Add/build tooling

.editorconfig

@@ -0,0 +1,25 @@
+# This file is for unifying the coding style for different editors and IDEs
+# editorconfig.org
+
+# WordPress Coding Standards
+# https://developer.wordpress.org/coding-standards/wordpress-coding-standards/
+
+# This is largely aligned with the .editorconfig in wordpress-develop and Gutenberg.
+# Matches: https://github.com/WordPress/wordpress-develop/blob/bff31ca3a823e89127a7d3c2d953eda3d9b2193e/.editorconfig#L7-L21
+# See also: https://github.com/WordPress/gutenberg/blob/trunk/.editorconfig
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = tab
+
+[*.yml]
+indent_style = space
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false

.github/PULL_REQUEST_TEMPLATE.md

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+<!-- Thanks for contributing to the Accessibility Lab plugin! Please follow the Contributing Guidelines:
+https://github.com/WordPress/accessibility-lab/blob/main/CONTRIBUTING.md -->
+
+## What?
+<!-- Link this PR to its associated issue with an appropriate keyword: Closes, See, Follow up to, etc. -->
+Closes <!-- #ISSUE-NUMBER or URL -->
+
+<!-- In a few words, what is the PR actually doing? -->
+
+## Why?
+<!-- Why is this PR necessary? What problem is it solving? Reference any existing previous issue(s) or PR(s), but please add a short summary here, too -->
+
+## How?
+<!-- How is your PR addressing the issue at hand? What are the implementation details? -->
+
+## Testing Instructions
+<!-- Please provide steps on how to test or validate that the change in this PR works as described. -->
+
+## Screenshots or screencast
+<!-- If this PR includes UI changes, please provide screenshots or a screen recording for clarity. -->
+<!-- This section can be removed if not applicable. -->
+
+| Before | After |
+| ------ | ----- |
+|        |       |
+
+## Changelog Entry
+<!--
+Please include a summary for this PR, noting whether this is something being Added / Changed / Deprecated / Removed / Fixed / or Security related.  You can replace the sample entries after this comment block with the single changelog entry line for this PR. -->
+
+> Added - New feature.
+> Changed - Existing functionality.
+> Deprecated - Soon-to-be removed feature.
+> Removed - Feature.
+> Fixed - Bug fix.
+> Security - Vulnerability.
+> Developer - Development related updates.

.github/workflows/ci.yml

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+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  php:
+    name: PHP (${{ matrix.php-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        php-version: ['8.1', '8.2', '8.3', '8.4']
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-version }}
+          tools: composer
+          coverage: none
+
+      - name: Install Composer dependencies
+        run: composer install --no-progress --no-interaction --prefer-dist
+
+      - name: PHPCS
+        run: composer lint
+
+      - name: PHPStan
+        run: composer phpstan
+
+  js:
+    name: JS & build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Lint JS
+        run: npm run lint:js
+
+      - name: Lint CSS
+        run: npm run lint:css
+
+      - name: Build
+        run: npm run build

.gitignore

@@ -1,6 +1,7 @@
-# Build artefacts (rebuilt via `npm run build`)
+# Build artefacts (rebuilt via `npm run build` / `npm run plugin-zip`)
 /build/
 /vendor/
+*.zip
 
 # Dependencies
 /node_modules/

.husky/pre-commit

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+#!/usr/bin/env sh
+
+# `printf` rather than `echo`: POSIX sh (dash, as on Linux/CI) does not
+# interpret \033 or \n in echo, so escapes would print literally.
+red() {
+  printf '\033[0;31m%s\033[0m\n' "$1"
+}
+
+rule() {
+  printf '\033[0;31m%s\033[0m\n' '--------------------------------------------------------------------------------'
+}
+
+# 1. Lint only staged files (CSS/JS/PHP) — fast, scoped to what's changing.
+printf '\n'
+red 'Linting staged files...'
+npx lint-staged --no-stash || {
+  printf '\n'
+  rule
+  red 'Linting failed. Commit aborted.'
+  rule
+  printf '\n'
+  exit 1
+}
+
+# 2. PHPStan runs project-wide — it needs whole-codebase context, so it can't
+#    be scoped to staged files like the linters above.
+red 'Running PHPStan...'
+composer phpstan || {
+  printf '\n'
+  rule
+  red 'PHPStan failed. Commit aborted.'
+  rule
+  printf '\n'
+  exit 1
+}

