Add WebhookTypes and EventForType methods

github/event.go

@@ -27,139 +27,16 @@ func (e Event) String() string {
 
 // ParsePayload parses the event payload. For recognized event types,
 // a value of the corresponding struct type will be returned.
-func (e *Event) ParsePayload() (payload interface{}, err error) {
-	switch *e.Type {
-	case "BranchProtectionRuleEvent":
- payload = &BranchProtectionRuleEvent{}
-	case "CheckRunEvent":
- payload = &CheckRunEvent{}
-	case "CheckSuiteEvent":
- payload = &CheckSuiteEvent{}
-	case "CodeScanningAlertEvent":
- payload = &CodeScanningAlertEvent{}
-	case "CommitCommentEvent":
- payload = &CommitCommentEvent{}
-	case "ContentReferenceEvent":
- payload = &ContentReferenceEvent{}
-	case "CreateEvent":
- payload = &CreateEvent{}
-	case "DeleteEvent":
- payload = &DeleteEvent{}
-	case "DeployKeyEvent":
- payload = &DeployKeyEvent{}
-	case "DeploymentEvent":
- payload = &DeploymentEvent{}
-	case "DeploymentProtectionRuleEvent":
- payload = &DeploymentProtectionRuleEvent{}
-	case "DeploymentStatusEvent":
- payload = &DeploymentStatusEvent{}
-	case "DiscussionEvent":
- payload = &DiscussionEvent{}
-	case "DiscussionCommentEvent":
- payload = &DiscussionCommentEvent{}
-	case "ForkEvent":
- payload = &ForkEvent{}
-	case "GitHubAppAuthorizationEvent":
- payload = &GitHubAppAuthorizationEvent{}
-	case "GollumEvent":
- payload = &GollumEvent{}
-	case "InstallationEvent":
- payload = &InstallationEvent{}
-	case "InstallationRepositoriesEvent":
- payload = &InstallationRepositoriesEvent{}
-	case "InstallationTargetEvent":
- payload = &InstallationTargetEvent{}
-	case "IssueCommentEvent":
- payload = &IssueCommentEvent{}
-	case "IssuesEvent":
- payload = &IssuesEvent{}
-	case "LabelEvent":
- payload = &LabelEvent{}
-	case "MarketplacePurchaseEvent":
- payload = &MarketplacePurchaseEvent{}
-	case "MemberEvent":
- payload = &MemberEvent{}
-	case "MembershipEvent":
- payload = &MembershipEvent{}
-	case "MergeGroupEvent":
- payload = &MergeGroupEvent{}
-	case "MetaEvent":
- payload = &MetaEvent{}
-	case "MilestoneEvent":
- payload = &MilestoneEvent{}
-	case "OrganizationEvent":
- payload = &OrganizationEvent{}
-	case "OrgBlockEvent":
- payload = &OrgBlockEvent{}
-	case "PackageEvent":
- payload = &PackageEvent{}
-	case "PageBuildEvent":
- payload = &PageBuildEvent{}
-	case "PersonalAccessTokenRequestEvent":
- payload = &PersonalAccessTokenRequestEvent{}
-	case "PingEvent":
- payload = &PingEvent{}
-	case "ProjectEvent":
- payload = &ProjectEvent{}
-	case "ProjectCardEvent":
- payload = &ProjectCardEvent{}
-	case "ProjectColumnEvent":
- payload = &ProjectColumnEvent{}
-	case "ProjectV2Event":
- payload = &ProjectV2Event{}
-	case "ProjectV2ItemEvent":
- payload = &ProjectV2ItemEvent{}
-	case "PublicEvent":
- payload = &PublicEvent{}
-	case "PullRequestEvent":
- payload = &PullRequestEvent{}
-	case "PullRequestReviewEvent":
- payload = &PullRequestReviewEvent{}
-	case "PullRequestReviewCommentEvent":
- payload = &PullRequestReviewCommentEvent{}
-	case "PullRequestReviewThreadEvent":
- payload = &PullRequestReviewThreadEvent{}
-	case "PullRequestTargetEvent":
- payload = &PullRequestTargetEvent{}
-	case "PushEvent":
- payload = &PushEvent{}
-	case "ReleaseEvent":
- payload = &ReleaseEvent{}
-	case "RepositoryEvent":
- payload = &RepositoryEvent{}
-	case "RepositoryDispatchEvent":
- payload = &RepositoryDispatchEvent{}
-	case "RepositoryImportEvent":
- payload = &RepositoryImportEvent{}
-	case "RepositoryVulnerabilityAlertEvent":
- payload = &RepositoryVulnerabilityAlertEvent{}
-	case "SecretScanningAlertEvent":
- payload = &SecretScanningAlertEvent{}
-	case "SecurityAdvisoryEvent":
- payload = &SecurityAdvisoryEvent{}
-	case "SecurityAndAnalysisEvent":
- payload = &SecurityAndAnalysisEvent{}
-	case "StarEvent":
- payload = &StarEvent{}
-	case "StatusEvent":
- payload = &StatusEvent{}
-	case "TeamEvent":
- payload = &TeamEvent{}
-	case "TeamAddEvent":
- payload = &TeamAddEvent{}
-	case "UserEvent":
- payload = &UserEvent{}
-	case "WatchEvent":
- payload = &WatchEvent{}
-	case "WorkflowDispatchEvent":
- payload = &WorkflowDispatchEvent{}
-	case "WorkflowJobEvent":
- payload = &WorkflowJobEvent{}
-	case "WorkflowRunEvent":
- payload = &WorkflowRunEvent{}
+func (e *Event) ParsePayload() (interface{}, error) {
+	// It would be nice if e.Type were the snake_case name of the event,
+	// but the existing interface uses the struct name instead.
+	payload := EventForType(typeToMessageMapping[e.GetType()])
+
+	if err := json.Unmarshal(e.GetRawPayload(), &payload); err != nil {
+ return nil, err
 	}
-	err = json.Unmarshal(*e.RawPayload, &payload)
-	return payload, err
+
+	return payload, nil
 }
 
