Make a custom marshaller for merge params

Fixes #626

event_types.go

@@ -17,6 +17,9 @@
 package gitlab
 
 import (
+	"encoding/json"
+	"fmt"
+	"strconv"
 	"time"
 )
 
@@ -533,9 +536,7 @@ type MergeEvent struct {
 		LockedAt                 string       `json:"locked_at"`
 		UpdatedByID              int          `json:"updated_by_id"`
 		MergeError               string       `json:"merge_error"`
-		MergeParams     struct {
-			ForceRemoveSourceBranch string `json:"force_remove_source_branch"`
-		} `json:"merge_params"`
+		MergeParams              *MergeParams `json:"merge_params"`
 		MergeWhenBuildSucceeds   bool         `json:"merge_when_build_succeeds"`
 		MergeUserID              int          `json:"merge_user_id"`
 		MergeCommitSHA           string       `json:"merge_commit_sha"`
@@ -594,6 +595,45 @@ type MergeEvent struct {
 	} `json:"changes"`
 }
 
+// MergeParams represents the merge params.
+type MergeParams struct {
+	ForceRemoveSourceBranch bool `json:"force_remove_source_branch"`
+}
+
+// UnmarshalJSON decodes the merge parameters
+//
+// This allows support of ForceRemoveSourceBranch for both type bool (>11.9) and string (<11.9)
+func (p *MergeParams) UnmarshalJSON(b []byte) error {
+	type Alias MergeParams
+	raw := struct {
+		*Alias
+		ForceRemoveSourceBranch interface{} `json:"force_remove_source_branch"`
+	}{
+		Alias: (*Alias)(p),
+	}
+
+	err := json.Unmarshal(b, &raw)
+	if err != nil {
+		return err
+	}
+
+	switch v := raw.ForceRemoveSourceBranch.(type) {
+	case nil:
+		// No action needed.
+	case bool:
+		p.ForceRemoveSourceBranch = v
+	case string:
+		p.ForceRemoveSourceBranch, err = strconv.ParseBool(v)
+		if err != nil {
+			return err
+		}
+	default:
+		return fmt.Errorf("failed to unmarshal ForceRemoveSourceBranch of type: %T", v)
+	}
+
+	return nil
+}
+
 // WikiPageEvent represents a wiki page event.
 //
 // GitLab API docs:

services.go

@@ -416,7 +416,7 @@ func (p *JiraServiceProperties) UnmarshalJSON(b []byte) error {
 
 	switch id := raw.JiraIssueTransitionID.(type) {
 	case nil:
-		p.JiraIssueTransitionID = ""
+		// No action needed.
 	case string:
 		p.JiraIssueTransitionID = id
 	case float64: