feat: derive next version from git history

README.md

@@ -23,6 +23,8 @@ For Kotlin DSL builds, pass the generated outputs into Gradle as project propert
 
 ```yaml
 - uses: actions/checkout@v6
+  with:
+    fetch-depth: 0
 
 - name: Bump version
   id: bump_version
@@ -41,6 +43,36 @@ Use `version_name` for Android's user-facing version, `version_code` for Android
 
 Pin to a version tag instead of `master` if you want fully repeatable workflow runs.
 
+#### Commit range
+
+By default, the action reads commit messages from git history between the previous matching tag and `HEAD`.
+Use `fetch-depth: 0` with `actions/checkout` so the runner has enough history and tags to find that range.
+If no matching previous tag exists, the action reads all reachable commits.
+If the git range cannot be read, the action falls back to the GitHub event payload for compatibility.
+
+| Range        | Behavior                                                                      |
+|--------------|-------------------------------------------------------------------------------|
+| previous-tag | Reads commits from the previous tag matching `commit_tag_pattern` to `HEAD`.  |
+| base-ref     | Reads commits from `commit_base_ref` to `HEAD`.                               |
+| payload      | Reads commit messages from the GitHub event payload, matching older behavior. |
+
+For pull request or protected-branch workflows, set an explicit base ref:
+
+```yaml
+- uses: actions/checkout@v6
+  with:
+    fetch-depth: 0
+
+- name: Bump version
+  id: bump_version
+  uses: oflynned/android-version-bump@master
+  env:
+    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  with:
+    commit_range: base-ref
+    commit_base_ref: origin/main
+```
+
 #### Private repos
 
 To use this action with `${{ secrets.GITHUB_TOKEN }}` in a private repo, set `contents: write` so the token can push the version commit and tag.
@@ -86,7 +118,7 @@ buildNumber=
 ```
 
 | Backend            | File                 | Behavior                                                          |
-| ------------------ | -------------------- | ----------------------------------------------------------------- |
+|--------------------|----------------------|-------------------------------------------------------------------|
 | version-properties | `version.properties` | Compatibility default. The action writes the version keys file.   |
 | gradle-properties  | `gradle.properties`  | The action updates the version keys and preserves unrelated keys. |
 
@@ -275,13 +307,16 @@ Enable this field by passing a build number/string/SHA as an input to the action
 
 Pass these in the `with:` block
 
-| Tag             | Effect                                                                                                                                                                         | Example                                                                            | Default value            |
-|-----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------|--------------------------|
-| version_storage | Selects where version metadata is read from and written to. Supported values are `version-properties` and `gradle-properties`.                                                 | `version_storage: gradle-properties` updates `gradle.properties`                   | `version-properties`     |
-| tag_prefix      | Prefix used in the generated release commit message. The git tag, `git_tag`, and `new_tag` outputs remain the unprefixed version.                                              | `tag_prefix: 'release-'` makes the default commit message `release: release-1.0.0` | `v`                      |
-| skip_ci         | Affixes `[skip-ci]` to the end of the commit message, even if you provide a custom message                                                                                     | `skip_ci: false`                                                                   | true                     |
-| build_number    | Sets the build run number in the version                                                                                                                                       | `build_number: ${{ github.run_number }}` generates `1.0.0.5`                       | ''                       |
-| commit_message  | Sets the commit message when a release bump is performed. Can optionally use `{{ version }}` to insert the generated version bump with the tag prefix into the commit message. | `ci: {{ version }} was just released into the wild! :tada: :partying_face:`        | `release: {{ version }}` |
+| Tag                | Effect                                                                                                                                                                         | Example                                                                            | Default value            |
+|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------|--------------------------|
+| commit_range       | Selects where version bump commit messages come from. Supported values are `previous-tag`, `base-ref`, and `payload`.                                                          | `commit_range: base-ref` reads from `commit_base_ref` to `HEAD`                    | `previous-tag`           |
+| commit_base_ref    | Base ref used when `commit_range` is `base-ref`. If omitted, pull request workflows use `origin/${{ github.base_ref }}` when available.                                        | `commit_base_ref: origin/main`                                                     | ''                       |
+| commit_tag_pattern | Tag glob used when `commit_range` is `previous-tag`.                                                                                                                           | `commit_tag_pattern: 'v*'`                                                         | `*`                      |
+| version_storage    | Selects where version metadata is read from and written to. Supported values are `version-properties` and `gradle-properties`.                                                 | `version_storage: gradle-properties` updates `gradle.properties`                   | `version-properties`     |
+| tag_prefix         | Prefix used in the generated release commit message. The git tag, `git_tag`, and `new_tag` outputs remain the unprefixed version.                                              | `tag_prefix: 'release-'` makes the default commit message `release: release-1.0.0` | `v`                      |
+| skip_ci            | Affixes `[skip-ci]` to the end of the commit message, even if you provide a custom message                                                                                     | `skip_ci: false`                                                                   | true                     |
+| build_number       | Sets the build run number in the version                                                                                                                                       | `build_number: ${{ github.run_number }}` generates `1.0.0.5`                       | ''                       |
+| commit_message     | Sets the commit message when a release bump is performed. Can optionally use `{{ version }}` to insert the generated version bump with the tag prefix into the commit message. | `ci: {{ version }} was just released into the wild! :tada: :partying_face:`        | `release: {{ version }}` |
 
