Fix data_constructor ignoring generics for struct

Author: kilpkonn

crates/hir/src/term_search.rs

@@ -329,7 +329,7 @@ pub fn term_search<DB: HirDatabase>(ctx: &TermSearchCtx<'_, DB>) -> Vec<Expr> {
     while should_continue() {
         lookup.new_round();
 
-        solutions.extend(tactics::type_constructor(ctx, &defs, &mut lookup, should_continue));
+        solutions.extend(tactics::data_constructor(ctx, &defs, &mut lookup, should_continue));
         solutions.extend(tactics::free_function(ctx, &defs, &mut lookup, should_continue));
         solutions.extend(tactics::impl_method(ctx, &defs, &mut lookup, should_continue));
         solutions.extend(tactics::struct_projection(ctx, &defs, &mut lookup, should_continue));

crates/hir/src/term_search/tactics.rs

@@ -87,9 +87,9 @@ pub(super) fn trivial<'a, DB: HirDatabase>(
     })
 }
 
-/// # Type constructor tactic
+/// # Data constructor tactic
 ///
-/// Attempts different type constructors for enums and structs in scope
+/// Attempts different data constructors for enums and structs in scope
 ///
 /// Updates lookup by new types reached and returns iterator that yields
 /// elements that unify with `goal`.
@@ -99,7 +99,7 @@ pub(super) fn trivial<'a, DB: HirDatabase>(
 /// * `defs` - Set of items in scope at term search target location
 /// * `lookup` - Lookup table for types
 /// * `should_continue` - Function that indicates when to stop iterating
-pub(super) fn type_constructor<'a, DB: HirDatabase>(
+pub(super) fn data_constructor<'a, DB: HirDatabase>(
     ctx: &'a TermSearchCtx<'a, DB>,
     defs: &'a FxHashSet<ScopeDef>,
     lookup: &'a mut LookupTable,
@@ -308,7 +308,9 @@ pub(super) fn type_constructor<'a, DB: HirDatabase>(
                         // Early exit if some param cannot be filled from lookup
                         let param_exprs: Vec<Vec<Expr>> = fields
                             .into_iter()
-                            .map(|field| lookup.find(db, &field.ty(db)))
+                            .map(|field| {
+                                lookup.find(db, &field.ty_with_args(db, generics.iter().cloned()))
+                            })
                             .collect::<Option<_>>()?;
 
                         // Note that we need special case for 0 param constructors because of multi cartesian

crates/ide-assists/src/handlers/term_search.rs

@@ -278,4 +278,16 @@ fn f() { let a = 1; let b = 0.0; let c: (i32, (i32, f64)) = todo$0!(); }"#,
             r#"fn f() { let a = 1; let b = 0.0; let c: (i32, (i32, f64)) = (a, (a, b)); }"#,
         )
     }
+
+    #[test]
+    fn test_tuple_struct_with_generics() {
+        check_assist(
+            term_search,
+            r#"//- minicore: todo, unimplemented
+struct Foo<T>(T);
+fn f() { let a = 1; let b: Foo<i32> = todo$0!(); }"#,
+            r#"struct Foo<T>(T);
+fn f() { let a = 1; let b: Foo<i32> = Foo(a); }"#,
+        )
+    }
 }