feat: use config-conventional as default config

Author: fredicious

src/action.js

@@ -120,11 +120,10 @@ const handleOnlyWarnings = formattedResults => {
 }
 
 const showLintResults = async ([from, to]) => {
-  const failOnWarnings = core.getInput('failOnWarnings')
   const commits = await getHistoryCommits(from, to)
   const config = existsSync(configPath)
     ? await load({}, { file: configPath })
-    : {}
+    : await load({ extends: ['@commitlint/config-conventional'] })
   const opts = getOptsFromConfig(config)
   const lintedCommits = await Promise.all(
     commits.map(async commit => ({

src/action.test.js

@@ -60,6 +60,20 @@ describe('Commit Linter action', () => {
     jest.resetModules()
   })
 
+  it('should use default config when config file does not exist', async () => {
+    td.when(core.getInput('configFile')).thenReturn('./not-existing-config.js')
+    cwd = await git.bootstrap('fixtures/conventional')
+    await gitEmptyCommit(cwd, 'wrong message')
+    const [to] = await getCommitHashes(cwd)
+    await createPushEventPayload(cwd, { to })
+    updatePushEnvVars(cwd, to)
+    td.replace(process, 'cwd', () => cwd)
+
+    await runAction()
+
+    td.verify(core.setFailed(contains('You have commit messages with errors')))
+  })
+
   it('should fail for single push with incorrect message', async () => {
     cwd = await git.bootstrap('fixtures/conventional')
     await gitEmptyCommit(cwd, 'wrong message')