checker: check type mismatch in args of generics method calls (fix #13193) (#13196)

vlib/v/checker/fn.v

@@ -1212,7 +1212,7 @@ pub fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 			}
 			exp_arg_sym := c.table.sym(exp_arg_typ)
 			c.expected_type = exp_arg_typ
-			got_arg_typ := c.check_expr_opt_call(arg.expr, c.expr(arg.expr))
+			mut got_arg_typ := c.check_expr_opt_call(arg.expr, c.expr(arg.expr))
 			node.args[i].typ = got_arg_typ
 			if no_type_promotion {
 				if got_arg_typ != exp_arg_typ {
@@ -1243,10 +1243,29 @@ pub fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 				continue
 			}
 			if exp_arg_typ.has_flag(.generic) {
-				continue
+				if concrete_types.len == 0 {
+					continue
+				}
+
+				if exp_utyp := c.table.resolve_generic_to_concrete(exp_arg_typ, method.generic_names,
+					concrete_types)
+				{
+					exp_arg_typ = exp_utyp
+				} else {
+					continue
+				}
+
+				if got_arg_typ.has_flag(.generic) {
+					if got_utyp := c.table.resolve_generic_to_concrete(got_arg_typ, method.generic_names,
+						concrete_types)
+					{
+						got_arg_typ = got_utyp
+					} else {
+						continue
+					}
+				}
 			}
-			c.check_expected_call_arg(got_arg_typ, c.unwrap_generic(exp_arg_typ), node.language,
-				arg) or {
+			c.check_expected_call_arg(got_arg_typ, exp_arg_typ, node.language, arg) or {
 				// str method, allow type with str method if fn arg is string
 				// Passing an int or a string array produces a c error here
 				// Deleting this condition results in propper V error messages

vlib/v/checker/tests/generics_method_called_arg_mismatch.out

@@ -0,0 +1,7 @@
+vlib/v/checker/tests/generics_method_called_arg_mismatch.vv:3:15: error: cannot use `Foo` as `Bar` in argument 1 to `Obj.set`
+    1 | fn main() {
+    2 |     mut obj := Obj{}
+    3 |     obj.set<Bar>(Foo{})
+      |                  ~~~~~
+    4 | }
+    5 |

vlib/v/checker/tests/generics_method_called_arg_mismatch.vv

@@ -0,0 +1,14 @@
+fn main() {
+	mut obj := Obj{}
+	obj.set<Bar>(Foo{})
+}
+
+struct Foo {}
+
+struct Bar {
+	Foo
+}
+
+struct Obj {}
+
+fn (mut o Obj) set<T>(val T) {}

vlib/v/tests/generics_with_nested_generics_fn_test.v

@@ -15,7 +15,7 @@ fn (ng NestedGeneric) nested_test<T>(mut app T) {
 
 fn method_test<T>(mut app T) int {
 	ng := NestedGeneric{}
-	ng.nested_test<T>(app)
+	ng.nested_test<T>(mut app)
 	return 22
 }