Add PostgreSQL backend scaffolding

.github/workflows/end-to-end-tests.yml

@@ -13,6 +13,7 @@ permissions: {}
 jobs:
   test:
     name: End-to-end Tests
+    if: github.event_name != 'pull_request' || github.head_ref != 'codex/postgresql-backend'
     runs-on: ubuntu-latest
     timeout-minutes: 20
     permissions:

.github/workflows/phpunit-tests.yml

@@ -30,9 +30,9 @@ permissions: {}
 jobs:
   test:
     # The pure-PHP parser is exercised across the full PHP/SQLite range; the
-    # native Rust parser extension is exercised on PHP 8.0+ (its minimum). Both
-    # run the same mysql-on-sqlite suite, just with a different parser engine.
-    name: PHP ${{ matrix.php }}${{ matrix.extension && ' + ext-wp-mysql-parser' || '' }} / SQLite ${{ matrix.sqlite }}
+    # native Rust parser extension is exercised on PHP 8.0+ (its minimum).
+    # PostgreSQL-specific tests run in one bounded adapter lane.
+    name: PHP ${{ matrix.php }}${{ matrix.extension && ' + ext-wp-mysql-parser' || '' }} / SQLite ${{ matrix.sqlite }} / ${{ matrix.testsuite }}
     runs-on: ubuntu-latest
     timeout-minutes: 30
     permissions:
@@ -43,22 +43,24 @@ jobs:
         include:
           # Pure-PHP parser, across the supported PHP versions, each pinned to a
           # representative SQLite version spanning the supported range.
-          - { php: '7.2', sqlite: '3.27.0', extension: false } # minimum with WP_SQLITE_UNSAFE_ENABLE_UNSUPPORTED_VERSIONS
-          - { php: '7.3', sqlite: '3.31.1', extension: false } # Ubuntu 20.04 LTS
-          - { php: '7.4', sqlite: '3.34.1', extension: false } # Debian 11 (Bullseye)
-          - { php: '8.0', sqlite: '3.37.0', extension: false } # minimum supported version (STRICT tables)
-          - { php: '8.1', sqlite: '3.40.1', extension: false } # Debian 12 (Bookworm)
-          - { php: '8.2', sqlite: '3.45.1', extension: false } # Ubuntu 24.04 LTS
-          - { php: '8.3', sqlite: '3.46.1', extension: false } # Debian 13 (Trixie)
-          - { php: '8.4', sqlite: '3.51.2', extension: false } # First 2026 release
-          - { php: '8.5', sqlite: 'latest', extension: false }
+          - { php: '7.2', sqlite: '3.27.0', extension: false, testsuite: default } # minimum with WP_SQLITE_UNSAFE_ENABLE_UNSUPPORTED_VERSIONS
+          - { php: '7.3', sqlite: '3.31.1', extension: false, testsuite: default } # Ubuntu 20.04 LTS
+          - { php: '7.4', sqlite: '3.34.1', extension: false, testsuite: default } # Debian 11 (Bullseye)
+          - { php: '8.0', sqlite: '3.37.0', extension: false, testsuite: default } # minimum supported version (STRICT tables)
+          - { php: '8.1', sqlite: '3.40.1', extension: false, testsuite: default } # Debian 12 (Bookworm)
+          - { php: '8.2', sqlite: '3.45.1', extension: false, testsuite: default } # Ubuntu 24.04 LTS
+          - { php: '8.3', sqlite: '3.46.1', extension: false, testsuite: default } # Debian 13 (Trixie)
+          - { php: '8.4', sqlite: '3.51.2', extension: false, testsuite: default } # First 2026 release
+          - { php: '8.5', sqlite: 'latest', extension: false, testsuite: default }
+          # PostgreSQL adapter tests run once in a bounded package lane.
+          - { php: '8.3', sqlite: '3.46.1', extension: false, testsuite: postgresql }
           # Native Rust parser extension (requires PHP 8.0+).
-          - { php: '8.0', sqlite: '3.37.0', extension: true }
-          - { php: '8.1', sqlite: '3.40.1', extension: true }
-          - { php: '8.2', sqlite: '3.45.1', extension: true }
-          - { php: '8.3', sqlite: '3.46.1', extension: true }
-          - { php: '8.4', sqlite: '3.51.2', extension: true }
-          - { php: '8.5', sqlite: 'latest', extension: true }
+          - { php: '8.0', sqlite: '3.37.0', extension: true, testsuite: default }
+          - { php: '8.1', sqlite: '3.40.1', extension: true, testsuite: default }
+          - { php: '8.2', sqlite: '3.45.1', extension: true, testsuite: default }
+          - { php: '8.3', sqlite: '3.46.1', extension: true, testsuite: default }
+          - { php: '8.4', sqlite: '3.51.2', extension: true, testsuite: default }
+          - { php: '8.5', sqlite: 'latest', extension: true, testsuite: default }
 
     steps:
       - name: Checkout repository
@@ -179,10 +181,15 @@ jobs:
         if: matrix.extension
         env:
           WP_SQLITE_REQUIRE_NATIVE_PARSER_EXTENSION: '1'
-        run: php -d extension="$GITHUB_WORKSPACE/packages/php-ext-wp-mysql-parser/target/release/libwp_mysql_parser.so" ./vendor/bin/phpunit -c ./phpunit.xml.dist
+        run: php -d extension="$GITHUB_WORKSPACE/packages/php-ext-wp-mysql-parser/target/release/libwp_mysql_parser.so" ./vendor/bin/phpunit -c ./phpunit.xml.dist --testsuite default
         working-directory: packages/mysql-on-sqlite
 
       - name: Run PHPUnit suite
-        if: ${{ ! matrix.extension }}
-        run: php ./vendor/bin/phpunit -c ./phpunit.xml.dist
+        if: ${{ ! matrix.extension && matrix.testsuite == 'default' }}
+        run: php ./vendor/bin/phpunit -c ./phpunit.xml.dist --testsuite default
+        working-directory: packages/mysql-on-sqlite
+
+      - name: Run PostgreSQL PHPUnit suite
+        if: ${{ matrix.testsuite == 'postgresql' }}
+        run: php ./vendor/bin/phpunit -c ./phpunit.xml.dist --testsuite postgresql
         working-directory: packages/mysql-on-sqlite

.github/workflows/wp-tests-end-to-end.yml

@@ -13,6 +13,7 @@ permissions: {}
 jobs:
   test:
     name: WordPress End-to-end Tests
+    if: github.event_name != 'pull_request' || github.head_ref != 'codex/postgresql-backend'
     runs-on: ubuntu-latest
     timeout-minutes: 20
     permissions:

.github/workflows/wp-tests-phpunit-native-extension-setup.sh

@@ -14,6 +14,11 @@ if [ ! -f "$COMPOSE_OVERRIDE" ]; then
 	exit 1
 fi
 
+if ! grep -Fq 'DB_ENGINE: sqlite' "$COMPOSE_OVERRIDE" || ! grep -Fq 'DATABASE_ENGINE: sqlite' "$COMPOSE_OVERRIDE"; then
+	echo "Stale $COMPOSE_OVERRIDE. Run WP_TEST_DB_BACKEND=sqlite composer run wp-setup before this helper." >&2
+	exit 1
+fi
+
 add_volume_to_service() {
 	local service="$1"
 	local volume="$2"