Add builtin setattr (#193)

Author: S-YOU

runtime/builtin_types.go

@@ -575,6 +575,13 @@ func builtinRepr(f *Frame, args Args, kwargs KWArgs) (*Object, *BaseException) {
 	return s.ToObject(), nil
 }
 
+func builtinSetAttr(f *Frame, args Args, _ KWArgs) (*Object, *BaseException) {
+	if raised := checkFunctionArgs(f, "setattr", args, ObjectType, StrType, ObjectType); raised != nil {
+		return nil, raised
+	}
+	return None, SetAttr(f, args[0], toStrUnsafe(args[1]), args[2])
+}
+
 func builtinSorted(f *Frame, args Args, _ KWArgs) (*Object, *BaseException) {
 	// TODO: Support (cmp=None, key=None, reverse=False)
 	if raised := checkFunctionArgs(f, "sorted", args, ObjectType); raised != nil {
@@ -663,6 +670,7 @@ func init() {
 		"print":          newBuiltinFunction("print", builtinPrint).ToObject(),
 		"range":          newBuiltinFunction("range", builtinRange).ToObject(),
 		"repr":           newBuiltinFunction("repr", builtinRepr).ToObject(),
+		"setattr":        newBuiltinFunction("setattr", builtinSetAttr).ToObject(),
 		"sorted":         newBuiltinFunction("sorted", builtinSorted).ToObject(),
 		"True":           True.ToObject(),
 		"unichr":         newBuiltinFunction("unichr", builtinUniChr).ToObject(),

runtime/builtin_types_test.go

@@ -357,3 +357,31 @@ func TestBuiltinPrint(t *testing.T) {
 		}
 	}
 }
+
+func TestBuiltinSetAttr(t *testing.T) {
+	fun := wrapFuncForTest(func(f *Frame, args ...*Object) (*Object, *BaseException) {
+		fooObject := newTestClass("Foo", []*Type{ObjectType}, newStringDict(map[string]*Object{})).ToObject()
+		result, raised := builtinSetAttr(f, append(Args{fooObject}, args...), nil)
+		if raised != nil {
+			return nil, raised
+		}
+		val, raised := GetAttr(f, fooObject, toStrUnsafe(args[0]), nil)
+		if raised != nil {
+			return nil, raised
+		}
+		return newTestTuple(result, val).ToObject(), nil
+	})
+	cases := []invokeTestCase{
+		{args: wrapArgs(), wantExc: mustCreateException(TypeErrorType, "'setattr' requires 3 arguments")},
+		{args: wrapArgs("foo", "bar"), want: newTestTuple(None, "bar").ToObject()},
+		{args: wrapArgs("foo", 123), want: newTestTuple(None, 123).ToObject()},
+		{args: wrapArgs("foo"), wantExc: mustCreateException(TypeErrorType, "'setattr' requires 3 arguments")},
+		{args: wrapArgs("foo", 123, None), wantExc: mustCreateException(TypeErrorType, "'setattr' requires 3 arguments")},
+		{args: wrapArgs(123, 123), wantExc: mustCreateException(TypeErrorType, "'setattr' requires a 'str' object but received a \"int\"")},
+	}
+	for _, cas := range cases {
+		if err := runInvokeTestCase(fun, &cas); err != "" {
+			t.Error(err)
+		}
+	}
+}

testing/builtin_test.py

@@ -247,6 +247,26 @@ def __init__(self, x):
 assert cmp(a, b) == -1
 assert b.cmp_called
 
+# Test setattr
+
+class Foo(object):
+  pass
+
+setattr(Foo, "a", 1)
+assert Foo.a == 1  # pylint: disable=no-member
+
+try:
+  setattr(Foo, 1, "a")
+  assert AssertionError
+except TypeError:
+  pass
+
+try:
+  setattr(Foo)
+  assert AssertionError
+except TypeError:
+  pass
+
 # Test sorted
 
 assert sorted([3, 2, 4, 1]) == [1, 2, 3, 4]