Fix deepening of shallow clones in latest git

change/change-d27a5175-146e-487e-86e5-d28822fb3467.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "type": "patch",
+      "comment": "Fix deepening of shallow clones in latest git by being more specific about the comparison ref being fetched. Also reduce git operations for the case where the branch ref doesn't exist locally.",
+      "packageName": "beachball",
+      "email": "elcraig@microsoft.com",
+      "dependentChangeType": "patch"
+    }
+  ]
+}

packages/beachball/src/__fixtures__/repositoryFactory.ts

@@ -162,6 +162,14 @@ export class RepositoryFactory {
   /** Cloned child repos, tracked so we can clean them up */
   private childRepos: Repository[] = [];
 
+  /** Get the root directory of the origin repository */
+  public get originRoot(): string {
+    if (!this.root) {
+      throw new Error('Factory was already cleaned');
+    }
+    return this.root;
+  }
+
   /**
    * Create the "origin" repo and create+commit fixture files.
    * If `fixture` is a string, the corresponding default fixture is used.

packages/beachball/src/__functional__/git/ensureSharedHistory.test.ts

@@ -18,15 +18,15 @@ describe('ensureSharedHistory', () => {
   let repositoryFactory: RepositoryFactory;
   const logs = initMockLogs();
   const testBranch = 'test';
+  const defaultRefSpec = `+refs/heads/${defaultBranchName}:refs/remotes/${defaultRemoteBranchName}`;
 
   const realGit = jest.requireActual<typeof workspaceTools>('workspace-tools').git;
   /**
    * Set this to override the git implementation for one test.
    * (Use this instead of `.mockImplementation()` to avoid interference with other mocks.)
    */
   let gitOverride: typeof workspaceTools.git | undefined;
-  const gitSpy = jest
-    .spyOn(workspaceTools, 'git')
+  const gitSpy = (workspaceTools.git as jest.MockedFunction<typeof workspaceTools.git>)
     // Attempt to force git to use English in logs, so we can check for absence of "warning" strings
     .mockImplementation((args, opts) => (gitOverride || realGit)(args, opts && optsWithLang(opts)));
 
@@ -77,10 +77,10 @@ describe('ensureSharedHistory', () => {
 
     ensureSharedHistory({ path: repo.rootPath, verbose: true, branch: defaultRemoteBranchName, fetch: true });
     // Ensure the expected git calls were made
-    expect(filteredGitCalls()).toEqual(['fetch origin master']);
+    expect(filteredGitCalls()).toEqual([`fetch origin ${defaultRefSpec}`]);
 
     const allLogs = logs.getMockLines('all');
-    expect(allLogs).toMatch('Fetching branch "master" from remote "origin"...');
+    expect(allLogs).toMatch(`Fetching branch "master" from remote "origin" (${defaultRefSpec})...`);
     expect(allLogs).toMatch('Fetching branch "master" from remote "origin" completed successfully');
     expect(allLogs).not.toMatch('warning');
   });
@@ -118,7 +118,7 @@ describe('ensureSharedHistory', () => {
     gitSpy.mockClear();
 
     ensureSharedHistory({ path: repo.rootPath, verbose: true, branch: defaultRemoteBranchName, fetch: true, depth: 1 });
-    expect(filteredGitCalls()).toEqual(['fetch origin master']);
+    expect(filteredGitCalls()).toEqual([`fetch origin ${defaultRefSpec}`]);
   });
 
   it('errors if fetching is disabled and target branch does not exist locally', () => {
@@ -168,10 +168,10 @@ describe('ensureSharedHistory', () => {
     expect(() =>
       ensureSharedHistory({ path: repo.rootPath, verbose: true, branch: defaultRemoteBranchName, fetch: true })
     ).toThrow('Fetching branch "master" from remote "origin" failed');
-    expect(filteredGitCalls()).toContain('fetch origin master');
+    expect(filteredGitCalls()).toContain(`fetch origin ${defaultRefSpec}`);
 
     const allLogs = logs.getMockLines('all');
-    expect(allLogs).toMatch('Fetching branch "master" from remote "origin"...');
+    expect(allLogs).toMatch(`Fetching branch "master" from remote "origin" (${defaultRefSpec})...`);
     expect(allLogs).toMatch('Fetching branch "master" from remote "origin" failed');
   });
 
@@ -183,8 +183,7 @@ describe('ensureSharedHistory', () => {
       ensureSharedHistory({ path: repo.rootPath, verbose: false, branch: 'origin/fake', fetch: true })
     ).toThrow('Fetching branch "fake" from remote "origin" failed');
     const gitOps = filteredGitCalls();
-    expect(gitOps).not.toContain('remote set-branches --add origin fake');
-    expect(gitOps).toContain('fetch origin fake');
+    expect(gitOps).toContain('fetch origin +refs/heads/fake:refs/remotes/origin/fake');
 
     expect(logs.getMockLines('all')).toEqual('');
   });
@@ -198,12 +197,12 @@ describe('ensureSharedHistory', () => {
     ).toThrow('Fetching branch "fake" from remote "origin" failed');
 
     const gitOps = filteredGitCalls();
-    expect(gitOps).toContain('remote set-branches --add origin fake');
-    expect(gitOps).toContain('fetch origin fake');
+    expect(gitOps).toContain('fetch origin +refs/heads/fake:refs/remotes/origin/fake');
 
     const allLogs = logs.getMockLines('all');
-    expect(allLogs).toMatch('Adding branch "fake" to fetch config for remote "origin"');
-    expect(allLogs).toMatch('Fetching branch "fake" from remote "origin"...');
+    expect(allLogs).toMatch(
+      `Fetching branch "fake" from remote "origin" (+refs/heads/fake:refs/remotes/origin/fake)...`
+    );
   });
 
   it('errors if fetching is disabled and adequate history is not available', () => {
@@ -237,13 +236,13 @@ describe('ensureSharedHistory', () => {
       branch: defaultRemoteBranchName,
       fetch: true,
       depth: 2,
-      // Run this with verbose git logs so we can verify arguments were correct (no "warning" logs).
-      // However, this adds noise including filesystem paths to the output, so we can't snapshot it.
+      // Run this with verbose git logs so we can verify arguments were correct (no "warning" logs)
       verbose: true,
     });
 
