fix(git): show Sync only when branch diverges from origin

packages/server/src/utils/checkout-git.test.ts

@@ -101,6 +101,43 @@ describe("checkout git utilities", () => {
     }
   });
 
+  it("reports ahead/behind relative to origin on the base branch", async () => {
+    const remoteDir = join(tempDir, "remote.git");
+    const cloneDir = join(tempDir, "clone");
+    execSync(`git init --bare -b main ${remoteDir}`);
+    execSync(`git remote add origin ${remoteDir}`, { cwd: repoDir });
+    execSync("git push -u origin main", { cwd: repoDir });
+
+    execSync(`git clone ${remoteDir} ${cloneDir}`);
+    execSync("git config user.email 'test@test.com'", { cwd: cloneDir });
+    execSync("git config user.name 'Test'", { cwd: cloneDir });
+    writeFileSync(join(cloneDir, "file.txt"), "remote\n");
+    execSync("git add file.txt", { cwd: cloneDir });
+    execSync("git -c commit.gpgsign=false commit -m 'remote update'", { cwd: cloneDir });
+    execSync("git push", { cwd: cloneDir });
+
+    execSync("git fetch origin", { cwd: repoDir });
+    const behindStatus = await getCheckoutStatus(repoDir);
+    expect(behindStatus.isGit).toBe(true);
+    if (!behindStatus.isGit) {
+      return;
+    }
+    expect(behindStatus.aheadOfOrigin).toBe(0);
+    expect(behindStatus.behindOfOrigin).toBe(1);
+
+    writeFileSync(join(repoDir, "local.txt"), "local\n");
+    execSync("git add local.txt", { cwd: repoDir });
+    execSync("git -c commit.gpgsign=false commit -m 'local update'", { cwd: repoDir });
+
+    const divergedStatus = await getCheckoutStatus(repoDir);
+    expect(divergedStatus.isGit).toBe(true);
+    if (!divergedStatus.isGit) {
+      return;
+    }
+    expect(divergedStatus.aheadOfOrigin).toBe(1);
+    expect(divergedStatus.behindOfOrigin).toBe(1);
+  });
+
   it("commits messages with quotes safely", async () => {
     const message = `He said "hello" and it's fine`;
     writeFileSync(join(repoDir, "file.txt"), "quoted\n");

packages/server/src/utils/checkout-git.ts

@@ -441,6 +441,7 @@ export type CheckoutStatusGitNonPaseo = {
   baseRef: string | null;
   aheadBehind: AheadBehind | null;
   aheadOfOrigin: number | null;
+  behindOfOrigin: number | null;
   hasRemote: boolean;
   remoteUrl: string | null;
   isPaseoOwnedWorktree: false;
@@ -455,6 +456,7 @@ export type CheckoutStatusGitPaseo = {
   baseRef: string;
   aheadBehind: AheadBehind | null;
   aheadOfOrigin: number | null;
+  behindOfOrigin: number | null;
   hasRemote: boolean;
   remoteUrl: string | null;
   isPaseoOwnedWorktree: true;
@@ -838,6 +840,22 @@ async function getAheadOfOrigin(cwd: string, currentBranch: string): Promise<num
   }
 }
 
+async function getBehindOfOrigin(cwd: string, currentBranch: string): Promise<number | null> {
+  if (!currentBranch) {
+    return null;
+  }
+  try {
+    const { stdout } = await execAsync(
+      `git rev-list --count ${currentBranch}..origin/${currentBranch}`,
+      { cwd, env: READ_ONLY_GIT_ENV }
+    );
+    const count = Number.parseInt(stdout.trim(), 10);
+    return Number.isNaN(count) ? null : count;
+  } catch {
+    return null;
+  }
+}
+
 type CheckoutInspectionContext = {
   worktreeRoot: string;
   currentBranch: string | null;
@@ -996,10 +1014,11 @@ export async function getCheckoutStatus(
   const isDirty = await isWorkingTreeDirty(cwd);
   const hasRemote = remoteUrl !== null;
   const baseRef = configured.baseRef ?? (await resolveBaseRef(cwd));
-  const aheadBehind =
-    baseRef && currentBranch ? await getAheadBehind(cwd, baseRef, currentBranch) : null;
-  const aheadOfOrigin =
-    hasRemote && currentBranch ? await getAheadOfOrigin(cwd, currentBranch) : null;
+  const [aheadBehind, aheadOfOrigin, behindOfOrigin] = await Promise.all([
+    baseRef && currentBranch ? getAheadBehind(cwd, baseRef, currentBranch) : Promise.resolve(null),
+    hasRemote && currentBranch ? getAheadOfOrigin(cwd, currentBranch) : Promise.resolve(null),
+    hasRemote && currentBranch ? getBehindOfOrigin(cwd, currentBranch) : Promise.resolve(null),
+  ]);
 
   if (configured.isPaseoOwnedWorktree) {
     const mainRepoRoot = await getMainRepoRoot(cwd);
@@ -1012,6 +1031,7 @@ export async function getCheckoutStatus(
       baseRef: configured.baseRef,
       aheadBehind,
       aheadOfOrigin,
+      behindOfOrigin,
       hasRemote,
       remoteUrl,
       isPaseoOwnedWorktree: true,
@@ -1026,6 +1046,7 @@ export async function getCheckoutStatus(
     baseRef,
     aheadBehind,
     aheadOfOrigin,
+    behindOfOrigin,
     hasRemote,
     remoteUrl,
     isPaseoOwnedWorktree: false,