x.json2: support time.Time values in encode (#16643)

* feat: json2 time.Time encode

* refactor: best var name

* fix: use 'RFC 3339' as pattern in json encode

* fix: unused var for unaliased_typ

* fix: improve test

* use the clearer test after V ad24c22, that made format_rfc3339 more stable

Co-authored-by: Delyan Angelov <delian66@gmail.com>

vlib/x/json2/any_test.v

@@ -107,11 +107,11 @@ fn test_bool() {
 	// valid conversions
 	assert sample_data['bool'] or { 0 }.bool() == false
 	assert json.Any('true').bool() == true
-	// invalid conversions
 	assert sample_data['int'] or { 0 }.bool() == true
 	assert sample_data['i64'] or { 0 }.bool() == true
 	assert sample_data['f32'] or { 0 }.bool() == true
 	assert sample_data['f64'] or { 0 }.bool() == true
+	// invalid conversions
 	assert sample_data['null'] or { 0 }.bool() == false
 	assert sample_data['arr'] or { 0 }.bool() == false
 	assert sample_data['obj'] or { 0 }.bool() == false

vlib/x/json2/decode_struct_test.v

@@ -1,4 +1,15 @@
 import x.json2 as json
+import time
+
+const fixed_time = time.Time{
+	year: 2022
+	month: 3
+	day: 11
+	hour: 13
+	minute: 54
+	second: 25
+	unix: 0
+}
 
 type StringAlias = string
 type BoolAlias = bool
@@ -6,6 +17,15 @@ type IntAlias = int
 
 type SumTypes = bool | int | string
 
+enum Enumerates {
+	a
+	b
+	c
+	d
+	e = 99
+	f
+}
+
 struct StructType[T] {
 mut:
 	val T

vlib/x/json2/encode_struct_test.v

@@ -1,4 +1,15 @@
 import x.json2 as json
+import time
+
+const fixed_time = time.Time{
+	year: 2022
+	month: 3
+	day: 11
+	hour: 13
+	minute: 54
+	second: 25
+	unix: 1647017665
+}
 
 type StringAlias = string
 type BoolAlias = bool
@@ -6,6 +17,15 @@ type IntAlias = int
 
 type SumTypes = bool | int | string
 
+enum Enumerates {
+	a
+	b
+	c
+	d
+	e = 99
+	f
+}
+
 struct StructType[T] {
 mut:
 	val T
@@ -33,6 +53,9 @@ fn test_types() {
 	assert json.encode(StructType[int]{}) == '{"val":0}'
 	assert json.encode(StructType[int]{ val: 0 }) == '{"val":0}'
 	assert json.encode(StructType[int]{ val: 1 }) == '{"val":1}'
+
+	assert json.encode(StructType[time.Time]{}) == '{"val":"0000-00-00T00:00:00.000Z"}'
+	assert json.encode(StructType[time.Time]{ val: fixed_time }) == '{"val":"2022-03-11T13:54:25.000Z"}'
 }
 
 fn test_optional_types() {
@@ -50,6 +73,9 @@ fn test_optional_types() {
 	assert json.encode(StructTypeOptional[int]{}) == '{"val":0}'
 	assert json.encode(StructTypeOptional[int]{ val: 0 }) == '{"val":0}'
 	assert json.encode(StructTypeOptional[int]{ val: 1 }) == '{"val":1}'
+
+	assert json.encode(StructTypeOptional[time.Time]{}) == '{"val":"0000-00-00T00:00:00.000Z"}'
+	assert json.encode(StructTypeOptional[time.Time]{ val: fixed_time }) == '{"val":"2022-03-11T13:54:25.000Z"}'
 }
 
 fn test_array() {

vlib/x/json2/encoder.v

@@ -5,6 +5,7 @@ module json2
 
 import io
 import strings
+import time
 
 // Encoder encodes the an `Any` type into JSON representation.
 // It provides parameters in order to change the end result.
@@ -112,6 +113,7 @@ fn (e &Encoder) encode_any(val Any, level int, mut wr io.Writer) ! {
 			e.encode_newline(level - 1, mut wr)!
 			wr.write([u8(`]`)])!
 		}
+		time.Time {}
 		Null {
 			wr.write(json2.null_in_bytes)!
 		}
@@ -176,6 +178,9 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut wr io.Writer) ! {
 			}
 			$if field.typ is string {
 				e.encode_string(value.str(), mut wr)!
+			} $else $if field.typ is time.Time {
+				parsed_time := val.$(field.name) as time.Time
+				e.encode_string(parsed_time.format_rfc3339(), mut wr)!
 			} $else $if field.typ is bool || field.typ is f32 || field.typ is f64 || field.typ is i8
 				|| field.typ is i16 || field.typ is int || field.typ is i64 || field.typ is u8
 				|| field.typ is u16 || field.typ is u32 || field.typ is u64 {
@@ -215,6 +220,10 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut wr io.Writer) ! {
 			} $else $if field.typ is ?[]int {
 				optional_value := val.$(field.name) as ?[]int
 				e.encode_array(optional_value, level, mut wr)!
+			} $else $if field.typ is ?time.Time {
+				optional_value := val.$(field.name) as ?time.Time
+				parsed_time := optional_value as time.Time
+				e.encode_string(parsed_time.format_rfc3339(), mut wr)!
 			} $else {
 				if field.unaliased_typ != field.typ {
 					match field.unaliased_typ {

vlib/x/json2/json2_test.v

@@ -1,5 +1,4 @@
 import x.json2 as json
-import time
 
 enum JobTitle {
 	manager

vlib/x/json2/types.v

@@ -1,5 +1,7 @@
 module json2
 
+import time
+
 // `Any` is a sum type that lists the possible types to be decoded and used.
 pub type Any = Null
 	| []Any
@@ -12,6 +14,7 @@ pub type Any = Null
 	| int
 	| map[string]Any
 	| string
+	| time.Time
 	| u16
 	| u32
 	| u64