ci: split push.yml into reusable workflows, share build steps via composite action

.github/actions/build-ts-loader/action.yml

@@ -0,0 +1,26 @@
+name: Build ts-loader
+description: >
+  Install and build ts-loader (expects actions/checkout to have already run).
+  On Windows runners this first copies the checkout to C:\source\ts-loader
+  and installs/builds there, giving a consistent path that the comparison
+  tests' output normalisation expects - later Windows steps should use
+  working-directory: C:\source\ts-loader.
+runs:
+  using: composite
+  steps:
+    - name: copy files
+      if: runner.os == 'Windows'
+      shell: pwsh
+      run: |
+        New-Item C:\source\ts-loader -ItemType Directory
+        Copy-Item .\* C:\source\ts-loader -Recurse -Force
+
+    - name: install
+      shell: bash
+      working-directory: ${{ runner.os == 'Windows' && 'C:\source\ts-loader' || '.' }}
+      run: yarn install
+
+    - name: build
+      shell: bash
+      working-directory: ${{ runner.os == 'Windows' && 'C:\source\ts-loader' || '.' }}
+      run: yarn build

.github/scripts/post-benchmark-comment.js

@@ -2,7 +2,7 @@ const fs = require('fs');
 
 /**
  * Creates or updates the benchmark result comment identified by `marker`.
- * Shared by the "comment on PR" steps in benchmark.yml (Ubuntu + Windows jobs).
+ * Used by the "comment on PR" step of each OS in benchmark.yml's matrix.
  *
  * @param {{
  *   github: { rest: { issues: {

.github/workflows/benchmark.yml

@@ -16,10 +16,34 @@ permissions:
   pull-requests: write
 
 jobs:
-  benchmark_ubuntu:
-    name: Benchmark Ubuntu
-    runs-on: ubuntu-latest
+  benchmark:
+    name: benchmark ${{ matrix.name }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            id: ubuntu
+            name: ubuntu
+            title: Ubuntu
+          - os: macos-latest
+            id: macos
+            name: macOS
+            title: macOS
+          - os: windows-latest
+            id: windows
+            name: windows
+            title: Windows
+    runs-on: ${{ matrix.os }}
     timeout-minutes: 20
+    defaults:
+      run:
+        shell: bash
+    env:
+      # Where the build-ts-loader action builds the PR branch - on Windows it
+      # copies the checkout to C:\source\ts-loader first. The base branch is
+      # checked out alongside it at "$ROOT-main".
+      ROOT: ${{ matrix.os == 'windows-latest' && 'C:/source/ts-loader' || github.workspace }}
     steps:
       - uses: actions/checkout@v7
         with:
@@ -30,42 +54,41 @@ jobs:
           node-version: 24
           cache: yarn
 
-      - name: install & build (PR branch)
-        run: |
-          yarn install
-          yarn build
+      - uses: ./.github/actions/build-ts-loader
 
       # Checked out into a sibling worktree rather than a second checkout step
       # so both builds can run from disk at the same time.
       - name: checkout base branch into a worktree
+        working-directory: ${{ env.ROOT }}
         env:
           BASE_SHA: ${{ github.event.pull_request.base.sha || 'origin/main' }}
-        run: git worktree add ../ts-loader-main "$BASE_SHA"
+        run: git worktree add "$ROOT-main" "$BASE_SHA"
 
       - name: install & build (base branch)
-        working-directory: ../ts-loader-main
+        working-directory: ${{ env.ROOT }}-main
         run: |
           yarn install
           yarn build
 
-      # --root-a is the PR branch checked out at $GITHUB_WORKSPACE above;
+      # --root-a is the PR branch built by the build-ts-loader action;
       # --root-b is the base branch worktree built in the previous step.
       - name: run benchmark
+        working-directory: ${{ env.ROOT }}
         run: |
           yarn benchmark -- \
-            --root-a "$GITHUB_WORKSPACE" --label-a "PR branch" \
-            --root-b "$GITHUB_WORKSPACE/../ts-loader-main" --label-b "base branch"
+            --root-a "$ROOT" --label-a "PR branch" \
+            --root-b "$ROOT-main" --label-b "base branch"
 
       - name: write job summary
         if: always()
-        run: cat .benchmark/benchmark-results.md >> "$GITHUB_STEP_SUMMARY" 2>/dev/null || true
+        run: cat "$ROOT/.benchmark/benchmark-results.md" >> "$GITHUB_STEP_SUMMARY" 2>/dev/null || true
 
       - name: upload results
         if: always()
         uses: actions/upload-artifact@v7
         with:
-          name: benchmark-results-ubuntu
-          path: .benchmark/benchmark-results.*
+          name: benchmark-results-${{ matrix.id }}
+          path: ${{ env.ROOT }}/.benchmark/benchmark-results.*
           if-no-files-found: ignore
 
