Fix start_param unmarshalling

parse.go

@@ -7,6 +7,13 @@ import (
 	"strings"
 )
 
+var (
+	// List of properties which should always be interpreted as strings.
+	_stringProps = map[string]bool{
+		"start_param": true,
+	}
+)
+
 // Parse converts passed init data presented as query string to InitData
 // object.
 func Parse(initData string) (InitData, error) {
@@ -27,9 +34,10 @@ func Parse(initData string) (InitData, error) {
 
 		// If passed value is valid in the context of JSON, it means, we could
 		// insert this value without formatting.
-		if json.Valid([]byte(val)) {
+		if isString := _stringProps[k]; !isString && json.Valid([]byte(val)) {
 			valFormat = "%q:%s"
 		}
+
 		pairs = append(pairs, fmt.Sprintf(valFormat, k, val))
 	}
 

parse_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 const (
-	parseTestInitData = "query_id=AAHdF6IQAAAAAN0XohDhrOrc&user=%7B%22id%22%3A279058397%2C%22first_name%22%3A%22Vladislav%22%2C%22last_name%22%3A%22Kibenko%22%2C%22username%22%3A%22vdkfrost%22%2C%22language_code%22%3A%22ru%22%2C%22is_premium%22%3Atrue%7D&auth_date=1662771648&hash=c501b71e775f74ce10e377dea85a7ea24ecd640b223ea86dfe453e0eaed2e2b2"
+	_parseTestInitData = "query_id=AAHdF6IQAAAAAN0XohDhrOrc&user=%7B%22id%22%3A279058397%2C%22first_name%22%3A%22Vladislav%22%2C%22last_name%22%3A%22Kibenko%22%2C%22username%22%3A%22vdkfrost%22%2C%22language_code%22%3A%22ru%22%2C%22is_premium%22%3Atrue%7D&auth_date=1662771648&hash=c501b71e775f74ce10e377dea85a7ea24ecd640b223ea86dfe453e0eaed2e2b2&start_param=abc"
 )
 
 type testParse struct {
@@ -17,11 +17,11 @@ type testParse struct {
 
 var testsParse = []testParse{
 	{
-		initData:    parseTestInitData + ";",
+		initData:    _parseTestInitData + ";",
 		expectedErr: ErrUnexpectedFormat,
 	},
 	{
-		initData: parseTestInitData,
+		initData: _parseTestInitData,
 		expectedRes: InitData{
 			QueryID: "AAHdF6IQAAAAAN0XohDhrOrc",
 			User: User{
@@ -34,6 +34,7 @@ var testsParse = []testParse{
 			},
 			CanSendAfterRaw: 0,
 			AuthDateRaw:     1662771648,
+			StartParam:      "abc",
 			Hash:            "c501b71e775f74ce10e377dea85a7ea24ecd640b223ea86dfe453e0eaed2e2b2",
 		},
 	},
@@ -42,9 +43,9 @@ var testsParse = []testParse{
 func TestParse(t *testing.T) {
 	for _, test := range testsParse {
 		if data, err := Parse(test.initData); err != test.expectedErr {
-			t.Errorf("expected error to be %q. Received %q", test.expectedErr, err)
+			t.Errorf("expected error to be %q. \nReceived %q", test.expectedErr, err)
 		} else if !reflect.DeepEqual(data, test.expectedRes) {
-			t.Errorf("expected result to be %+v. Received %+v", test.expectedRes, data)
+			t.Errorf("expected result to be %+v. \nReceived %+v", test.expectedRes, data)
 		}
 	}
 }