fix(errors): Introduce thiserror to make error types simpler (#836)

Cargo.lock

@@ -2926,6 +2926,7 @@ dependencies = [
  "strum",
  "tempfile",
  "termion",
+ "thiserror",
  "unicode-width",
  "url",
  "vte",

zellij-utils/Cargo.toml

@@ -28,6 +28,7 @@ strip-ansi-escapes = "0.1.0"
 structopt = "0.3"
 strum = "0.20.0"
 termion = "1.5.0"
+thiserror = "1.0.30"
 url = { version = "2.2.2", features = ["serde"] }
 vte = "0.10.1"
 zellij-tile = { path = "../zellij-tile/", version = "0.20.0" }

zellij-utils/src/input/config.rs

@@ -1,9 +1,9 @@
 //! Deserializes configuration options.
-use std::error;
-use std::fmt::{self, Display};
+use std::fmt;
 use std::fs::File;
 use std::io::{self, Read};
 use std::path::{Path, PathBuf};
+use thiserror::Error;
 
 use serde::Deserialize;
 use std::convert::{TryFrom, TryInto};
@@ -39,20 +39,26 @@ pub struct Config {
     pub plugins: PluginsConfig,
 }
 
-#[derive(Debug)]
+#[derive(Error, Debug)]
 pub enum ConfigError {
     // Deserialization error
-    Serde(serde_yaml::Error),
+    #[error("Deserialization error: {0}")]
+    Serde(#[from] serde_yaml::Error),
     // Io error
-    Io(io::Error),
+    #[error("IoError: {0}")]
+    Io(#[from] io::Error),
     // Io error with path context
+    #[error("IoError: {0}, File: {1}")]
     IoPath(io::Error, PathBuf),
     // Internal Deserialization Error
-    FromUtf8(std::string::FromUtf8Error),
+    #[error("FromUtf8Error: {0}")]
+    FromUtf8(#[from] std::string::FromUtf8Error),
     // Naming a part in a tab is unsupported
-    LayoutNameInTab(LayoutNameInTabError),
+    #[error("There was an error in the layout file, {0}")]
+    LayoutNameInTab(#[from] LayoutNameInTabError),
     // Plugins have a semantic error, usually trying to parse two of the same tag
-    PluginsError(PluginsConfigError),
+    #[error("PluginsError: {0}")]
+    PluginsError(#[from] PluginsConfigError),
 }
 
 impl Default for Config {
@@ -195,66 +201,6 @@ impl std::error::Error for LayoutNameInTabError {
     }
 }
 
-impl Display for ConfigError {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            ConfigError::Io(ref err) => write!(formatter, "IoError: {}", err),
-            ConfigError::IoPath(ref err, ref path) => {
-                write!(formatter, "IoError: {}, File: {}", err, path.display(),)
-            }
-            ConfigError::Serde(ref err) => write!(formatter, "Deserialization error: {}", err),
-            ConfigError::FromUtf8(ref err) => write!(formatter, "FromUtf8Error: {}", err),
-            ConfigError::LayoutNameInTab(ref err) => {
-                write!(formatter, "There was an error in the layout file, {}", err)
-            }
-            ConfigError::PluginsError(ref err) => write!(formatter, "PluginsError: {}", err),
-        }
-    }
-}
-
-impl std::error::Error for ConfigError {
-    fn cause(&self) -> Option<&dyn error::Error> {
-        match *self {
-            ConfigError::Io(ref err) => Some(err),
-            ConfigError::IoPath(ref err, _) => Some(err),
-            ConfigError::Serde(ref err) => Some(err),
-            ConfigError::FromUtf8(ref err) => Some(err),
-            ConfigError::LayoutNameInTab(ref err) => Some(err),
-            ConfigError::PluginsError(ref err) => Some(err),
-        }
-    }
-}
-
-impl From<io::Error> for ConfigError {
-    fn from(err: io::Error) -> ConfigError {
-        ConfigError::Io(err)
-    }
-}
-
-impl From<serde_yaml::Error> for ConfigError {
-    fn from(err: serde_yaml::Error) -> ConfigError {
-        ConfigError::Serde(err)
-    }
-}
-
-impl From<std::string::FromUtf8Error> for ConfigError {
-    fn from(err: std::string::FromUtf8Error) -> ConfigError {
-        ConfigError::FromUtf8(err)
-    }
-}
-
-impl From<LayoutNameInTabError> for ConfigError {
-    fn from(err: LayoutNameInTabError) -> ConfigError {
-        ConfigError::LayoutNameInTab(err)
-    }
-}
-
-impl From<PluginsConfigError> for ConfigError {
-    fn from(err: PluginsConfigError) -> ConfigError {
-        ConfigError::PluginsError(err)
-    }
-}
-
 // The unit test location.
 #[cfg(test)]
 mod config_test {

zellij-utils/src/input/plugins.rs

@@ -2,9 +2,9 @@
 use std::borrow::Borrow;
 use std::collections::HashMap;
 use std::convert::TryFrom;
-use std::fmt::{self, Display};
 use std::fs;
 use std::path::{Path, PathBuf};
+use thiserror::Error;
 
 use lazy_static::lazy_static;
 use serde::{Deserialize, Serialize};
@@ -189,35 +189,16 @@ impl Default for PluginTypeFromYaml {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Error, Debug, PartialEq)]
 pub enum PluginsConfigError {
+    #[error("Duplication in plugin tag names is not allowed: '{}'", String::from(.0.clone()))]
     DuplicatePlugins(PluginTag),
+    #[error("Only 'file:' and 'zellij:' url schemes are supported for plugin lookup. '{0}' does not match either.")]
     InvalidUrl(Url),
+    #[error("Could not find plugin at the path: '{0:?}'")]
     InvalidPluginLocation(PathBuf),
 }
 
-impl std::error::Error for PluginsConfigError {}
-impl Display for PluginsConfigError {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            PluginsConfigError::DuplicatePlugins(tag) => write!(
-                formatter,
-                "Duplication in plugin tag names is not allowed: '{}'",
-                String::from(tag.clone())
-            ),
-            PluginsConfigError::InvalidUrl(url) => write!(
-                formatter,
-                "Only 'file:' and 'zellij:' url schemes are supported for plugin lookup. '{}' does not match either.",
-                url
-            ),
-            PluginsConfigError::InvalidPluginLocation(path) => write!(
-                formatter,
-                "Could not find plugin at the path: '{:?}'", path
-            ),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;