fix(tests): scrub GIT_* env vars leaking from the pre-commit hook into git-fixture tests

server/lib/update-check.js's execGit() and two test helpers
(lanes-cli.test.js, update-check.test.js) shelled out to git with an
explicit `cwd` but no `env` override. A parent git hook process (this
repo's own .husky/pre-commit, which runs `npm run test:server`) sets
GIT_DIR/GIT_INDEX_FILE in its own environment; those leak to every
child process and take precedence over `cwd` for repo discovery, so
every git command these tests ran against their throwaway tmp repos
was silently redirected at the real repo running the hook instead —
reproduced firsthand as four foreign "init"/"fixture" commits
overwriting a worktree branch mid pre-commit run. Fixes it the same
way server/lib/worktree.js already documented and did for its own git
calls: strip the GIT_* vars before exec.

server/__tests__/lanes-cli.test.js

@@ -45,9 +45,25 @@ const CLI = path.join(__dirname, "..", "..", "bin", "ccam.js");
 let server;
 let BASE;
 
+// Strip GIT_* vars a parent git hook (e.g. the pre-commit hook running this
+// very suite) sets in its own environment — those leak to every child
+// process and override an explicit `cwd`, so without this a git command
+// meant for this test's throwaway tmp repo silently operates on the real
+// repo running the hook instead.
+const GIT_ENV = { ...process.env };
+delete GIT_ENV.GIT_DIR;
+delete GIT_ENV.GIT_WORK_TREE;
+delete GIT_ENV.GIT_INDEX_FILE;
+delete GIT_ENV.GIT_COMMON_DIR;
+delete GIT_ENV.GIT_OBJECT_DIRECTORY;
+delete GIT_ENV.GIT_ALTERNATE_OBJECT_DIRECTORIES;
+delete GIT_ENV.GIT_PREFIX;
+delete GIT_ENV.GIT_NAMESPACE;
+delete GIT_ENV.GIT_CONFIG_PARAMETERS;
+
 function git(args, cwd) {
   return new Promise((resolve, reject) => {
-    const child = spawn("git", args, { cwd });
+    const child = spawn("git", args, { cwd, env: GIT_ENV });
     let stderr = "";
     child.stderr.on("data", (chunk) => (stderr += chunk));
     child.on("error", reject);

server/__tests__/update-check.test.js

@@ -14,11 +14,28 @@ const { execFileSync } = require("child_process");
 
 const { getUpdatesStatus } = require("../lib/update-check");
 
+// Strip GIT_* vars a parent git hook (e.g. the pre-commit hook running this
+// very suite) sets in its own environment — those leak to every child
+// process and override an explicit `cwd`, so without this a git command
+// meant for this test's throwaway tmp repo silently operates on the real
+// repo running the hook instead.
+const GIT_ENV = { ...process.env };
+delete GIT_ENV.GIT_DIR;
+delete GIT_ENV.GIT_WORK_TREE;
+delete GIT_ENV.GIT_INDEX_FILE;
+delete GIT_ENV.GIT_COMMON_DIR;
+delete GIT_ENV.GIT_OBJECT_DIRECTORY;
+delete GIT_ENV.GIT_ALTERNATE_OBJECT_DIRECTORIES;
+delete GIT_ENV.GIT_PREFIX;
+delete GIT_ENV.GIT_NAMESPACE;
+delete GIT_ENV.GIT_CONFIG_PARAMETERS;
+
 function git(cwd, args) {
   return execFileSync("git", args, {
     cwd,
     stdio: ["ignore", "pipe", "pipe"],
     encoding: "utf8",
+    env: GIT_ENV,
   }).trim();
 }
 
@@ -29,6 +46,7 @@ function makeBareRemote(parent, name) {
   // i.e. far older than --initial-branch.
   execFileSync("git", ["-c", "init.defaultBranch=master", "init", "--bare", repo], {
     stdio: "ignore",
+    env: GIT_ENV,
   });
   return repo;
 }
@@ -36,7 +54,10 @@ function makeBareRemote(parent, name) {
 function makeWorkingRepo(parent, dir, originUrl) {
   const repo = path.join(parent, dir);
   fs.mkdirSync(repo, { recursive: true });
-  execFileSync("git", ["-c", "init.defaultBranch=master", "init", repo], { stdio: "ignore" });
+  execFileSync("git", ["-c", "init.defaultBranch=master", "init", repo], {
+    stdio: "ignore",
+    env: GIT_ENV,
+  });
   fs.writeFileSync(path.join(repo, "README.md"), "fixture\n");
   git(repo, ["-c", "user.email=t@t", "-c", "user.name=t", "add", "."]);
   git(repo, ["-c", "user.email=t@t", "-c", "user.name=t", "commit", "-m", "init"]);
@@ -146,7 +167,10 @@ describe("getUpdatesStatus — no remotes configured", () => {
   it("returns a soft no-remotes payload", async () => {
     const repo = path.join(tmpDir, "noremote");
     fs.mkdirSync(repo, { recursive: true });
-    execFileSync("git", ["-c", "init.defaultBranch=master", "init", repo], { stdio: "ignore" });
+    execFileSync("git", ["-c", "init.defaultBranch=master", "init", repo], {
+      stdio: "ignore",
+      env: GIT_ENV,
+    });
     fs.writeFileSync(path.join(repo, "README.md"), "lonely\n");
     git(repo, ["-c", "user.email=t@t", "-c", "user.name=t", "add", "."]);
     git(repo, ["-c", "user.email=t@t", "-c", "user.name=t", "commit", "-m", "init"]);

server/lib/update-check.js

@@ -19,13 +19,33 @@ const DEFAULT_ROOT = path.join(__dirname, "..", "..");
 // never make the update checker report commits from somebody else's repo.
 const REMOTE_PRIORITY = ["origin"];
 
+// Scrub git hook environment variables (GIT_DIR, GIT_INDEX_FILE, etc.) that
+// leak from a parent git hook process — e.g. this repo's own pre-commit
+// hook, which runs `npm run test:server` and therefore this module too.
+// Without this, every git call below silently targets the OUTER repo (the
+// hook's) instead of `cwd`, since GIT_DIR takes precedence over cwd-based
+// discovery. Same scrub `server/lib/worktree.js` already applies.
+const GIT_ENV = { ...process.env };
+delete GIT_ENV.GIT_DIR;
+delete GIT_ENV.GIT_WORK_TREE;
+delete GIT_ENV.GIT_INDEX_FILE;
+delete GIT_ENV.GIT_COMMON_DIR;
+delete GIT_ENV.GIT_OBJECT_DIRECTORY;
+delete GIT_ENV.GIT_ALTERNATE_OBJECT_DIRECTORIES;
+delete GIT_ENV.GIT_PREFIX;
+delete GIT_ENV.GIT_NAMESPACE;
+delete GIT_ENV.GIT_CONFIG_PARAMETERS;
+for (const name of Object.keys(GIT_ENV)) {
+  if (/^GIT_CONFIG_(COUNT|KEY_\d+|VALUE_\d+|GLOBAL|SYSTEM)$/.test(name)) delete GIT_ENV[name];
+}
+
 function execGit(cwd, args, opts = {}) {
   const timeout = opts.timeout ?? 120_000;
   return new Promise((resolve, reject) => {
     execFile(
       "git",
       args,
-      { cwd, timeout, maxBuffer: 2_000_000, encoding: "utf8" },
+      { cwd, timeout, maxBuffer: 2_000_000, encoding: "utf8", env: GIT_ENV },
       (err, stdout) => {
         if (err) reject(err);
         else resolve(String(stdout).trim());