Top 7 Koa11y Features Every Node.js Developer Should Know

Troubleshooting Common Accessibility Issues with Koa11y

1) App won’t launch (Windows/macOS/Linux)

• Check dependencies: Ensure Node.js (v4+) is installed for source runs; on Linux install libgconf if using older NW.js builds.
• Run from source for errors: Clone repo, run npm install then npm start to view console errors.
• Permission/packaging issues: Use the platform-specific packaged build for your OS; if it fails on macOS, check code-signing/permissions; on Ubuntu/Pop!_OS check missing libraries noted in issues.

2) Scans return fewer results than pa11y CLI

• Fetch mode differences: Koa11y uses Pa11y under the hood; paste vs URL scans may use different fetching contexts. Run pa11y directly on the same page to compare.
• Dynamic content: If the page relies on client-side rendering, ensure Koa11y waits for content (or test with pa11y + PhantomJS/Puppeteer and appropriate waitFor options).

3) Image alt text checks stuck at 0% or inaccurate image stats

• Resource loading: If images fail to load (CORS, blocked resources), stats/alt checks will be off—test page in a browser and check console.
• Manual verification: Use Koa11y’s image verification UI to confirm descriptive alt text; export JSON/HTML reports if you need to re-check programmatically.

4) WCAG version, ruleset, or guideline mismatches

• Outdated rules: Koa11y’s built-in guidelines may be out of date (project maintenance paused). Cross-check reported issues against current WCAG 2.⁄₂.2 or your target standard.
• Adjust severity/filtering: Use report filters to view Errors/Warnings/Notices and re-evaluate items manually when necessary.

5) Screen reader / ARIA reporting issues

• False positives/negatives: Automated tools can’t fully assess ARIA semantics—treat results as guidance and test with actual screen readers (NVDA, VoiceOver).
• Shadow DOM / Web Components: Koa11y may not fully support shadow DOM. Check open issues; use pa11y or in-browser accessibility tools that support shadow DOM testing.

6) App UI bugs (buttons disabled, no icon on macOS, etc.)

• Check Issues on GitHub: Many platform-specific UI bugs are documented (run button disabled, missing macOS icon). Search open/closed issues for workarounds.
• Developer tools: Right-click the logo in-app to open dev tools and inspect runtime errors.

7) Report generation problems (missing formats or inconsistent data)

• Export formats: HTML/JSON/Markdown/XML are supported; CSV may be limited for complex data like image stats. Export JSON and transform to CSV if needed.
• Self-contained HTML: Verify the generated HTML loads resources locally—if not, open on the same machine that ran the scan.

Quick checklist to resolve a problem

1. Reproduce the issue using pa11y CLI on the same page.
2. Run Koa11y from source (npm install → npm start) to view console logs.
3. Verify external resources load (images, scripts) in a regular browser.
4. Cross-check Koa11y findings with manual testing and screen readers.
5. Search/open issues on the Koa11y GitHub repository for known bugs or workarounds.

If you want, I can:

• give exact pa11y commands to reproduce a specific Koa11y report, or
• look up any Koa11y GitHub issue matching the problem you’re seeing. Which would you like?