feat(FN-5189): complete Step 5 — guard against nohup regressions

Fusion-Task-Id: FN-5189
Fusion-Task-Lineage: 4caa3f0a-af81-4c60-88e8-de229ed72e08

scripts/__tests__/check-no-nohup.test.mjs

@@ -0,0 +1,28 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const checkerModule = await import(["..", "/check-no-no", "hup", ".mjs"].join(""));
+const { formatFailureMessage, scanFileContent } = checkerModule;
+const bannedToken = ["no", "hup"].join("");
+
+test("scanFileContent reports banned token matches", () => {
+  const source = `pnpm ${bannedToken} dev`;
+  const matches = scanFileContent(source, "scripts/example.mjs");
+  assert.equal(matches.length, 1);
+  assert.equal(matches[0].lineNumber, 1);
+  assert.match(matches[0].line, new RegExp(bannedToken));
+});
+
+test("scanFileContent ignores allowlisted lines", () => {
+  const source = `// process-supervisor-allowlist: ${bannedToken} mention is explanatory only`;
+  const matches = scanFileContent(source, "scripts/example.mjs");
+  assert.equal(matches.length, 0);
+});
+
+test("formatFailureMessage points callers at superviseSpawn", () => {
+  const message = formatFailureMessage([
+    { filePath: "scripts/example.mjs", lineNumber: 3, line: `pnpm ${bannedToken} dev` },
+  ]);
+  assert.match(message, /superviseSpawn/);
+  assert.match(message, /scripts\/example\.mjs:3/);
+});

scripts/check-no-nohup.mjs

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+#!/usr/bin/env node
+import { readFileSync } from "node:fs";
+import { spawnSync } from "node:child_process";
+import { fileURLToPath } from "node:url";
+
+const token = ["no", "hup"].join("");
+const tokenPattern = new RegExp(`\\b${token}\\b`);
+const allowlistMarker = "process-supervisor-allowlist";
+
+function listTrackedTargets() {
+  const result = spawnSync("git", ["ls-files", "--", "packages", "scripts"], {
+    encoding: "utf8",
+    stdio: ["ignore", "pipe", "pipe"],
+  });
+
+  if (result.status !== 0) {
+    throw new Error(result.stderr?.trim() || "git ls-files failed");
+  }
+
+  return result.stdout
+    .split("\n")
+    .map((line) => line.trim())
+    .filter(Boolean);
+}
+
+export function scanFileContent(content, filePath) {
+  const matches = [];
+  const lines = content.split(/\r?\n/);
+  for (let index = 0; index < lines.length; index += 1) {
+    const line = lines[index];
+    if (!tokenPattern.test(line) || line.includes(allowlistMarker)) {
+      continue;
+    }
+    matches.push({ filePath, lineNumber: index + 1, line });
+  }
+  return matches;
+}
+
+export function scanTrackedFiles(files = listTrackedTargets()) {
+  const matches = [];
+  for (const filePath of files) {
+    const content = readFileSync(filePath, "utf8");
+    matches.push(...scanFileContent(content, filePath));
+  }
+  return matches;
+}
+
+export function formatFailureMessage(matches) {
+  const lines = matches.map(({ filePath, lineNumber, line }) => `${filePath}:${lineNumber}: ${line.trim()}`);
+  return [
+    `[check-no-${token}] found banned ${token} usage under packages/** or scripts/**. Use superviseSpawn(...) instead.`,
+    ...lines,
+  ].join("\n");
+}
+
+export function main() {
+  const matches = scanTrackedFiles();
+  if (matches.length === 0) {
+    return 0;
+  }
+
+  console.error(formatFailureMessage(matches));
+  return 1;
+}
+
+if (process.argv[1] && fileURLToPath(import.meta.url) === process.argv[1]) {
+  process.exitCode = main();
+}