Replace `snafu` with `thiserror` (#630)

Cargo.lock

@@ -371,12 +371,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "doc-comment"
-version = "0.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fea41bba32d969b513997752735605054bc0dfa92b4c56bf1189f2e174be7a10"
-
 [[package]]
 name = "dtoa"
 version = "0.4.8"
@@ -498,12 +492,12 @@ dependencies = [
  "serde_json",
  "serial_test",
  "shell-escape",
- "snafu",
  "structopt",
  "sysinfo",
  "tar",
  "tempfile",
  "test-log",
+ "thiserror",
  "url",
  "xz2",
  "zip",
@@ -1477,28 +1471,6 @@ version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ecab6c735a6bb4139c0caafd0cc3635748bbb3acf4550e8138122099251f309"
 
-[[package]]
-name = "snafu"
-version = "0.6.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eab12d3c261b2308b0d80c26fffb58d17eba81a4be97890101f416b478c79ca7"
-dependencies = [
- "backtrace",
- "doc-comment",
- "snafu-derive",
-]
-
-[[package]]
-name = "snafu-derive"
-version = "0.6.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1508efa03c362e23817f96cde18abed596a25219a8b2c66e8db33c03543d315b"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "socket2"
 version = "0.4.2"
@@ -1637,18 +1609,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.29"
+version = "1.0.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "602eca064b2d83369e2b2f34b09c70b605402801927c65c11071ac911d299b88"
+checksum = "854babe52e4df1653706b98fcfc05843010039b406875930a70e4d9644e5c417"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.29"
+version = "1.0.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bad553cc2c78e8de258400763a647e80e6d1b31ee237275d756f6836d204494c"
+checksum = "aa32fd3f627f367fe16f893e2597ae3c05020f8bba2666a4e6ea73d377e5714b"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -22,7 +22,6 @@ colored = "2.0.0"
 zip = "0.5.13"
 tempfile = "3.2.0"
 indoc = "1.0.3"
-snafu = { version = "0.6.10", features = ["backtrace"] }
 log = "0.4.14"
 env_logger = "0.9.0"
 atty = "0.2.14"
@@ -30,6 +29,7 @@ encoding_rs_io = "0.1.7"
 reqwest = { version = "0.11.8", features = ["blocking", "json", "rustls-tls", "rustls-tls-native-roots", "brotli"], default-features = false }
 url = "2.2.2"
 sysinfo = "0.22.4"
+thiserror = "1.0.30"
 
 [dev-dependencies]
 pretty_assertions = "1.0.0"

src/choose_version_for_user_input.rs

@@ -6,8 +6,8 @@ use crate::user_version::UserVersion;
 use crate::version::Version;
 use colored::Colorize;
 use log::info;
-use snafu::{ensure, ResultExt, Snafu};
 use std::path::{Path, PathBuf};
+use thiserror::Error;
 
 #[derive(Debug)]
 pub struct ApplicableVersion {
@@ -29,8 +29,8 @@ pub fn choose_version_for_user_input<'a>(
     requested_version: &'a UserVersion,
     config: &'a FnmConfig,
 ) -> Result<Option<ApplicableVersion>, Error> {
-    let all_versions =
+    let all_versions = installed_versions::list(config.installations_dir())
-        installed_versions::list(config.installations_dir()).context(VersionListing)?;
+        .map_err(|source| Error::VersionListing { source })?;
 
     let result = if let UserVersion::Full(Version::Bypassed) = requested_version {
         info!(
@@ -54,18 +54,16 @@ pub fn choose_version_for_user_input<'a>(
                 path: alias_path,
                 version: Version::Bypassed,
             })
-        } else {
+        } else if alias_path.exists() {
-            ensure!(
-                alias_path.exists(),
-                CantFindVersion {
-                    requested_version: requested_version.clone()
-                }
-            );
             info!("Using Node for alias {}", alias_name.cyan());
             Some(ApplicableVersion {
                 path: alias_path,
                 version: Version::Alias(alias_name),
             })
+        } else {
+            return Err(Error::CantFindVersion {
+                requested_version: requested_version.clone(),
+            });
         }
     } else {
         let current_version = requested_version.to_version(&all_versions, config);
@@ -86,10 +84,10 @@ pub fn choose_version_for_user_input<'a>(
     Ok(result)
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't find requested version: {}", requested_version))]
+    #[error("Can't find requested version: {}", requested_version)]
     CantFindVersion { requested_version: UserVersion },
-    #[snafu(display("Can't list local installed versions: {}", source))]
+    #[error("Can't list local installed versions: {}", source)]
     VersionListing { source: installed_versions::Error },
 }

src/commands/alias.rs

@@ -4,10 +4,9 @@ use crate::choose_version_for_user_input::{
     choose_version_for_user_input, Error as ApplicableVersionError,
 };
 use crate::config::FnmConfig;
-use crate::installed_versions;
 use crate::user_version::UserVersion;
-use snafu::{OptionExt, ResultExt, Snafu};
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug)]
 pub struct Alias {
@@ -20,26 +19,24 @@ impl Command for Alias {
 
