json: make enums work with json encode+decode (serialised as string names by default; the old integer one is supported too, using [json_as_number]) (#17696)

vlib/json/json_encode_enum_test.v

@@ -0,0 +1,134 @@
+import json
+
+[json_as_number]
+pub enum MessageType {
+	error = 1
+	warning = 2
+	info = 3
+	log = 4
+}
+
+pub enum MessageType2 {
+	error = 1
+	warning = 2
+	info = 3
+	log = 4
+}
+
+enum TestEnum {
+	one = 1
+	two
+}
+
+type TestAlias = TestEnum
+type TestSum = TestEnum | string
+type TestSum2 = MessageType | string
+type TestAliasAttr = MessageType
+
+struct TestStruct {
+	test  []TestEnum
+	test2 TestEnum
+	test3 TestAlias
+	test4 TestSum
+	test5 MessageType
+}
+
+struct TestStruct2 {
+	a TestAliasAttr
+	b TestSum2
+	c TestSum2
+}
+
+struct Test {
+	ab ?int
+	a  ?MessageType
+}
+
+struct Test2 {
+	a ?MessageType2
+}
+
+type TSum = MessageType | string
+type TSum2 = MessageType2 | string
+
+struct Test3 {
+	a ?TSum
+}
+
+struct Test4 {
+	a ?TSum2
+}
+
+fn test_encode_with_enum() {
+	out := json.encode(TestStruct{
+		test: [TestEnum.one, TestEnum.one]
+		test2: TestEnum.two
+		test3: TestEnum.one
+		test4: TestEnum.two
+		test5: .log
+	})
+	assert out == '{"test":["one","one"],"test2":"two","test3":"one","test4":"two","test5":4}'
+}
+
+fn test_encode_direct_enum() {
+	assert json.encode(TestEnum.one) == '"one"'
+}
+
+fn test_encode_alias_and_sumtype() {
+	assert json.decode(TestStruct, '{"test":["one","one"],"test2":"two","test3": "one", "test4": "two", "test5":4}')! == TestStruct{
+		test: [.one, .one]
+		test2: .two
+		test3: TestAlias(.one)
+		test4: TestSum('two')
+		test5: .log
+	}
+}
+
+fn test_enum_attr() {
+	assert dump(json.encode(MessageType.log)) == '4'
+	assert dump(json.encode(MessageType.error)) == '1'
+}
+
+fn test_enum_attr_decode() {
+	assert json.decode(TestStruct2, '{"a": 1, "b":4, "c": "test"}')! == TestStruct2{
+		a: .error
+		b: MessageType.log
+		c: 'test'
+	}
+}
+
+fn test_enum_attr_encode() {
+	assert json.encode(TestStruct2{
+		a: .error
+		b: MessageType.log
+		c: 'test'
+	}) == '{"a":1,"b":4,"c":"test"}'
+}
+
+fn test_option_enum() {
+	assert dump(json.encode(Test{none, none})) == '{}'
+	assert dump(json.encode(Test{none, MessageType.log})) == '{"a":4}'
+	t := dump(json.decode(Test, '{"a":4}')!)
+	assert t.ab == none
+	assert t.a? == .log
+
+	t2 := dump(json.decode(Test, '{"a":null}')!)
+	assert t2.a == none
+
+	assert json.encode(Test2{none}) == '{}'
+	assert dump(json.encode(Test2{MessageType2.log})) == '{"a":"log"}'
+	z := dump(json.decode(Test2, '{"a":"log"}')!)
+	assert z.a? == .log
+	a := dump(json.decode(Test2, '{"a": null}')!)
+	assert a.a == none
+}
+
+fn test_option_sumtype_enum() {
+	assert dump(json.encode(Test3{none})) == '{}'
+	assert dump(json.encode(Test3{ a: 'foo' })) == '{"a":"foo"}'
+	assert dump(json.encode(Test3{ a: MessageType.warning })) == '{"a":2}'
+
+	assert dump(json.encode(Test4{none})) == '{}'
+	assert dump(json.encode(Test4{ a: 'foo' })) == '{"a":"foo"}'
+	assert dump(json.encode(Test4{ a: MessageType2.warning })) == '{"a":"warning"}'
+}