-    const allLogs = logs.getMockLines('all');
-    expect(allLogs).toMatch('Adding branch "master" to fetch config for remote "origin"');
+    const allLogs = logs.getMockLines('all', {
+      replacePaths: { [repo.rootPath]: '<repo-root>', [repositoryFactory.originRoot]: '<origin-root>' },
+    });
     expect(allLogs).toMatch('This is a shallow clone. Deepening to check for changes...');
     expect(allLogs).toMatch('Deepening by 2 more commits (attempt 1/3)...');
     expect(allLogs).toMatch('Deepening by 2 more commits (attempt 2/3)...');
@@ -252,17 +251,40 @@ describe('ensureSharedHistory', () => {
     expect(logs.mocks.warn).not.toHaveBeenCalled();
     expect(logs.mocks.error).not.toHaveBeenCalled();
 
-    expect(filteredGitCalls().filter(line => !line.startsWith('rev-parse') && !line.startsWith('merge-base')))
-      .toMatchInlineSnapshot(`
-      [
-        "config --get-all remote.origin.fetch",
-        "remote set-branches --add origin master",
-        "fetch --depth=2 origin master",
-        "fetch --deepen=2 origin master",
-        "fetch --deepen=2 origin master",
-        "fetch --deepen=2 origin master",
-      ]
-    `);
+    const deepen = `fetch --deepen=2 origin ${defaultRefSpec}`;
+    expect(filteredGitCalls()).toEqual([`fetch --depth=2 origin ${defaultRefSpec}`, deepen, deepen, deepen]);
+  });
+
+  it('deepens history if needed when tracking ref already exists locally', () => {
+    // singleBranch: false means origin/master is already fetched at depth 1 before ensureSharedHistory
+    // runs, so hasBranchRef returns true and the ref already exists — but history is still too shallow.
+    // This verifies that deepening correctly updates the existing tracking ref (requires explicit refspec).
+    const repo = repositoryFactory.cloneRepository({ depth: 1, branch: testBranch, singleBranch: false });
+
+    // Verify the precondition: origin/master already exists locally (at depth 1)
+    expect(realGit(['rev-parse', '--verify', defaultRemoteBranchName], { cwd: repo.rootPath }).success).toBe(true);
+
+    gitSpy.mockClear();
+
+    ensureSharedHistory({
+      path: repo.rootPath,
+      branch: defaultRemoteBranchName,
+      fetch: true,
+      depth: 2,
+      verbose: true,
+    });
+
+    const allLogs = logs.getMockLines('all', {
+      replacePaths: { [repo.rootPath]: '<repo-root>', [repositoryFactory.originRoot]: '<origin-root>' },
+    });
+    expect(allLogs).toMatch('This is a shallow clone. Deepening to check for changes...');
+    expect(allLogs).toMatch('Deepening by 2 more commits (attempt 1/3)...');
+    expect(allLogs).not.toMatch('warning');
+    expect(logs.mocks.warn).not.toHaveBeenCalled();
+    expect(logs.mocks.error).not.toHaveBeenCalled();
+
+    const deepen = `fetch --deepen=2 origin ${defaultRefSpec}`;
+    expect(filteredGitCalls()).toEqual([`fetch --depth=2 origin ${defaultRefSpec}`, deepen, deepen, deepen]);
   });
 
   it('unshallows if deepening attempts fail', () => {
@@ -279,17 +301,14 @@ describe('ensureSharedHistory', () => {
     });
 
     expect(logs.getMockLines('all')).toMatch("Still didn't find a common commit after deepening by 3. Unshallowing...");
-    expect(filteredGitCalls()).toMatchInlineSnapshot(`
-      [
-        "config --get-all remote.origin.fetch",
-        "remote set-branches --add origin master",
-        "fetch --depth=1 origin master",
-        "fetch --deepen=1 origin master",
-        "fetch --deepen=1 origin master",
-        "fetch --deepen=1 origin master",
-        "fetch --unshallow origin master",
-      ]
-    `);
+    const deepen = `fetch --deepen=1 origin ${defaultRefSpec}`;
+    expect(filteredGitCalls()).toEqual([
+      `fetch --depth=1 origin ${defaultRefSpec}`,
+      deepen,
+      deepen,
+      deepen,
+      `fetch --unshallow origin ${defaultRefSpec}`,
+    ]);
   });
 
   it('errors if there is no common history', () => {
@@ -309,12 +328,12 @@ describe('ensureSharedHistory', () => {
 
     // The fetch part succeeded
     const allLogs = logs.getMockLines('all');
-    expect(allLogs).toMatch('Fetching branch "master" from remote "origin"...');
+    expect(allLogs).toMatch(`Fetching branch "master" from remote "origin" (${defaultRefSpec})...`);
     expect(allLogs).toMatch('Fetching branch "master" from remote "origin" completed successfully');
 
     expect(filteredGitCalls([])).toEqual([
       'rev-parse --verify origin/master',
-      'fetch origin master',
+      `fetch origin ${defaultRefSpec}`,
       'merge-base origin/master HEAD',
       'rev-parse --is-shallow-repository',
     ]);