     fn apply(self, config: &FnmConfig) -> Result<(), Self::Error> {
         let applicable_version = choose_version_for_user_input(&self.to_version, config)
-            .context(CantUnderstandVersion)?
+            .map_err(|source| Error::CantUnderstandVersion { source })?
-            .context(VersionNotFound {
+            .ok_or(Error::VersionNotFound {
                 version: self.to_version,
             })?;
 
         create_alias(config, &self.name, applicable_version.version())
-            .context(CantCreateSymlink)?;
+            .map_err(|source| Error::CantCreateSymlink { source })?;
 
         Ok(())
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't create symlink for alias: {}", source))]
+    #[error("Can't create symlink for alias: {}", source)]
     CantCreateSymlink { source: std::io::Error },
-    #[snafu(display("Can't list local installed versions: {}", source))]
+    #[error("Version {} not found locally", version)]
-    VersionListingError { source: installed_versions::Error },
-    #[snafu(display("Version {} not found locally", version))]
     VersionNotFound { version: UserVersion },
-    #[snafu(display("{}", source))]
+    #[error(transparent)]
     CantUnderstandVersion { source: ApplicableVersionError },
 }

src/commands/completions.rs

@@ -2,9 +2,9 @@ use super::command::Command;
 use crate::cli::Cli;
 use crate::config::FnmConfig;
 use crate::shell::{infer_shell, AVAILABLE_SHELLS};
-use snafu::{OptionExt, Snafu};
 use structopt::clap::Shell;
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug)]
 pub struct Completions {
@@ -21,21 +21,21 @@ impl Command for Completions {
         let shell = self
             .shell
             .or_else(|| infer_shell().map(Into::into))
-            .context(CantInferShell)?;
+            .ok_or(Error::CantInferShell)?;
         Cli::clap().gen_completions_to(env!("CARGO_PKG_NAME"), shell, &mut stdio);
         Ok(())
     }
 }
 
-#[derive(Snafu, Debug)]
+#[derive(Error, Debug)]
 pub enum Error {
-    #[snafu(display(
+    #[error(
         "{}\n{}\n{}\n{}",
         "Can't infer shell!",
         "fnm can't infer your shell based on the process tree.",
         "Maybe it is unsupported? we support the following shells:",
         shells_as_string()
-    ))]
+    )]
     CantInferShell,
 }
 

src/commands/env.rs

@@ -5,9 +5,9 @@ use crate::outln;
 use crate::path_ext::PathExt;
 use crate::shell::{infer_shell, Shell, AVAILABLE_SHELLS};
 use colored::Colorize;
-use snafu::{OptionExt, Snafu};
 use std::fmt::Debug;
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug, Default)]
 pub struct Env {
@@ -59,7 +59,10 @@ impl Command for Env {
             );
         }
 
-        let shell: Box<dyn Shell> = self.shell.or_else(&infer_shell).context(CantInferShell)?;
+        let shell: Box<dyn Shell> = self
+            .shell
+            .or_else(&infer_shell)
+            .ok_or(Error::CantInferShell)?;
         let multishell_path = make_symlink(config);
         let binary_path = if cfg!(windows) {
             multishell_path.clone()
@@ -104,15 +107,15 @@ impl Command for Env {
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display(
+    #[error(
         "{}\n{}\n{}\n{}",
         "Can't infer shell!",
         "fnm can't infer your shell based on the process tree.",
         "Maybe it is unsupported? we support the following shells:",
         shells_as_string()
-    ))]
+    )]
     CantInferShell,
 }
 

src/commands/exec.rs

@@ -7,9 +7,9 @@ use crate::outln;
 use crate::user_version::UserVersion;
 use crate::user_version_reader::UserVersionReader;
 use colored::Colorize;
-use snafu::{OptionExt, ResultExt, Snafu};
 use std::process::{Command, Stdio};
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(Debug, StructOpt)]
 #[structopt(setting = structopt::clap::AppSettings::TrailingVarArg)]
@@ -38,7 +38,10 @@ impl Cmd for Exec {
             );
         }
 
-        let (binary, arguments) = self.arguments.split_first().context(NoBinaryProvided)?;
+        let (binary, arguments) = self
+            .arguments
+            .split_first()
+            .ok_or(Error::NoBinaryProvided)?;
 
         let version = self
             .version
@@ -47,11 +50,11 @@ impl Cmd for Exec {
                 UserVersionReader::Path(current_dir)
             })
             .into_user_version(config)
-            .context(CantInferVersion)?;
+            .ok_or(Error::CantInferVersion)?;
 
         let applicable_version = choose_version_for_user_input(&version, config)
-            .context(ApplicableVersionError)?
+            .map_err(|source| Error::ApplicableVersionError { source })?
-            .context(VersionNotFound { version })?;
+            .ok_or(Error::VersionNotFound { version })?;
 
