[fix] fix example and add it to ci

- continuously build example
- add example as executable to *cabal file

Author: MangoIV

HaskellNet-SSL.cabal

@@ -43,3 +43,15 @@ library
                        network-bsd >= 2.7 && < 2.9
   else
     build-depends:     network >= 2.4 && < 3.0
+
+executable HaskellNet-SSL-example
+  hs-source-dirs:   examples
+  main-is:          gmail.hs
+  other-modules:
+  build-depends:
+      base         <5
+    , HaskellNet-SSL
+    , HaskellNet
+    , bytestring
+
+  default-language: Haskell2010

examples/gmail.hs

@@ -3,34 +3,52 @@
 import           Network.HaskellNet.IMAP.SSL
 import           Network.HaskellNet.SMTP.SSL as SMTP
 
-import           Network.HaskellNet.Auth (AuthType(LOGIN))
+import           Network.HaskellNet.Auth (AuthType(LOGIN), Password)
+import           Network.Mail.Mime
 
 import qualified Data.ByteString.Char8 as B
+import           Data.String
 
+username :: IsString s => s
 username = "[email protected]"
+
+password :: Password
 password = "password"
+
+recipient :: Address
 recipient = "[email protected]"
 
+imapTest :: IO ()
 imapTest = do
     c <- connectIMAPSSLWithSettings "imap.gmail.com" cfg
     login c username password
     mboxes <- list c
     mapM_ print mboxes
     select c "INBOX"
-    msgs <- search c [ALLs]
-    let firstMsg = head msgs
+    msgs@(firstMsg : _) <- search c [ALLs]
     msgContent <- fetch c firstMsg
     B.putStrLn msgContent
     logout c
   where cfg = defaultSettingsIMAPSSL { sslMaxLineLength = 100000 }
 
+smtpTest :: IO ()
 smtpTest = doSMTPSTARTTLS "smtp.gmail.com" $ \c -> do
     authSucceed <- SMTP.authenticate LOGIN username password c
     if authSucceed
-      then sendPlainTextMail recipient username subject body c
+      then do 
+        mail <- simpleMail
+          recipient
+          username 
+          subject
+          body
+          mempty
+          mempty
+        sendMail mail c -- recipient username subject body
       else print "Authentication error."
   where subject = "Test message"
         body    = "This is a test message"
 
 main :: IO ()
-main = smtpTest >> imapTest >> return ()
+main = do 
+  smtpTest 
+  imapTest