fix(guardrails): block merge bypass commands by terisuke · Pull Request #191 · Cor-Incorporated/opencode

terisuke · 2026-04-25T16:27:55Z

Summary

Treat GitHub REST API PR merges as guarded PR merges, including review and post-merge validation gates
Block reset-to-base soft/mixed syncs that bypass rebase/merge conflict guardrails
Require explicit worktree selection for codex exec reviews to avoid reviewing the wrong checkout
Add focused guardrail tests for the NFC-profile-card failure modes

Validation

bun test test/plugin/guardrail-git.test.ts test/plugin/guardrail-review.test.ts test/plugin/guardrail-secret-mask.test.ts
bun typecheck
git diff --check
bun run build
~/.local/bin/opencode --version
packages/opencode/dist/opencode-darwin-arm64/bin/opencode --version

github-actions · 2026-04-25T16:28:06Z

This PR doesn't fully meet our contributing guidelines and PR template.

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github-actions · 2026-04-25T16:28:07Z

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

Open an issue describing the bug/feature (if one doesn't exist)
Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

Copilot

Pull request overview

This PR tightens the guardrail-git plugin so PR merges can’t bypass review/conflict gates via alternative merge commands, and adds regression tests to cover newly blocked flows.

Changes:

Treat gh api .../pulls/<n>/merge as a PR merge so merge/review gates run for GitHub REST API merges.
Block git reset --soft|--mixed resets to base branches to prevent bypassing rebase/merge conflict guardrails.
Require an explicit worktree flag for codex exec to avoid reviewing the wrong checkout; add focused tests for these guardrails.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
packages/opencode/test/plugin/guardrail-git.test.ts	Adds unit tests for API-merge bypass, reset-to-base bypass, and codex exec worktree requirement.
packages/guardrails/profile/plugins/guardrail-git.ts	Expands merge detection to include `gh api` merges, adds reset-to-base blocking, and enforces explicit worktree for `codex exec`.

Comments suppressed due to low confidence (1)

packages/guardrails/profile/plugins/guardrail-git.ts:313

The reset-to-base detection regex will also match refs like origin/dev-feature because dev is followed by - (a word boundary), so it can over-block resets that are not targeting the protected base branches. Tighten the ref matching so it only triggers when the target is exactly (origin/)?main|master|develop|dev as a whole token (e.g., require (?:\s|$) or end-of-ref delimiters after the branch name).

    if (/\bgit\s+rebase\b/i.test(cmd) && !/--abort\b/i.test(cmd)) {
      if (/\bgit\s+rebase\s+(origin\/)?(main|master|develop)\b/i.test(cmd)) {
        await ctx.mark({ rebase_session_active: true, rebase_session_at: new Date().toISOString() })

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Copilot · 2026-04-25T16:31:59Z

+      cmd.match(/\bgh\s+api\b(?=[\s\S]*(?:^|\s)-X(?:=|\s*)PUT\b)[\s\S]*\brepos\/\S+\/pulls\/(\d+)\/merge\b/i)?.[1] ??
+      cmd.match(
+        /\bgh\s+api\b(?=[\s\S]*(?:^|\s)--method(?:=|\s+)PUT\b)[\s\S]*\brepos\/\S+\/pulls\/(\d+)\/merge\b/i,


ghPrMergeNumber only detects gh api merges when the method is spelled with a space (-X PUT / --method PUT). gh api (cobra/pflag) also supports --method=PUT and commonly -X=PUT / -XPUT, which would bypass the merge guard. Update the method detection regexes to accept the =PUT (and no-space short flag) forms so the bypass is reliably blocked.

Suggested change

cmd.match(/\bgh\s+api\b(?=[\s\S]*(?:^|\s)-X(?:=|\s*)PUT\b)[\s\S]*\brepos\/\S+\/pulls\/(\d+)\/merge\b/i)?.[1] ??

cmd.match(

/\bgh\s+api\b(?=[\s\S]*(?:^|\s)--method(?:=|\s+)PUT\b)[\s\S]*\brepos\/\S+\/pulls\/(\d+)\/merge\b/i,

cmd.match(/\bgh\s+api\b(?=[\s\S]*(?:^|\s)-X(?:PUT|=PUT|\s+PUT\b))[\s\S]*\brepos\/\S+\/pulls\/(\d+)\/merge\b/i)?.[1] ??