         #[cfg(windows)]
         let bin_path = applicable_version.path().to_path_buf();
@@ -60,10 +63,11 @@ impl Cmd for Exec {
         let bin_path = applicable_version.path().join("bin");
 
         let path_env = {
-            let paths_env = std::env::var_os("PATH").context(CantReadPathVariable)?;
+            let paths_env = std::env::var_os("PATH").ok_or(Error::CantReadPathVariable)?;
             let mut paths: Vec<_> = std::env::split_paths(&paths_env).collect();
             paths.insert(0, bin_path);
-            std::env::join_paths(paths).context(CantAddPathToEnvironment)?
+            std::env::join_paths(paths)
+                .map_err(|source| Error::CantAddPathToEnvironment { source })?
         };
 
         let exit_status = Command::new(&binary)
@@ -77,34 +81,28 @@ impl Cmd for Exec {
             .wait()
             .expect("Failed to grab exit code");
 
-        let code = exit_status.code().context(CantReadProcessExitCode)?;
+        let code = exit_status.code().ok_or(Error::CantReadProcessExitCode)?;
         std::process::exit(code);
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't read path environment variable"))]
+    #[error("Can't read path environment variable")]
     CantReadPathVariable,
-    #[snafu(display("Can't add path to environment variable: {}", source))]
+    #[error("Can't add path to environment variable: {}", source)]
-    CantAddPathToEnvironment {
+    CantAddPathToEnvironment { source: std::env::JoinPathsError },
-        source: std::env::JoinPathsError,
+    #[error("Can't find version in dotfiles. Please provide a version manually to the command.")]
-    },
-    #[snafu(display(
-        "Can't find version in dotfiles. Please provide a version manually to the command."
-    ))]
     CantInferVersion,
-    #[snafu(display("Requested version {} is not currently installed", version))]
+    #[error("Requested version {} is not currently installed", version)]
-    VersionNotFound {
+    VersionNotFound { version: UserVersion },
-        version: UserVersion,
+    #[error(transparent)]
-    },
     ApplicableVersionError {
+        #[from]
         source: UserInputError,
     },
-    #[snafu(display(
+    #[error("Can't read exit code from process.\nMaybe the process was killed using a signal?")]
-        "Can't read exit code from process.\nMaybe the process was killed using a signal?"
-    ))]
     CantReadProcessExitCode,
-    #[snafu(display("command not provided. Please provide a command to run as an argument, like {} or {}.\n{} {}", "node".italic(), "bash".italic(), "example:".yellow().bold(), "fnm exec --using=12 node --version".italic().yellow()))]
+    #[error("command not provided. Please provide a command to run as an argument, like {} or {}.\n{} {}", "node".italic(), "bash".italic(), "example:".yellow().bold(), "fnm exec --using=12 node --version".italic().yellow())]
     NoBinaryProvided,
 }

src/commands/install.rs

@@ -10,8 +10,8 @@ use crate::version::Version;
 use crate::version_files::get_user_version_for_directory;
 use colored::Colorize;
 use log::debug;
-use snafu::{ensure, OptionExt, ResultExt, Snafu};
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug, Default)]
 pub struct Install {
@@ -51,20 +51,19 @@ impl super::command::Command for Install {
         let current_version = self
             .version()?
             .or_else(|| get_user_version_for_directory(current_dir, config))
-            .context(CantInferVersion)?;
+            .ok_or(Error::CantInferVersion)?;
 
         let version = match current_version.clone() {
             UserVersion::Full(Version::Semver(actual_version)) => Version::Semver(actual_version),
             UserVersion::Full(v @ (Version::Bypassed | Version::Alias(_))) => {
-                ensure!(false, UninstallableVersion { version: v });
+                return Err(Error::UninstallableVersion { version: v });
-                unreachable!();
             }
             UserVersion::Full(Version::Lts(lts_type)) => {
                 let available_versions: Vec<_> = remote_node_index::list(&config.node_dist_mirror)
-                    .context(CantListRemoteVersions)?;
+                    .map_err(|source| Error::CantListRemoteVersions { source })?;
                 let picked_version = lts_type
                     .pick_latest(&available_versions)
-                    .with_context(|| CantFindRelevantLts {
+                    .ok_or_else(|| Error::CantFindRelevantLts {
                         lts_type: lts_type.clone(),
                     })?
                     .version
@@ -78,14 +77,14 @@ impl super::command::Command for Install {
             }
             current_version => {
                 let available_versions: Vec<_> = remote_node_index::list(&config.node_dist_mirror)
-                    .context(CantListRemoteVersions)?
+                    .map_err(|source| Error::CantListRemoteVersions { source })?
                     .drain(..)
                     .map(|x| x.version)
                     .collect();
 
