From 6be2fbb700781cffff42cb8f82b451a0b30364fd Mon Sep 17 00:00:00 2001
From: gechandesu <47027335+gechandesu@users.noreply.github.com>
Date: Mon, 26 Jan 2026 11:32:55 +0300
Subject: [PATCH] x.json2: add `@[json: name]` attr support for enum values
 (fix #26437) (#26441)

---
 vlib/x/json2/decode.v                 |  6 ++++++
 vlib/x/json2/encode.v                 | 13 +++++++++++++
 vlib/x/json2/tests/decode_enum_test.v | 24 +++++++++++++++++++++---
 vlib/x/json2/tests/encode_test.v      |  8 +++++++-
 4 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/vlib/x/json2/decode.v b/vlib/x/json2/decode.v
index f9aafc2ad..17fbd0a3b 100644
--- a/vlib/x/json2/decode.v
+++ b/vlib/x/json2/decode.v
@@ -853,6 +853,12 @@ fn (mut decoder Decoder) decode_enum[T](mut val T) ! {
 		decoder.decode_string(mut result)!
 
 		$for value in T.values {
+			for attr in value.attrs {
+				if attr.starts_with('json: ') && attr[6..] == result {
+					val = value.value
+					return
+				}
+			}
 			if value.name == result {
 				val = value.value
 				return
diff --git a/vlib/x/json2/encode.v b/vlib/x/json2/encode.v
index ff4f185d6..c79c3a004 100644
--- a/vlib/x/json2/encode.v
+++ b/vlib/x/json2/encode.v
@@ -299,6 +299,19 @@ fn (mut encoder Encoder) encode_enum[T](val T) {
 
 			enum_val = enum_val[i + 1..enum_val.len - 1]
 		}
+		mut attr_value := ''
+		$for member in T.values {
+			if member.value == val {
+				for attr in member.attrs {
+					if attr.starts_with('json: ') {
+						attr_value = attr[6..]
+					}
+				}
+			}
+		}
+		if attr_value != '' {
+			enum_val = attr_value
+		}
 		encoder.output << `"`
 		unsafe { encoder.output.push_many(enum_val.str, enum_val.len) }
 		encoder.output << `"`
diff --git a/vlib/x/json2/tests/decode_enum_test.v b/vlib/x/json2/tests/decode_enum_test.v
index 21ed64974..bf39bc6f1 100644
--- a/vlib/x/json2/tests/decode_enum_test.v
+++ b/vlib/x/json2/tests/decode_enum_test.v
@@ -2,8 +2,9 @@ import x.json2 as json
 
 enum Bar {
 	a
-	b
+	b  @[json: 'BBB']
 	c = 10
+	e  @[badattr: 'bad'; foobar]
 }
 
 type BarAlias = Bar
@@ -42,14 +43,31 @@ fn test_number_decode_fails() {
 
 fn test_string_decode() {
 	assert json.decode[Bar]('"a"')! == Bar.a
-	assert json.decode[Bar]('"b"')! == Bar.b
+	assert json.decode[Bar]('"BBB"')! == 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]('"BBB"')! == Bar.b
 	assert json.decode[BarAlias]('"c"')! == Bar.c
 }
 
+fn test_string_decode_uses_only_json_attr() {
+	assert json.decode[Bar]('"e"')! == Bar.e
+	assert json.decode[BarAlias]('"e"')! == Bar.e
+	for badval in ['"badattr: bad"', '"bad"', '"foobar"'] {
+		if _ := json.decode[Bar](badval) {
+			assert false, '${badval} must not be decoded to Bar'
+		} else {
+			assert true
+		}
+		if _ := json.decode[BarAlias](badval) {
+			assert false, '${badval} must not be decoded to BarAlias'
+		} else {
+			assert true
+		}
+	}
+}
+
 fn test_string_decode_fails() {
 	if _ := json.decode[Bar]('"d"') {
 		assert false
diff --git a/vlib/x/json2/tests/encode_test.v b/vlib/x/json2/tests/encode_test.v
index 4e93fb676..815359fb3 100644
--- a/vlib/x/json2/tests/encode_test.v
+++ b/vlib/x/json2/tests/encode_test.v
@@ -9,8 +9,9 @@ type FloatAlias = f64
 
 enum TestEnum {
 	a
-	b
+	b  @[json: 'BBB']
 	c = 10
+	d  @[badattr: 'bad'; foobar]
 }
 
 type EnumAlias = TestEnum
@@ -122,6 +123,11 @@ fn test_enums() {
 	assert json.encode(EnumAlias(TestEnum.c)) == '"c"'
 	assert json.encode(TestEnum.c, enum_as_int: true) == '10'
 	assert json.encode(EnumAlias(TestEnum.c), enum_as_int: true) == '10'
+	assert json.encode(TestEnum.b) == '"BBB"'
+	assert json.encode(EnumAlias(TestEnum.b)) == '"BBB"'
+	// Ensure that only `json: ` attrs is applied
+	assert json.encode(TestEnum.d) == '"d"'
+	assert json.encode(EnumAlias(TestEnum.d)) == '"d"'
 }
 
 fn test_sumtypes() {
-- 
2.39.5