Upgrade error handeling

src/command.rs

@@ -7,12 +7,22 @@ use std::process::{Command, ExitStatus, Stdio};
 use std::{fmt, fs, io};
 
 #[derive(Debug, Serialize, Deserialize, PartialEq)]
-enum UpdateSteps {
+pub enum UpdateSteps {
     PreInstall,
     Install,
     PostInstall,
 }
 
+impl Display for UpdateSteps {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            UpdateSteps::PreInstall => write!(f, "PreInstall"),
+            UpdateSteps::Install => write!(f, "Install"),
+            UpdateSteps::PostInstall => write!(f, "PostInstall"),
+        }
+    }
+}
+
 // TODO: change the struct’s names for the `topgrade`’s one. They are much better.
 
 /// Root of the machine’s dependency graph
@@ -43,7 +53,7 @@ pub struct Executor {
 
 /// A command to execute on the system as part of an executor
 #[derive(Debug, Clone, Serialize, Deserialize)]
-struct Cmd {
+pub struct Cmd {
     exe: String,
     params: Option<Vec<String>>,
     current_dir: Option<PathBuf>,
@@ -52,7 +62,7 @@ struct Cmd {
 
 /// The actual (cleaned) command that will be executed on the system as part of an executor
 #[derive(Debug, Clone, Serialize, Deserialize)]
-pub(crate) struct ActualCmd {
+pub struct ActualCmd {
     exe: String,
     params: Vec<String>,
     current_dir: Option<PathBuf>,
@@ -72,6 +82,10 @@ impl From<&String> for UpdateSteps {
 }
 
 pub fn get_packages_folder(opt: &Opt) -> io::Result<PathBuf> {
+    if let Some(p) = opt.config_folder.clone() {
+        return Ok(p);
+    }
+
     let config_folder = directories::ProjectDirs::from("net", "ZykiCorp", "System Updater")
         .ok_or(io::Error::new(
             io::ErrorKind::NotFound,
@@ -154,6 +168,7 @@ impl Updater {
         }
 
         let packages_folder = get_packages_folder(&opt)?;
+        // TODO: Useless match? Still a risck for "time-of-check to time-of-use" bug
         match packages_folder.try_exists() {
             Ok(true) => {} // Ok: Exist and should be readable
             Ok(false) => {
@@ -178,7 +193,7 @@ impl Updater {
             }
             Err(..) => false,
         }) {
-            let file = packages_folder.join(file?.path()); // "default.yaml");
+            let file = file?.path();
             let sys = std::fs::read_to_string(&file).unwrap();
             let sys = serde_yaml::from_str(&sys).map_err(|err| {
                 io::Error::new(
@@ -244,16 +259,18 @@ impl Executor {
         if let Some(pre_install) = &self.pre_install {
             for cmd in pre_install {
                 let cmd = cmd.clone().prepare(opt);
-                let exit_status = cmd
-                    .execute(opt)
-                    .map_err(|err| MyError::new(MyErrorKind::PreInstall, err, cmd.clone()))?;
+                let exit_status = cmd.execute(opt).map_err(|err| Error::Execution {
+                    source: err,
+                    step: UpdateSteps::PreInstall,
+                    cmd: cmd.clone(),
+                })?;
 
                 if !exit_status.success() {
-                    return Err(MyError::new(
-                        MyErrorKind::PreInstall,
-                        io::Error::new(io::ErrorKind::Other, format!("{}", exit_status)),
-                        cmd.clone(),
-                    ));
+                    return Err(Error::Execution {
+                        source: io::Error::new(io::ErrorKind::Other, format!("{}", exit_status)),
+                        step: UpdateSteps::PreInstall,
+                        cmd,
+                    });
                 }
             }
         }
@@ -262,16 +279,18 @@ impl Executor {
 
     pub fn install(&self, opt: &Opt) -> Result<()> {
         let cmd = self.install.clone().prepare(opt);
-        let exit_status = cmd
-            .execute(opt)
-            .map_err(|err| MyError::new(MyErrorKind::Install, err, cmd.clone()))?;
+        let exit_status = cmd.execute(opt).map_err(|err| Error::Execution {
+            source: err,
+            step: UpdateSteps::Install,
+            cmd: cmd.clone(),
+        })?;
 
