patch 8.2.4441: Vim9: function argument of filter() not checked like map()

Problem:    Vim9: function argument of filter() not checked like map().
Solution:   Also check the function argument of filter().

src/evalfunc.c

@@ -486,51 +486,12 @@ arg_list_or_dict_or_blob_or_string(type_T *type, type_T *decl_type UNUSED, argco
 }
 
 /*
- * Check second argument of filter(): func must return a bool.
+ * Check second argument of map() or filter().
  */
     static int
-arg_filter_func(type_T *type, type_T *decl_type UNUSED, argcontext_T *context)
+check_map_filter_arg2(type_T *type, argcontext_T *context, int is_map)
 {
-    if (type->tt_type == VAR_STRING
+    type_T *expected_member = NULL;
-	    || type->tt_type == VAR_PARTIAL
-	    || type == &t_unknown
-	    || type == &t_any)
-	return OK;
-
-    if (type->tt_type == VAR_FUNC)
-    {
-	if (!(type->tt_member->tt_type == VAR_BOOL
-		|| type->tt_member->tt_type == VAR_NUMBER
-		|| type->tt_member->tt_type == VAR_UNKNOWN
-		|| type->tt_member->tt_type == VAR_ANY))
-	{
-	    arg_type_mismatch(&t_func_bool, type, context->arg_idx + 1);
-	    return FAIL;
-	}
-    }
-    else
-    {
-	semsg(_(e_string_or_function_required_for_argument_nr), 2);
-	return FAIL;
-    }
-    return OK;
-}
-
-/*
- * Check second argument of map(), the function.
- */
-    static int
-arg_map_func(type_T *type, type_T *decl_type UNUSED, argcontext_T *context)
-{
-    if (type->tt_type == VAR_STRING
-	    || type->tt_type == VAR_PARTIAL
-	    || type == &t_unknown
-	    || type == &t_any)
-	return OK;
-
-    if (type->tt_type == VAR_FUNC)
-    {
-	type_T *expected_ret = NULL;
     type_T *(args[2]);
     type_T t_func_exp = {VAR_FUNC, 2, 0, 0, NULL, args};
 
@@ -542,14 +503,14 @@ arg_map_func(type_T *type, type_T *decl_type UNUSED, argcontext_T *context)
 	// type.
 	if (context->arg_types[0].type_decl->tt_type == VAR_LIST
 		|| context->arg_types[0].type_decl->tt_type == VAR_DICT)
-		expected_ret = context->arg_types[0].type_decl->tt_member;
+	    expected_member = context->arg_types[0].type_decl->tt_member;
 	else
-		expected_ret = context->arg_types[0].type_curr->tt_member;
+	    expected_member = context->arg_types[0].type_curr->tt_member;
     }
     else if (context->arg_types[0].type_curr->tt_type == VAR_STRING)
-	    expected_ret = &t_string;
+	expected_member = &t_string;
     else if (context->arg_types[0].type_curr->tt_type == VAR_BLOB)
-	    expected_ret = &t_number;
+	expected_member = &t_number;
 
     args[0] = NULL;
     args[1] = &t_unknown;
@@ -573,7 +534,7 @@ arg_map_func(type_T *type, type_T *decl_type UNUSED, argcontext_T *context)
 	    else if (context->arg_types[0].type_decl->tt_type == VAR_DICT)
 		args[0] = &t_string;
 	    if (args[0] != NULL)
-		    args[1] = expected_ret;
+		args[1] = expected_member;
 	}
     }
 
@@ -582,23 +543,56 @@ arg_map_func(type_T *type, type_T *decl_type UNUSED, argcontext_T *context)
     {
 	where_T where = WHERE_INIT;
 
-	    t_func_exp.tt_member = expected_ret == NULL
+	if (is_map)
+	    t_func_exp.tt_member = expected_member == NULL
 				    || type->tt_member == &t_any
 				    || type->tt_member == &t_unknown
-				    ? &t_any : expected_ret;
+				? &t_any : expected_member;
+	else
+	    t_func_exp.tt_member = &t_bool;
 	if (args[0] == NULL)
 	    args[0] = &t_unknown;
 
