go conversations: add support for conversations.inviteShared

Taken from slack-go#1195.

conversation.go

@@ -690,3 +690,53 @@ func (api *Client) MarkConversationContext(ctx context.Context, channel, ts stri
 	}
 	return response.Err()
 }
+
+type InviteSharedParams struct {
+	// Emails are the emails to be invited to the Slack Connect
+	Emails []string
+	// ExternalLimited determines whether the invitee is an external limited member.
+	// External limited members cannot invite other cannot invite others, export channel history,
+	// change channel visibility, topic, or name, and the channel will be set as private in the guest workspace.
+	// Defaults to true
+	ExternalLimited *bool
+	// UserIDs are the Slack IDs to be invited to the Slack Connect
+	UserIDs []string
+}
+
+var InvalidSharedInviteParamsError = errors.New("one of Emails or UserIDs must be supplied to InviteSharedParams")
+
+// InviteSharedContext sends array(s) of user IDs and/or emails an invitation to a Slack Connect channel with a custom context
+// At least one array of either emails or user IDs must be supplied to invite the recipient
+func (api *Client) InviteSharedContext(ctx context.Context, channelID string, params InviteSharedParams) error {
+	if len(params.UserIDs) < 1 && len(params.Emails) < 1 {
+		return InvalidSharedInviteParamsError
+	}
+
+	values := url.Values{
+		"channel": {channelID},
+	}
+	if params.Emails != nil {
+		values.Add("emails", strings.Join(params.Emails, ","))
+	}
+	// the externalLimited parameter defaults to true; ignore it unless it is explicitly false
+	if params.ExternalLimited != nil && !*params.ExternalLimited {
+		values.Add("external_limited", "false")
+	}
+	if params.UserIDs != nil {
+		values.Add("user_ids", strings.Join(params.Emails, ","))
+	}
+
+	response := &SlackResponse{}
+	err := api.getMethod(ctx, "conversations.inviteShared", api.token, values, &response)
+	if err != nil {
+		return err
+	}
+
+	return response.Err()
+}
+
+// InviteShared sends array(s) of user IDs and/or emails an invitation to a Slack Connect channel
+// At least one array of either emails or user IDs must be supplied to invite the recipient
+func (api *Client) InviteShared(channelID string, params InviteSharedParams) error {
+	return api.InviteSharedContext(context.Background(), channelID, params)
+}

conversation_test.go

@@ -591,3 +591,19 @@ func TestMarkConversation(t *testing.T) {
 		return
 	}
 }
+
+func TestInviteShared(t *testing.T) {
+	http.HandleFunc("/conversations.inviteShared", okJSONHandler)
+	once.Do(startServer)
+	api := New("testing-token", OptionAPIURL("http://"+serverAddr+"/"))
+	params := &InviteSharedParams{}
+	err := api.InviteShared("CXXXXXXXX", *params)
+	assert.EqualError(t, err, InvalidSharedInviteParamsError.Error())
+
+	params.Emails = []string{"fake@email.com", "another@email.com"}
+	err = api.InviteShared("CXXXXXXXX", *params)
+	if err != nil {
+		t.Errorf("Unexpected error: %s", err)
+		return
+	}
+}