add enum string decoding and tests

vlib/x/json2/decoder2/attributes_test.v

@@ -38,6 +38,16 @@ struct StruWithRequiredAttribute {
 	b                 int
 }
 
+struct Foo {
+	a int @[required]
+}
+
+fn test_last_field_requiered() {
+	assert json.decode[Foo]('{"a":0}')! == Foo{
+		a: 0
+	}
+}
+
 fn test_skip_and_rename_attributes() {
 	assert json.decode[StruWithJsonAttribute]('{"name": "hola1", "a": 2, "b": 3}')! == StruWithJsonAttribute{
 		a:     2

vlib/x/json2/decoder2/decode.v

@@ -904,8 +904,18 @@ fn (mut decoder Decoder) decode_enum[T](mut val T) ! {
 				return
 			}
 		}
-		decoder.decode_error('Number value: ${result} does not match any field in enum: ${typeof(val).name}')!
+		decoder.decode_error('Number value: `${result}` does not match any field in enum: ${typeof(val).name}')!
 	} else if enum_info.value_kind == .string {
+		mut result := ''
+		unsafe { decoder.decode_value(mut result)! }
+
+		$for value in T.values {
+			if value.name == result {
+				val = value.value
+				return
+			}
+		}
+		decoder.decode_error('String value: `${result}` does not match any field in enum: ${typeof(val).name}')!
 	}
 
 	decoder.decode_error('Expected number or string value for enum, got: ${enum_info.value_kind}')!

vlib/x/json2/decoder2/tests/decode_enum_test.v

@@ -0,0 +1,95 @@
+import x.json2.decoder2 as json
+
+enum Bar {
+	a
+	b
+	c = 10
+}
+
+type BarAlias = Bar
+
+fn test_number_decode() {
+	assert json.decode[Bar]('0')! == Bar.a
+	assert json.decode[Bar]('1')! == Bar.b
+	assert json.decode[Bar]('10')! == Bar.c
+
+	assert json.decode[BarAlias]('0')! == Bar.a
+	assert json.decode[BarAlias]('1')! == Bar.b
+	assert json.decode[BarAlias]('10')! == Bar.c
+}
+
+fn test_number_decode_fails() {
+	if _ := json.decode[Bar]('2') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Number value: `2` does not match any field in enum: &Bar'
+		}
+	}
+
+	if _ := json.decode[BarAlias]('2') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Number value: `2` does not match any field in enum: &BarAlias'
+		}
+	}
+}
+
+fn test_string_decode() {
+	assert json.decode[Bar]('"a"')! == Bar.a
+	assert json.decode[Bar]('"b"')! == Bar.b
+	assert json.decode[Bar]('"c"')! == Bar.c
+
+	assert json.decode[BarAlias]('"a"')! == Bar.a
+	assert json.decode[BarAlias]('"b"')! == Bar.b
+	assert json.decode[BarAlias]('"c"')! == Bar.c
+}
+
+fn test_string_decode_fails() {
+	if _ := json.decode[Bar]('"d"') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: String value: `d` does not match any field in enum: &Bar'
+		}
+	}
+
+	if _ := json.decode[BarAlias]('"d"') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: String value: `d` does not match any field in enum: &BarAlias'
+		}
+	}
+}
+
+fn test_invalid_decode_fails() {
+	if _ := json.decode[Bar]('true') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Expected number or string value for enum, got: boolean'
+		}
+	}
+
+	if _ := json.decode[BarAlias]('true') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Expected number or string value for enum, got: boolean'
+		}
+	}
+}

vlib/x/json2/decoder2/tests/decode_escaped_string_test.v

@@ -3,7 +3,7 @@ import x.json2.decoder2
 
 fn test_decode_escaped_string() {
 	escaped_strings := ['test', 'test\\sd', 'test\nsd', '\ntest', 'test\\"', 'test\\', 'test\u1234ps',
-		'test\u1234', '\u1234\\\t"', '']
+		'test\u1234', '\u1234\\\t"', '', '\uff0f', 'test \uff0f test', '😀', 'text 😀 text']
 
 	json_string := json2.encode[[]string](escaped_strings)
 	decoded_strings := decoder2.decode[[]string](json_string)!