refactor(dev-infra): use a singleton for GitClient (#41515)

Creates a singleton class for GitClient rather than relying on creating an instance to
require being passed around throughout its usages.

PR Close #41515

dev-infra/utils/testing/virtual-git-client.ts

@@ -58,7 +58,21 @@ export interface Commit {
  * Virtual git client that mocks Git commands and keeps track of the repository state
  * in memory. This allows for convenient test assertions with Git interactions.
  */
-export class VirtualGitClient extends GitClient {
+export class VirtualGitClient<Authenticated extends boolean> extends GitClient<Authenticated> {
+  static getInstance(config = mockNgDevConfig, tmpDir = testTmpDir): VirtualGitClient<false> {
+    return new VirtualGitClient(undefined, config, tmpDir);
+  }
+
+  static getAuthenticatedInstance(config = mockNgDevConfig, tmpDir = testTmpDir):
+      VirtualGitClient<true> {
+    return new VirtualGitClient('abc123', config, tmpDir);
+  }
+
+  private constructor(token: Authenticated extends true? string: undefined, config: NgDevConfig,
+                                                   tmpDir: string) {
+    super(token, config, tmpDir);
+  }
+
   /** Current Git HEAD that has been previously fetched. */
   fetchHeadRef: RemoteRef|null = null;
   /** List of known branches in the repository. */
@@ -190,10 +204,10 @@ export class VirtualGitClient extends GitClient {
 }
 
 
-/**
- * Builds a Virtual Git Client instance with the provided config and set the temporary test
- * directory.
- */
-export function buildVirtualGitClient(config = mockNgDevConfig, tmpDir = testTmpDir) {
-  return (new VirtualGitClient(undefined, config, tmpDir));
+export function installVirtualGitClientSpies() {
+  const authenticatedVirtualGitClient = VirtualGitClient.getAuthenticatedInstance();
+  spyOn(GitClient, 'getAuthenticatedInstance').and.returnValue(authenticatedVirtualGitClient);
+
+  const unauthenticatedVirtualGitClient = VirtualGitClient.getInstance();
+  spyOn(GitClient, 'getInstance').and.returnValue(unauthenticatedVirtualGitClient);
 }

dev-infra/utils/testing/virtual-git-matchers.ts

@@ -27,13 +27,13 @@ export function getBranchPushMatcher(options: BranchPushMatchParameters) {
   const {targetRepo, targetBranch, baseBranch, baseRepo, expectedCommits} = options;
   return jasmine.objectContaining({
     remote: {
-      repoUrl: `https://github.com/${targetRepo.owner}/${targetRepo.name}.git`,
+      repoUrl: `https://abc123@github.com/${targetRepo.owner}/${targetRepo.name}.git`,
       name: `refs/heads/${targetBranch}`
     },
     head: jasmine.objectContaining({
       newCommits: expectedCommits,
       ref: {
-        repoUrl: `https://github.com/${baseRepo.owner}/${baseRepo.name}.git`,
+        repoUrl: `https://abc123@github.com/${baseRepo.owner}/${baseRepo.name}.git`,
         name: baseBranch,
       },
     })