fix(autoplan): list renames as delete and add so a renamed secret file stays out of the draft (GST-1164)

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

changelog.d/gsta258-s1-envrc-redact.md

@@ -1,9 +1,9 @@
 **Security: the lean /autoplan reviewer no longer gets `.envrc`, `.env-production` or a key pasted into an ordinary file (GST-1164, #3914).** Since v1.93.36.0 (#3897), the lean run puts the branch's draft code into a prompt that goes to an outside model provider. It left out only some secret-named untracked files: `.env` and `.env.*`, but not `.envrc` or `.env-production`. It applied no name rule to tracked files and no content check at all. So a direnv `.envrc`, a `.env-production`, a committed or edited secret file, or a key sitting in any source file could reach the provider.
 
 ### Fixed
-- **`lib/autoplan-lean.ts` `captureDraft`:** the secret-name rule now covers the whole `.env*` family, `.envrc` included, every `*credentials*` name, `_netrc`, `.pgpass`, `*.jks` and `id_*_sk` keys. Matching files are never diffed, tracked or untracked, and the draft names each one it left out. Every other file's patch goes through gstack's redact engine (`redactFindingSpans`), so a key in an ordinary file reaches the reviewer as `<REDACTED-…>`. A patch the engine can't redact safely, including one over 1 MiB, is left out with a note.
+- **`lib/autoplan-lean.ts` `captureDraft`:** the secret-name rule now covers the whole `.env*` family, `.envrc` included, every `*credentials*` name, `_netrc`, `.pgpass`, `*.jks` and `id_*_sk` keys. Matching files are never diffed, tracked or untracked, and the draft names each one it left out. Renames are listed as a delete and an add, so a secret file renamed on the branch stays out under both names. Every other file's patch goes through gstack's redact engine (`redactFindingSpans`), so a key in an ordinary file reaches the reviewer as `<REDACTED-…>`. A patch the engine can't redact safely, including one over 1 MiB, is left out with a note.
 
 ### Tests
-- `test/autoplan-lean.test.ts`: an untracked `.envrc`, `.env-production` and six other secret files stay out of `draft.diff` and the prompt; a committed and edited `.envrc` stays out of the tracked diff; a fake key in an untracked file and in a working-tree edit to a tracked file comes out redacted. All three fail on main at b42ad1e.
+- `test/autoplan-lean.test.ts`: an untracked `.envrc`, `.env-production` and six other secret files stay out of `draft.diff` and the prompt; a committed and edited `.envrc` stays out of the tracked diff, and so does one renamed to `.envrc.local`; a fake key in an untracked file and in a working-tree edit to a tracked file comes out redacted. All four fail on main at b42ad1e.
 
 Thanks to the /ship pre-landing review of #3901, which filed the finding.

lib/autoplan-lean.ts

@@ -75,8 +75,8 @@ export function captureDraft(cwd: string, dir: string, out: string, base?: strin
   const inRun = (f: string) => !runDir.startsWith('..') && !path.isAbsolute(runDir) && (runDir === '' || f === runDir || f.startsWith(`${runDir}/`));
   const failed = (r: ReturnType<typeof git>, what: string, ok = [0]) => r.error || r.status === null || !ok.includes(r.status)
     ? `draft capture failed: ${what} ${r.error ? `errored (${r.error.message})` : `exited ${r.status ?? r.signal}`}${r.stderr?.trim() ? `: ${r.stderr.trim().split('\n')[0]}` : ''}` : undefined;
-  const raw = ['diff', '--no-color', '--no-ext-diff', '--no-textconv'];
-  const names = git(['diff', '--name-only', '-z', mergeBase, '--'], root);
+  const raw = ['diff', '--no-color', '--no-ext-diff', '--no-textconv', '--no-renames'];
+  const names = git(['diff', '--name-only', '-z', '--no-renames', mergeBase, '--'], root);
   const others = git(['ls-files', '--others', '--exclude-standard', '-z'], root);
   const listed = failed(names, 'git diff') ?? failed(others, 'git ls-files');
   if (listed) return { base: ref, none: listed };

test/autoplan-lean.test.ts

@@ -423,6 +423,27 @@ describe('draft capture edges', () => {
     expect(diff).toContain('+export const JITTER = 0.1;');
   });
 
+  test('a secret file renamed on the branch stays out under both names', () => {
+    const cwd = repo('rename-envrc', false);
+    git(cwd, 'checkout', '-q', 'main');
+    fs.writeFileSync(path.join(cwd, '.envrc'), 'dotenv_if_exists marker-zz9-old\n');
+    git(cwd, 'add', '.envrc');
+    git(cwd, 'commit', '-q', '-m', 'direnv');
+    git(cwd, 'checkout', '-q', 'feature');
+    git(cwd, 'merge', '-q', 'main');
+    git(cwd, 'mv', '.envrc', '.envrc.local');
+    fs.appendFileSync(path.join(cwd, '.envrc.local'), 'dotenv_if_exists marker-zz9-new\n');
+    fs.appendFileSync(path.join(cwd, 'lib', 'worker.ts'), 'export const JITTER = 0.1;\n');
+    const { ps, prompt } = lean('rename-envrc', cwd);
+    const diff = fs.readFileSync(path.join(ps.snapshot_dir, 'draft.diff'), 'utf8');
+    for (const text of [diff, prompt]) {
+      expect(text).not.toContain('marker-zz9');
+      expect(text).toContain('# draft: .envrc left out (its name looks like a secret)');
+      expect(text).toContain('# draft: .envrc.local left out (its name looks like a secret)');
+    }
+    expect(diff).toContain('+export const JITTER = 0.1;');
+  });
+
   test('a key inside an ordinary file is redacted, untracked or edited in the working tree', () => {
     const cwd = repo('redact', true);
     fs.writeFileSync(path.join(cwd, 'lib', 'client.ts'), `export const KEY = '${FAKE_KEY}';\n`);