cache build on CI

.github/workflows/ci.yml

@@ -7,23 +7,9 @@ on:
   pull_request:
 
 jobs:
-  test:
+  build-plutobook:
     runs-on: ubuntu-22.04
 
-    env:
-      PAGE_PRINT_PLUTOBOOK_PREFIX: ${{ github.workspace }}/tmp/plutobook-ci-install
-      PKG_CONFIG_PATH: ${{ github.workspace }}/tmp/plutobook-ci-install/lib/pkgconfig
-      LD_LIBRARY_PATH: ${{ github.workspace }}/tmp/plutobook-ci-install/lib
-
-    strategy:
-      fail-fast: false
-      matrix:
-        ruby:
-          - "3.2"
-          - "3.3"
-          - "3.4"
-          - "4.0"
-
     steps:
       - uses: actions/checkout@v4
 
@@ -37,7 +23,6 @@ jobs:
             ninja-build \
             pipx \
             python3-pip \
-            poppler-utils \
             libcairo2-dev \
             libexpat1-dev \
             libicu-dev \
@@ -47,7 +32,17 @@ jobs:
           pipx install meson==1.3.2
           echo "$HOME/.local/bin" >> "$GITHUB_PATH"
 
+      - name: Cache PlutoBook install
+        uses: actions/cache@v4
+        id: plutobook-cache
+        with:
+          path: tmp/plutobook-ci-install
+          key: plutobook-v0.17.0-${{ runner.os }}-${{ hashFiles('.github/workflows/ci.yml') }}
+          restore-keys: |
+            plutobook-v0.17.0-${{ runner.os }}-
+
       - name: Build PlutoBook
+        if: steps.plutobook-cache.outputs.cache-hit != 'true'
         run: |
           git clone --depth 1 --branch v0.17.0 https://github.com/plutoprint/plutobook.git tmp/plutobook-ci-src
           meson setup tmp/plutobook-ci-build tmp/plutobook-ci-src \
@@ -64,6 +59,45 @@ jobs:
           meson compile -C tmp/plutobook-ci-build
           meson install -C tmp/plutobook-ci-build
 
+      - uses: actions/upload-artifact@v4
+        with:
+          name: plutobook-ci-install
+          path: tmp/plutobook-ci-install
+          retention-days: 1
+
+  test:
+    needs: build-plutobook
+    runs-on: ubuntu-22.04
+
+    env:
+      PAGE_PRINT_PLUTOBOOK_PREFIX: ${{ github.workspace }}/tmp/plutobook-ci-install
+      PKG_CONFIG_PATH: ${{ github.workspace }}/tmp/plutobook-ci-install/lib/pkgconfig
+      LD_LIBRARY_PATH: ${{ github.workspace }}/tmp/plutobook-ci-install/lib
+
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby:
+          - "3.2"
+          - "3.3"
+          - "3.4"
+          - "4.0"
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install test dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            build-essential \
+            poppler-utils
+
+      - uses: actions/download-artifact@v4
+        with:
+          name: plutobook-ci-install
+          path: tmp/plutobook-ci-install
+
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}