Agent skill · software engineering · yonatangross
expect
Diff-aware browser testing: maps the git diff to affected pages, plans and runs targeted checks via agent-browser. Use when testing UI changes before merge. Not for writing tests (use cover), grading a suite (use verify) or unit tests.
Why this skill is useful
Adds a specialized testing framework that automates browser tests based on git diffs, which the AI wouldn't generate on its own.
What it needs
Requires agent-browser installed locally. About 10k tokens when loaded. Last updated 2026-08-06. 215 stars on the source repository.
What this skill does
Expect — Diff-Aware AI Browser Testing Analyze git changes, generate targeted test plans, and execute them via AI-driven browser automation. Note: If disableSkillShellExecution is enabled, the agent-browser install check won't run. Verify it's installed: npx agent-browser --version. Core principle: Only test what changed. Git diff drives scope — no wasted cycles on unaffected pages. Argument Resolution STEP 0: MCP Probe + Prerequisite Check CRITICAL: Task Management Pipeline Overview Phase What Output Reference ------- ------ -------- ----------- 1. Fingerprint SHA-256 hash of changed files Skip if unchanged since last run references/fingerprint.md 2. Diff Scan Parse git diff, classify changes ChangesFor data (files, components, routes) references/diff-scanner.md 3. Route Map Map changed files to affected pages/URLs Scoped page list references/route-map.md 4. Test Plan Generate AI test plan from diff + route map Markdown test plan with steps references/test-plan.md 5. Execute Run test plan via agent-browser Pass/fail per step, screenshots references/execution.md 6. Report Aggregate results, artifacts, exit code Structured report + artifacts references/report.md Phase 1: Fingerprint Check Check if the current changes have already been tested: Load: Read("references/fingerprint.md") Phase 2: Diff Scan Analyze git changes based on --target: Classify each changed file into 3 levels: 1. Direct — the file itself changed 2. Imported — a file that imports the changed file 3. Routed — the page/route that renders the changed component Load: Read("references/diff-scanner.md") Phase 3: Route Map Map changed files to testable URLs using .expect/config.yaml: If no route map exists, infer from Next.js App Router / Pages Router conventions. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills yonatangross/expect--a82ebd