                 current_version
                     .to_version(&available_versions, config)
-                    .context(CantFindNodeVersion {
+                    .ok_or(Error::CantFindNodeVersion {
                         requested_version: current_version,
                     })?
                     .clone()
@@ -113,7 +112,7 @@ impl super::command::Command for Install {
             Err(err @ DownloaderError::VersionAlreadyInstalled { .. }) => {
                 outln!(config, Error, "{} {}", "warning:".bold().yellow(), err);
             }
-            other_err => other_err.context(DownloadError)?,
+            other_err => other_err.map_err(|source| Error::DownloadError { source })?,
         };
 
         if let UserVersion::Full(Version::Lts(lts_type)) = current_version {
@@ -123,51 +122,41 @@ impl super::command::Command for Install {
                 alias_name.cyan(),
                 version.v_str().cyan()
             );
-            create_alias(config, &alias_name, &version).context(IoError)?;
+            create_alias(config, &alias_name, &version)?;
         }
 
         if !config.default_version_dir().exists() {
             debug!("Tagging {} as the default version", version.v_str().cyan());
-            create_alias(config, "default", &version).context(IoError)?;
+            create_alias(config, "default", &version)?;
         }
 
         Ok(())
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't download the requested binary: {}", source))]
+    #[error("Can't download the requested binary: {}", source)]
-    DownloadError {
+    DownloadError { source: DownloaderError },
-        source: DownloaderError,
+    #[error(transparent)]
-    },
     IoError {
+        #[from]
         source: std::io::Error,
     },
-    #[snafu(display(
+    #[error("Can't find version in dotfiles. Please provide a version manually to the command.")]
-        "Can't find version in dotfiles. Please provide a version manually to the command."
-    ))]
     CantInferVersion,
-    #[snafu(display("Having a hard time listing the remote versions: {}", source))]
+    #[error("Having a hard time listing the remote versions: {}", source)]
-    CantListRemoteVersions {
+    CantListRemoteVersions { source: crate::http::Error },
-        source: crate::http::Error,
+    #[error(
-    },
-    #[snafu(display(
         "Can't find a Node version that matches {} in remote",
         requested_version
-    ))]
+    )]
-    CantFindNodeVersion {
+    CantFindNodeVersion { requested_version: UserVersion },
-        requested_version: UserVersion,
+    #[error("Can't find relevant LTS named {}", lts_type)]
-    },
+    CantFindRelevantLts { lts_type: crate::lts::LtsType },
-    #[snafu(display("Can't find relevant LTS named {}", lts_type))]
+    #[error("The requested version is not installable: {}", version.v_str())]
-    CantFindRelevantLts {
+    UninstallableVersion { version: Version },
-        lts_type: crate::lts::LtsType,
+    #[error("Too many versions provided. Please don't use --lts with a version string.")]
-    },
-    #[snafu(display("The requested version is not installable: {}", version.v_str()))]
-    UninstallableVersion {
-        version: Version,
-    },
-    #[snafu(display("Too many versions provided. Please don't use --lts with a version string."))]
     TooManyVersionsProvided,
 }
 

src/commands/ls_local.rs

@@ -3,9 +3,9 @@ use crate::config::FnmConfig;
 use crate::current_version::current_version;
 use crate::version::Version;
 use colored::Colorize;
-use snafu::{ResultExt, Snafu};
 use std::collections::HashMap;
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug)]
 pub struct LsLocal {}
@@ -15,11 +15,12 @@ impl super::command::Command for LsLocal {
 
     fn apply(self, config: &FnmConfig) -> Result<(), Self::Error> {
         let base_dir = config.installations_dir();
-        let mut versions =
+        let mut versions = crate::installed_versions::list(base_dir)
-            crate::installed_versions::list(base_dir).context(CantListLocallyInstalledVersion)?;
+            .map_err(|source| Error::CantListLocallyInstalledVersion { source })?;
         versions.insert(0, Version::Bypassed);
         versions.sort();
-        let aliases_hash = generate_aliases_hash(config).context(CantReadAliases)?;
+        let aliases_hash =
+            generate_aliases_hash(config).map_err(|source| Error::CantReadAliases { source })?;
         let curr_version = current_version(config).ok().flatten();
 
         for version in versions {
@@ -60,12 +61,12 @@ fn generate_aliases_hash(config: &FnmConfig) -> std::io::Result<HashMap<String,
     Ok(hashmap)
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't list locally installed versions: {}", source))]
+    #[error("Can't list locally installed versions: {}", source)]
     CantListLocallyInstalledVersion {
         source: crate::installed_versions::Error,
     },
-    #[snafu(display("Can't read aliases: {}", source))]
+    #[error("Can't read aliases: {}", source)]
     CantReadAliases { source: std::io::Error },
 }

src/commands/ls_remote.rs

@@ -1,7 +1,7 @@
 use crate::config::FnmConfig;
 use crate::remote_node_index;
-use snafu::{ResultExt, Snafu};
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug)]
 pub struct LsRemote {}
@@ -10,7 +10,7 @@ impl super::command::Command for LsRemote {
     type Error = Error;
 
