Add Get Webhook Message endpoint

Closes #452

Author: sebm253

rest/rest_endpoints.go

@@ -259,6 +259,7 @@ var (
 	UpdateWebhookWithToken = NewNoBotAuthEndpoint(http.MethodPatch, "/webhooks/{webhook.id}/{webhook.token}")
 	DeleteWebhookWithToken = NewNoBotAuthEndpoint(http.MethodDelete, "/webhooks/{webhook.id}/{webhook.token}")
 
+	GetWebhookMessage          = NewNoBotAuthEndpoint(http.MethodGet, "/webhooks/{webhook.id}/{webhook.token}/messages/{message.id}")
 	CreateWebhookMessage       = NewNoBotAuthEndpoint(http.MethodPost, "/webhooks/{webhook.id}/{webhook.token}")
 	CreateWebhookMessageSlack  = NewNoBotAuthEndpoint(http.MethodPost, "/webhooks/{webhook.id}/{webhook.token}/slack")
 	CreateWebhookMessageGitHub = NewNoBotAuthEndpoint(http.MethodPost, "/webhooks/{webhook.id}/{webhook.token}/github")

rest/webhooks.go

@@ -21,6 +21,7 @@ type Webhooks interface {
 	UpdateWebhookWithToken(webhookID snowflake.ID, webhookToken string, webhookUpdate discord.WebhookUpdateWithToken, opts ...RequestOpt) (discord.Webhook, error)
 	DeleteWebhookWithToken(webhookID snowflake.ID, webhookToken string, opts ...RequestOpt) error
 
+	GetWebhookMessage(webhookID snowflake.ID, webhookToken string, messageID snowflake.ID, opts ...RequestOpt) (*discord.Message, error)
 	CreateWebhookMessage(webhookID snowflake.ID, webhookToken string, messageCreate discord.WebhookMessageCreate, params CreateWebhookMessageParams, opts ...RequestOpt) (*discord.Message, error)
 	CreateWebhookMessageSlack(webhookID snowflake.ID, webhookToken string, messageCreate discord.Payload, params CreateWebhookMessageParams, opts ...RequestOpt) (*discord.Message, error)
 	CreateWebhookMessageGitHub(webhookID snowflake.ID, webhookToken string, messageCreate discord.Payload, params CreateWebhookMessageParams, opts ...RequestOpt) (*discord.Message, error)
@@ -112,6 +113,11 @@ func (s *webhookImpl) DeleteWebhookWithToken(webhookID snowflake.ID, webhookToke
 	return s.client.Do(DeleteWebhookWithToken.Compile(nil, webhookID, webhookToken), nil, nil, opts...)
 }
 
+func (s *webhookImpl) GetWebhookMessage(webhookID snowflake.ID, webhookToken string, messageID snowflake.ID, opts ...RequestOpt) (message *discord.Message, err error) {
+	err = s.client.Do(GetWebhookMessage.Compile(nil, webhookID, webhookToken, messageID), nil, &message, opts...)
+	return
+}
+
 func (s *webhookImpl) createWebhookMessage(webhookID snowflake.ID, webhookToken string, messageCreate discord.Payload, params CreateWebhookMessageParams, endpoint *Endpoint, opts []RequestOpt) (message *discord.Message, err error) {
 	compiledEndpoint := endpoint.Compile(params.ToQueryValues(), webhookID, webhookToken)
 

webhook/webhook_client.go

@@ -32,6 +32,9 @@ type Client interface {
 	// DeleteWebhook deletes the current Webhook
 	DeleteWebhook(opts ...rest.RequestOpt) error
 
+	// GetMessage fetches a webhook Message by its id
+	GetMessage(messageID snowflake.ID, opts ...rest.RequestOpt) (*discord.Message, error)
+
 	// CreateMessage creates a new Message from the discord.WebhookMessageCreate
 	CreateMessage(messageCreate discord.WebhookMessageCreate, opts ...rest.RequestOpt) (*discord.Message, error)
 	// CreateMessageInThread creates a new Message from the discord.WebhookMessageCreate in the provided thread

webhook/webhook_client_impl.go

@@ -92,6 +92,10 @@ func (c *clientImpl) DeleteWebhook(opts ...rest.RequestOpt) error {
 	return c.Rest().DeleteWebhookWithToken(c.id, c.token, opts...)
 }
 
+func (c *clientImpl) GetMessage(messageID snowflake.ID, opts ...rest.RequestOpt) (*discord.Message, error) {
+	return c.Rest().GetWebhookMessage(c.id, c.token, messageID, opts...)
+}
+
 func (c *clientImpl) CreateMessageInThread(messageCreate discord.WebhookMessageCreate, threadID snowflake.ID, opts ...rest.RequestOpt) (*discord.Message, error) {
 	return c.Rest().CreateWebhookMessage(c.id, c.token, messageCreate, rest.CreateWebhookMessageParams{Wait: true, ThreadID: threadID}, opts...)
 }