v2.4.0 - support local execution with act + allow tags (#40)

* Avoid code repetition with exec() and output listeners

* Improve behavior for new branches and when it's running in ACT

* Detect parent commit only if needed

* Fix parent commit detection for initial commit

* Improve logging

* Improve current ref detection

* Fix issue when base is a already fetched tag

* Fix issue when base is a already fetched tag

* Update README

* Document usage with act

* Use `git log` to get changes in latest commit

* Disable other output for `git log`

* get short name from base ref + improve loggig

* update CHANGELOG

src/exec.ts

@@ -0,0 +1,21 @@
+import {exec as execImpl, ExecOptions} from '@actions/exec'
+
+// Wraps original exec() function
+// Returns exit code and whole stdout/stderr
+export default async function exec(commandLine: string, args?: string[], options?: ExecOptions): Promise<ExecResult> {
+  options = options || {}
+  let stdout = ''
+  let stderr = ''
+  options.listeners = {
+    stdout: (data: Buffer) => (stdout += data.toString()),
+    stderr: (data: Buffer) => (stderr += data.toString())
+  }
+  const code = await execImpl(commandLine, args, options)
+  return {code, stdout, stderr}
+}
+
+export interface ExecResult {
+  code: number
+  stdout: string
+  stderr: string
+}