     fn apply(self, config: &FnmConfig) -> Result<(), Self::Error> {
-        let all_versions = remote_node_index::list(&config.node_dist_mirror).context(HttpError)?;
+        let all_versions = remote_node_index::list(&config.node_dist_mirror)?;
 
         for version in all_versions {
             print!("{}", version.version);
@@ -24,7 +24,11 @@ impl super::command::Command for LsRemote {
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    HttpError { source: crate::http::Error },
+    #[error(transparent)]
+    HttpError {
+        #[from]
+        source: crate::http::Error,
+    },
 }

src/commands/unalias.rs

@@ -3,8 +3,8 @@ use crate::fs::remove_symlink_dir;
 use crate::user_version::UserVersion;
 use crate::version::Version;
 use crate::{choose_version_for_user_input, config::FnmConfig};
-use snafu::{OptionExt, ResultExt, Snafu};
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug)]
 pub struct Unalias {
@@ -21,20 +21,21 @@ impl Command for Unalias {
         )
         .ok()
         .flatten()
-        .with_context(|| AliasNotFound {
+        .ok_or(Error::AliasNotFound {
             requested_alias: self.requested_alias,
         })?;
 
-        remove_symlink_dir(&requested_version.path()).context(CantDeleteSymlink)?;
+        remove_symlink_dir(&requested_version.path())
+            .map_err(|source| Error::CantDeleteSymlink { source })?;
 
         Ok(())
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't delete symlink: {}", source))]
+    #[error("Can't delete symlink: {}", source)]
     CantDeleteSymlink { source: std::io::Error },
-    #[snafu(display("Requested alias {} not found", requested_alias))]
+    #[error("Requested alias {} not found", requested_alias)]
     AliasNotFound { requested_alias: String },
 }

src/commands/uninstall.rs

@@ -8,8 +8,8 @@ use crate::version::Version;
 use crate::version_files::get_user_version_for_directory;
 use colored::Colorize;
 use log::debug;
-use snafu::{ensure, OptionExt, ResultExt, Snafu};
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug)]
 pub struct Uninstall {
@@ -20,49 +20,48 @@ impl Command for Uninstall {
     type Error = Error;
 
     fn apply(self, config: &FnmConfig) -> Result<(), Self::Error> {
-        let all_versions =
+        let all_versions = installed_versions::list(config.installations_dir())
-            installed_versions::list(config.installations_dir()).context(VersionListingError)?;
+            .map_err(|source| Error::VersionListingError { source })?;
         let requested_version = self
             .version
             .or_else(|| {
                 let current_dir = std::env::current_dir().unwrap();
                 get_user_version_for_directory(current_dir, config)
             })
-            .context(CantInferVersion)?;
+            .ok_or(Error::CantInferVersion)?;
 
-        ensure!(
+        if matches!(requested_version, UserVersion::Full(Version::Bypassed)) {
-            !matches!(requested_version, UserVersion::Full(Version::Bypassed)),
+            return Err(Error::CantUninstallSystemVersion);
-            CantUninstallSystemVersion
+        }
-        );
 
         let available_versions: Vec<&Version> = all_versions
             .iter()
             .filter(|v| requested_version.matches(v, config))
             .collect();
 
-        ensure!(
+        if available_versions.len() >= 2 {
-            available_versions.len() < 2,
+            return Err(Error::PleaseBeMoreSpecificToDelete {
-            PleaseBeMoreSpecificToDelete {
                 matched_versions: available_versions
                     .iter()
-                    .map(|x| x.v_str())
+                    .map(std::string::ToString::to_string)
-                    .collect::<Vec<_>>()
+                    .collect(),
-            }
+            });
-        );
+        }
 
         let version = requested_version
             .to_version(&all_versions, config)
-            .context(CantFindVersion)?;
+            .ok_or(Error::CantFindVersion)?;
 
-        let matching_aliases = version.find_aliases(config).context(IoError)?;
+        let matching_aliases = version.find_aliases(config)?;
         let root_path = version
             .root_path(config)
-            .with_context(|| RootPathNotFound {
+            .ok_or_else(|| Error::RootPathNotFound {
                 version: version.clone(),
             })?;
 
         debug!("Removing Node version from {:?}", root_path);
-        std::fs::remove_dir_all(root_path).context(CantDeleteNodeVersion)?;
+        std::fs::remove_dir_all(root_path)
+            .map_err(|source| Error::CantDeleteNodeVersion { source })?;
         outln!(
             config,
             Info,
@@ -72,7 +71,8 @@ impl Command for Uninstall {
 