.nvmrc

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+24.19.0

.stylelintignore

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+build/
+node_modules/
+vendor/

.stylelintrc.json

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+{
+	"extends": ["@wordpress/stylelint-config/scss"],
+	"rules": {
+		"selector-class-pattern": null
+	}
+}

CHANGELOG.md

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+# Changelog
+
+All notable changes to this project will be documented in this file, per [the Keep a Changelog standard](http://keepachangelog.com/), and will adhere to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased] - TBD
+
+### Added
+
+- Linting and static analysis: ESLint, Stylelint, PHP_CodeSniffer (WordPress Coding Standards) and PHPStan at level 8, all runnable through `npm run lint` and `npm run format`.
+- Continuous integration via GitHub Actions, running PHPCS and PHPStan against PHP 8.1 through 8.4 alongside JavaScript and CSS linting and a production build.
+- A pre-commit hook that lints staged files and runs PHPStan across the project, so failures surface before review.
+- Scripts for the bundled `wp-env` environment (`env:start`, `env:stop`, `env:clean`), giving contributors a disposable WordPress install with debugging enabled.
+- Contributor documentation: contributing guidelines, a pull request template, and this changelog.
+- A pinned Node version (`.nvmrc`) and shared editor settings (`.editorconfig`).
+- A declared minimum PHP version of 8.1 in `composer.json`.
+
+### Changed
+
+- Reformatted the JavaScript, TypeScript, SCSS and PHP source to the WordPress Coding Standards, and documented every PHP class, method and property.
+- Expanded the README with a full script reference, the Node version requirement, and instructions for running the plugin locally.
+- Narrowed the `credits()` return type on modules that always supply attribution.
+
+### Fixed
+
+- The Media Library view-preference handler now sanitises the submitted value before use.
+- Uninstalling no longer assigns to WordPress's global `$plugin` variable.
+- Corrected CSS selector specificity ordering in the Media Library view options, so the thumbnail density rules apply as intended.
+- Replaced an invalid design-system colour token in the validation settings table with the intended value, restoring the muted styling of the description text.
+- Removed an unused registry dependency from the settings page, along with several unused variables and imports across the editor scripts.
+- Corrected the supported PHP range in CI, which previously claimed 8.0 despite the plugin requiring 8.1.
+- Committed the dependency lock files, without which continuous integration could not install dependencies.

