Add integration test against a real Rails app

.github/workflows/integration.yml

@@ -0,0 +1,70 @@
+name: Integration test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  integration:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      pull-requests: read
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+
+      - name: Create test Rails app
+        run: |
+          gem install rails --no-document
+          rails new /tmp/test-app \
+            --skip-git \
+            --skip-action-mailer \
+            --skip-action-mailbox \
+            --skip-action-text \
+            --skip-active-record \
+            --skip-active-storage \
+            --skip-action-cable \
+            --skip-bootsnap \
+            --skip-test \
+            --quiet
+
+      - name: Pin outdated packages
+        run: |
+          cat >> /tmp/test-app/config/importmap.rb << 'EOF'
+
+          pin "is-svg",     to: "https://cdn.jsdelivr.net/npm/is-svg@3.0.0/index.js"
+          pin "md5",        to: "https://cdn.jsdelivr.net/npm/md5@2.2.0/dist/md5.min.js"
+          pin "local-time", to: "https://cdn.jsdelivr.net/npm/local-time@3.0.2/app/assets/javascripts/local-time.es2017-esm.js"
+          pin "hotkeys-js", to: "https://cdn.jsdelivr.net/npm/hotkeys-js@4.0.3/dist/hotkeys.esm.js"
+          pin "tom-select", to: "https://cdn.jsdelivr.net/npm/tom-select@2.3.1/dist/esm/tom-select.complete.js"
+          pin "just-extend", to: "https://cdn.jsdelivr.net/npm/just-extend@5.1.1/index.mjs"
+          EOF
+
+      - name: Run in dry-run mode
+        uses: ./
+        env:
+          IMPORTMAP_RUN_LOG: /tmp/dry-run-output.txt
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          dry-run: "true"
+          working-directory: /tmp/test-app
+
+      - name: Assert all outdated packages appear in dry-run output
+        run: |
+          failed=0
+          for pkg in hotkeys-js is-svg just-extend local-time md5 tom-select; do
+            if grep -q "$pkg" /tmp/dry-run-output.txt; then
+              echo "✓ $pkg"
+            else
+              echo "✗ $pkg not found in output"
+              failed=1
+            fi
+          done
+          exit $failed

action.yml

@@ -32,6 +32,10 @@ inputs:
     description: "Git author email for commits."
     required: false
     default: "github-actions[bot]@users.noreply.github.com"
+  working-directory:
+    description: "Directory containing the Rails app to run against. Useful when the app lives in a subdirectory or for integration testing."
+    required: false
+    default: "."
 
 runs:
   using: "composite"
@@ -44,6 +48,7 @@ runs:
 
     - name: Run importmap-update
       shell: bash
+      working-directory: ${{ inputs.working-directory }}
       env:
         GH_TOKEN:                 ${{ inputs.github-token }}
         GITHUB_TOKEN:             ${{ inputs.github-token }}
@@ -53,4 +58,4 @@ runs:
         IMPORTMAP_DRY_RUN:        ${{ inputs.dry-run }}
         IMPORTMAP_AUTHOR_NAME:    ${{ inputs.author-name }}
         IMPORTMAP_AUTHOR_EMAIL:   ${{ inputs.author-email }}
-      run: ${{ github.action_path }}/exe/importmap-update
+      run: ${{ github.action_path }}/exe/importmap-update 2>&1 | tee "${IMPORTMAP_RUN_LOG:-/dev/null}"

lib/executor.rb

@@ -105,9 +105,10 @@ def handle_noop(action)
       def handle_open(action)
         spec = action.pr_spec
         if @dry_run
+          names = spec.packages.map(&:name).join(", ")
           return Outcome.new(
             type: :open, status: :skipped, branch: spec.branch,
-            detail: "DRY RUN: would open PR for #{spec.packages.size} package(s)."
+            detail: "DRY RUN: would open PR for #{names}."
           )
         end
 
@@ -134,9 +135,10 @@ def handle_force_push(action)
         existing = action.existing_pr
 
         if @dry_run
+          names = spec.packages.map(&:name).join(", ")
           return Outcome.new(
             type: :force_push, status: :skipped, branch: spec.branch, pr_number: existing.number,
-            detail: "DRY RUN: would force-push (#{action.reason})."
+            detail: "DRY RUN: would force-push #{names} (#{action.reason})."
           )
         end
 

test/executor_test.rb

@@ -230,8 +230,11 @@ def test_dry_run_records_skipped_outcomes_and_invokes_nothing
     assert_empty @gh.created
     assert_empty @gh.updated
     assert_empty @gh.closed
-    # All "would have" details should be informative.
     assert(report.outcomes.all? { |o| o.detail.start_with?("DRY RUN") })
+    open_outcome = report.outcomes.find { |o| o.type == :open }
+    fp_outcome = report.outcomes.find { |o| o.type == :force_push }
+    assert_includes open_outcome.detail, "lodash"
+    assert_includes fp_outcome.detail, "stim"
   end
 
   # ---- failure isolation ----