 ## Outputs
 

action.yml

@@ -8,6 +8,17 @@ branding:
   icon: chevron-up
   color: blue
 inputs:
+  commit_range:
+    required: false
+    description: 'Commit range source for version bumping: previous-tag, base-ref, or payload'
+    default: 'previous-tag'
+  commit_base_ref:
+    required: false
+    description: 'Base ref used when commit_range is base-ref, such as origin/main'
+  commit_tag_pattern:
+    required: false
+    description: 'Git tag pattern used when commit_range is previous-tag'
+    default: '*'
   version_storage:
     required: false
     description: 'Version metadata storage backend: version-properties or gradle-properties'

e2e/action.e2e.test.ts

@@ -135,6 +135,8 @@ describe('packaged action with local git repositories', () => {
       commits: ['feat: add login'],
       headRef: 'feature/login',
       inputs: {
+        commit_range: 'base-ref',
+        commit_base_ref: 'origin/main',
         tag_prefix: 'release-',
         skip_ci: 'false',
         build_number: '42',
@@ -168,6 +170,44 @@ describe('packaged action with local git repositories', () => {
     );
   });
 
+  it('uses squash-style git history instead of payload commit details', () => {
+    const fixture = run({
+      version: '1.2.3',
+      commits: ['feat: squash login branch (#42)'],
+      eventCommits: [
+        { id: 'fixture-1', message: 'fix: payload detail one' },
+        { id: 'fixture-2', message: 'fix: payload detail two' },
+      ],
+    });
+
+    expect(fixture.result.status).toBe(0);
+    expect(gitInRemote(fixture, 'show', 'main:version.properties')).toContain(
+      'minorVersion=3',
+    );
+  });
+
+  it('uses the previous matching tag to HEAD range', () => {
+    const fixture = run({
+      version: '1.2.3',
+      previousTag: '1.2.3',
+      preTagCommits: ['feat: already released login'],
+      commits: ['fix: repair launch'],
+    });
+
+    expect(fixture.result.status).toBe(0);
+    expect(gitInRemote(fixture, 'show', 'main:version.properties')).toBe(
+      [
+        'majorVersion=1',
+        'minorVersion=2',
+        'patchVersion=4',
+        'buildNumber=',
+      ].join('\n'),
+    );
+    expect(gitInRemote(fixture, 'rev-parse', 'refs/tags/1.2.4')).toBe(
+      gitInRemote(fixture, 'rev-parse', 'refs/heads/main'),
+    );
+  });
+
   it('reports a rejected push and leaves the remote unchanged', () => {
     const fixture = run({
       version: '1.2.3',
@@ -192,10 +232,13 @@ describe('packaged action with local git repositories', () => {
     );
   });
 
-  it('reads commit messages from real GitHub push payload objects (#122)', () => {
+  it('can use commit messages from real GitHub push payload objects (#122)', () => {
     const fixture = run({
       version: '1.2.3',
-      commits: ['feat: add login'],
+      commits: ['fix: repair launch'],
+      inputs: {
+        commit_range: 'payload',
+      },
       eventCommits: [{ id: 'fixture', message: 'feat: add login' }],
     });
 

