handle merge_group event without failing

Author: motatoes

cli/cmd/digger/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log"
 	"net/http"
@@ -302,7 +303,11 @@ func gitHubCI(lock core_locking.Lock, policyChecker core_policy.Checker, backend
 
 		impactedProjects, requestedProject, prNumber, err := dg_github.ProcessGitHubEvent(ghEvent, diggerConfig, &githubPrService)
 		if err != nil {
-			reportErrorAndExit(githubActor, fmt.Sprintf("Failed to process GitHub event. %s", err), 6)
+			if errors.Is(err, &dg_github.EventToIgnoreError{}) {
+				reportErrorAndExit(githubActor, fmt.Sprintf("Graceful handling of GitHub event. %s", err), 0)
+			} else {
+				reportErrorAndExit(githubActor, fmt.Sprintf("Failed to process GitHub event. %s", err), 6)
+			}
 		}
 		impactedProjectsMsg := getImpactedProjectsAsString(impactedProjects, prNumber)
 		log.Println(impactedProjectsMsg)

cli/pkg/github/models/models.go

@@ -81,6 +81,12 @@ func (g *GithubAction) UnmarshalJSON(data []byte) error {
 			return err
 		}
 		g.Event = event
+	case "merge_group":
+		var event github.MergeGroupEvent
+		if err := json.Unmarshal(rawEvent, &event); err != nil {
+			return err
+		}
+		g.Event = event
 	case "schedule":
 		// TODO: Find appropriate event for workflow scheduled run
 		var event github.WorkflowDispatchEvent

libs/orchestrator/github/errors.go

@@ -0,0 +1,11 @@
+package github
+
+import "fmt"
+
+type EventToIgnoreError struct {
+	Message string
+}
+
+func (e *EventToIgnoreError) Error() string {
+	return fmt.Sprintf("Unsupported event: %s", e.Message)
+}

libs/orchestrator/github/github.go

@@ -490,7 +490,8 @@ func ProcessGitHubEvent(ghEvent interface{}, diggerConfig *digger_config.DiggerC
 			}
 		}
 		return nil, nil, 0, fmt.Errorf("requested project not found in modified projects")
-
+	case github.MergeGroupEvent:
+		return nil, nil, 0, &EventToIgnoreError{"ignoring event of type merge_group"}
 	default:
 		return nil, nil, 0, fmt.Errorf("unsupported event type")
 	}