x.json2: fix encoder commas (#20916)

vlib/x/json2/encoder.v

@@ -177,17 +177,27 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut buf []u8) ! {
 	mut fields_len := 0
 
 	$for field in U.fields {
-		$if field.is_option {
-			if val.$(field.name) != none {
+		mut @continue := false
+		for attr in field.attrs {
+			if attr.contains('json: ') {
+				if attr.replace('json: ', '') == '-' {
+					@continue = true
+				}
+				break
+			}
+		}
+		if !@continue {
+			$if field.is_option {
+				if val.$(field.name) != none {
+					fields_len++
+				}
+			} $else {
 				fields_len++
 			}
-		} $else {
-			fields_len++
 		}
 	}
 	$for field in U.fields {
 		mut ignore_field := false
-		mut skip_field := false
 
 		value := val.$(field.name)
 
@@ -200,16 +210,12 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut buf []u8) ! {
 				json_name = attr.replace('json: ', '')
 				if json_name == '-' {
 					ignore_field = true
-					skip_field = true
 				}
 				break
 			}
 		}
 
-		if skip_field {
-			i++
-			fields_len--
-		} else {
+		if !ignore_field {
 			$if value is $option {
 				workaround := val.$(field.name)
 				if workaround != none { // smartcast

vlib/x/json2/tests/encode_struct_skippable_fields_test.v

@@ -0,0 +1,134 @@
+import time
+import x.json2 as json
+
+struct StructTypeSkippedFields[T] {
+mut:
+	val  T @[json: '-']
+	val1 T
+	val2 T @[json: '-']
+	val3 T
+}
+
+struct StructTypeSkippedFields1[T] {
+mut:
+	val  T
+	val1 T @[json: '-']
+	val2 T
+	val3 T @[json: '-']
+}
+
+struct StructTypeSkippedFields2[T] {
+mut:
+	val  T @[json: '-']
+	val1 T @[json: '-']
+	val2 T @[json: '-']
+	val3 T @[json: '-']
+}
+
+struct StructTypeSkippedFields3[T, U, V] {
+mut:
+	val  T @[json: '-']
+	val1 U
+	val2 V
+	val3 T @[json: '-']
+}
+
+struct StructTypeSkippedFields4 {
+mut:
+	val  string    @[json: '-']
+	val1 i64
+	val2 f64
+	val3 time.Time
+}
+
+struct StructTypeSkippedFields5 {
+mut:
+	val  string    @[json: '-']
+	val1 i64       @[json: '-']
+	val2 f64
+	val3 time.Time
+}
+
+struct StructTypeSkippedFields6 {
+mut:
+	val  string    @[json: '-']
+	val1 i64
+	val2 f64       @[json: '-']
+	val3 time.Time
+}
+
+struct StructTypeSkippedFields7 {
+mut:
+	val  string
+	val1 i64       @[json: '-']
+	val2 f64       @[json: '-']
+	val3 time.Time
+}
+
+struct StructTypeSkippedFields8 {
+mut:
+	val  string
+	val1 i64       @[json: '-']
+	val2 f64
+	val3 time.Time @[json: '-']
+}
+
+fn test_encode_struct_skipped_fields() {
+	assert json.encode(StructTypeSkippedFields[string]{
+		val: 'string_val'
+		val1: 'string_val1'
+		val2: 'string_val2'
+		val3: 'string_val3'
+	}) == '{"val1":"string_val1","val3":"string_val3"}'
+
+	assert json.encode(StructTypeSkippedFields1[string]{
+		val: 'string_val'
+		val1: 'string_val1'
+		val2: 'string_val2'
+		val3: 'string_val3'
+	}) == '{"val":"string_val","val2":"string_val2"}'
+
+	assert json.encode(StructTypeSkippedFields2[string]{
+		val: 'string_val'
+		val1: 'string_val1'
+		val2: 'string_val2'
+		val3: 'string_val3'
+	}) == '{}'
+
+	assert json.encode(StructTypeSkippedFields3[string, i64, f64]{
+		val: 'string_val'
+		val1: 1
+		val2: 1.0
+		val3: 'string_val'
+	}) == '{"val1":1,"val2":1.0}'
+
+	assert json.encode(StructTypeSkippedFields4{
+		val: 'string_val'
+		val1: 1
+		val2: 1.0
+	}) == '{"val1":1,"val2":1.0,"val3":"0000-00-00T00:00:00.000Z"}'
+
+	assert json.encode(StructTypeSkippedFields5{
+		val: 'string_val'
+		val1: 1
+		val2: 1.0
+	}) == '{"val2":1.0,"val3":"0000-00-00T00:00:00.000Z"}'
+
+	assert json.encode(StructTypeSkippedFields6{
+		val: 'string_val'
+		val1: 1
+		val2: 1.0
+	}) == '{"val1":1,"val3":"0000-00-00T00:00:00.000Z"}'
+
+	assert json.encode(StructTypeSkippedFields7{
+		val: 'string_val'
+		val1: 1
+		val2: 1.0
+	}) == '{"val":"string_val","val3":"0000-00-00T00:00:00.000Z"}'
+
+	assert json.encode(StructTypeSkippedFields8{
+		val: 'string_val'
+		val1: 1
+		val2: 1.0
+	}) == '{"val":"string_val","val2":1.0}'
+}

vlib/x/json2/tests/encode_struct_test.v

@@ -44,30 +44,6 @@ mut:
 	val &T
 }
 
-struct StructTypeSkippedFields[T] {
-mut:
-	val  T @[json: '-']
-	val1 T
-	val2 T @[json: '-']
-	val3 T
-}
-
-struct StructTypeSkippedFields2[T] {
-mut:
-	val  T
-	val1 T @[json: '-']
-	val2 T
-	val3 T @[json: '-']
-}
-
-struct StructTypeSkippedFields3[T] {
-mut:
-	val  T @[json: '-']
-	val1 T @[json: '-']
-	val2 T @[json: '-']
-	val3 T @[json: '-']
-}
-
 fn test_types() {
 	assert json.encode(StructType[string]{}) == '{"val":""}'
 	assert json.encode(StructType[string]{ val: '' }) == '{"val":""}'
@@ -235,29 +211,6 @@ fn test_option_array() {
 	// }) == '{"val":[[0,1],[0,2,3],[2],[5,1]]}'
 }
 
-fn test_skipped_fields() {
-	assert json.encode(StructTypeSkippedFields[string]{
-		val: ''
-		val1: ''
-		val2: ''
-		val3: ''
-	}) == '{"val1":"","val3":""}'
-
-	assert json.encode(StructTypeSkippedFields2[string]{
-		val: ''
-		val1: ''
-		val2: ''
-		val3: ''
-	}) == '{"val":"","val2":""}'
-
-	assert json.encode(StructTypeSkippedFields3[string]{
-		val: ''
-		val1: ''
-		val2: ''
-		val3: ''
-	}) == '{}'
-}
-
 fn test_alias() {
 	assert json.encode(StructType[StringAlias]{}) == '{"val":""}'
 	assert json.encode(StructType[StringAlias]{ val: '' }) == '{"val":""}'