fix(guard-push): make the gh availability probe injectable so its unit test is hermetic

scripts/guard-push.mjs

@@ -414,13 +414,18 @@ export function defaultRunsFetch(branch, exec = execFileSync) {
 export function inFlightCiGuard(
  branches,
  _ranges = [],
- { prViewer = defaultPrView, runFetcher = defaultRunsFetch } = {},
+ // `ghAvailable` is injectable for the same reason `prViewer`/`runFetcher` are:
+ // without it this "unit" test still spawned the real `gh` binary just to ask
+ // whether it exists, so the test's runtime was hostage to an external process.
+ // On a loaded machine `gh --version` was measured at 97 s, blowing vitest's 30 s
+ // limit and failing a test that injects every other dependency.
+ { prViewer = defaultPrView, runFetcher = defaultRunsFetch, ghAvailable = ghIsAvailable } = {},
 ) {
  void _ranges;
  if (process.env.SKIP_IN_FLIGHT_CI_GUARD === "1") {
  return { name: "in-flight-ci", ok: true, skipped: "SKIP_IN_FLIGHT_CI_GUARD=1" };
  }
- if (!ghIsAvailable()) {
+ if (!ghAvailable()) {
  return { name: "in-flight-ci", ok: true, note: "gh not available — in-flight CI check skipped (fail-open)" };
  }
 

tests/guard-push.test.ts

@@ -464,6 +464,7 @@ describe("in-flight CI push guard (#HSSHRG)", () => {
  const result = inFlightCiGuard(["claude/my-fix"], [], {
  prViewer: () => ({ state: "OPEN", number: 77 }),
  runFetcher: () => runs,
+ ghAvailable: () => true,
  });
  expect(result.ok).toBe(false);
  expect(result.message).toContain("PR #77 on claude/my-fix has required CI run(s) currently IN-FLIGHT");
@@ -472,13 +473,47 @@ describe("in-flight CI push guard (#HSSHRG)", () => {
  expect(result.message).toContain("#HSSHRG");
  });
 
+ it("inFlightCiGuard fails open when gh is unavailable, without consulting the PR", () => {
+ let prViewerCalls = 0;
+ const result = inFlightCiGuard(["claude/my-fix"], [], {
+ prViewer: () => {
+ prViewerCalls += 1;
+ return { state: "OPEN", number: 77 };
+ },
+ runFetcher: () => [{ databaseId: 555, name: "CI", status: "in_progress" }],
+ ghAvailable: () => false,
+ });
+ expect(result.ok).toBe(true);
+ expect(result.note).toContain("gh not available");
+ expect(prViewerCalls).toBe(0);
+ });
+
+ it("inFlightCiGuard never spawns a process when every dependency is injected (#HSSHRG)", () => {
+ // Regression guard: the availability probe used to call the real `gh` binary
+ // even here. `gh --version` was measured at 97 s on a loaded machine, which
+ // timed this suite out at vitest's 30 s limit — a unit test must not be
+ // hostage to an external process it never asked for.
+ let spawned = 0;
+ const result = inFlightCiGuard(["claude/my-fix"], [], {
+ prViewer: () => ({ state: "OPEN", number: 77 }),
+ runFetcher: () => [{ databaseId: 555, name: "CI", status: "in_progress" }],
+ ghAvailable: () => {
+ spawned += 1;
+ return true;
+ },
+ });
+ expect(spawned).toBe(1);
+ expect(result.ok).toBe(false);
+ });
+
  it("inFlightCiGuard skips when SKIP_IN_FLIGHT_CI_GUARD=1 is set", () => {
  const previous = process.env.SKIP_IN_FLIGHT_CI_GUARD;
  process.env.SKIP_IN_FLIGHT_CI_GUARD = "1";
  try {
  const result = inFlightCiGuard(["claude/my-fix"], [], {
  prViewer: () => ({ state: "OPEN", number: 77 }),
  runFetcher: () => [{ databaseId: 555, name: "CI", status: "in_progress" }],
+ ghAvailable: () => true,
  });
  expect(result.ok).toBe(true);
  expect(result.skipped).toBe("SKIP_IN_FLIGHT_CI_GUARD=1");