 // Payload returns the parsed event payload. For recognized event types,

github/event_test.go

@@ -30,6 +30,18 @@ func TestPayload_NoPanic(t *testing.T) {
 	e.Payload()
 }
 
+func TestEmptyEvent_NoPanic(t *testing.T) {
+	e := &Event{}
+	if _, err := e.ParsePayload(); err == nil {
+ t.Error("ParsePayload unexpectedly succeeded on empty event")
+	}
+
+	e = nil
+	if _, err := e.ParsePayload(); err == nil {
+ t.Error("ParsePayload unexpectedly succeeded on nil event")
+	}
+}
+
 func TestEvent_Marshal(t *testing.T) {
 	testJSONMarshal(t, &Event{}, "{}")
 

github/messages.go

@@ -22,6 +22,8 @@ import (
 	"mime"
 	"net/http"
 	"net/url"
+	"reflect"
+	"sort"
 	"strings"
 )
 
@@ -43,74 +45,86 @@ const (
 
 var (
 	// eventTypeMapping maps webhooks types to their corresponding go-github struct types.
-	eventTypeMapping = map[string]string{
- "branch_protection_rule": "BranchProtectionRuleEvent",
- "check_run": "CheckRunEvent",
- "check_suite": "CheckSuiteEvent",
- "code_scanning_alert": "CodeScanningAlertEvent",
- "commit_comment": "CommitCommentEvent",
- "content_reference": "ContentReferenceEvent",
- "create": "CreateEvent",
- "delete": "DeleteEvent",
- "deploy_key": "DeployKeyEvent",
- "deployment": "DeploymentEvent",
- "deployment_status": "DeploymentStatusEvent",
- "deployment_protection_rule": "DeploymentProtectionRuleEvent",
- "discussion": "DiscussionEvent",
- "discussion_comment": "DiscussionCommentEvent",
- "fork": "ForkEvent",
- "github_app_authorization": "GitHubAppAuthorizationEvent",
- "gollum": "GollumEvent",
- "installation": "InstallationEvent",
- "installation_repositories": "InstallationRepositoriesEvent",
- "installation_target": "InstallationTargetEvent",
- "issue_comment": "IssueCommentEvent",
- "issues": "IssuesEvent",
- "label": "LabelEvent",
- "marketplace_purchase": "MarketplacePurchaseEvent",
- "member": "MemberEvent",
- "membership": "MembershipEvent",
- "merge_group": "MergeGroupEvent",
- "meta": "MetaEvent",
- "milestone": "MilestoneEvent",
- "organization": "OrganizationEvent",
- "org_block": "OrgBlockEvent",
- "package": "PackageEvent",
- "page_build": "PageBuildEvent",
- "personal_access_token_request": "PersonalAccessTokenRequestEvent",
- "ping": "PingEvent",
- "project": "ProjectEvent",
- "project_card": "ProjectCardEvent",
- "project_column": "ProjectColumnEvent",
- "projects_v2": "ProjectV2Event",
- "projects_v2_item": "ProjectV2ItemEvent",
- "public": "PublicEvent",
- "pull_request": "PullRequestEvent",
- "pull_request_review": "PullRequestReviewEvent",
- "pull_request_review_comment": "PullRequestReviewCommentEvent",
- "pull_request_review_thread": "PullRequestReviewThreadEvent",
- "pull_request_target": "PullRequestTargetEvent",
- "push": "PushEvent",
- "repository": "RepositoryEvent",
- "repository_dispatch": "RepositoryDispatchEvent",
- "repository_import": "RepositoryImportEvent",
- "repository_vulnerability_alert": "RepositoryVulnerabilityAlertEvent",
- "release": "ReleaseEvent",
- "secret_scanning_alert": "SecretScanningAlertEvent",
- "security_advisory": "SecurityAdvisoryEvent",
- "security_and_analysis": "SecurityAndAnalysisEvent",
- "star": "StarEvent",