 	where.wt_index = 2;
 	return check_type(&t_func_exp, type, TRUE, where);
     }
+    return OK;
 }
-    else
+
+/*
+ * Check second argument of filter(): func must return a bool.
+ */
+    static int
+arg_filter_func(type_T *type, type_T *decl_type UNUSED, argcontext_T *context)
 {
+    if (type->tt_type == VAR_STRING
+	    || type->tt_type == VAR_PARTIAL
+	    || type == &t_unknown
+	    || type == &t_any)
+	return OK;
+
+    if (type->tt_type == VAR_FUNC)
+	return check_map_filter_arg2(type, context, FALSE);
     semsg(_(e_string_or_function_required_for_argument_nr), 2);
     return FAIL;
 }
+
+/*
+ * Check second argument of map(), the function.
+ */
+    static int
+arg_map_func(type_T *type, type_T *decl_type UNUSED, argcontext_T *context)
+{
+    if (type->tt_type == VAR_STRING
+	    || type->tt_type == VAR_PARTIAL
+	    || type == &t_unknown
+	    || type == &t_any)
 	return OK;
+
+    if (type->tt_type == VAR_FUNC)
+	return check_map_filter_arg2(type, context, TRUE);
+    semsg(_(e_string_or_function_required_for_argument_nr), 2);
+    return FAIL;
 }
 
 /*

src/testdir/test_vim9_builtin.vim

@@ -1315,17 +1315,6 @@ def Wrong_dict_key_type(items: list<number>): list<number>
 enddef
 
 def Test_filter()
-  v9.CheckDefAndScriptFailure(['filter(1.1, "1")'], ['E1013: Argument 1: type mismatch, expected list<any> but got float', 'E1251: List, Dictionary, Blob or String required for argument 1'])
-  v9.CheckDefAndScriptFailure(['filter([1, 2], 4)'], ['E1256: String or function required for argument 2', 'E1024: Using a Number as a String'])
-
-  var lines =<< trim END
-    def F(i: number, v: any): string
-      return 'bad'
-    enddef
-    echo filter([1, 2, 3], F)
-  END
-  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(...): bool', 'E1135: Using a String as a Bool:'])
-
   assert_equal([], filter([1, 2, 3], '0'))
   assert_equal([1, 2, 3], filter([1, 2, 3], '1'))
   assert_equal({b: 20}, filter({a: 10, b: 20}, 'v:val == 20'))
@@ -1335,6 +1324,61 @@ def Test_filter()
     return range(3)->filter(Odd)
   enddef
   assert_equal([1], GetFiltered())
+
+  v9.CheckDefAndScriptFailure(['filter(1.1, "1")'], ['E1013: Argument 1: type mismatch, expected list<any> but got float', 'E1251: List, Dictionary, Blob or String required for argument 1'])
+  v9.CheckDefAndScriptFailure(['filter([1, 2], 4)'], ['E1256: String or function required for argument 2', 'E1024: Using a Number as a String'])
+
+  var lines =<< trim END
+    def F(i: number, v: any): string
+      return 'bad'
+    enddef
+    echo filter([1, 2, 3], F)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?number, ?any): bool but got func(number, any): string', 'E1135: Using a String as a Bool:'])
+
+  # check first function argument type
+  lines =<< trim END
+    var l = [1, 2, 3]
+    filter(l, (i: string, v: number) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?number, ?number): bool but got func(string, number): bool', 'E1013: Argument 1: type mismatch, expected string but got number'])
+  lines =<< trim END
+    var d = {a: 1}
+    filter(d, (i: number, v: number) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?string, ?number): bool but got func(number, number): bool', 'E1013: Argument 1: type mismatch, expected number but got string'])
+  lines =<< trim END
+    var b = 0z1122
+    filter(b, (i: string, v: number) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?number, ?number): bool but got func(string, number): bool', 'E1013: Argument 1: type mismatch, expected string but got number'])
+  lines =<< trim END
+    var s = 'text'
+    filter(s, (i: string, v: string) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?number, ?string): bool but got func(string, string): bool', 'E1013: Argument 1: type mismatch, expected string but got number'])
+
+  # check second function argument type
+  lines =<< trim END
+    var l = [1, 2, 3]
+    filter(l, (i: number, v: string) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?number, ?number): bool but got func(number, string): bool', 'E1013: Argument 2: type mismatch, expected string but got number'])
+  lines =<< trim END
+    var d = {a: 1}
+    filter(d, (i: string, v: string) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?string, ?number): bool but got func(string, string): bool', 'E1013: Argument 2: type mismatch, expected string but got number'])
+  lines =<< trim END
+    var b = 0z1122
+    filter(b, (i: number, v: string) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?number, ?number): bool but got func(number, string): bool', 'E1013: Argument 2: type mismatch, expected string but got number'])
+  lines =<< trim END
+    var s = 'text'
+    filter(s, (i: number, v: number) => true)
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1013: Argument 2: type mismatch, expected func(?number, ?string): bool but got func(number, number): bool', 'E1013: Argument 2: type mismatch, expected number but got string'])
 enddef
 
 def Test_filter_wrong_dict_key_type()

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4441,
 /**/
     4440,
 /**/