usize
+            kw mut
+            kw ref
+        "#]],
+    );
+}
+
+#[test]
+fn first_param() {
+    check(
+        r#"
+fn foo(file_id: usize) {}
+fn bar(file_id: usize) {}
+fn baz(file$0 id: u32) {}
+"#,
+        expect![[r#"
+            bn file_id: usize,
+            kw mut
+            kw ref
+        "#]],
+    );
+}
+
+#[test]
+fn repeated_param_name() {
+    check(
+        r#"
+fn foo(file_id: usize) {}
+fn bar(file_id: u32, $0) {}
+"#,
+        expect![[r#"
+            kw mut
+            kw ref
+        "#]],
+    );
+
+    check(
+        r#"
+fn f(#[foo = "bar"] baz: u32,) {}
+fn g(baz: (), ba$0)
+"#,
+        expect![[r#"
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+#[test]
+fn trait_param() {
+    check(
+        r#"
+pub(crate) trait SourceRoot {
+    pub fn contains(file_id: usize) -> bool;
+    pub fn syntax(file$0)
+}
+"#,
+        expect![[r#"
+            bn file_id: usize
+            kw mut
+            kw ref
+        "#]],
+    );
+}
+
+#[test]
+fn in_inner_function() {
+    check(
+        r#"
+fn outer(text: &str) {
+    fn inner($0)
+}
+"#,
+        expect![[r#"
+            bn text: &str
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+#[test]
+fn trigger_by_l_paren() {
+    check_with_trigger_character(
+        r#"
+fn foo($0)
+"#,
+        '(',
+        expect![[]],
+    )
+}
+
+#[test]
+fn shows_non_ident_pat_param() {
+    check(
+        r#"
+struct Bar { bar: u32 }
+fn foo(Bar { bar }: Bar) {}
+fn foo2($0) {}
+"#,
+        expect![[r#"
+            st Bar
+            bn Bar { bar }: Bar
+            bn Bar {…}          Bar { bar$1 }: Bar$0
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+#[test]
+fn in_impl_only_param() {
+    check(
+        r#"
+struct A {}
+
+impl A {
+    fn foo(file_id: usize) {}
+    fn new($0) {}
+}
+"#,
+        expect![[r#"
+            sp Self
+            st A
+            bn &mut self
+            bn &self
+            bn file_id: usize
+            bn mut self
+            bn self
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+#[test]
+fn in_impl_after_self() {
+    check(
+        r#"
+struct A {}
+
+impl A {
+    fn foo(file_id: usize) {}
+    fn new(self, $0) {}
+}
+"#,
+        expect![[r#"
+            sp Self
+            st A
+            bn file_id: usize
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+// doesn't complete qux due to there being no expression after
+// see source_analyzer::adjust comment
+#[test]
+fn local_fn_shows_locals_for_params() {
+    check(
+        r#"
+fn outer() {
+    let foo = 3;
+    {
+        let bar = 3;
+        fn inner($0) {}
+        let baz = 3;
+        let qux = 3;
+    }
+    let fez = 3;
+}
+"#,
+        expect![[r#"
+            bn bar: i32
+            bn baz: i32
+            bn foo: i32
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+#[test]
+fn closure_shows_locals_for_params() {
+    check(
+        r#"
+fn outer() {
+    let foo = 3;
+    {
+        let bar = 3;
+        |$0| {};
+        let baz = 3;
+        let qux = 3;
+    }
+    let fez = 3;
+}
+"#,
+        expect![[r#"
+            bn bar: i32
+            bn baz: i32
+            bn foo: i32
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+#[test]
+fn completes_fully_equal() {
+    check(
+        r#"
+fn foo(bar: u32) {}
+fn bar(bar$0) {}
+"#,
+        expect![[r#"
+            bn bar: u32
+            kw mut
+            kw ref
+        "#]],
+    )
+}
+
+#[test]
+fn completes_for_params_with_attributes() {
+    check(
+        r#"
+fn f(foo: (), #[baz = "qux"] mut bar: u32) {}
+fn g(foo: (), #[baz = "qux"] mut ba$0)
+"#,
+        expect![[r##"
+            bn #[baz = "qux"] mut bar: u32
+        "##]],
+    )
+}