style(all): Fix LOGIN auth detection and improve response tests

lettre/src/smtp/extension.rs

@@ -67,7 +67,7 @@ impl Display for ServerInfo {
 }
 
 impl ServerInfo {
-    /// Parses a response to create a `ServerInfo`
+    /// Parses a EHLO response to create a `ServerInfo`
     pub fn from_response(response: &Response) -> Result<ServerInfo, Error> {
         let name = match response.first_word() {
             Some(name) => name,
@@ -77,7 +77,6 @@ impl ServerInfo {
         let mut features: HashSet<Extension> = HashSet::new();
 
         for line in response.message() {
-
             let splitted: Vec<&str> = line.split_whitespace().collect();
             match splitted[0] {
                 "8BITMIME" => {
@@ -95,6 +94,9 @@ impl ServerInfo {
                             "PLAIN" => {
                                 features.insert(Extension::Authentication(Mechanism::Plain));
                             }
+                            "LOGIN" => {
+                                features.insert(Extension::Authentication(Mechanism::Login));
+                            }
                             "CRAM-MD5" => {
                                 features.insert(Extension::Authentication(Mechanism::CramMd5));
                             }

lettre/src/smtp/mod.rs

@@ -156,13 +156,13 @@ pub enum SecurityLevel {
     EncryptedWrapper,
     /// Only send an email on encrypted connection (with STARTTLS)
     ///
-    /// Recommended mode, prevents MITM when used with verified certificates.
+    /// Default mode, prevents MITM when used with verified certificates.
     AlwaysEncrypt,
     /// Use TLS when available (with STARTTLS)
     ///
-    /// Default mode.
+    /// Should be used when not possible to always encrypt the connection
     Opportunistic,
-    /// Never use TLS
+    /// Never use encryption
     NeverEncrypt,
 }
 
@@ -460,7 +460,7 @@ impl EmailTransport<SmtpResult> for SmtpTransport {
                             // Login is obsolete so try it last
                             vec![Mechanism::Plain, Mechanism::CramMd5, Mechanism::Login]
                         } else {
-                            // If not encrypted, do not allow clear-text passwords
+                            // If not encrypted, do not allow clear-text passwords by default
                             vec![Mechanism::CramMd5]
                         }
                     }

lettre/src/smtp/response.rs

@@ -150,6 +150,10 @@ impl FromStr for Code {
 impl Code {
     /// Creates a new `Code` structure
     pub fn new(severity: Severity, category: Category, detail: u8) -> Code {
+        if detail > 9 {
+            panic!("The detail code must be between 0 and 9");
+        }
+
         Code {
             severity: severity,
             category: category,
@@ -174,7 +178,7 @@ impl ResponseParser {
 
         if line.len() < 3 {
             return Err(Error::ResponseParsing(
-                "Wrong code length (should be 3 digit)",
+                "Incorrect response code (should be 3 digits)",
             ));
         }
 
@@ -283,13 +287,9 @@ impl Response {
         }
     }
 
-    /// Returns only the line word of the message if possible
+    /// Returns only the line of the message if possible
     pub fn first_line(&self) -> Option<&str> {
-        if self.message.is_empty() {
+        self.message.first().map(String::as_str)
-            None
-        } else {
-            Some(&self.message[0])
-        }
     }
 }
 
@@ -308,6 +308,7 @@ mod test {
             Severity::TransientNegativeCompletion
         );
         assert!("1".parse::<Severity>().is_err());
+        assert!("51".parse::<Severity>().is_err());
     }
 
     #[test]
@@ -343,6 +344,16 @@ mod test {
         );
     }
 
+    #[test]
+    #[should_panic]
+    fn test_code_new_panic() {
+        let _ = Code::new(
+            Severity::TransientNegativeCompletion,
+            Category::Connections,
+            11,
+        );
+    }
+
     #[test]
     fn test_code_from_str() {
         assert_eq!(
@@ -353,6 +364,12 @@ mod test {
                 detail: 1,
             }
         );
+        assert!("2222".parse::<Code>().is_err());
+        assert!("aaa".parse::<Code>().is_err());
+        assert!("-32".parse::<Code>().is_err());
+        assert!("-333".parse::<Code>().is_err());
+        assert!("".parse::<Code>().is_err());
+        assert!("292".parse::<Code>().is_err());
     }
 
     #[test]
@@ -707,4 +724,82 @@ mod test {
             None
         );
     }
+
+    #[test]
+    fn test_response_first_line() {
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: "2".parse::<Severity>().unwrap(),
+                    category: "4".parse::<Category>().unwrap(),
+                    detail: 1,
+                },
+                vec![
+                    "me".to_string(),
+                    "8BITMIME".to_string(),
+                    "SIZE 42".to_string(),
+                ],
+            ).first_line(),
+            Some("me")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: "2".parse::<Severity>().unwrap(),
+                    category: "4".parse::<Category>().unwrap(),
+                    detail: 1,
+                },
+                vec![
+                    "me mo".to_string(),
+                    "8BITMIME".to_string(),
+                    "SIZE 42".to_string(),
+                ],
+            ).first_line(),
+            Some("me mo")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: "2".parse::<Severity>().unwrap(),
+                    category: "4".parse::<Category>().unwrap(),
+                    detail: 1,
+                },
+                vec![],
+            ).first_line(),
+            None
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: "2".parse::<Severity>().unwrap(),
+                    category: "4".parse::<Category>().unwrap(),
+                    detail: 1,
+                },
+                vec![" ".to_string()],
+            ).first_line(),
+            Some(" ")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: "2".parse::<Severity>().unwrap(),
+                    category: "4".parse::<Category>().unwrap(),
+                    detail: 1,
+                },
+                vec!["  ".to_string()],
+            ).first_line(),
+            Some("  ")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: "2".parse::<Severity>().unwrap(),
+                    category: "4".parse::<Category>().unwrap(),
+                    detail: 1,
+                },
+                vec!["".to_string()],
+            ).first_line(),
+            Some("")
+        );
+    }
 }