Merge pull request #9 from z0rc/main

Allow `pull_request_target` event to run action

README.md

@@ -16,7 +16,7 @@ commits.message = "Upgrade ${artifactName} from ${currentVersion} to ${nextVersi
 ```
 
 ## Caveats and future work
-At the moment the action only runs in response to [`pull_request` events](https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request). This means that, for the merge to take place, the check suite triggered by the PR being opened must pass and if this isn't the case (for example if a test fails), the merge action won't run, and the PR will need to be merged manually.
+At the moment the action only runs in response to [`pull_request`](https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request) and [`pull_request_target`](https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request_target) events. This means that, for the merge to take place, the check suite triggered by the PR being opened must pass and if this isn't the case (for example if a test fails), the merge action won't run, and the PR will need to be merged manually.
 
 It would be possible to update the action to also run on successful [`check_suite` events](https://docs.github.com/en/actions/reference/events-that-trigger-workflows#check_suite); this would require some changes to access the PR title, which is not included in the event payload for non-`pull_request` events.
 

main.go

@@ -18,6 +18,10 @@ const (
 	mergeMethodVariable   = "INPUT_MERGE_METHOD"
 )
 
+var (
+	allowedEvents = []string{"pull_request", "pull_request_target"}
+)
+
 type pullRequestEvent struct {
 	PullRequest github.PullRequest `json:"pull_request"`
 }
@@ -31,9 +35,19 @@ func getRequiredEnvVar(name string) string {
 	return value
 }
 
+func checkAllowedEvent(event string) bool {
+	for _, i := range allowedEvents {
+		if i == event {
+			return true
+		}
+	}
+	return false
+}
+
 func main() {
-	if eventName := getRequiredEnvVar(eventNameVariable); eventName != "pull_request" {
-		log.Println("event is not `pull_request`, exiting")
+	eventName := getRequiredEnvVar(eventNameVariable)
+	if checkAllowedEvent(eventName) == false {
+		log.Printf("event `%v` is not one of %v, exiting", eventName, allowedEvents)
 		os.Exit(0)
 		return
 	}