Add thiserror error handling

Cargo.toml

@@ -11,6 +11,7 @@ serde_yaml = "0.9.3"
 serde = { version = "1.0.141", features = ["derive"] }
 lazy_static = "1.4.0"
 skim = "0.9.4"
+thiserror = "1.0.56"
 
 [dev-dependencies]
 assert_cmd = "2.0"

src/commands.rs

@@ -1,7 +1,6 @@
-use crate::model::KubeConfig;
+use crate::{error::SetContextError, model::KubeConfig};
 use crate::config;
 
-use core::fmt;
 use std::{
     io::Cursor,
     process::{Command, Stdio},
@@ -92,21 +91,6 @@ pub fn set_context(ctx: &str, temp_dir: &str, config: &KubeConfig) -> Result<(),
         config::write(choice, None, temp_dir);
         Ok(())
     } else {
-        Err(SetContextError::ContextNotFound{ctx: ctx.to_owned()})
-    }
-}
-
-#[derive(Debug, Clone)]
-pub enum SetContextError {
-    ContextNotFound {
-        ctx : String
-    },
-}
-
-impl fmt::Display for SetContextError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            SetContextError::ContextNotFound{ctx} => write!(f, "no context exists with the name: \"{}\"", ctx),
-        }
+        Err(SetContextError::KubeContextNotFound{ctx: ctx.to_owned()})
     }
 }

src/error.rs

@@ -0,0 +1,19 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("failed to set context: {0}")]
+    SetContext(#[source] SetContextError),
+    #[error("no item selected when prompted to select {prompt}")]
+    NoItemSelected {
+        prompt: &'static str 
+    },
+}
+
+#[derive(Error, Debug)]
+pub enum SetContextError {
+    #[error("no context exists with the name {ctx}")]
+    KubeContextNotFound {
+        ctx: String
+    },
+}

src/main.rs

@@ -2,7 +2,9 @@ mod commands;
 mod config;
 mod model;
 mod modes;
+mod error;
 
+use crate::error::Error;
 use clap::Parser;
 use std::env;
 use std::io;
@@ -69,7 +71,7 @@ enum Mode {
 }
 
 impl Mode {
-    fn invoke(&self) -> Result <(), String> {
+    fn invoke(&self) -> Result <(), Error> {
         let args = Cli::parse();
         match self {
             Mode::Namespace => modes::namespace(args),

src/modes.rs

@@ -1,6 +1,6 @@
-use crate::{commands::{self}, config, Cli, DEST, KUBECONFIG};
+use crate::{commands::{self}, config, error::Error, Cli, DEST, KUBECONFIG};
 
-pub fn default_context(args: Cli) -> Result<(), String> {
+pub fn default_context(args: Cli) -> Result<(), Error> {
     let config = config::get();
 
     if args.current {
@@ -14,15 +14,16 @@ pub fn default_context(args: Cli) -> Result<(), String> {
                 .map(|context| context.name.to_string())
                 .collect();
 
-            commands::selectable_list(options).expect("No item selected")
+            commands::selectable_list(options)
+                .ok_or(Error::NoItemSelected{prompt: "context" })?
         }
         Some(x) => x.trim().to_string(),
     };
 
     commands::set_default_context(&ctx);
 
     let set_context_result = commands::set_context(&ctx, &DEST, &config)
-        .map_err(|err| err.to_string());
+        .map_err(Error::SetContext);
 
     if set_context_result.is_ok() {
         println!("{}", KUBECONFIG.as_str());
@@ -31,7 +32,7 @@ pub fn default_context(args: Cli) -> Result<(), String> {
     set_context_result
 }
 
-pub fn context(args: Cli) -> Result<(), String> {
+pub fn context(args: Cli) -> Result<(), Error> {
     if args.current {
         let config = config::get_current_session();
         println!("{}", config.current_context);
@@ -45,13 +46,14 @@ pub fn context(args: Cli) -> Result<(), String> {
                 .map(|context| context.name.to_string())
                 .collect();
 
-            commands::selectable_list(options).ok_or("No item selected")?
+            commands::selectable_list(options)
+                .ok_or(Error::NoItemSelected{prompt: "context"})?
         }
         Some(x) => x.trim().to_string(),
     };
 
     let set_context_result = commands::set_context(&ctx, &DEST, &config)
-        .map_err(|err| err.to_string());
+        .map_err(Error::SetContext);
 
     if set_context_result.is_ok() {
         println!(
@@ -65,7 +67,7 @@ pub fn context(args: Cli) -> Result<(), String> {
     set_context_result
 }
 
-pub fn namespace(args: Cli) -> Result<(), String> {
+pub fn namespace(args: Cli) -> Result<(), Error> {
     let config = config::get_current_session();
     if args.current {
         let ctx = config
@@ -89,7 +91,8 @@ pub fn namespace(args: Cli) -> Result<(), String> {
     let ns = match args.value {
         None => {
             let namespaces : Vec<String> = commands::get_namespaces();
-            commands::selectable_list(namespaces).ok_or("No item selected")?
+            commands::selectable_list(namespaces)
+                .ok_or(Error::NoItemSelected{prompt: "namespace"})?
         }
         Some(x) => x.trim().to_string(),
     };
@@ -105,7 +108,7 @@ pub fn namespace(args: Cli) -> Result<(), String> {
     Ok(())
 }
 
-pub fn default_namespace(args: Cli) -> Result<(), String> {
+pub fn default_namespace(args: Cli) -> Result<(), Error> {
     let config = config::get();
     let ctx = commands::get_current_context();
 
@@ -132,7 +135,8 @@ pub fn default_namespace(args: Cli) -> Result<(), String> {
     let ns = match args.value {
         None => {
             let namespaces : Vec<String> = commands::get_namespaces();
-            commands::selectable_list(namespaces).ok_or("No item selected")?
+            commands::selectable_list(namespaces)
+                .ok_or(Error::NoItemSelected{prompt: "namespace"})?
         }
         Some(x) => x.trim().to_string(),
     };