update temporary status codes api

src/client/connection/response/failure/temporary/default.rs

@@ -0,0 +1,78 @@
+pub mod error;
+pub use error::Error;
+
+/// [Unspecified Temporary Error](https://geminiprotocol.net/docs/protocol-specification.gmi#status-40) status code
+pub const CODE: &[u8] = b"40";
+
+/// Default message if the optional value was not provided by the server
+/// * useful to skip match cases in external applications,
+///   by using `super::message_or_default` method.
+pub const DEFAULT_MESSAGE: &str = "Temporary error";
+
+/// Hold header `String` for [Unspecified Temporary Error](https://geminiprotocol.net/docs/protocol-specification.gmi#status-40) status code
+/// * this response type does not contain body data
+/// * the header member is closed to require valid construction
+pub struct Default(String);
+
+impl Default {
+    // Constructors
+
+    /// Parse `Self` from buffer contains header bytes
+    pub fn from_utf8(buffer: &[u8]) -> Result<Self, Error> {
+        if !buffer.starts_with(CODE) {
+            return Err(Error::Code);
+        }
+        Ok(Self(
+            std::str::from_utf8(
+                crate::client::connection::response::header_bytes(buffer).map_err(Error::Header)?,
+            )
+            .map_err(Error::Utf8Error)?
+            .to_string(),
+        ))
+    }
+
+    // Getters
+
+    /// Get optional message for `Self`
+    /// * return `None` if the message is empty
+    pub fn message(&self) -> Option<&str> {
+        self.0.get(2..).map(|s| s.trim()).filter(|x| !x.is_empty())
+    }
+
+    /// Get optional message for `Self`
+    /// * if the optional message not provided by the server, return `DEFAULT_MESSAGE`
+    pub fn message_or_default(&self) -> &str {
+        self.message().unwrap_or(DEFAULT_MESSAGE)
+    }
+
+    /// Get header string of `Self`
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+
+    /// Get header bytes of `Self`
+    pub fn as_bytes(&self) -> &[u8] {
+        self.0.as_bytes()
+    }
+}
+
+#[test]
+fn test() {
+    // ok
+    let d = Default::from_utf8("40 Message\r\n".as_bytes()).unwrap();
+    assert_eq!(d.message(), Some("Message"));
+    assert_eq!(d.message_or_default(), "Message");
+    assert_eq!(d.as_str(), "40 Message\r\n");
+    assert_eq!(d.as_bytes(), "40 Message\r\n".as_bytes());
+
+    let d = Default::from_utf8("40\r\n".as_bytes()).unwrap();
+    assert_eq!(d.message(), None);
+    assert_eq!(d.message_or_default(), DEFAULT_MESSAGE);
+    assert_eq!(d.as_str(), "40\r\n");
+    assert_eq!(d.as_bytes(), "40\r\n".as_bytes());
+
+    // err
+    assert!(Default::from_utf8("13 Fail\r\n".as_bytes()).is_err());
+    assert!(Default::from_utf8("Fail\r\n".as_bytes()).is_err());
+    assert!(Default::from_utf8("Fail".as_bytes()).is_err());
+}