- "status": "StatusEvent",
- "team": "TeamEvent",
- "team_add": "TeamAddEvent",
- "user": "UserEvent",
- "watch": "WatchEvent",
- "workflow_dispatch": "WorkflowDispatchEvent",
- "workflow_job": "WorkflowJobEvent",
- "workflow_run": "WorkflowRunEvent",
+	eventTypeMapping = map[string]interface{}{
+ "branch_protection_rule": &BranchProtectionRuleEvent{},
+ "check_run": &CheckRunEvent{},
+ "check_suite": &CheckSuiteEvent{},
+ "code_scanning_alert": &CodeScanningAlertEvent{},
+ "commit_comment": &CommitCommentEvent{},
+ "content_reference": &ContentReferenceEvent{},
+ "create": &CreateEvent{},
+ "delete": &DeleteEvent{},
+ "deploy_key": &DeployKeyEvent{},
+ "deployment": &DeploymentEvent{},
+ "deployment_status": &DeploymentStatusEvent{},
+ "deployment_protection_rule": &DeploymentProtectionRuleEvent{},
+ "discussion": &DiscussionEvent{},
+ "discussion_comment": &DiscussionCommentEvent{},
+ "fork": &ForkEvent{},
+ "github_app_authorization": &GitHubAppAuthorizationEvent{},
+ "gollum": &GollumEvent{},
+ "installation": &InstallationEvent{},
+ "installation_repositories": &InstallationRepositoriesEvent{},
+ "installation_target": &InstallationTargetEvent{},
+ "issue_comment": &IssueCommentEvent{},
+ "issues": &IssuesEvent{},
+ "label": &LabelEvent{},
+ "marketplace_purchase": &MarketplacePurchaseEvent{},
+ "member": &MemberEvent{},
+ "membership": &MembershipEvent{},
+ "merge_group": &MergeGroupEvent{},
+ "meta": &MetaEvent{},
+ "milestone": &MilestoneEvent{},
+ "organization": &OrganizationEvent{},
+ "org_block": &OrgBlockEvent{},
+ "package": &PackageEvent{},
+ "page_build": &PageBuildEvent{},
+ "personal_access_token_request": &PersonalAccessTokenRequestEvent{},
+ "ping": &PingEvent{},
+ "project": &ProjectEvent{},
+ "project_card": &ProjectCardEvent{},
+ "project_column": &ProjectColumnEvent{},
+ "projects_v2": &ProjectV2Event{},
+ "projects_v2_item": &ProjectV2ItemEvent{},
+ "public": &PublicEvent{},
+ "pull_request": &PullRequestEvent{},
+ "pull_request_review": &PullRequestReviewEvent{},
+ "pull_request_review_comment": &PullRequestReviewCommentEvent{},
+ "pull_request_review_thread": &PullRequestReviewThreadEvent{},
+ "pull_request_target": &PullRequestTargetEvent{},
+ "push": &PushEvent{},
+ "repository": &RepositoryEvent{},
+ "repository_dispatch": &RepositoryDispatchEvent{},
+ "repository_import": &RepositoryImportEvent{},
+ "repository_vulnerability_alert": &RepositoryVulnerabilityAlertEvent{},
+ "release": &ReleaseEvent{},
+ "secret_scanning_alert": &SecretScanningAlertEvent{},
+ "security_advisory": &SecurityAdvisoryEvent{},
+ "security_and_analysis": &SecurityAndAnalysisEvent{},
+ "star": &StarEvent{},
+ "status": &StatusEvent{},
+ "team": &TeamEvent{},
+ "team_add": &TeamAddEvent{},
+ "user": &UserEvent{},
+ "watch": &WatchEvent{},
+ "workflow_dispatch": &WorkflowDispatchEvent{},
+ "workflow_job": &WorkflowJobEvent{},
+ "workflow_run": &WorkflowRunEvent{},
 	}
+	// forward mapping of event types to the string names of the structs
+	messageToTypeName = make(map[string]string, len(eventTypeMapping))
+	// Inverse map of the above
+	typeToMessageMapping = make(map[string]string, len(eventTypeMapping))
 )
 
