chore: shallow clone repositories

src/domain/create-entry.spec.ts

@@ -113,7 +113,8 @@ describe("createEntryFiles", () => {
 
     await createEntryService.createEntryFiles(rulesetRepo, bcrRepo, tag, ".");
 
-    expect(mockGitClient.checkout).toHaveBeenCalledWith(
+    expect(mockGitClient.shallowClone).toHaveBeenCalledWith(
+      rulesetRepo.url,
       rulesetRepo.diskPath,
       tag
     );
@@ -124,11 +125,13 @@ describe("createEntryFiles", () => {
 
     const tag = "v1.2.3";
     const rulesetRepo = await RulesetRepository.create("repo", "owner", tag);
-    const bcrRepo = CANONICAL_BCR;
+    const bcrRepo = Repository.fromCanonicalName(CANONICAL_BCR.canonicalName);
 
     await createEntryService.createEntryFiles(rulesetRepo, bcrRepo, tag, ".");
 
-    expect(mockGitClient.checkout).toHaveBeenCalledWith(
+    expect(mockGitClient.shallowClone).toHaveBeenCalledTimes(2);
+    expect(mockGitClient.shallowClone).toHaveBeenCalledWith(
+      bcrRepo.url,
       bcrRepo.diskPath,
       "main"
     );
@@ -1256,8 +1259,8 @@ function mockRulesetFiles(
     patches?: { [path: string]: string };
   } = {}
 ) {
-  mockGitClient.checkout.mockImplementation(
-    async (repoPath: string, ref?: string) => {
+  mockGitClient.shallowClone.mockImplementation(
+    async (url: string, diskPath: string, ref?: string) => {
       const moduleRoot = options?.moduleRoot || ".";
       if (options.extractedModuleContent) {
         mockedFileReads[EXTRACTED_MODULE_PATH] = options.extractedModuleContent;
@@ -1268,7 +1271,7 @@ function mockRulesetFiles(
         });
       }
       const templatesDir = path.join(
-        repoPath,
+        diskPath,
         RulesetRepository.BCR_TEMPLATE_DIR
       );
       mockedFileReads[

src/domain/create-entry.ts

@@ -44,7 +44,7 @@ export class CreateEntryService {
     tag: string,
     moduleRoot: string
   ): Promise<{ moduleName: string }> {
-    await Promise.all([rulesetRepo.checkout(tag), bcrRepo.checkout("main")]);
+    await Promise.all([rulesetRepo.shallowCloneAndCheckout(tag), bcrRepo.shallowCloneAndCheckout("main")]);
 
     const version = RulesetRepository.getVersionFromTag(tag);
 

src/domain/repository.spec.ts

@@ -28,46 +28,40 @@ describe("canonicalName", () => {
 describe("diskPath", () => {
   test("is a temp dir", async () => {
     const repository = new Repository("foo", "bar");
-    await repository.checkout();
+    await repository.shallowCloneAndCheckout();
     expect(repository.diskPath.startsWith(os.tmpdir())).toEqual(true);
   });
 
   test("is a unique path", async () => {
     const repositoryA = new Repository("foo", "bar");
-    await repositoryA.checkout();
+    await repositoryA.shallowCloneAndCheckout();
 
     const repositoryB = new Repository("foo", "bar");
-    await repositoryB.checkout();
+    await repositoryB.shallowCloneAndCheckout();
 
     expect(repositoryA.diskPath).not.toEqual(repositoryB.diskPath);
   });
 });
 
-describe("checkout", () => {
-  test("clones and checks out the repository", async () => {
+describe("shallowCloneAndCheckout", () => {
+  test("clones the repository at the specified branch ", async () => {
     const repository = new Repository("foo", "bar");
-    await repository.checkout("main");
+    await repository.shallowCloneAndCheckout("main");
 
     const mockGitClient = mocked(GitClient).mock.instances[0];
-    expect(mockGitClient.clone).toHaveBeenCalledWith(
+    expect(mockGitClient.shallowClone).toHaveBeenCalledWith(
       repository.url,
-      repository.diskPath
-    );
-    expect(mockGitClient.checkout).toHaveBeenCalledWith(
       repository.diskPath,
       "main"
     );
   });
 
   test("clones and checks out the default branch when branch not specified", async () => {
     const repository = new Repository("foo", "bar");
-    await repository.checkout();
+    await repository.shallowCloneAndCheckout();
     const mockGitClient = mocked(GitClient).mock.instances[0];
-    expect(mockGitClient.clone).toHaveBeenCalledWith(
+    expect(mockGitClient.shallowClone).toHaveBeenCalledWith(
       repository.url,
-      repository.diskPath
-    );
-    expect(mockGitClient.checkout).toHaveBeenCalledWith(
       repository.diskPath,
       undefined
     );
@@ -82,7 +76,7 @@ describe("isCheckedOut", () => {
 
