Fix URL scan failure exit codes

Return exit 1 when browser setup or a URL scan fails, including partial multi-target scans, while preserving JSON findings output. Document the detector exit contract and cover isolated installs without Puppeteer.\n\nAI assistance disclosure: Codex implemented and tested this fix under maintainer direction.

README.md

@@ -427,7 +427,7 @@ npx impeccable ignores add-value overused-font Inter --reason "Brand font"
 
 The detector catches 61 deterministic issues across AI slop (side-tab borders, purple gradients, bounce easing, dark glows) and general design quality (line length, cramped padding, small touch targets, skipped headings, and more).
 
-Human-readable findings are diagnostics written to stderr, so redirect them with `2> findings.txt`. Use `--json` for machine-readable results on stdout. URL scans inspect the rendered DOM, computed layout, and accessible linked stylesheets; browser security still prevents reading cross-origin CSS without CORS. A clean detector run is evidence, not proof of visual or accessibility quality: it does not replace inspecting the rendered experience across relevant viewports.
+Human-readable findings are diagnostics written to stderr, so redirect them with `2> findings.txt`. Use `--json` for machine-readable results on stdout. Exit `0` means the scan completed without primary findings, exit `2` means it completed with primary findings, and exit `1` means at least one requested target could not be scanned; operational failure takes precedence for a partial multi-target scan. URL scans inspect the rendered DOM, computed layout, and accessible linked stylesheets; browser security still prevents reading cross-origin CSS without CORS. A clean detector run is evidence, not proof of visual or accessibility quality: it does not replace inspecting the rendered experience across relevant viewports.
 
 By default, `detect` respects the same `.impeccable/config.json` and `.impeccable/config.local.json` detector config as the design hook: `detector.ignoreRules`, `detector.ignoreFiles`, `detector.ignoreValues`, and `detector.designSystem.enabled`. Hook lifecycle settings such as `hook.enabled` only affect automatic hook execution.
 

README.npm.md

@@ -60,8 +60,11 @@ npx impeccable detect --fast src/
 
 ## Exit Codes
 
-- `0`: no issues found
-- `2`: anti-patterns detected
+- `0`: scan completed with no primary findings (advisories may still be listed)
+- `1`: at least one requested target could not be scanned
+- `2`: scan completed with primary findings
+
+Operational failure takes precedence when a multi-target scan is partial. In JSON mode, stdout remains a findings array and diagnostics are written to stderr.
 
 ## Options
 

cli/engine/cli/main.mjs

@@ -189,6 +189,12 @@ Output streams:
   Human-readable findings go to stderr so stdout stays available for structured
   output. Use --json for JSON on stdout, or redirect text with 2> findings.txt.
 
+Exit status:
+  0  Scan completed with no primary findings (advisories may still be listed)
+  1  At least one requested target could not be scanned
+  2  Scan completed with primary findings
+  Operational failure takes precedence when a multi-target scan is partial.
+
 Project config:
   Respects .impeccable/config.json and .impeccable/config.local.json detector
   settings: detector.ignoreRules, detector.ignoreFiles, detector.ignoreValues,
@@ -309,6 +315,7 @@ async function detectCli() {
   if (helpMode) { printUsage(); process.exit(0); }
 
   let allFindings = [];
+  let hadOperationalFailure = false;
 
   if (!process.stdin.isTTY && targets.length === 0) {
     allFindings = await handleStdin(scanOptionsFor);
@@ -319,11 +326,22 @@ async function detectCli() {
     // browser-grade scan of a local artifact can pass file:///abs/path.html
     // instead of the bare path (which stays on the static engine).
     const urlTargetCount = paths.filter(target => URL_TARGET_RE.test(target)).length;
-    const browserDetector = urlTargetCount > 1 ? await createBrowserDetector() : null;
+    let browserDetector = null;
+    let browserSetupFailed = false;
+    if (urlTargetCount > 1) {
+      try {
+        browserDetector = await createBrowserDetector();
+      } catch (e) {
+        browserSetupFailed = true;
+        hadOperationalFailure = true;
+        process.stderr.write(`Error: ${e.message}\n`);
+      }
+    }
 
     try {
       for (const target of paths) {
         if (URL_TARGET_RE.test(target)) {
+          if (browserSetupFailed) continue;
           // A file:// URL points at a local artifact, so its design system
           // resolves from that file's project. A remote http(s) URL has no
           // local project — it gets base options (no design system), never
@@ -336,7 +354,10 @@ async function detectCli() {
               ? (url) => browserDetector.detectUrl(url, urlOptions)
               : (url) => detectUrl(url, urlOptions);
             allFindings.push(...await scanner(target));
-          } catch (e) { process.stderr.write(`Error: ${e.message}\n`); }
+          } catch (e) {
+            hadOperationalFailure = true;
+            process.stderr.write(`Error: ${e.message}\n`);
+          }
           continue;
         }
 