+func init() {
+	for k, v := range eventTypeMapping {
+ typename := reflect.TypeOf(v).Elem().Name()
+ messageToTypeName[k] = typename
+ typeToMessageMapping[typename] = k
+	}
+}
+
 // genMAC generates the HMAC signature for a message provided the secret key
 // and hashFunc.
 func genMAC(message, key []byte, hashFunc func() hash.Hash) []byte {
@@ -299,7 +313,7 @@ func DeliveryID(r *http.Request) string {
 // }
 //	}
 func ParseWebHook(messageType string, payload []byte) (interface{}, error) {
-	eventType, ok := eventTypeMapping[messageType]
+	eventType, ok := messageToTypeName[messageType]
 	if !ok {
  return nil, fmt.Errorf("unknown X-Github-Event in message: %v", messageType)
 	}
@@ -310,3 +324,28 @@ func ParseWebHook(messageType string, payload []byte) (interface{}, error) {
 	}
 	return event.ParsePayload()
 }
+
+// WebhookTypes returns a sorted list of all the known GitHub event type strings
+// supported by go-github.
+func MessageTypes() []string {
+	types := make([]string, 0, len(eventTypeMapping))
+	for t := range eventTypeMapping {
+ types = append(types, t)
+	}
+	sort.Strings(types)
+	return types
+}
+
+// EventForType returns an empty struct matching the specified GitHub event type.
+// If messageType does not match any known event types, it returns nil.
+func EventForType(messageType string) interface{} {
+	prototype := eventTypeMapping[messageType]
+	if prototype == nil {
+ return nil
+	}
+	// return a _copy_ of the pointed-to-object. Unfortunately, for this we
+	// need to use reflection. If we store the actual objects in the map,
+	// we still need to use reflection to convert from `any` to the actual
+	// type, so this was deemed the lesser of two evils. (#2865)
+	return reflect.New(reflect.TypeOf(prototype).Elem()).Interface()
+}

github/messages_test.go

@@ -525,6 +525,23 @@ func TestParseWebHook(t *testing.T) {
 	}
 }
 
+func TestAllMessageTypesMapped(t *testing.T) {
+	for _, mt := range MessageTypes() {
+ if obj := EventForType(mt); obj == nil {
+ t.Errorf("messageMap missing message type %q", mt)
+ }
+	}
+}
+
+func TestUnknownMessageType(t *testing.T) {
+	if obj := EventForType("unknown"); obj != nil {
+ t.Errorf("EventForType(unknown) = %#v, want nil", obj)
+	}
+	if obj := EventForType(""); obj != nil {
+ t.Errorf(`EventForType("") = %#v, want nil`, obj)
+	}
+}
+
 func TestParseWebHook_BadMessageType(t *testing.T) {
 	if _, err := ParseWebHook("bogus message type", []byte("{}")); err == nil {
  t.Fatal("ParseWebHook returned nil; wanted error")