Fix call typed to exclude named functions

Author: antonmedv

Diff for: checker/checker.go

@@ -568,7 +568,10 @@ func (v *visitor) checkFunc(fn reflect.Type, method bool, node *ast.CallNode, na
 		}
 	}
 
-	if !fn.IsVariadic() {
+	// OnCallTyped doesn't work for functions with variadic arguments,
+	// and doesn't work named function, like `type MyFunc func() int`.
+	// In PkgPath() is an empty string, it's unnamed function.
+	if !fn.IsVariadic() && fn.PkgPath() == "" {
 	funcTypes:
 		for i := range vm.FuncTypes {
 			if i == 0 {

Diff for: checker/checker_test.go

@@ -734,6 +734,19 @@ func TestCheck_CallFastTyped_Method(t *testing.T) {
 	require.Equal(t, 42, tree.Node.(*ast.CallNode).Typed)
 }
 
+func TestCheck_CallTyped_excludes_named_functions(t *testing.T) {
+	env := mock.Env{}
+
+	tree, err := parser.Parse("FuncNamed('bar')")
+	require.NoError(t, err)
+
+	_, err = checker.Check(tree, conf.New(env))
+	require.NoError(t, err)
+
+	require.False(t, tree.Node.(*ast.CallNode).Fast)
+	require.Equal(t, 0, tree.Node.(*ast.CallNode).Typed)
+}
+
 func TestCheck_works_with_nil_types(t *testing.T) {
 	env := map[string]interface{}{
 		"null": nil,

Diff for: test/mock/mock.go

@@ -28,6 +28,7 @@ type Env struct {
 	FuncParam          func(_ bool, _ int, _ string) bool
 	FuncParamAny       func(_ interface{}) bool
 	FuncTooManyReturns func() (int, int, error)
+	FuncNamed          MyFunc
 	NilFn              func()
 	Variadic           func(_ int, _ ...int) bool
 	Fast               func(...interface{}) interface{}
@@ -75,3 +76,5 @@ type Bar struct {
 type Abstract interface {
 	Method(int) int
 }
+
+type MyFunc func(string) int