   test("true when checked out", async () => {
     const repository = new Repository("foo", "bar");
-    await repository.checkout();
+    await repository.shallowCloneAndCheckout();
     expect(repository.isCheckedOut()).toEqual(true);
   });
 });
@@ -96,7 +90,7 @@ describe("equals", () => {
 
   test("true when one is checked out", async () => {
     const a = new Repository("foo", "bar");
-    await a.checkout();
+    await a.shallowCloneAndCheckout();
     const b = new Repository("foo", "bar");
     expect(a.equals(b)).toEqual(true);
   });

src/domain/repository.ts

@@ -38,14 +38,12 @@ export class Repository {
     return this._diskPath;
   }
 
-  public async checkout(ref?: string): Promise<void> {
+  public async shallowCloneAndCheckout(branchOrTag?: string): Promise<void> {
     const gitClient = new GitClient();
     if (!this.isCheckedOut()) {
       this._diskPath = path.join(os.tmpdir(), randomUUID(), this.name);
-      await gitClient.clone(this.url, this._diskPath);
+      await gitClient.shallowClone(this.url, this._diskPath, branchOrTag);
     }
-
-    await gitClient.checkout(this._diskPath, ref);
   }
 
   public equals(other: Repository): boolean {

src/domain/ruleset-repository.spec.ts

@@ -396,19 +396,19 @@ function mockRulesetFiles(
 ) {
   mocked(GitClient).mockImplementation(() => {
     return {
-      checkout: jest.fn(),
-      clone: jest.fn().mockImplementation(async (url, repoPath) => {
+      // checkout: jest.fn(),
+      shallowClone: jest.fn().mockImplementation(async (url, diskPath, branchOrTag) => {
         const templatesDir = path.join(
-          repoPath,
+          diskPath,
           RulesetRepository.BCR_TEMPLATE_DIR
         );
 
         mocked(fs.existsSync).mockImplementation(((p: string) => {
           if (
             options.fileExistsMocks &&
-            path.relative(repoPath, p) in options.fileExistsMocks!
+            path.relative(diskPath, p) in options.fileExistsMocks!
           ) {
-            return options.fileExistsMocks[path.relative(repoPath, p)];
+            return options.fileExistsMocks[path.relative(diskPath, p)];
           } else if (p === path.join(templatesDir, "metadata.template.json")) {
             return !options.skipMetadataFile;
           } else if (p === path.join(templatesDir, "presubmit.yml")) {
@@ -420,7 +420,7 @@ function mockRulesetFiles(
             path.join(templatesDir, `config.${options.configExt || "yml"}`)
           ) {
             return options.configExists || options.configContent !== undefined;
-          } else if (p === repoPath) {
+          } else if (p === diskPath) {
             return true;
           }
           return (jest.requireActual("node:fs") as any).existsSync(path);
@@ -432,9 +432,9 @@ function mockRulesetFiles(
         ) => {
           if (
             options.fileContentMocks &&
-            path.relative(repoPath, p) in options.fileContentMocks!
+            path.relative(diskPath, p) in options.fileContentMocks!
           ) {
-            return options.fileContentMocks[path.relative(repoPath, p)];
+            return options.fileContentMocks[path.relative(diskPath, p)];
           } else if (p === path.join(templatesDir, "metadata.template.json")) {
             return fakeMetadataFile({
               malformed: options.invalidMetadataFile,

src/domain/ruleset-repository.ts

@@ -110,7 +110,7 @@ export class RulesetRepository extends Repository {
     verifyAtRef?: string
   ): Promise<RulesetRepository> {
     const rulesetRepo = new RulesetRepository(name, owner);
-    await rulesetRepo.checkout(verifyAtRef);
+    await rulesetRepo.shallowCloneAndCheckout(verifyAtRef);
 
     rulesetRepo._config = loadConfiguration(rulesetRepo);
 

src/infrastructure/git.ts

@@ -3,12 +3,20 @@ import { simpleGit } from "simple-git";
 
 @Injectable()
 export class GitClient {
-  public async clone(url: string, repoPath: string): Promise<void> {
-    await simpleGit().clone(url, repoPath);
-  }
-
-  public async checkout(repoPath: string, ref?: string): Promise<void> {
-    await simpleGit(repoPath).clean(["f", "f", "x", "d"]).checkout(ref);
+  public async shallowClone(url: string, diskPath: string, branchOrTag?: string): Promise<void> {
+    await simpleGit().clone(url, diskPath, [
+      ...(branchOrTag ? [
+        // Check out a single commit on the tip of the branch or at a tag
+        // From the docs: "--branch can also take tags and detaches the HEAD at that commit in the resulting repository"
+        // https://git-scm.com/docs/git-clone#Documentation/git-clone.txt-code--branchcodeemltnamegtem
+        "--branch",
+        branchOrTag,
+        "--single-branch"
+      ] : [
+        // Check out a single commit on the main branch
+        "--depth", "1"
+      ])
+    ]);
   }
 
   public async setUserNameAndEmail(