meta: add output-watcher GHA to help check output diff

.github/workflows/output-watcher.yml

@@ -0,0 +1,136 @@
+name: Compare JS output
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    # We want all branches so we configure types to be the GH default again
+    types: [opened, synchronize, reopened]
+    paths:
+      - 'packages/@uppy/*/src/**/*'
+      - 'bin/*'
+      - '.github/workflows/output-watcher.yml'
+
+env:
+  YARN_ENABLE_GLOBAL_CACHE: false
+
+jobs:
+  build_new_version:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v3
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run:
+          echo "dir=$(corepack yarn config get cacheFolder)" >> $GITHUB_OUTPUT
+
+      - uses: actions/cache@v3
+        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
+      - name: Install Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{matrix.node-version}}
+      - name: Install dependencies
+        run:
+          corepack yarn workspaces focus $(corepack yarn workspaces list --json
+          | jq -r .name | awk '/^@uppy-example/{ next } { if ($0!="uppy.io")
+          print $0 }')
+        env:
+          # https://docs.cypress.io/guides/references/advanced-installation#Skipping-installation
+          CYPRESS_INSTALL_BINARY: 0
+      - run: corepack yarn build:lib
+      - name: Store output file
+        run: tar czf /tmp/newVersion.tar.gz packages/@uppy/*/lib
+      - name: Upload artifact
+        if: success()
+        uses: actions/upload-artifact@v3
+        with:
+          name: newVersion.tar.gz
+          path: /tmp/newVersion.tar.gz
+          retention-days: 5
+
+  build_previous_version:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 2
+      - run: git reset HEAD^ --hard
+      - name: Get yarn cache directory path
+        id: yarn-cache-dir-path
+        run:
+          echo "dir=$(corepack yarn config get cacheFolder)" >> $GITHUB_OUTPUT
+
+      - uses: actions/cache@v3
+        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
+      - name: Install Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{matrix.node-version}}
+      - name: Install dependencies
+        run:
+          corepack yarn workspaces focus $(corepack yarn workspaces list --json
+          | jq -r .name | awk '/^@uppy-example/{ next } { if ($0!="uppy.io")
+          print $0 }')
+        env:
+          # https://docs.cypress.io/guides/references/advanced-installation#Skipping-installation
+          CYPRESS_INSTALL_BINARY: 0
+      - run: corepack yarn build:lib
+      - name: Store output file
+        run: tar czf /tmp/previousVersion.tar.gz packages/@uppy/*/lib
+      - name: Upload artifact
+        if: success()
+        uses: actions/upload-artifact@v3
+        with:
+          name: previousVersion.tar.gz
+          path: /tmp/previousVersion.tar.gz
+          retention-days: 1
+
+  compare:
+    needs: [build_new_version, build_previous_version]
+    name: Compare output files for both versions
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download tarballs
+        uses: actions/download-artifact@v3
+        with:
+          path: /tmp/
+      - name: Setup git
+        run: |
+          git config --global user.email "actions@github.com"
+          git config --global user.name "GitHub Actions"
+          git init /tmp/uppy
+          echo '*.map' > /tmp/uppy/.gitignore
+      - name: Extract previous version
+        run:
+          cd /tmp/uppy && tar xzf
+          /tmp/previousVersion.tar.gz/previousVersion.tar.gz
+      - name: Commit previous version
+        run: cd /tmp/uppy && git add -A . && git commit -m 'previous version'
+      - name: Extract new version
+        run: cd /tmp/uppy && tar xzf /tmp/newVersion.tar.gz/newVersion.tar.gz
+      - name: Commit new version
+        run:
+          cd /tmp/uppy && git add -A . && git commit -m 'new version'
+          --allow-empty
+      - name: Show diff
+        run: cd /tmp/uppy && git --no-pager diff HEAD^..HEAD
+      - run: cd /tmp/uppy && git format-patch HEAD^ -o /tmp/patch
+      - name: Upload artifact
+        if: success()
+        uses: actions/upload-artifact@v3
+        with:
+          name: diff
+          path: /tmp/patch