         if !exit_status.success() {
-            return Err(MyError::new(
-                MyErrorKind::Install,
-                io::Error::new(io::ErrorKind::Other, format!("{}", exit_status)),
-                cmd.clone(),
-            ));
+            return Err(Error::Execution {
+                source: io::Error::new(io::ErrorKind::Other, format!("{}", exit_status)),
+                step: UpdateSteps::Install,
+                cmd,
+            });
         }
         Ok(())
     }
@@ -280,16 +299,18 @@ impl Executor {
         if let Some(post_install) = &self.post_install {
             for cmd in post_install {
                 let cmd = cmd.clone().prepare(opt);
-                let exit_status = cmd
-                    .execute(opt)
-                    .map_err(|err| MyError::new(MyErrorKind::PostInstall, err, cmd.clone()))?;
+                let exit_status = cmd.execute(opt).map_err(|err| Error::Execution {
+                    source: err,
+                    step: UpdateSteps::PostInstall,
+                    cmd: cmd.clone(),
+                })?;
 
                 if !exit_status.success() {
-                    return Err(MyError::new(
-                        MyErrorKind::PostInstall,
-                        io::Error::new(io::ErrorKind::Other, format!("{}", exit_status)),
-                        cmd.clone(),
-                    ));
+                    return Err(Error::Execution {
+                        source: io::Error::new(io::ErrorKind::Other, format!("{}", exit_status)),
+                        step: UpdateSteps::PostInstall,
+                        cmd,
+                    });
                 }
             }
         }

src/errors.rs

@@ -1,75 +1,27 @@
+// Use https://kazlauskas.me/entries/errors as a reference
+
 use crate::*;
 
-use std::error::Error;
-use std::fmt;
-use std::fmt::{Display, Formatter};
 use std::io;
 use std::result;
+use thiserror::Error;
 
-pub type Result<T> = result::Result<T, MyError>;
+pub type Result<T> = result::Result<T, Error>;
 
 /// An error that can occur in this crate.
 ///
 /// Generally, this error corresponds to problems with underlying process.
-#[derive(Debug)]
-pub struct MyError {
-    source: io::Error,
-    kind: MyErrorKind,
-    cmd: ActualCmd,
-}
-
-#[derive(Debug)]
 #[non_exhaustive]
-pub enum MyErrorKind {
-    Config,
-    PreInstall,
-    Install,
-    PostInstall,
-}
-
-impl MyError {
-    pub(crate) fn new(kind: MyErrorKind, source: io::Error, cmd: ActualCmd) -> MyError {
-        MyError { source, kind, cmd }
-    }
-
-    /// Return the kind of this error.
-    pub fn kind(&self) -> &MyErrorKind {
-        &self.kind
-    }
-}
-
-impl Error for MyError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        Some(&self.source)
-    }
-}
-
-impl Display for MyError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self.kind {
-            MyErrorKind::Config => write!(
-                f,
-                "Could not read configuration file: {}",
-                self.source().unwrap()
-            ),
-            MyErrorKind::PreInstall => write!(
-                f,
-                "Could not do the pre_install with command {}: {}",
-                self.cmd,
-                self.source().unwrap()
-            ),
-            MyErrorKind::Install => write!(
-                f,
-                "Could not install with command {}: {}",
-                self.cmd,
-                self.source().unwrap()
-            ),
-            MyErrorKind::PostInstall => write!(
-                f,
-                "Could not do the post_install command {}: {}",
-                self.cmd,
-                self.source().unwrap()
-            ),
-        }
-    }
+#[derive(Debug, Error)]
+pub enum Error {
+    // #[error("TODO")]
+    // Config,
+    #[error(
+        "Could not achieve the \"{step}\" step. Command `{cmd}` resulted in an exited with: {source}"
+    )]
+    Execution {
+        source: io::Error,
+        step: UpdateSteps,
+        cmd: ActualCmd,
+    },
 }

src/lib.rs

@@ -12,7 +12,7 @@ use std::path::PathBuf;
 #[derive(Parser)]
 pub struct Opt {
     #[arg(hide = true)] // TODO: hidden option for debug? or usefull for everyone?
-    pub config_file: Option<PathBuf>,
+    pub config_folder: Option<PathBuf>,
 
     #[arg(short, long)]
     pub quiet: bool, // TODO: use clap_verbosity_flag instead
@@ -24,7 +24,7 @@ pub struct Opt {
 enum Status {
     /// All steps asked were successful
     Ok,
-    Err(MyError),
+    Err(Error),
 }
 
 impl Display for Status {