CONTRIBUTING.md

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+# Contributing Guidelines
+
+Welcome to the Accessibility Lab plugin! Here you'll find information on how to get started contributing to the plugin.
+
+## Getting Started
+
+### Prerequisites
+
+- Composer
+- Node.js — the version is pinned in `.nvmrc`; the toolchain requires 22.12 or newer
+- Docker, only if you plan to use the bundled `wp-env` environment
+
+### Local development setup
+
+1. **Clone the repository:**
+
+The repository *is* the plugin directory, so the simplest setup is to clone it
+straight into the `wp-content/plugins/` of a WordPress install you already have
+(WordPress Studio, Local, or any other local server):
+
+```bash
+cd path/to/wp-content/plugins
+git clone https://github.com/WordPress/accessibility-lab.git accessibility-lab
+cd accessibility-lab
+```
+
+2. **Install dependencies and build assets:**
+
+If you use `nvm`, run `nvm use` first to switch to the pinned Node version.
+On older Node, `npm run lint:js` fails with `ERR_REQUIRE_ESM`.
+
+```bash
+nvm use
+composer install && npm i && npm run build
+```
+
+3. **Activate the plugin:**
+
+Through WordPress admin or via WP-CLI:
+
+```bash
+wp plugin activate accessibility-lab
+```
+
+Alternatively, `npm run env:start` spins up a throwaway Docker-based WordPress
+with the plugin mounted and debugging enabled. See the
+[README](README.md) for the full list of scripts.
+
+### Quality checks
+
+Before submitting a pull request:
+
+```bash
+# Lint everything — JS, CSS, PHPCS, PHPStan
+npm run lint
+
+# Auto-fix what can be fixed
+npm run format
+```
+
+The pre-commit hook already runs `lint-staged` plus a project-wide PHPStan, so
+a commit that goes through has passed most of this. CI runs the same checks
+against PHP 8.1–8.4.
+
+There is no automated test suite yet. Please describe how you verified your
+change in the pull request's testing instructions.
+
+### Coding standards
+
+All code must follow the [WordPress Coding Standards](https://developer.wordpress.org/coding-standards/). This ensures consistency across the WordPress ecosystem and makes the codebase maintainable.
+
+### PHP compatibility
+
+The minimum supported PHP version is **8.1**. The codebase uses `readonly`
+properties, constructor promotion, and enum-style class constants accordingly.
+
+### WordPress compatibility
+
+The plugin requires **WordPress 6.5** or higher. Ensure all WordPress functions
+and hooks used are available in that version.
+
+### Naming conventions
+
+The following conventions must be followed for consistency and autoloading:
+
+- Namespaces follow the pattern `AccessibilityLab\{Component}`.
+- Autoloading is PSR-4-ish (see `includes/autoload.php`): **the file name matches
+  the class name** — `Bucket.php` contains `Bucket`. This project does *not* use
+  WordPress core's `class-bucket.php` convention, which is why
+  `WordPress.Files.FileName` is excluded in `phpcs.xml.dist`.
+- Classes use WordPress naming conventions with underscores where useful for
+  readability (e.g. `Settings_Page`, `Abstract_Module`).
+- Modules extend `AccessibilityLab\Abstracts\Abstract_Module` and live under
+  `includes/Modules/Features/` or `includes/Modules/Experiments/`.
+
+### Documentation standards
+
+Every class, method, and property needs a docblock with a summary line — PHPCS
+runs the `WordPress-Docs` ruleset and the codebase currently passes clean. Use
+explicit type hints on parameters and return values, and document array shapes
+with generics (e.g. `array<string, Abstract_Module>`) so PHPStan can check them
+at level 8.
+
+```php
+/**
+ * Holds every registered module and their enabled/disabled state.
+ */
+final class Registry {
+
+	/**
+	 * Registered modules, keyed by id.
+	 *
+	 * @var array<string, Abstract_Module>
+	 */
+	private array $modules = array();
+
+	/**
+	 * Register a module. No-ops on duplicate id or invalid bucket/track.
+	 *
+	 * @param Abstract_Module $module Module instance to register.
+	 */
+	public function register( Abstract_Module $module ): void {
+		// Implementation
+	}
+}
+```
+
+### Internationalization
+
+All user-facing strings must be translatable using WordPress i18n functions,
+with the `accessibility-lab` text domain:
+
+```php
+// Good
+__( 'Hello World', 'accessibility-lab' );
+esc_html__( 'Hello World', 'accessibility-lab' );
+
+// Bad
+echo 'Hello World';
+```
+
+Strings with placeholders need a `translators:` comment immediately above the
+`__()` call.
+
+## Guidelines
+
+- As with all WordPress projects, we want to ensure a welcoming environment for everyone. With that in mind, all contributors are expected to follow our [Code of Conduct](https://make.wordpress.org/handbook/community-code-of-conduct/).
+- All WordPress projects are licensed under the GPLv2+, and all contributions to the Accessibility Lab plugin will be released under the GPLv2+ license. You maintain copyright over any contribution you make, and by submitting a pull request, you are agreeing to release that contribution under the GPLv2+ license.
+
+---
+
+## Additional resources
+
+- [README](README.md) — architecture, the Feature/Experiment and Core-track/Practical model, registering your own modules and validation checks, and the full script reference
+- [CHANGELOG](CHANGELOG.md) — release history