chore: import upstream snapshot with attribution

scripts/check/check-pr-test-policy.mjs

@@ -0,0 +1,136 @@
+import { execFileSync } from "node:child_process";
+import { mkdirSync, writeFileSync } from "node:fs";
+import path from "node:path";
+
+const SOURCE_ROOTS = ["src/", "open-sse/", "electron/", "bin/"];
+const TEST_PATTERNS = [/^tests\//, /(?:^|\/)__tests__\//, /\.(?:test|spec)\.[cm]?[jt]sx?$/];
+// Test files for specific source types (e.g., Python validation scripts for i18n)
+const TEST_FILE_PATTERNS = {
+  "src/i18n/messages/": [
+    /\/scripts\/validate_translation\.py$/,
+    /\/scripts\/check_translations\.py$/,
+  ],
+};
+// Exclude directories that don't require tests (i18n has Python validation, docs, config)
+const EXCLUDED_PATTERNS = [
+  /\/i18n\/messages\//, // i18n files have their own Python test scripts
+  /\.md$/, // Documentation
+  /\.yaml$/, // Config files
+  /\.yml$/, // Config files
+  /(?:^|\/)package(?:-lock)?\.json$/, // Dependency manifests/lockfiles (e.g. Dependabot bumps) — not testable code
+];
+
+function getArg(name, fallbackValue = "") {
+  const index = process.argv.indexOf(name);
+  if (index === -1 || index === process.argv.length - 1) {
+    return fallbackValue;
+  }
+  return process.argv[index + 1];
+}
+
+function runGit(args) {
+  return execFileSync("git", args, { encoding: "utf8" }).trim();
+}
+
+function isSourceFile(filePath) {
+  // Exclude patterns that don't require tests
+  if (EXCLUDED_PATTERNS.some((pattern) => pattern.test(filePath))) {
+    return false;
+  }
+  return SOURCE_ROOTS.some((root) => filePath.startsWith(root));
+}
+
+function isTestFile(filePath) {
+  // Check standard test patterns
+  if (TEST_PATTERNS.some((pattern) => pattern.test(filePath))) {
+    return true;
+  }
+  // Check custom test file patterns for specific directories
+  for (const [dir, patterns] of Object.entries(TEST_FILE_PATTERNS)) {
+    if (filePath.startsWith(dir) && patterns.some((pattern) => pattern.test(filePath))) {
+      return true;
+    }
+  }
+  return false;
+}
+
+function buildReport(lines) {
+  return `${lines.join("\n")}\n`;
+}
+
+const summaryFile = getArg("--summary-file", "");
+const baseRef = process.env.GITHUB_BASE_REF;
+
+if (!baseRef) {
+  const report = buildReport([
+    "## PR Test Policy",
+    "",
+    "Skipped: not running in a pull request context.",
+  ]);
+
+  if (summaryFile) {
+    mkdirSync(path.dirname(summaryFile), { recursive: true });
+    writeFileSync(summaryFile, report);
+  }
+
+  process.stdout.write(report);
+  process.exit(0);
+}
+
+const baseTarget = process.env.GITHUB_BASE_SHA || `origin/${baseRef}`;
+const changedFiles = runGit(["diff", "--name-only", "--diff-filter=ACMR", `${baseTarget}...HEAD`])
+  .split(/\r?\n/)
+  .map((line) => line.trim())
+  .filter(Boolean);
+
+const changedSourceFiles = changedFiles.filter(isSourceFile);
+const changedTestFiles = changedFiles.filter(isTestFile);
+const hasRequiredTests = changedSourceFiles.length === 0 || changedTestFiles.length > 0;
+
+const reportLines = [
+  "## PR Test Policy",
+  "",
+  `Base ref: \`${baseRef}\``,
+  `Changed production files: ${changedSourceFiles.length}`,
+  `Changed automated test files: ${changedTestFiles.length}`,
+  "",
+];
+
+if (changedSourceFiles.length > 0) {
+  reportLines.push("### Production files in scope", "");
+  for (const filePath of changedSourceFiles.slice(0, 20)) {
+    reportLines.push(`- \`${filePath}\``);
+  }
+  reportLines.push("");
+}
+
+if (changedTestFiles.length > 0) {
+  reportLines.push("### Tests in this PR", "");
+  for (const filePath of changedTestFiles.slice(0, 20)) {
+    reportLines.push(`- \`${filePath}\``);
+  }
+  reportLines.push("");
+}
+
+if (hasRequiredTests) {
+  reportLines.push("Result: PASS");
+} else {
+  reportLines.push(
+    "Result: FAIL",
+    "",
+    "This PR changes production code under `src/`, `open-sse/`, `electron/`, or `bin/` but does not add or update automated tests."
+  );
+}
+
+const report = buildReport(reportLines);
+
+if (summaryFile) {
+  mkdirSync(path.dirname(summaryFile), { recursive: true });
+  writeFileSync(summaryFile, report);
+}
+
+process.stdout.write(report);
+
+if (!hasRequiredTests) {
+  process.exit(1);
+}