diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v index a3641fe0b3c743..76fba44f175888 100644 --- a/vlib/v/checker/fn.v +++ b/vlib/v/checker/fn.v @@ -1719,7 +1719,15 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast. } else { func.params[i] } - c.expected_type = param.typ + if param.typ.has_flag(.generic) { + if unwrap_typ := c.table.convert_generic_type(param.typ, func.generic_names, + concrete_types) + { + c.expected_type = unwrap_typ + } + } else { + c.expected_type = param.typ + } already_checked := node.language != .js && call_arg.expr is ast.CallExpr typ := c.check_expr_option_or_result_call(call_arg.expr, if already_checked && mut call_arg.expr is ast.CallExpr { diff --git a/vlib/v/tests/generics/generics_with_empty_array_arg_test.v b/vlib/v/tests/generics/generics_with_empty_array_arg_test.v new file mode 100644 index 00000000000000..6139af792db524 --- /dev/null +++ b/vlib/v/tests/generics/generics_with_empty_array_arg_test.v @@ -0,0 +1,29 @@ +fn count_str(array []string) int { + return array.len +} + +fn count_int(array []int) int { + return array.len +} + +fn count[T](array []T) int { + return array.len +} + +fn test_generics_with_empty_array_arg() { + assert count_str(['one', 'two']) == 2 + assert count_str([]string{}) == 0 + assert count_str([]) == 0 + + assert count_int([1, 2]) == 2 + assert count_int([]int{}) == 0 + assert count_int([]) == 0 + + assert count[f64]([1.0, 2.0]) == 2 + assert count[f64]([]f64{}) == 0 + assert count[f64]([]) == 0 + + assert count[int]([1, 2]) == 2 + assert count[int]([]int{}) == 0 + assert count[int]([]) == 0 +}