json2: decode refactor/fix (#16588)

vlib/x/json2/json2_test.v

@@ -44,14 +44,6 @@ fn (e Employee) to_json() string {
 	return mp.str()
 }
 
-fn (mut e Employee) from_json(any json.Any) {
-	mp := any.as_map()
-	e.name = mp['name'] or { json.Any('') }.str()
-	e.age = mp['age'] or { json.Any(0) }.int()
-	e.salary = mp['salary'] or { json.Any(0) }.f32()
-	e.title = unsafe { JobTitle(mp['title'] or { json.Any(0) }.int()) }
-}
-
 // ! BUGFIX
 // fn test_simplegg() {
 // 	// x := EmployeeOp{'Peter', 28, 95000.5, .worker}
@@ -102,92 +94,34 @@ fn test_character_unescape() {
 	assert lines['slash'] or { 0 }.str() == '/dev/null'
 }
 
-fn (mut u User2) from_json(an json.Any) {
-	mp := an.as_map()
-	mut js_field_name := ''
-	$for field in User.fields {
-		js_field_name = field.name
-		for attr in field.attrs {
-			if attr.starts_with('json:') {
-				js_field_name = attr.all_after('json:').trim_left(' ')
-				break
-			}
-		}
-		match field.name {
-			'age' { u.age = mp[js_field_name] or { 0 }.int() }
-			'nums' { u.nums = mp[js_field_name] or { 0 }.arr().map(it.int()) }
-			else {}
-		}
-	}
+struct MultTypeTest[T] {
+mut:
+	val T
 }
 
-struct User2 {
-pub mut:
-	age      int
-	nums     []int
-	reg_date time.Time
-}
+// NOTE - This can substitute a lot of others tests
+fn test_bool_decode() {
+	assert json.decode[MultTypeTest[bool]]('{"val": ""}')!.val == false
+	assert json.decode[MultTypeTest[bool]]('{"val": "0"}')!.val == false
+	assert json.decode[MultTypeTest[bool]]('{"val": "1"}')!.val == true
+	assert json.decode[MultTypeTest[bool]]('{"val": "2"}')!.val == true
+	assert json.decode[MultTypeTest[bool]]('{"val": 0}')!.val == false
+	assert json.decode[MultTypeTest[bool]]('{"val": 1}')!.val == true
+	assert json.decode[MultTypeTest[bool]]('{"val": 2}')!.val == true
+	assert json.decode[MultTypeTest[bool]]('{"val": "true"}')!.val == true
+	assert json.decode[MultTypeTest[bool]]('{"val": "false"}')!.val == false
+	assert json.decode[MultTypeTest[bool]]('{"val": true}')!.val == true
+	assert json.decode[MultTypeTest[bool]]('{"val": false}')!.val == false
 
-struct User {
-pub mut:
-	age           int
-	nums          []int
-	last_name     string [json: lastName]
-	is_registered bool   [json: IsRegistered]
-	typ           int    [json: 'type']
-	pets          string [json: 'pet_animals'; raw]
-}
-
-fn (mut u User) from_json(an json.Any) {
-	mp := an.as_map()
-	mut js_field_name := ''
-	$for field in User.fields {
-		// FIXME: C error when initializing js_field_name inside comptime for
-		js_field_name = field.name
-		for attr in field.attrs {
-			if attr.starts_with('json:') {
-				js_field_name = attr.all_after('json:').trim_left(' ')
-				break
-			}
-		}
-		match field.name {
-			'age' { u.age = mp[js_field_name] or { 0 }.int() }
-			'nums' { u.nums = mp[js_field_name] or { 0 }.arr().map(it.int()) }
-			'last_name' { u.last_name = mp[js_field_name] or { 0 }.str() }
-			'is_registered' { u.is_registered = mp[js_field_name] or { 0 }.bool() }
-			'typ' { u.typ = mp[js_field_name] or { 0 }.int() }
-			'pets' { u.pets = mp[js_field_name] or { 0 }.str() }
-			else {}
-		}
-	}
-}
-
-fn (u User) to_json() string {
-	// TODO: derive from field
-	mut mp := {
-		'age': json.Any(u.age)
-	}
-	mp['nums'] = u.nums.map(json.Any(it))
-	mp['lastName'] = json.Any(u.last_name)
-	mp['IsRegistered'] = json.Any(u.is_registered)
-	mp['type'] = json.Any(u.typ)
-	mp['pet_animals'] = json.Any(u.pets)
-	return mp.str()
-}
-
-struct Color {
-pub mut:
-	space string
-	point string [raw]
-}
-
-fn (mut c Color) from_json(an json.Any) {
-	mp := an.as_map()
-	$for field in Color.fields {
-		match field.name {
-			'space' { c.space = mp[field.name] or { 0 }.str() }
-			'point' { c.point = mp[field.name] or { 0 }.str() }
-			else {}
-		}
-	}
+	assert json.decode[MultTypeTest[int]]('{"val": ""}')!.val == 0
+	assert json.decode[MultTypeTest[int]]('{"val": "0"}')!.val == 0
+	assert json.decode[MultTypeTest[int]]('{"val": "1"}')!.val == 1
+	assert json.decode[MultTypeTest[int]]('{"val": "2"}')!.val == 2
+	assert json.decode[MultTypeTest[int]]('{"val": 0}')!.val == 0
+	assert json.decode[MultTypeTest[int]]('{"val": 1}')!.val == 1
+	assert json.decode[MultTypeTest[int]]('{"val": 2}')!.val == 2
+	assert json.decode[MultTypeTest[int]]('{"val": "true"}')!.val == 1
+	assert json.decode[MultTypeTest[int]]('{"val": "false"}')!.val == 0
+	assert json.decode[MultTypeTest[int]]('{"val": true}')!.val == 1
+	assert json.decode[MultTypeTest[int]]('{"val": false}')!.val == 0
 }