Added extra error type for unknown dependency type

models/error.go

@@ -1275,3 +1275,18 @@ func IsErrDependenciesLeft(err error) bool {
 func (err ErrDependenciesLeft) Error() string {
 	return fmt.Sprintf("cannot close this issue as it still has open dependencies [issue id: %d]", err.IssueID)
 }
+
+// ErrUnknownDependencyType represents an error where an unknown dependency type was passed
+type ErrUnknownDependencyType struct {
+	Type DependencyType
+}
+
+// IsErrUnknownDependencyType checks if an error is ErrUnknownDependencyType
+func IsErrUnknownDependencyType(err error) bool {
+	_, ok := err.(ErrUnknownDependencyType)
+	return ok
+}
+
+func (err ErrUnknownDependencyType) Error() string {
+	return fmt.Sprintf("unknown dependency type [type: %d]", err.Type)
+}

models/issue_dependency.go

@@ -8,6 +8,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
+	"fmt"
 )
 
 // IssueDependency represents an issue dependency
@@ -83,7 +84,7 @@ func RemoveIssueDependency(user *User, issue *Issue, dep *Issue, depType Depende
 	case DependencyTypeBlocking:
 		err = issueDepExists(sess, dep.ID, issue.ID)
 	default:
-		return
+		return ErrUnknownDependencyType{depType}
 	}
 	if err != nil {
 		if IsErrDependencyExists(err) {
@@ -104,7 +105,7 @@ func RemoveIssueDependency(user *User, issue *Issue, dep *Issue, depType Depende
 		case DependencyTypeBlocking:
 			issueDepToDelete = IssueDependency{IssueID: dep.ID, DependencyID: issue.ID}
 		default:
-			return
+			return ErrUnknownDependencyType{depType}
 		}
 
 		if _, err := sess.Delete(&issueDepToDelete); err != nil {