feat: Add caching for Jython binaries (#19)

* feat: Add Jython cache
* feat: Add `cache-hit` output
* ci(lint): Add PR title linting

Author: LukeSavefrogs

.github/workflows/lint-pr.yml

@@ -0,0 +1,45 @@
+name: "Lint Pull Requests"
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - synchronize
+
+permissions:
+  pull-requests: write
+
+jobs:
+  main:
+    name: Validate PR title
+    runs-on: ubuntu-latest
+    steps:
+      - uses: amannn/action-semantic-pull-request@v5
+        id: lint_pr_title
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: marocchino/sticky-pull-request-comment@v2
+        # When the previous steps fails, the workflow would stop. By adding this
+        # condition you can continue the execution with the populated error message.
+        if: always() && (steps.lint_pr_title.outputs.error_message != null)
+        with:
+          header: pr-title-lint-error
+          message: |
+            Hey there and thank you for opening this pull request! 👋🏼
+            
+            We require pull request titles to follow the [Conventional Commits specification](https://www.conventionalcommits.org/en/v1.0.0/) and it looks like your proposed title needs to be adjusted.
+
+            Details:
+            
+            ```
+            ${{ steps.lint_pr_title.outputs.error_message }}
+            ```
+
+      # Delete a previous comment when the issue has been resolved
+      - if: ${{ steps.lint_pr_title.outputs.error_message == null }}
+        uses: marocchino/sticky-pull-request-comment@v2
+        with:   
+          header: pr-title-lint-error
+          delete: true

CHANGELOG.md

@@ -9,6 +9,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Add installer and jython binaries caching
+- Add `cache-hit` output value, which is set to `true` if the Jython data/binaries are retrieved from cache.
+
+## [v5] - 2024-05-16
+
+### Added
+
 - Now it is possible to use Jython 2.0 and 2.1 on `ubuntu` and `macos` runners!
 - Added support for Powershell on all runners (previously only on `windows` runners)
 - Added support for Windows Command Prompt (`cmd`) on windows runners. Notice that because of how the `cmd` handles single quotes it only works if no single quotes are used to enclose parameters: `jython.bat -c "print 'Hello world'"` will work, while `jython.bat -c 'print "Hello world"'` will not.

README.md

@@ -68,6 +68,16 @@ Specify the path where Jython will be installed. Please note that this is usuall
     </tbody>
 </table>
 
+## Outputs
+
+### `download-url`
+
+The URL from which the Jython installer was downloaded.
+
+### `cache-hit`
+
+Boolean value that indicates whether a cache hit occurred on the primary key.
+
 ## Supported versions
 
 This action supports all versions (_both stable and development releases_) currently listed on the official repositories:

action.yml

@@ -20,6 +20,9 @@ outputs:
   download-url:
     description: "The URL from which the installer is downloaded"
     value: ${{ steps.find_installer.outputs.url }}
+  cache-hit:
+    description: "Whether the Jython binaries were restored from the cache"
+    value: ${{ steps.cache-jython.outputs.cache-hit }}
 
 runs:
   using: "composite"
@@ -29,9 +32,34 @@ runs:
         echo "Action running on ${{ runner.os }} ${{ runner.arch }} (name: '${{ runner.name }}')"
       shell: bash
 
+    # See https://github.com/actions/toolkit/issues/1035        
+    - uses: actions/github-script@v7
+      id: resources-hash
+      with:
+        script: return require('fs').createReadStream(require('path').join(process.env.GITHUB_ACTION_PATH, 'bin', 'resources.json')).pipe(require('crypto').createHash('sha1').setEncoding('hex'), 'finish').digest('hex')
+        result-encoding: string
+
+    - name: Cache Jython binaries
+      id: cache-jython
+      uses: actions/cache@v4
+      with:
+        key: ${{ runner.os }}-${{ runner.arch }}-${{ inputs.jython-version }}-${{ steps.resources-hash.outputs.result }}
+        restore-keys: |
+          ${{ runner.os }}-${{ runner.arch }}-${{ inputs.jython-version }}-
+        path: |
+          ${{ inputs.installation-path }}
+          ~/.local/bin/
+
+    - name: Set up JDK 8
+      uses: actions/setup-java@v4
+      with:
+        java-version: '8'
+        distribution: 'zulu'
+
     # Sadly, macos-latest images use Python 2.7 (dunno why)
     - name: Find Jython installer from resource list
       id: find_installer
+      if: ${{ steps.cache-jython.outputs.cache-hit != 'true' }}
       shell: python
       run: |
         import sys, os
@@ -75,14 +103,9 @@ runs:
           ]
           f.write('\n'.join(lines))
 
-    - name: Set up JDK 8
-      uses: actions/setup-java@v4
-      with:
-        java-version: '8'
-        distribution: 'zulu'
-
     - name: Download Jython Installer
       id: download_installer
+      if: ${{ steps.cache-jython.outputs.cache-hit != 'true' }}
       shell: bash
       run: |
         download_url="${{ steps.find_installer.outputs.url }}";
@@ -96,6 +119,7 @@ runs:
     
     - name: Install Jython
       id: installation
+      if: ${{ steps.cache-jython.outputs.cache-hit != 'true' }}
       shell: bash
       run: |
             case "${{ steps.find_installer.outputs.file_type }}" in
@@ -138,6 +162,7 @@ runs:
             # rm -f ${{ steps.download_installer.outputs.temporary_file }}
             
     - name: Setup Jython alias
+      if: ${{ steps.cache-jython.outputs.cache-hit != 'true' }}
       shell: bash
       run: |
         installation_path="$(sed -r 's/^\s+//; s/\s+$//; s/\/+$//;' <<< "${{ inputs.installation-path }}")"
@@ -166,6 +191,7 @@ runs:
         chmod +x ~/.local/bin/jython;
 
     - name: Setup Jython alias (pwsh)
+      if: ${{ steps.cache-jython.outputs.cache-hit != 'true' }}
       shell: pwsh
       run: |
         $installation_path = Convert-Path "${{ inputs.installation-path }}"