e2e/harness.ts

@@ -15,6 +15,8 @@ type VersionStorage = 'version-properties' | 'gradle-properties';
 type FixtureOptions = {
   version?: string;
   versionStorage?: VersionStorage;
+  previousTag?: string;
+  preTagCommits?: string[];
   commits?: string[];
   eventCommits?: EventCommit[];
   inputs?: Record<string, string>;
@@ -108,8 +110,25 @@ export const runActionFixture = (
   }
   git(workspace, ['add', '.']);
   git(workspace, ['commit', '-m', 'chore: initial fixture']);
+
+  for (const [index, message] of (options.preTagCommits ?? []).entries()) {
+    fs.appendFileSync(
+      path.join(workspace, 'README.md'),
+      `pre-tag-${index}:${message}\n`,
+    );
+    git(workspace, ['add', 'README.md']);
+    git(workspace, ['commit', '-m', message]);
+  }
+
+  if (options.previousTag) {
+    git(workspace, ['tag', options.previousTag]);
+  }
+
   git(workspace, ['remote', 'add', 'origin', remote]);
   git(workspace, ['push', '-u', 'origin', 'main']);
+  if (options.previousTag) {
+    git(workspace, ['push', 'origin', options.previousTag]);
+  }
 
   if (branch !== 'main') {
     git(workspace, ['checkout', '-b', branch]);

src/commits.ts

@@ -0,0 +1,126 @@
+import {
+  CommitRange,
+  getCommitBaseRef,
+  getCommitRange,
+  getCommitTagPattern,
+} from './env';
+import { runCommandOutput } from './run';
+import { Toolkit } from './toolkit';
+import { Commit } from './version';
+
+const commitSeparator = '\0';
+
+const parseGitLog = (output: string): string[] => {
+  return output
+    .split(commitSeparator)
+    .map((message) => message.trim())
+    .filter((message) => message.length > 0);
+};
+
+const getPayloadCommits = (toolkit: Toolkit): Commit[] => {
+  return toolkit.context.payload.commits ?? [];
+};
+
+const getDefaultBaseRef = (): string => {
+  const baseRef = process.env.GITHUB_BASE_REF;
+
+  if (baseRef) {
+    return `origin/${baseRef}`;
+  }
+
+  return '';
+};
+
+const resolveGitRange = async (
+  toolkit: Toolkit,
+  commitRange: Exclude<CommitRange, 'payload'>,
+): Promise<string> => {
+  if (commitRange === 'base-ref') {
+    const baseRef = getCommitBaseRef(toolkit) || getDefaultBaseRef();
+
+    if (!baseRef) {
+      throw new Error(
+        'commit_range base-ref requires commit_base_ref or GITHUB_BASE_REF',
+      );
+    }
+
+    return `${baseRef}..HEAD`;
+  }
+
+  const tagPattern = getCommitTagPattern(toolkit);
+  const previousTag = (
+    await runCommandOutput('git', [
+      'describe',
+      '--tags',
+      '--abbrev=0',
+      '--match',
+      tagPattern,
+    ])
+  ).trim();
+
+  return `${previousTag}..HEAD`;
+};
+
+const getGitCommits = async (
+  toolkit: Toolkit,
+  commitRange: Exclude<CommitRange, 'payload'>,
+): Promise<string[]> => {
+  let range: string | undefined;
+
+  try {
+    range = await resolveGitRange(toolkit, commitRange);
+  } catch (error) {
+    if (commitRange === 'previous-tag') {
+      toolkit.log.warn(
+        `No previous tag matched ${getCommitTagPattern(
+          toolkit,
+        )}; reading all reachable commits`,
+      );
+    } else {
+      throw error;
+    }
+  }
+
+  const args = ['log', '--format=%B%x00'];
+
+  if (range) {
+    args.push(range);
+  }
+
+  return parseGitLog(await runCommandOutput('git', args));
+};
+
+export const getCommitsForVersionBump = async (
+  toolkit: Toolkit,
+): Promise<Commit[]> => {
+  const commitRange = getCommitRange(toolkit);
+
+  if (commitRange === 'payload') {
+    toolkit.log.log('Reading version bump commits from GitHub event payload');
+
+    return getPayloadCommits(toolkit);
+  }
+
+  try {
+    const commits = await getGitCommits(toolkit, commitRange);
+
+    if (commits.length > 0) {
+      toolkit.log.log(
+        `Reading version bump commits from git ${commitRange} range`,
+      );
+
+      return commits;
+    }
+
+    toolkit.log.warn(
+      `Git ${commitRange} range did not contain commits; falling back to GitHub event payload`,
+    );
+  } catch (error) {
+    toolkit.log.warn(
+      `Could not read git ${commitRange} range; falling back to GitHub event payload`,
+    );
+    toolkit.log.warn(error);
+  }
+
+  return getPayloadCommits(toolkit);
+};