feat: adds commitDepth as new input param

Author: Sakethtadimeti

README.md

@@ -58,6 +58,12 @@ Link to a page explaining your commit message convention.
 
 default: `https://github.com/conventional-changelog/commitlint/#what-is-commitlint`
 
+### `commitDepth`
+
+When set to a valid Integer value - X, considers only the latest X number of commits.
+
+default: `null` (Equivalent to linting all commits)
+
 ### `token`
 
 Personal access token (PAT) used to interact with the GitHub API.
@@ -144,6 +150,10 @@ jobs:
       # Run the commitlint action, considering its own dependencies and yours as well 🚀
       # `github.workspace` is the path to your repository.
       - uses: wagoid/commitlint-github-action@v5
+        # Optinally, add a commitDepth parameter
+        # This example would only consider the last 10 commits.
+        with:
+          commitDepth: 10
         env:
           NODE_PATH: ${{ github.workspace }}/node_modules
 ```

src/action.js

@@ -16,6 +16,13 @@ const { GITHUB_EVENT_NAME, GITHUB_SHA } = process.env
 
 const configPath = resolve(process.env.GITHUB_WORKSPACE, getInput('configFile'))
 
+const getCommitDepth = () => {
+  const commitDepthString = getInput('commitDepth')
+  if (!commitDepthString?.trim()) return null
+  const commitDepth = parseInt(commitDepthString, 10)
+  return Number.isNaN(commitDepth) ? null : Math.max(commitDepth, 0)
+}
+
 const pushEventHasOnlyOneCommit = (from) => {
   const gitEmptySha = '0000000000000000000000000000000000000000'
 
@@ -118,7 +125,11 @@ const handleOnlyWarnings = (formattedResults) => {
 }
 
 const showLintResults = async ([from, to]) => {
-  const commits = await getHistoryCommits(from, to)
+  let commits = await getHistoryCommits(from, to)
+  const commitDepth = getCommitDepth()
+  if (commitDepth) {
+    commits = commits?.slice(0, commitDepth)
+  }
   const config = existsSync(configPath)
     ? await load({}, { file: configPath })
     : await load({ extends: ['@commitlint/config-conventional'] })
@@ -130,7 +141,6 @@ const showLintResults = async ([from, to]) => {
     })),
   )
   const formattedResults = formatErrors(lintedCommits, { config })
-
   generateOutputs(lintedCommits)
 
   if (hasOnlyWarnings(lintedCommits)) {

src/action.test.js

@@ -605,4 +605,41 @@ describe('Commit Linter action', () => {
       td.verify(core.setFailed(contains(' https://example.org')))
     })
   })
+
+  describe('when commitDepth is provided in the config', () => {
+    beforeEach(async () => {
+      cwd = await git.bootstrap('fixtures/conventional')
+      await gitEmptyCommit(cwd, 'message from before push')
+      await gitEmptyCommit(cwd, 'incorrect message within commit depth')
+      await gitEmptyCommit(cwd, 'chore: correct message 2')
+      const [before, , to] = await getCommitHashes(cwd)
+      await createPushEventPayload(cwd, { before, to })
+      updatePushEnvVars(cwd, to)
+      td.replace(process, 'cwd', () => cwd)
+      td.replace(console, 'log')
+    })
+    it('should pass when only considering messages defined by commitDepth', async () => {
+      td.when(core.getInput('commitDepth')).thenReturn('1')
+      await runAction()
+
+      td.verify(core.setFailed(), { times: 0, ignoreExtraArgs: true })
+      td.verify(console.log('Lint free! 🎉'))
+    })
+    it('should fail when older commits have lint errors', async () => {
+      td.when(core.getInput('commitDepth')).thenReturn('2')
+      await runAction()
+
+      td.verify(
+        core.setFailed(contains('incorrect message within commit depth')),
+      )
+    })
+    it('should consider all commits when an invalid commit depth is passed in config', async () => {
+      td.when(core.getInput('commitDepth')).thenReturn('xzy')
+      await runAction()
+
+      td.verify(
+        core.setFailed(contains('incorrect message within commit depth')),
+      )
+    })
+  })
 })