Merge #6477

6477: Add infer_function_return_type assist r=matklad a=Veykril

This adds an assist to insert a functions return type if it hasn't been specified yet by inferring it from the functions tail expression. This assist only becomes active if the cursor is on the tail expression. See https://github.com/rust-analyzer/rust-analyzer/issues/6303#issuecomment-714657326

Co-authored-by: Lukas Wirth <[email protected]>

1 files changed, 13 insertions, 0 deletions

diff --git a/crates/assists/src/tests/generated.rs b/crates/assists/src/tests/generated.rs
index acbf5b652..168e1626a 100644
--- a/crates/assists/src/tests/generated.rs
+++ b/crates/assists/src/tests/generated.rs
@@ -506,6 +506,19 @@ impl<T: Clone> Ctx<T> {
 }
 
 #[test]
+fn doctest_infer_function_return_type() {
+    check_doc_test(
+        "infer_function_return_type",
+        r#####"
+fn foo() { 4<|>2i32 }
+"#####,
+        r#####"
+fn foo() -> i32 { 42i32 }
+"#####,
+    )
+}
+
+#[test]
 fn doctest_inline_local_variable() {
     check_doc_test(
         "inline_local_variable",