feat: Add pre-commit script file (hook)

The idea is to have a way for users to be able to manipulate their repositories
in different ways right before the git-add-git-commit phase. Might be useful in a
lot of different ways: updating arbitrary files that are not directly related to
the package version, but need to have an information about the next version and
being commited before the said version released; or running some chores right
before the commit: including updating docs, dependencies, running scripts, etc.

.github/workflows/test.yml

@@ -21,6 +21,29 @@ jobs:
         with:
           github-token: ${{ secrets.github_token }}
 
+  test-pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+        with:
+          path: "./"
+
+      - run: test -f pre-commit.test.json && (echo should not be here yet && exit 1) || exit 0
+
+      - name: Generate changelog
+        id: changelog
+        uses: ./
+        env:
+          ENV: 'dont-use-git'
+        with:
+          github-token: ${{ secrets.github_token }}
+          pre-commit: ${{ github.workspace }}/test/pre-commit.js
+          skip-on-empty: 'false'
+
+      - run: test -f pre-commit.test.json || (echo should be here && exit 1)
+      - run: cat pre-commit.test.json
+
   test-git:
     runs-on: ubuntu-latest
     steps:

action.yml

@@ -79,6 +79,10 @@ inputs:
     default: 'false'
     required: false
 
+  pre-commit:
+    description: 'Path to the pre-commit script file'
+    required: false
+
 
 outputs:
   changelog:

src/index.js

@@ -13,6 +13,7 @@ async function run() {
     const gitUserEmail = core.getInput('git-user-email')
     const tagPrefix = core.getInput('tag-prefix')
     const preset = core.getInput('preset')
+    const preCommit = core.getInput('pre-commit')
     const outputFile = core.getInput('output-file')
     const releaseCount = core.getInput('release-count')
     const versionFile = core.getInput('version-file')
@@ -31,6 +32,10 @@ async function run() {
     core.info(`Using "${tagPrefix}" as tag prefix`)
     core.info(`Using "${outputFile}" as output file`)
 
+    if (preCommit) {
+      core.info(`Using "${preCommit}" as pre-commit script`)
+    }
+
     core.info(`Skipping empty releases is "${skipEmptyRelease ? 'enabled' : 'disabled'}"`)
     core.info(`Skipping the update of the version file is "${skipVersionFile ? 'enabled' : 'disabled'}"`)
 
@@ -97,6 +102,13 @@ async function run() {
 
       if (!skipCommit) {
         // Add changed files to git
+        if (preCommit) {
+          await require(preCommit).preCommit({
+            workspace: process.env.GITHUB_WORKSPACE,
+            tag: gitTag,
+            version: versioning.newVersion,
+          })
+        }
         await git.add('.')
         await git.commit(gitCommitMessage.replace('{version}', gitTag))
       }

test/pre-commit.js

@@ -0,0 +1,15 @@
+const fs = require('fs')
+const path = require('path')
+
+exports.preCommit = (props) => {
+  const body = {
+    workspace: props.workspace,
+    tag: props.tag,
+    version: props.version,
+    random: Math.random(),
+  }
+
+  const dest = path.resolve(props.workspace, 'pre-commit.test.json')
+
+  fs.writeFileSync(dest, JSON.stringify(body, null, 2))
+}