@@ -433,6 +454,10 @@ async function detectCli() {
   // advisory-only scan still prints its notes but exits 0 (a clean pass), so
   // advisory rules never break CI or block automation.
   const { primary, advisory } = partitionAdvisory(allFindings);
+  // Exit 1 means at least one requested scan could not complete. It takes
+  // precedence over exit 2 because findings from the remaining targets do not
+  // turn a partial scan into a complete one.
+  const exitCode = hadOperationalFailure ? 1 : (primary.length > 0 ? 2 : 0);
 
   if (allFindings.length > 0) {
     if (jsonMode) process.stdout.write(formatFindings(allFindings, true) + '\n');
@@ -443,10 +468,10 @@ async function detectCli() {
       }
     }
     else process.stderr.write(formatFindings(allFindings, false) + '\n');
-    process.exit(primary.length > 0 ? 2 : 0);
+    process.exit(exitCode);
   }
   if (jsonMode) process.stdout.write('[]\n');
-  process.exit(0);
+  process.exit(exitCode);
 }
 
 export { formatFindings, handleStdin, confirm, printUsage, detectCli };

tests/detect-url-launch.test.mjs

@@ -1,7 +1,14 @@
 import { describe, test, expect, afterEach } from 'bun:test';
+import { spawnSync } from 'node:child_process';
+import fs from 'node:fs';
 import http from 'node:http';
+import os from 'node:os';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
 import { launchBrowser, detectUrl, splitScanUrl } from '../cli/engine/engines/browser/detect-url.mjs';
 
+const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
+
 // launchBrowser prefers the system-installed Chrome on Windows to dodge the
 // bundled-Chrome GPU crash-loop (issue #372), and keeps the pinned bundled
 // build everywhere else. The function takes the puppeteer module as a
@@ -38,6 +45,28 @@ function makePuppeteer({ failChannel = false } = {}) {
   };
 }
 
+function runWithoutPuppeteer(args, files = {}) {
+  const isolatedRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'impeccable-no-puppeteer-'));
+  try {
+    const cliRoot = path.join(isolatedRoot, 'cli');
+    fs.mkdirSync(cliRoot, { recursive: true });
+    fs.cpSync(path.join(ROOT, 'cli', 'engine'), path.join(cliRoot, 'engine'), { recursive: true });
+    fs.cpSync(path.join(ROOT, 'cli', 'lib'), path.join(cliRoot, 'lib'), { recursive: true });
+    for (const [relativePath, contents] of Object.entries(files)) {
+      const filePath = path.join(isolatedRoot, relativePath);
+      fs.mkdirSync(path.dirname(filePath), { recursive: true });
+      fs.writeFileSync(filePath, contents);
+    }
+    return spawnSync(
+      'node',
+      [path.join(cliRoot, 'engine', 'detect-antipatterns.mjs'), '--json', ...args],
+      { cwd: isolatedRoot, encoding: 'utf8' },
+    );
+  } finally {
+    fs.rmSync(isolatedRoot, { recursive: true, force: true });
+  }
+}
+
 describe('launchBrowser', () => {
   test('Windows: prefers system Chrome via channel:chrome', async () => {
     setPlatform('win32');
@@ -81,6 +110,36 @@ describe('launchBrowser', () => {
   });
 });
 
+describe('detect CLI browser failures', () => {
+  test('exits 1 with valid empty JSON when Puppeteer is unavailable', () => {
+    const result = runWithoutPuppeteer(['https://example.com']);
+
+    expect(result.status).toBe(1);
+    expect(result.stdout).toBe('[]\n');
+    expect(result.stderr).toContain('puppeteer is required for URL scanning');
+  });
+
+  test('reports a shared multi-URL setup failure once and exits 1', () => {
+    const result = runWithoutPuppeteer(['https://example.com', 'https://example.org']);
+
+    expect(result.status).toBe(1);
+    expect(result.stdout).toBe('[]\n');
+    expect(result.stderr.match(/puppeteer is required for URL scanning/g)).toHaveLength(1);
+  });
+
+  test('operational failure takes precedence over findings from another target', () => {
+    const result = runWithoutPuppeteer(
+      ['https://example.com', 'page.css'],
+      { 'page.css': '.hero { animation: bounce 1s linear infinite; }\n' },
+    );
+    const findings = JSON.parse(result.stdout);
+
+    expect(result.status).toBe(1);
+    expect(findings.some(finding => finding.antipattern === 'bounce-easing')).toBe(true);
+    expect(result.stderr).toContain('puppeteer is required for URL scanning');
+  });
+});
+
 describe('splitScanUrl', () => {
   test('strips http(s) userinfo and returns credentials', () => {
     expect(splitScanUrl('https://user:pass@example.com')).toEqual({