Ce Test Browser

# Browser Test Skill

Run end-to-end browser tests on pages affected by a PR or branch changes using the `agent-browser` CLI.

## Use `agent-browser` Only For Browser Automation

This workflow uses the `agent-browser` CLI exclusively. Do not use any alternative browser automation system, browser MCP integration, or built-in browser-control tool. If the platform offers multiple ways to control a browser, always choose `agent-browser`.

Use `agent-browser` for: opening pages, clicking elements, filling forms, taking screenshots, and scraping rendered content.

Platform-specific hints:
- In Claude Code, do not use Chrome MCP tools (`mcp__claude-in-chrome__*`).
- In Codex, do not substitute unrelated browsing tools.

## Prerequisites

- Local development server running (e.g., `bin/dev`, `rails server`, `npm run dev`)
- `agent-browser` CLI installed (see Setup below)
- Git repository with changes to test

## Setup

Check whether `agent-browser` is installed:

```bash
command -v agent-browser >/dev/null 2>&1 && echo "Installed" || echo "NOT INSTALLED"
```

If not installed, inform the user: "`agent-browser` is not installed. Run `/ce-setup` to install required dependencies." Then stop — this skill cannot function without agent-browser.

## Workflow

### 1. Verify Installation

Before starting, verify `agent-browser` is available:

```bash
command -v agent-browser >/dev/null 2>&1 && echo "Ready" || echo "NOT INSTALLED"
```

If not installed, inform the user: "`agent-browser` is not installed. Run `/ce-setup` to install required dependencies." Then stop.

### 2. Ask Browser Mode

**Pipeline mode (`mode:pipeline`):** Skip this step entirely. Default to headless — no question, no blocking. Proceed directly to step 3.

**Manual mode:** Ask the user whether to run headed or headless using the platform's blocking question tool: `AskUserQuestion` in Claude Code (call `ToolSearch` with `select:AskUserQuestion` first if its schema isn't loaded), `request_user_input` in Codex, `ask_user` in Gemini, `ask_user` in Pi (requires the `pi-ask-user` extension). Fall back to presenting options in chat only when no blocking tool exists in the harness or the call errors (e.g., Codex edit modes) — not because a schema load is required. Never silently skip the question:

```
Do you want to watch the browser tests run?

1. Headed (watch) - Opens visible browser window so you can see tests run
2. Headless (faster) - Runs in background, faster but invisible
```

Store the choice and use the `--headed` flag when the user selects option 1.

### 3. Determine Test Scope

**If PR number provided:**
```bash
gh pr view [number] --json files -q '.files[].path'
```

**If 'current' or empty:**
```bash
git diff --name-only main...HEAD
```

**If branch name provided:**
```bash
git diff --name-only main...[branch]
```

### 4. Map Files to Routes

Map changed files to testable routes:

| File Pattern | Route(s) |
|-------------|----------|
| `app/views/users/*` | `/users`, `/users/:id`, `/users/new` |
| `app/controllers/settings_controller.rb` | `/settings` |
| `app/javascript/controllers/*_controller.js` | Pages using that Stimulus controller |
| `app/components/*_component.rb` | Pages rendering that component |
| `app/views/layouts/*` | All pages (test homepage at minimum) |
| `app/assets/stylesheets/*` | Visual regression on key pages |
| `app/helpers/*_helper.rb` | Pages using that helper |
| `src/app/*` (Next.js) | Corresponding routes |
| `src/components/*` | Pages using those components |

Build a list of URLs to test based on the mapping.

### 5. Detect and Claim a Free Port

**Pipeline mode only (`mode:pipeline`):** When invoked from LFG or another automated pipeline, always find a port that is actually free — never assume 3000 is available, as multiple agents may be running in parallel on the