       # Only runs with a writable token - GitHub automatically issues a
@@ -74,108 +97,17 @@ jobs:
       - name: comment on PR
         if: always() && github.event_name == 'pull_request'
         uses: actions/github-script@v7
-        with:
-          script: |
-            const path = require('path');
-            const postComment = require(path.join(process.env.GITHUB_WORKSPACE, '.github/scripts/post-benchmark-comment.js'));
-            await postComment({
-              github,
-              context,
-              resultsPath: '.benchmark/benchmark-results.md',
-              marker: '<!-- ts-loader-benchmark:ubuntu -->',
-              title: 'Benchmark (Ubuntu)',
-            });
-
-  benchmark_windows:
-    name: Benchmark Windows
-    runs-on: windows-latest
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@v7
-        with:
-          fetch-depth: 0
-
-      - uses: actions/setup-node@v7
-        with:
-          node-version: 24
-          cache: yarn
-
-      # Windows Defender's real-time scanning adds unpredictable latency to
-      # file I/O, and this benchmark does a lot of it (a 300-file fixture,
-      # webpack output per build, a touched file on every incremental
-      # iteration) - excluding the working directories keeps that noise out
-      # of the measurements.
-      - name: exclude working directories from Windows Defender
-        shell: pwsh
-        run: |
-          Add-MpPreference -ExclusionPath "C:\source"
-          Add-MpPreference -ExclusionPath "$env:GITHUB_WORKSPACE"
-
-      - name: copy files
-        shell: pwsh
-        run: |
-          New-Item C:\source\ts-loader -ItemType Directory
-          Copy-Item .\* C:\source\ts-loader -Recurse -Force
-
-      - name: install & build (PR branch)
-        run: |
-          yarn install
-          yarn build
-        working-directory: C:\source\ts-loader
-
-      # Checked out into a sibling worktree rather than a second checkout step
-      # so both builds can run from disk at the same time.
-      - name: checkout base branch into a worktree
-        shell: pwsh
         env:
-          BASE_SHA: ${{ github.event.pull_request.base.sha || 'origin/main' }}
-        run: git worktree add C:\source\ts-loader-main $env:BASE_SHA
-        working-directory: C:\source\ts-loader
-
-      - name: install & build (base branch)
-        run: |
-          yarn install
-          yarn build
-        working-directory: C:\source\ts-loader-main
-
-      # --root-a is the PR branch copied to C:\source\ts-loader above;
-      # --root-b is the base branch worktree built in the previous step.
-      - name: run benchmark
-        shell: pwsh
-        run: |
-          yarn benchmark -- `
-            --root-a C:\source\ts-loader --label-a "PR branch" `
-            --root-b C:\source\ts-loader-main --label-b "base branch"
-        working-directory: C:\source\ts-loader
-
-      - name: write job summary
-        if: always()
-        shell: pwsh
-        run: |
-          if (Test-Path .benchmark\benchmark-results.md) {
-            Get-Content .benchmark\benchmark-results.md | Out-File -Append -Encoding utf8 $env:GITHUB_STEP_SUMMARY
-          }
-        working-directory: C:\source\ts-loader
-
-      - name: upload results
-        if: always()
-        uses: actions/upload-artifact@v7
-        with:
-          name: benchmark-results-windows
-          path: C:\source\ts-loader\.benchmark\benchmark-results.*
-          if-no-files-found: ignore
-
-      - name: comment on PR
-        if: always() && github.event_name == 'pull_request'
-        uses: actions/github-script@v7
+          MARKER: <!-- ts-loader-benchmark:${{ matrix.id }} -->
+          TITLE: Benchmark (${{ matrix.title }})
         with:
           script: |
             const path = require('path');
             const postComment = require(path.join(process.env.GITHUB_WORKSPACE, '.github/scripts/post-benchmark-comment.js'));
             await postComment({
               github,
               context,
-              resultsPath: 'C:\\source\\ts-loader\\.benchmark\\benchmark-results.md',
-              marker: '<!-- ts-loader-benchmark:windows -->',
-              title: 'Benchmark (Windows)',
+              resultsPath: path.join(process.env.ROOT, '.benchmark/benchmark-results.md'),
+              marker: process.env.MARKER,
+              title: process.env.TITLE,
             });

.github/workflows/ci.yml

@@ -0,0 +1,27 @@
+name: ci
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
+jobs:
+  comparison-tests:
+    name: comparison tests
+    uses: ./.github/workflows/comparison-tests.yml
+
+  execution-tests:
+    name: execution tests
+    uses: ./.github/workflows/execution-tests.yml
+
+  lint:
+    name: lint
+    uses: ./.github/workflows/lint.yml

.github/workflows/comparison-tests.yml

@@ -0,0 +1,57 @@
+name: comparison tests
+
+on:
+  workflow_call:
+
+jobs:
+  comparison_test_ubuntu:
+    name: ubuntu
+    runs-on: ubuntu-latest
+    timeout-minutes: 25
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: 24
+          cache: yarn
+
+      - uses: ./.github/actions/build-ts-loader
+
+      - name: test
+        run: yarn comparison-tests
+
+  comparison_test_macos:
+    name: macOS
+    runs-on: macos-latest
+    timeout-minutes: 25
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: 24
+          cache: yarn
+
+      - uses: ./.github/actions/build-ts-loader
+
+      - name: test
+        run: yarn comparison-tests
+
+  comparison_test_windows:
+    name: windows
+    runs-on: windows-latest
+    timeout-minutes: 25
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: 24
+          cache: yarn
+
+      - uses: ./.github/actions/build-ts-loader
+
+      - name: test
+        run: yarn comparison-tests
+        working-directory: C:\source\ts-loader