Fixes API result transformation

(#3788, #3795)

Author: sergeibbb

src/plus/integrations/providers/gitlab/gitlab.ts

@@ -47,8 +47,10 @@ import { fromGitLabMergeRequest, fromGitLabMergeRequestREST, fromGitLabMergeRequ
 const gitlabUserIdPrefix = 'gid://gitlab/User/';
 const gitlabMergeRequestIdPrefix = 'gid://gitlab/MergeRequest/';
 
-function buildGitLabUserId(id: string | undefined): string | undefined {
-	return id?.startsWith(gitlabUserIdPrefix) ? id.substring(gitlabUserIdPrefix.length) : id;
+function buildGitLabUserId(id: string | number | undefined): string | undefined {
+	return typeof id === 'string' && id?.startsWith(gitlabUserIdPrefix)
+		? id.substring(gitlabUserIdPrefix.length)
+		: String(id);
 }
 
 export class GitLabApi implements Disposable {

src/plus/integrations/providers/gitlab/models.ts

@@ -80,7 +80,7 @@ export interface GitLabMergeRequestFull extends GitLabMergeRequest {
 		headSha: string;
 	} | null;
 	project: GitLabRepositoryStub;
-	sourceProject: GitLabRepositoryStub;
+	sourceProject: GitLabRepositoryStub | null;
 }
 
 export type GitLabMergeRequestState = 'opened' | 'closed' | 'locked' | 'merged';
@@ -213,6 +213,9 @@ export function fromGitLabMergeRequest(pr: GitLabMergeRequestFull, provider: Pro
 }
 
 function fromGitLabMergeRequestRefs(pr: GitLabMergeRequestFull): PullRequestRefs | undefined {
+	if (pr.sourceProject == null) {
+		return undefined;
+	}
 	return {
 		base: {
 			owner: getRepoNamespace(pr.sourceProject.fullPath),