README: add CI-measured cross-platform numbers (Windows 116s -> 67s)

Author: TomasVotruba

.github/workflows/benchmark_phpunit.yaml

@@ -0,0 +1,56 @@
+name: Benchmark PHPUnit
+
+# A/B wall-time benchmark: serial phpunit vs the Go parallel runner.
+# Scheduled only (not on pull requests); runs every 2 hours on ubuntu + windows.
+# Reminder: cron fires only from the default branch, so this starts running
+# once the file is on `main`.
+on:
+    schedule:
+        - cron: '0 */2 * * *'
+    workflow_dispatch: null
+
+env:
+    COMPOSER_ROOT_VERSION: "dev-main"
+
+jobs:
+    benchmark:
+        strategy:
+            fail-fast: false
+            matrix:
+                os: [ubuntu-latest, windows-latest]
+                php-versions: ['8.4', '8.5']
+
+        runs-on: ${{ matrix.os }}
+        timeout-minutes: 15
+
+        name: benchmark (${{ matrix.os }})
+        steps:
+            -   uses: actions/checkout@v5
+
+            -
+                uses: shivammathur/setup-php@v2
+                with:
+                    php-version: ${{ matrix.php-versions }}
+                    coverage: none
+                    ini-values: zend.assertions=1
+
+            -   uses: "ramsey/composer-install@v4"
+
+            -   uses: actions/setup-go@v5
+                with:
+                    go-version: 'stable'
+
+            -   name: Serial phpunit
+                shell: bash
+                run: |
+                    printf '| platform | php | mode | wall time |\n| --- | --- | --- | --- |\n' >> "$GITHUB_STEP_SUMMARY"
+                    start=$SECONDS
+                    vendor/bin/phpunit
+                    echo "| ${{ matrix.os }} | ${{ matrix.php-versions }} | serial | $((SECONDS - start))s |" >> "$GITHUB_STEP_SUMMARY"
+
+            -   name: Go parallel runner
+                shell: bash
+                run: |
+                    start=$SECONDS
+                    go run ./utils-tests-runner/main.go
+                    echo "| ${{ matrix.os }} | ${{ matrix.php-versions }} | go-runner | $((SECONDS - start))s |" >> "$GITHUB_STEP_SUMMARY"

.github/workflows/tests.yaml

@@ -39,38 +39,3 @@ jobs:
             -   uses: "ramsey/composer-install@v4"
 
             -   run: vendor/bin/phpunit --colors
-
-    # proof of concept: same suite via the Go parallel runner, for an A/B time comparison
-    fast_tests:
-        strategy:
-            fail-fast: false
-            matrix:
-                os: [ubuntu-latest, windows-latest]
-                php-versions: ['8.4']
-
-        runs-on: ${{ matrix.os }}
-        timeout-minutes: 4
-
-        name: PHP ${{ matrix.php-versions }} fast-phpunit (${{ matrix.os }})
-        steps:
-            -   uses: actions/checkout@v5
-
-            -
-                uses: shivammathur/setup-php@v2
-                with:
-                    php-version: ${{ matrix.php-versions }}
-                    coverage: none
-                    ini-values: zend.assertions=1
-
-            -   uses: "ramsey/composer-install@v4"
-
-            -   uses: actions/setup-go@v5
-                with:
-                    go-version: 'stable'
-
-            # `-o` writes the exact name, so add .exe on Windows ourselves
-            -   run: go build -o fast-phpunit${{ runner.os == 'Windows' && '.exe' || '' }} .
-                working-directory: utils-tests-runner
-
-            # run from repo root so test-dir discovery and phpunit.xml resolve
-            -   run: ./utils-tests-runner/fast-phpunit${{ runner.os == 'Windows' && '.exe' || '' }}

utils-tests-runner/README.md

@@ -3,9 +3,21 @@
 Run the PHPUnit suite **~4x faster** by splitting test classes across parallel
 workers that each boot PHP **once** and run many classes in a single process.
 
-## Speed — measured on this suite
+## Speed — CI, per platform (GitHub runners, 4 vCPU, full suite)
 
-Full suite: **685 test classes / 5833 fixtures**, 24-core host.
+Serial `vendor/bin/phpunit` vs this runner, measured on the CI run step:
+
+| Platform | Serial | Go runner | Speedup |
+| --- | --- | --- | --- |
+| ubuntu-latest | 31s | **16s** | ~1.9x |
+| windows-latest | **116s** | **67s** | **~1.7x** |
+
+Windows is the slow platform (~3.7x slower than Ubuntu serial); the runner cuts
+~49s off it. Both run the full suite and pass.
+
+## Speed — local (24-core host, full suite)
+
+Full suite: **685 test classes / 5833 fixtures**.
 
 | Mode | Wall time | vs serial |
 | --- | --- | --- |