         for alias in matching_aliases {
             debug!("Removing alias from {:?}", alias.path());
-            remove_symlink_dir(alias.path()).context(CantDeleteSymlink)?;
+            remove_symlink_dir(alias.path())
+                .map_err(|source| Error::CantDeleteSymlink { source })?;
             outln!(
                 config,
                 Info,
@@ -85,26 +85,27 @@ impl Command for Uninstall {
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't get locally installed versions: {}", source))]
+    #[error("Can't get locally installed versions: {}", source)]
     VersionListingError { source: installed_versions::Error },
-    #[snafu(display(
+    #[error("Can't find version in dotfiles. Please provide a version manually to the command.")]
-        "Can't find version in dotfiles. Please provide a version manually to the command."
-    ))]
     CantInferVersion,
-    #[snafu(display("Can't uninstall system version"))]
+    #[error("Can't uninstall system version")]
     CantUninstallSystemVersion,
-    #[snafu(display("Too many versions had matched, please be more specific.\nFound {} matching versions, expected 1:\n{}", matched_versions.len(), matched_versions.iter().map(|v| format!("* {}", v)).collect::<Vec<_>>().join("\n")))]
+    #[error("Too many versions had matched, please be more specific.\nFound {} matching versions, expected 1:\n{}", matched_versions.len(), matched_versions.iter().map(|v| format!("* {}", v)).collect::<Vec<_>>().join("\n"))]
     PleaseBeMoreSpecificToDelete { matched_versions: Vec<String> },
-    #[snafu(display("Can't find a matching version"))]
+    #[error("Can't find a matching version")]
     CantFindVersion,
-    #[snafu(display("Root path not found for version {}", version))]
+    #[error("Root path not found for version {}", version)]
     RootPathNotFound { version: Version },
-    #[snafu(display("io error: {}", source))]
+    #[error("io error: {}", source)]
-    IoError { source: std::io::Error },
+    IoError {
-    #[snafu(display("Can't delete Node.js version: {}", source))]
+        #[from]
+        source: std::io::Error,
+    },
+    #[error("Can't delete Node.js version: {}", source)]
     CantDeleteNodeVersion { source: std::io::Error },
-    #[snafu(display("Can't delete symlink: {}", source))]
+    #[error("Can't delete symlink: {}", source)]
     CantDeleteSymlink { source: std::io::Error },
 }

src/commands/use.rs

@@ -10,9 +10,9 @@ use crate::version::Version;
 use crate::version_file_strategy::VersionFileStrategy;
 use crate::{config::FnmConfig, user_version_reader::UserVersionReader};
 use colored::Colorize;
-use snafu::{ensure, OptionExt, ResultExt, Snafu};
 use std::path::Path;
 use structopt::StructOpt;
+use thiserror::Error;
 
 #[derive(StructOpt, Debug)]
 pub struct Use {
@@ -31,11 +31,11 @@ impl Command for Use {
     type Error = Error;
 
     fn apply(self, config: &FnmConfig) -> Result<(), Self::Error> {
-        let multishell_path = config.multishell_path().context(FnmEnvWasNotSourced)?;
+        let multishell_path = config.multishell_path().ok_or(Error::FnmEnvWasNotSourced)?;
         warn_if_multishell_path_not_in_path_env_var(multishell_path, config);
 
-        let all_versions =
+        let all_versions = installed_versions::list(config.installations_dir())
-            installed_versions::list(config.installations_dir()).context(VersionListingError)?;
+            .map_err(|source| Error::VersionListingError { source })?;
         let requested_version = self
             .version
             .unwrap_or_else(|| {
@@ -47,7 +47,7 @@ impl Command for Use {
                 VersionFileStrategy::Local => InferVersionError::Local,
                 VersionFileStrategy::Recursive => InferVersionError::Recursive,
             })
-            .context(CantInferVersion)?;
+            .map_err(|source| Error::CantInferVersion { source })?;
 
         let (message, version_path) = if let UserVersion::Full(Version::Bypassed) =
             requested_version
@@ -101,7 +101,8 @@ impl Command for Use {
             })?;
         }
 
-        replace_symlink(&version_path, multishell_path).context(SymlinkingCreationIssue)?;
+        replace_symlink(&version_path, multishell_path)
+            .map_err(|source| Error::SymlinkingCreationIssue { source })?;
 
         Ok(())
     }
@@ -120,19 +121,18 @@ fn install_new_version(
     config: &FnmConfig,
     install_if_missing: bool,
 ) -> Result<(), Error> {
-    ensure!(
+    if !install_if_missing && !should_install_interactively(&requested_version) {
-        install_if_missing || should_install_interactively(&requested_version),
+        return Err(Error::CantFindVersion {
-        CantFindVersion {
+            version: requested_version,
-            version: requested_version
+        });
-        }
+    }
-    );
 
     Install {
         version: Some(requested_version.clone()),
         ..Install::default()
     }
     .apply(config)
-    .context(InstallError)?;
+    .map_err(|source| Error::InstallError { source })?;
 
