Add options to specify header level and version prefix

Author: RaumZeit

README.md

@@ -17,10 +17,12 @@ This GitHub Action extracts release notes from a [Keep a Changelog](https://keep
 
 ### Inputs
 
-| Input                             | Description                                                   |
-|-----------------------------------|---------------------------------------------------------------|
-| `changelog_file` _(optional)_     | The input path of the changelog file. Default: `CHANGELOG.md` |
-| `release_notes_file` _(optional)_ | The output path of the (optional) release notes file.         |
+| Input                             | Description                                                                                           |
+| --------------------------------- | ----------------------------------------------------------------------------------------------------- |
+| `changelog_file` _(optional)_     | The input path of the changelog file. Default: `CHANGELOG.md`                                         |
+| `release_notes_file` _(optional)_ | The output path of the (optional) release notes file.                                                 |
+| `version_prefix` _(optional)_     | A prefix before the version number in the changelog header tag, e.g. `version` as in [version x.y.z]. |
+| `header_level` _(optional)_       | The header level where the version description is expected. Default: `2`                              |
 
 ### Outputs
 
@@ -76,6 +78,38 @@ jobs:
           changelog_file: MY_CHANGELOG.md
 ```
 
+### Change expected version header level to H3
+
+```yaml
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Extract release notes
+        id: extract-release-notes
+        uses: ffurrer2/extract-release-notes@v1
+        with:
+          header_level: 3
+```
+
+### Accept CHANGELOG.md files with [Version x.y.z] titles
+
+```yaml
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Extract release notes
+        id: extract-release-notes
+        uses: ffurrer2/extract-release-notes@v1
+        with:
+          version_prefix: Version
+```
+
 ### Create a release notes file
 
 ```yaml

action.yml

@@ -17,6 +17,14 @@ inputs:
     description: '`true` to get release notes from the `[Unreleased]` section. `false` to get release notes for the latest release. Default: `false`'
     required: false
     default: 'false'
+  version_prefix:
+    description: 'A prefix before the version number in the changelog.md header tag, e.g. `version` as in [version x.y.z]. Default: ``'
+    required: false
+    default: ''
+  header_level:
+    description:  'The header level where the version description is expected. Default: `2`'
+    required: false
+    default:  2
 outputs:
   release_notes:
     description: 'The escaped release notes.'

src/index.js

@@ -20,26 +20,41 @@ async function main() {
     const prerelease = core.getInput('prerelease')
     core.debug(`prerelease = '${prerelease}'`)
 
-    const releaseNotes = await extractReleaseNotes(changelogFile, prerelease)
+    const versionPrefix = core.getInput('version_prefix')
+    core.debug(`version-prefix = '${versionPrefix}'`)
+
+    const headerLevel = parseInt(core.getInput('header_level'))
+    core.debug(`header_level = '${headerLevel}'`)
+
+    const releaseNotes = await extractReleaseNotes(changelogFile, prerelease, versionPrefix, headerLevel)
     core.debug(`release-notes = '${releaseNotes}'`)
 
     writeReleaseNotesFile(releaseNotesFile, releaseNotes)
 
     core.setOutput("release_notes", releaseNotes)
 }
 
-async function extractReleaseNotes(changelogFile, prerelease) {
+async function extractReleaseNotes(changelogFile, prerelease, versionPrefix, headerLevel) {
     const fileStream = fs.createReadStream(changelogFile, {encoding: encoding})
     const rl = readline.createInterface({
         input: fileStream
     })
     const lines = []
     let inside_release = false
+    const header_level = (Number.isInteger(headerLevel) && (headerLevel > 0) && (headerLevel < 7)) ? headerLevel : 2
+    const level_match_regex = "^#{" + header_level + "}\\s+"
+    const levelup_match_regex = (header_level > 1) ? "^#{1," + (header_level - 1) + "}\\s+" : level_match_regex
+    const version_match_regex = "\\[" + versionPrefix + "\\s*[0-9]"
+    const unreleases_match_regex = "\\[Unreleased\\]"
+    core.debug(`version_match_regex: '${version_match_regex}'`)
+    core.debug(`unrelease_match_regex: '${unreleases_match_regex}'`)
     for await (const line of rl) {
-        const start_of_release = (!!line.match("^#+ \\[[0-9]") || (prerelease === 'true' && !!line.match("^#+ \\[Unreleased\\]")))
+        let header_match = (!!line.match(level_match_regex))
+        let headerup_match = (!!line.match(levelup_match_regex))
+        let start_of_release = (!!line.match(level_match_regex + version_match_regex) || (prerelease === 'true' && !!line.match(level_match_regex + unreleases_match_regex)))
         if (inside_release) {
-            if (start_of_release) {
-                core.debug(`next version found: '${line}'`)
+            if (header_match || headerup_match) {
+                core.debug(`end of version block: '${line}'`)
                 break
             } else {
                 lines.push(line)