Add tests for Msg.GetRecipients method

Implemented comprehensive tests for the Msg.GetRecipients method, covering various scenarios such as recipients in "to", "cc", "bcc" fields and combinations of these. Ensured correct handling of each case and validation against expected recipient counts and specific addresses.

msg_test.go

@@ -2193,6 +2193,197 @@ func TestMsg_GetSender(t *testing.T) {
 	})
 }
 
+func TestMsg_GetRecipients(t *testing.T) {
+	t.Run("GetRecipients with only to", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err := message.To("toni.tester@example.com"); err != nil {
+			t.Fatalf("failed to set to address: %s", err)
+		}
+		rcpts, err := message.GetRecipients()
+		if err != nil {
+			t.Errorf("failed to get recipients: %s", err)
+		}
+		if len(rcpts) != 1 {
+			t.Fatalf("GetRecipients: expected 1 recipient, got: %d", len(rcpts))
+		}
+		if !strings.EqualFold(rcpts[0], "toni.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"toni.tester@example.com", rcpts[0])
+		}
+	})
+	t.Run("GetRecipients with only cc", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err := message.Cc("toni.tester@example.com"); err != nil {
+			t.Fatalf("failed to set cc address: %s", err)
+		}
+		rcpts, err := message.GetRecipients()
+		if err != nil {
+			t.Errorf("failed to get recipients: %s", err)
+		}
+		if len(rcpts) != 1 {
+			t.Fatalf("GetRecipients: expected 1 recipient, got: %d", len(rcpts))
+		}
+		if !strings.EqualFold(rcpts[0], "toni.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"toni.tester@example.com", rcpts[0])
+		}
+	})
+	t.Run("GetRecipients with only bcc", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err := message.Bcc("toni.tester@example.com"); err != nil {
+			t.Fatalf("failed to set bcc address: %s", err)
+		}
+		rcpts, err := message.GetRecipients()
+		if err != nil {
+			t.Errorf("failed to get recipients: %s", err)
+		}
+		if len(rcpts) != 1 {
+			t.Fatalf("GetRecipients: expected 1 recipient, got: %d", len(rcpts))
+		}
+		if !strings.EqualFold(rcpts[0], "toni.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"toni.tester@example.com", rcpts[0])
+		}
+	})
+	t.Run("GetRecipients with to and cc", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err := message.To("toni.tester@example.com"); err != nil {
+			t.Fatalf("failed to set to address: %s", err)
+		}
+		if err := message.Cc("tina.tester@example.com"); err != nil {
+			t.Fatalf("failed to set cc address: %s", err)
+		}
+		rcpts, err := message.GetRecipients()
+		if err != nil {
+			t.Errorf("failed to get recipients: %s", err)
+		}
+		if len(rcpts) != 2 {
+			t.Fatalf("GetRecipients: expected 2 recipient, got: %d", len(rcpts))
+		}
+		if !strings.EqualFold(rcpts[0], "toni.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"toni.tester@example.com", rcpts[0])
+		}
+		if !strings.EqualFold(rcpts[1], "tina.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"tina.tester@example.com", rcpts[1])
+		}
+	})
+	t.Run("GetRecipients with to and bcc", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err := message.To("toni.tester@example.com"); err != nil {
+			t.Fatalf("failed to set to address: %s", err)
+		}
+		if err := message.Bcc("tina.tester@example.com"); err != nil {
+			t.Fatalf("failed to set bcc address: %s", err)
+		}
+		rcpts, err := message.GetRecipients()
+		if err != nil {
+			t.Errorf("failed to get recipients: %s", err)
+		}
+		if len(rcpts) != 2 {
+			t.Fatalf("GetRecipients: expected 2 recipient, got: %d", len(rcpts))
+		}
+		if !strings.EqualFold(rcpts[0], "toni.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"toni.tester@example.com", rcpts[0])
+		}
+		if !strings.EqualFold(rcpts[1], "tina.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"tina.tester@example.com", rcpts[1])
+		}
+	})
+	t.Run("GetRecipients with cc and bcc", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err := message.Cc("toni.tester@example.com"); err != nil {
+			t.Fatalf("failed to set cc address: %s", err)
+		}
+		if err := message.Bcc("tina.tester@example.com"); err != nil {
+			t.Fatalf("failed to set bcc address: %s", err)
+		}
+		rcpts, err := message.GetRecipients()
+		if err != nil {
+			t.Errorf("failed to get recipients: %s", err)
+		}
+		if len(rcpts) != 2 {
+			t.Fatalf("GetRecipients: expected 2 recipient, got: %d", len(rcpts))
+		}
+		if !strings.EqualFold(rcpts[0], "toni.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"toni.tester@example.com", rcpts[0])
+		}
+		if !strings.EqualFold(rcpts[1], "tina.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"tina.tester@example.com", rcpts[1])
+		}
+	})
+	t.Run("GetRecipients with to, cc and bcc", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err := message.To("toni.tester@example.com"); err != nil {
+			t.Fatalf("failed to set to address: %s", err)
+		}
+		if err := message.Cc("tina.tester@example.com"); err != nil {
+			t.Fatalf("failed to set cc address: %s", err)
+		}
+		if err := message.Bcc("tom.tester@example.com"); err != nil {
+			t.Fatalf("failed to set bcc address: %s", err)
+		}
+		rcpts, err := message.GetRecipients()
+		if err != nil {
+			t.Errorf("failed to get recipients: %s", err)
+		}
+		if len(rcpts) != 3 {
+			t.Fatalf("GetRecipients: expected 3 recipient, got: %d", len(rcpts))
+		}
+		if !strings.EqualFold(rcpts[0], "toni.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"toni.tester@example.com", rcpts[0])
+		}
+		if !strings.EqualFold(rcpts[1], "tina.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"tina.tester@example.com", rcpts[1])
+		}
+		if !strings.EqualFold(rcpts[2], "tom.tester@example.com") {
+			t.Errorf("GetRecipients: expected recipient not returned. Want: %s, got: %s",
+				"tina.tester@example.com", rcpts[2])
+		}
+	})
+	t.Run("GetRecipients with no recipients", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		_, err := message.GetRecipients()
+		if err == nil {
+			t.Errorf("GetRecipients: expected error, got nil")
+		}
+		if !errors.Is(err, ErrNoRcptAddresses) {
+			t.Errorf("GetRecipients: expected ErrNoRcptAddresses, got: %s", err)
+		}
+	})
+}
+
 // checkAddrHeader verifies the correctness of an AddrHeader in a Msg based on the provided criteria.
 // It checks whether the AddrHeader contains the correct address, name, and number of fields.
 func checkAddrHeader(t *testing.T, message *Msg, header AddrHeader, fn string, field, wantFields int,