Add Initial E2E tests

.gitattributes

@@ -12,3 +12,7 @@
 /CREDITS.md export-ignore
 /LICENSE.md export-ignore
 /README.md export-ignore
+/node_modules export-ignore
+/tests export-ignore
+/package.json export-ignore
+/package-lock.json export-ignore

.github/workflows/cypress.yml

@@ -0,0 +1,35 @@
+name: E2E test
+
+on:
+  push:
+    branches:
+      - develop
+      - trunk
+  pull_request:
+    branches:
+      - develop
+jobs:
+  cypress:
+    name: ${{ matrix.core.name }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        core:
+          - {name: 'WP latest', version: 'latest'}
+          - {name: 'WP minimum', version: 'WordPress/WordPress#6.5'}
+          - {name: 'WP trunk', version: 'WordPress/WordPress#master'}
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Install dependencies
+      run: npm install
+
+    - name: Set the core version
+      run: ./tests/bin/set-core-version.js ${{ matrix.core.version }}
+
+    - name: Set up WP environment
+      run: npm run env:start
+
+    - name: Test
+      run: npm run cypress:run

.gitignore

@@ -1,2 +1,3 @@
 .idea/
 .DS_Store
+/node_modules/

.wp-env.json

@@ -0,0 +1,10 @@
+{
+  "plugins": ["."],
+  "env": {
+    "tests": {
+      "mappings": {
+        "wp-cli.yml": "./tests/bin/wp-cli.yml"
+      }
+    }
+  }
+}