     Use {
         version: Some(UserVersionReader::Direct(requested_version)),
@@ -207,37 +207,36 @@ fn warn_if_multishell_path_not_in_path_env_var(
     );
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display("Can't create the symlink: {}", source))]
+    #[error("Can't create the symlink: {}", source)]
     SymlinkingCreationIssue { source: std::io::Error },
-    #[snafu(display("Can't read the symlink: {}", source))]
+    #[error(transparent)]
-    SymlinkReadFailed { source: std::io::Error },
-    #[snafu(display("{}", source))]
     InstallError { source: <Install as Command>::Error },
-    #[snafu(display("Can't get locally installed versions: {}", source))]
+    #[error("Can't get locally installed versions: {}", source)]
     VersionListingError { source: installed_versions::Error },
-    #[snafu(display("Requested version {} is not currently installed", version))]
+    #[error("Requested version {} is not currently installed", version)]
     CantFindVersion { version: UserVersion },
-    #[snafu(display("{}", source))]
+    #[error(transparent)]
-    CantInferVersion { source: InferVersionError },
+    CantInferVersion {
-    #[snafu(display(
+        #[from]
+        source: InferVersionError,
+    },
+    #[error(
         "{}\n{}\n{}",
         "We can't find the necessary environment variables to replace the Node version.",
         "You should setup your shell profile to evaluate `fnm env`, see https://github.com/Schniz/fnm#shell-setup on how to do this",
         "Check out our documentation for more information: https://fnm.vercel.app"
-    ))]
+    )]
     FnmEnvWasNotSourced,
-    #[snafu(display("Can't create the multishell directory: {}", path.display()))]
+    #[error("Can't create the multishell directory: {}", path.display())]
     MultishellDirectoryCreationIssue { path: std::path::PathBuf },
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum InferVersionError {
-    #[snafu(display(
+    #[error("Can't find version in dotfiles. Please provide a version manually to the command.")]
-        "Can't find version in dotfiles. Please provide a version manually to the command."
-    ))]
     Local,
-    #[snafu(display("Could not find any version to use. Maybe you don't have a default version set?\nTry running `fnm default <VERSION>` to set one,\nor create a .node-version file inside your project to declare a Node.js version."))]
+    #[error("Could not find any version to use. Maybe you don't have a default version set?\nTry running `fnm default <VERSION>` to set one,\nor create a .node-version file inside your project to declare a Node.js version.")]
     Recursive,
 }

src/current_version.rs

@@ -1,10 +1,11 @@
+use thiserror::Error;
+
 use crate::config::FnmConfig;
 use crate::system_version;
 use crate::version::Version;
-use snafu::{OptionExt, ResultExt, Snafu};
 
 pub fn current_version(config: &FnmConfig) -> Result<Option<Version>, Error> {
-    let multishell_path = config.multishell_path().context(EnvNotApplied)?;
+    let multishell_path = config.multishell_path().ok_or(Error::EnvNotApplied)?;
 
     if multishell_path.read_link().ok() == Some(system_version::path()) {
         return Ok(Some(Version::Bypassed));
@@ -19,20 +20,21 @@ pub fn current_version(config: &FnmConfig) -> Result<Option<Version>, Error> {
             .expect("Can't get filename")
             .to_str()
             .expect("Invalid OS string");
-        let version = Version::parse(file_name).context(VersionError { version: file_name })?;
+        let version = Version::parse(file_name).map_err(|source| Error::VersionError {
+            source,
+            version: file_name.to_string(),
+        })?;
         Ok(Some(version))
     } else {
         Ok(None)
     }
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    #[snafu(display(
+    #[error("`fnm env` was not applied in this context.\nCan't find fnm's environment variables")]
-        "`fnm env` was not applied in this context.\nCan't find fnm's environment variables"
-    ))]
     EnvNotApplied,
-    #[snafu(display("Can't read the version as a valid semver"))]
+    #[error("Can't read the version as a valid semver")]
     VersionError {
         source: semver::Error,
         version: String,

src/downloader.rs

@@ -4,38 +4,34 @@ use crate::archive::{Error as ExtractError, Extract};
 use crate::directory_portal::DirectoryPortal;
 use crate::version::Version;
 use log::debug;
-use snafu::{ensure, OptionExt, ResultExt, Snafu};
 use std::path::Path;
 use std::path::PathBuf;
+use thiserror::Error;
 use url::Url;
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
+    #[error(transparent)]
     HttpError {
+        #[from]
         source: crate::http::Error,
     },
+    #[error(transparent)]
     IoError {
+        #[from]
         source: std::io::Error,
     },
-    #[snafu(display("Can't extract the file: {}", source))]
+    #[error("Can't extract the file: {}", source)]
     CantExtractFile {
+        #[from]
         source: ExtractError,
     },
-    #[snafu(display("The downloaded archive is empty"))]
+    #[error("The downloaded archive is empty")]
     TarIsEmpty,
-    #[snafu(display(
+    #[error("{} for {} not found upstream.\nYou can `fnm ls-remote` to see available versions or try a different `--arch`.", version, arch)]
-        "{} for {} not found upstream.\nYou can `fnm ls-remote` to see available versions or try a different `--arch`.",
+    VersionNotFound { version: Version, arch: Arch },
-        version,
+    #[error("Version already installed at {:?}", path)]
-        arch
+    VersionAlreadyInstalled { path: PathBuf },
-    ))]
-    VersionNotFound {
-        version: Version,
-        arch: Arch,
-    },
-    #[snafu(display("Version already installed at {:?}", path))]
-    VersionAlreadyInstalled {
-        path: PathBuf,
-    },
 }
 
