imapclient: return greeting text on WaitGreeting

imap.go

@@ -68,6 +68,7 @@ const (
 	MailboxAttrSent      MailboxAttr = "\\Sent"
 	MailboxAttrTrash     MailboxAttr = "\\Trash"
 	MailboxAttrImportant MailboxAttr = "\\Important" // RFC 8457
+	MailboxAttrTemplates MailboxAttr = "\\Templates"
 )
 
 // Flag is a message flag.

imapclient/client.go

@@ -138,7 +138,7 @@ type Client struct {
 	dec      *imapwire.Decoder
 	encMutex sync.Mutex
 
-	greetingCh   chan struct{}
+	greetingCh   chan string
 	greetingRecv bool
 	greetingErr  error
 
@@ -177,7 +177,7 @@ func New(conn net.Conn, options *Options) *Client {
 		br:         br,
 		bw:         bw,
 		dec:        imapwire.NewDecoder(br, imapwire.ConnSideClient),
-		greetingCh: make(chan struct{}),
+		greetingCh: make(chan string, 1),
 		decCh:      make(chan struct{}),
 		state:      imap.ConnStateNone,
 		enabled:    make(imap.CapSet),
@@ -295,7 +295,7 @@ func (c *Client) setState(state imap.ConnState) {
 // and block until it's received. If the capabilities cannot be fetched, nil is
 // returned.
 func (c *Client) Caps() imap.CapSet {
-	if err := c.WaitGreeting(); err != nil {
+	if _, err := c.WaitGreeting(); err != nil {
 		return nil
 	}
 
@@ -905,6 +905,7 @@ func (c *Client) readResponseData(typ string) error {
 			if c.greetingErr == nil && code != "CAPABILITY" {
 				c.setCaps(nil) // request initial capabilities
 			}
+			c.greetingCh <- text
 			close(c.greetingCh)
 		}
 	case "CAPABILITY":
@@ -982,16 +983,16 @@ func (c *Client) readResponseData(typ string) error {
 	return nil
 }
 
-// WaitGreeting waits for the server's initial greeting.
-func (c *Client) WaitGreeting() error {
+// WaitGreeting waits for the server's initial greeting and its text.
+func (c *Client) WaitGreeting() (string, error) {
 	select {
-	case <-c.greetingCh:
-		return c.greetingErr
+	case greetingText := <-c.greetingCh:
+		return greetingText, c.greetingErr
 	case <-c.decCh:
 		if c.decErr != nil {
-			return fmt.Errorf("got error before greeting: %v", c.decErr)
+			return "", fmt.Errorf("got error before greeting: %v", c.decErr)
 		}
-		return fmt.Errorf("connection closed before greeting")
+		return "", fmt.Errorf("connection closed before greeting")
 	}
 }
 

imapclient/client_test.go

@@ -204,6 +204,22 @@ func (sw *swapWriter) Swap(w io.Writer) {
 	sw.mutex.Unlock()
 }
 
+func TestWaitGreeting(t *testing.T) {
+	client, server := newClientServerPair(t, imap.ConnStateAuthenticated)
+	defer client.Close()
+	defer server.Close()
+
+	greetingText, err := client.WaitGreeting()
+	if err != nil {
+		t.Errorf("WaitGreeting() = %v", err)
+	}
+
+	// imapmemserver or dovecot PREAUTH greetings
+	if greetingText != "IMAP server ready" && greetingText != "Logged in as test-user" {
+		t.Errorf("Unexpected greeting text = %s", greetingText)
+	}
+}
+
 func TestLogin(t *testing.T) {
 	client, server := newClientServerPair(t, imap.ConnStateNotAuthenticated)
 	defer client.Close()
@@ -271,7 +287,7 @@ func TestWaitGreeting_eof(t *testing.T) {
 		t.Fatalf("serverConn.Close() = %v", err)
 	}
 
-	if err := client.WaitGreeting(); err == nil {
+	if _, err := client.WaitGreeting(); err == nil {
 		t.Fatalf("WaitGreeting() should fail")
 	}
 }

internal/internal.go

@@ -136,6 +136,7 @@ func canonInit() {
 		imap.MailboxAttrSent,
 		imap.MailboxAttrTrash,
 		imap.MailboxAttrImportant,
+		imap.MailboxAttrTemplates,
 	}
 
 	canonFlag = make(map[string]imap.Flag)