implement custom error

peach-oled/src/error.rs

@@ -1,44 +1,68 @@
-use std::error;
+use std::{error, fmt};
 
-use jsonrpc_core::{types::error::Error, ErrorCode};
-use linux_embedded_hal as hal;
-use snafu::Snafu;
+use jsonrpc_core::types::error::Error as JsonRpcError;
+use jsonrpc_core::ErrorCode;
+use linux_embedded_hal::i2cdev::linux::LinuxI2CError;
 
-pub type BoxError = Box<dyn error::Error>;
-
-#[derive(Debug, Snafu)]
-#[snafu(visibility(pub(crate)))]
+#[derive(Debug)]
 pub enum OledError {
-    #[snafu(display("Failed to create interface for I2C device: {}", source))]
     I2CError {
-        source: hal::i2cdev::linux::LinuxI2CError,
+        source: LinuxI2CError,
     },
-
-    #[snafu(display("Coordinate {} out of range {}: {}", coord, range, value))]
     InvalidCoordinate {
         coord: String,
         range: String,
         value: i32,
     },
-
-    // TODO: implement for validate() in src/lib.rs
-    #[snafu(display("Font size invalid: {}", font))]
-    InvalidFontSize { font: String },
-
-    #[snafu(display("String length out of range 0-21: {}", len))]
-    InvalidString { len: usize },
-
-    #[snafu(display("Missing expected parameter: {}", e))]
-    MissingParameter { e: Error },
-
-    #[snafu(display("Failed to parse parameter: {}", e))]
-    ParseError { e: Error },
+    InvalidFontSize {
+        font: String,
+    },
+    InvalidString {
+        len: usize,
+    },
+    MissingParameter {
+        source: JsonRpcError,
+    },
+    ParseError {
+        source: JsonRpcError,
+    },
 }
 
-impl From<OledError> for Error {
+impl error::Error for OledError {}
+
+impl fmt::Display for OledError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            OledError::ParseError { ref source } => {
+                write!(f, "Failed to parse parameter: {}", source)
+            }
+            OledError::MissingParameter { ref source } => {
+                write!(f, "Missing expected parameter: {}", source)
+            }
+            OledError::InvalidString { len } => {
+                write!(f, "String length out of range 0-21: {}", len)
+            }
+            OledError::InvalidFontSize { ref font } => {
+                write!(f, "Invalid font size: {}", font)
+            }
+            OledError::InvalidCoordinate {
+                ref coord,
+                ref range,
+                value,
+            } => {
+                write!(f, "Coordinate {} out of range {}: {}", coord, range, value)
+            }
+            OledError::I2CError { ref source } => {
+                write!(f, "Failed to create interface for I2C device: {}", source)
+            }
+        }
+    }
+}
+
+impl From<OledError> for JsonRpcError {
     fn from(err: OledError) -> Self {
         match &err {
-            OledError::I2CError { source } => Error {
+            OledError::I2CError { source } => JsonRpcError {
                 code: ErrorCode::ServerError(-32000),
                 message: format!("Failed to create interface for I2C device: {}", source),
                 data: None,
@@ -47,7 +71,7 @@ impl From<OledError> for Error {
                 coord,
                 value,
                 range,
-            } => Error {
+            } => JsonRpcError {
                 code: ErrorCode::ServerError(-32001),
                 message: format!(
                     "Validation error: coordinate {} out of range {}: {}",
@@ -55,18 +79,18 @@ impl From<OledError> for Error {
                 ),
                 data: None,
             },
-            OledError::InvalidFontSize { font } => Error {
+            OledError::InvalidFontSize { font } => JsonRpcError {
                 code: ErrorCode::ServerError(-32002),
                 message: format!("Validation error: {} is not an accepted font size. Use 6x8, 6x12, 8x16 or 12x16 instead", font),
                 data: None,
             },
-            OledError::InvalidString { len } => Error {
+            OledError::InvalidString { len } => JsonRpcError {
                 code: ErrorCode::ServerError(-32003),
                 message: format!("Validation error: string length {} out of range 0-21", len),
                 data: None,
             },
-            OledError::MissingParameter { e } => e.clone(),
-            OledError::ParseError { e } => e.clone(),
+            OledError::MissingParameter { source } => source.clone(),
+            OledError::ParseError { source } => source.clone(),
         }
     }
 }