cmd.match(

/\bgh\s+api\b(?=[\s\S]*(?:^|\s)--method(?:=PUT\b|\s+PUT\b))[\s\S]*\brepos\/\S+\/pulls\/(\d+)\/merge\b/i,

Copilot · 2026-04-25T16:31:59Z

+  function codexExecWorktree(cmd: string) {
+    return (
+      cmd
+        .match(/\bcodex\s+exec\b[\s\S]*(?:\s-C|\s--cd|\s--cwd)\s+(?:"([^"]+)"|'([^']+)'|(\S+))/i)


The codex exec worktree check only matches -C <path>, --cd <path>, --cwd <path> with a whitespace-separated value. If the CLI is invoked with --cwd=<path> / --cd=<path> (or quoted paths with spaces), this guard will incorrectly block even though an explicit worktree was provided. Consider broadening the regex to accept --cwd= / --cd= / -C= forms and quoted values.

Suggested change

.match(/\bcodex\s+exec\b[\s\S]*(?:\s-C|\s--cd|\s--cwd)\s+(?:"([^"]+)"|'([^']+)'|(\S+))/i)

.match(

/\bcodex\s+exec\b[\s\S]*(?:\s-C|\s--cd|\s--cwd)(?:\s*=\s*|\s+)(?:"([^"]+)"|'([^']+)'|(\S+))/i,

)

Copilot · 2026-04-25T16:32:00Z

+  }
+
+  function sameWorktree(left: string, right: string) {


This guard currently blocks any codex exec invocation without an explicit worktree, but the error message says "codex exec review must…". Either scope the check to review-related codex commands, or adjust the message so it matches the actual behavior (all codex exec commands).

Copilot · 2026-04-25T16:32:00Z

+  test("blocks GitHub API pull request merge bypasses", async () => {
+    await using fixture = await context()
+    const git = createGitHandlers(fixture.ctx, review())
+
+    await expect(
+      git.bashBeforeGit("gh api -X PUT repos/Cor-Incorporated/nfc-profile-card/pulls/42/merge", {}, {}),
+    ).rejects.toThrow("merge blocked")
+
+    expect(fixture.marks.some((item) => String(item.last_reason).includes("GLM code-reviewer"))).toBe(true)
+  })
+
+  test("blocks GitHub API pull request merge bypasses with equals method flags", async () => {
+    await using fixture = await context()
+    const git = createGitHandlers(fixture.ctx, review())
+
+    await expect(
+      git.bashBeforeGit("gh api --method=PUT repos/Cor-Incorporated/nfc-profile-card/pulls/42/merge", {}, {}),
+    ).rejects.toThrow("merge blocked")
+  })
+
+  test("blocks reset-to-base sync bypasses", async () => {
+    await using fixture = await context()
+    const git = createGitHandlers(fixture.ctx, review())
+
+    await expect(git.bashBeforeGit("git reset --soft origin/dev", {}, {})).rejects.toThrow("reset-to-base sync blocked")
+
+    expect(fixture.marks.at(-1)?.last_reason).toBe("branch reset sync blocked")
+  })
+
+  test("requires explicit worktree for codex exec reviews", async () => {


The new tests cover gh api -X PUT …/merge and codex exec -C …, but they don’t cover important accepted flag variants that could regress or bypass the guardrails (e.g. gh api --method=PUT …/merge, codex exec --cwd=/tmp/project …, and a non-base ref like git reset --soft origin/dev-feature). Adding these cases would help ensure the regexes don’t allow bypasses or cause false positives.

Copilot AI review requested due to automatic review settings April 25, 2026 16:27

github-actions Bot added the needs:compliance label Apr 25, 2026

github-actions Bot added the needs:issue label Apr 25, 2026

Copilot started reviewing on behalf of terisuke April 25, 2026 16:28 View session

fix(guardrails): block merge bypass commands

c36d867

terisuke force-pushed the codex/fix-merge-guardrail-bypasses branch from c333d10 to c36d867 Compare April 25, 2026 16:30

Copilot AI reviewed Apr 25, 2026

View reviewed changes

terisuke merged commit 35baa6f into dev Apr 25, 2026
2 of 8 checks passed

terisuke deleted the codex/fix-merge-guardrail-bypasses branch April 25, 2026 16:35

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fix(guardrails): block merge bypass commands#191

fix(guardrails): block merge bypass commands#191
terisuke merged 1 commit intodevfrom
codex/fix-merge-guardrail-bypasses

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terisuke commented Apr 25, 2026

Summary

Validation

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