 #[cfg(unix)]
@@ -75,7 +71,7 @@ pub fn extract_archive_into<P: AsRef<Path>>(
     let extractor = archive::TarXz::new(response);
     #[cfg(windows)]
     let extractor = archive::Zip::new(response);
-    extractor.extract_into(path).context(CantExtractFile)?;
+    extractor.extract_into(path)?;
     Ok(())
 }
 
@@ -88,23 +84,22 @@ pub fn install_node_dist<P: AsRef<Path>>(
 ) -> Result<(), Error> {
     let installation_dir = PathBuf::from(installations_dir.as_ref()).join(version.v_str());
 
-    ensure!(
+    if installation_dir.exists() {
-        !installation_dir.exists(),
+        return Err(Error::VersionAlreadyInstalled {
-        VersionAlreadyInstalled {
+            path: installation_dir,
-            path: installation_dir
+        });
-        }
+    }
-    );
 
-    std::fs::create_dir_all(installations_dir.as_ref()).context(IoError)?;
+    std::fs::create_dir_all(installations_dir.as_ref())?;
 
     let temp_installations_dir = installations_dir.as_ref().join(".downloads");
-    std::fs::create_dir_all(&temp_installations_dir).context(IoError)?;
+    std::fs::create_dir_all(&temp_installations_dir)?;
 
     let portal = DirectoryPortal::new_in(&temp_installations_dir, installation_dir);
 
     let url = download_url(node_dist_mirror, version, arch);
     debug!("Going to call for {}", &url);
-    let response = crate::http::get(url.as_str()).context(HttpError)?;
+    let response = crate::http::get(url.as_str())?;
 
     if response.status() == 404 {
         return Err(Error::VersionNotFound {
@@ -117,17 +112,15 @@ pub fn install_node_dist<P: AsRef<Path>>(
     extract_archive_into(&portal, response)?;
     debug!("Extraction completed");
 
-    let installed_directory = std::fs::read_dir(&portal)
+    let installed_directory = std::fs::read_dir(&portal)?
-        .context(IoError)?
         .next()
-        .context(TarIsEmpty)?
+        .ok_or(Error::TarIsEmpty)??;
-        .context(IoError)?;
     let installed_directory = installed_directory.path();
 
     let renamed_installation_dir = portal.join("installation");
-    std::fs::rename(installed_directory, renamed_installation_dir).context(IoError)?;
+    std::fs::rename(installed_directory, renamed_installation_dir)?;
 
-    portal.teleport().context(IoError)?;
+    portal.teleport()?;
 
     Ok(())
 }

src/installed_versions.rs

@@ -1,11 +1,11 @@
 use crate::version::Version;
-use snafu::{ResultExt, Snafu};
 use std::path::Path;
+use thiserror::Error;
 
 pub fn list<P: AsRef<Path>>(installations_dir: P) -> Result<Vec<Version>, Error> {
     let mut vec = vec![];
-    for result_entry in installations_dir.as_ref().read_dir().context(IoError)? {
+    for result_entry in installations_dir.as_ref().read_dir()? {
-        let entry = result_entry.context(IoError)?;
+        let entry = result_entry?;
         if entry
             .file_name()
             .to_str()
@@ -17,19 +17,25 @@ pub fn list<P: AsRef<Path>>(installations_dir: P) -> Result<Vec<Version>, Error>
         let path = entry.path();
         let filename = path
             .file_name()
-            .ok_or_else(|| std::io::Error::from(std::io::ErrorKind::NotFound))
+            .ok_or_else(|| std::io::Error::from(std::io::ErrorKind::NotFound))?
-            .context(IoError)?
             .to_str()
-            .ok_or_else(|| std::io::Error::from(std::io::ErrorKind::NotFound))
+            .ok_or_else(|| std::io::Error::from(std::io::ErrorKind::NotFound))?;
-            .context(IoError)?;
+        let version = Version::parse(filename)?;
-        let version = Version::parse(filename).context(SemverError)?;
         vec.push(version);
     }
     Ok(vec)
 }
 
-#[derive(Debug, Snafu)]
+#[derive(Debug, Error)]
 pub enum Error {
-    IoError { source: std::io::Error },
+    #[error(transparent)]
-    SemverError { source: semver::Error },
+    IoError {
+        #[from]
+        source: std::io::Error,
+    },
+    #[error(transparent)]
+    SemverError {
+        #[from]
+        source: semver::Error,
+    },
 }