om health: Shell dotfiles are Nix-managed

crates/omnix-health/src/check/direnv.rs

@@ -87,7 +87,7 @@ fn install_check(
 }
 
 /// Check that the path is in the Nix store (usually /nix/store)
-fn is_path_in_nix_store(path: &std::path::Path) -> bool {
+pub fn is_path_in_nix_store(path: &std::path::Path) -> bool {
     path.starts_with("/nix/store")
 }
 

crates/omnix-health/src/check/mod.rs

@@ -5,4 +5,5 @@ pub mod flake_enabled;
 pub mod max_jobs;
 pub mod min_nix_version;
 pub mod rosetta;
+pub mod shell;
 pub mod trusted_users;

crates/omnix-health/src/check/shell.rs

@@ -0,0 +1,158 @@
+use serde::{Deserialize, Serialize};
+use std::path::{Path, PathBuf};
+
+use crate::traits::{Check, CheckResult, Checkable};
+
+/// Shell types
+///
+#[derive(Debug, Serialize, Deserialize, Clone, Hash, Eq, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub enum Shell {
+    Zsh,
+    Bash,
+    Undeterminable,
+    #[serde(other)]
+    Other,
+}
+
+impl std::fmt::Display for Shell {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let shell_str = match self {
+            Shell::Zsh => "zsh",
+            Shell::Bash => "bash",
+            Shell::Other => "<unsupported shell>",
+            Shell::Undeterminable => "<undeterminable shell>",
+        };
+        write!(f, "{}", shell_str)
+    }
+}
+
+impl Shell {
+    /// Creates a `Shell` from a path string.
+    fn from_path(path: &str) -> Self {
+        let shell_name = Path::new(path).file_name().and_then(|name| name.to_str());
+
+        match shell_name {
+            None => Shell::Undeterminable,
+            Some("zsh") => Shell::Zsh,
+            Some("bash") => Shell::Bash,
+            Some(_) => Shell::Other,
+        }
+    }
+
+    /// Returns the dotfiles for a given `shell`
+    fn get_dotfiles_of_shell(shell: &Shell) -> Result<Vec<String>, ShellError> {
+        match shell {
+            Shell::Zsh => Ok(vec![".zshrc".to_string()]),
+            Shell::Bash => Ok(vec![
+                ".bashrc".to_string(),
+                ".bash_profile".to_string(),
+                ".profile".to_string(),
+            ]),
+            Shell::Other => Err(ShellError::UnsupportedShell),
+            Shell::Undeterminable => Err(ShellError::UndeterminableShell),
+        }
+    }
+}
+
+impl Default for Shell {
+    fn default() -> Self {
+        let shell_path = std::env::var("SHELL").expect("Environment variable `SHELL` not set");
+        Shell::from_path(&shell_path)
+    }
+}
+
+impl Checkable for Shell {
+    fn check(
+        &self,
+        _nix_info: &nix_rs::info::NixInfo,
+        _flake: Option<&nix_rs::flake::url::FlakeUrl>,
+    ) -> Vec<Check> {
+        let check = Check {
+            title: "Shell Configurations".to_string(),
+            info: "Dotfiles managed by Nix".to_string(),
+            result: match are_dotfiles_nix_managed(self) {
+                Ok(true) => CheckResult::Green,
+                Ok(false) => {
+                    let shell = Shell::default();
+                    CheckResult::Red {
+                        msg: format!(
+                            "Default Shell: {} is not managed by Nix", 
+                            shell
+                        ),
+                        suggestion: format!("Manage {} configurations through https://github.com/juspay/nixos-unified-template", shell) 
+                    }
+                }
+                Err(err@ShellError::UnsupportedShell) => CheckResult::Red {
+                    msg: err.to_string(),
+                    suggestion: "We support only Bash & Zsh Shells. Manage Zsh or Bash through https://github.com/juspay/nixos-unified-template".to_owned(),
+                },
+                Err(ShellError::DotfilesNotFound(err)) => CheckResult::Red {
+                    msg: err.to_string(),
+                    suggestion: "Manage Zsh or Bash shells through https://github.com/juspay/nixos-unified-template".to_owned(),
+                },
+                Err(error) => {
+                    panic!(
+                        "Error occurred while checking shell configuration: {}",
+                        error
+                    );
+                }
+            },
+            required: false,
+        };
+        vec![check]
+    }
+}
+
+/// Checks if all dotfiles for a given shell are managed by nix
+///
+/// # Returns
+/// * `true` if all dotfiles are nix-managed
+/// * `false` if any dotfile is not nix-managed
+/// * `Err` if there was an error during the check
+fn are_dotfiles_nix_managed(shell: &Shell) -> Result<bool, ShellError> {
+    let home_dir = PathBuf::from(
+        std::env::var("HOME").map_err(|_| ShellError::EnvVarNotSet("HOME".to_string()))?,
+    );
+
+    let dotfiles = Shell::get_dotfiles_of_shell(shell)?;
+
+    // Iterate over each dotfile and check if it is managed by nix
+    for dotfile in dotfiles {
+        if !check_dotfile_is_managed_by_nix(&home_dir, &dotfile)? {
+            return Ok(false);
+        }
+    }
+    Ok(true)
+}
+
+fn check_dotfile_is_managed_by_nix(home_dir: &Path, dotfile: &str) -> Result<bool, ShellError> {
+    let path = home_dir.join(dotfile);
+    let target =
+        std::fs::read_link(path).map_err(|_| ShellError::DotfilesNotFound(dotfile.to_owned()))?;
+    Ok(super::direnv::is_path_in_nix_store(&target))
+}
+
+#[derive(thiserror::Error, Debug)]
+pub struct DotfilesNotFound(#[from] std::io::Error);
+
+impl std::fmt::Display for DotfilesNotFound {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{:?}", self.0)
+    }
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum ShellError {
+    #[error("Checking configurations for shell is not supported")]
+    UnsupportedShell,
+
+    #[error("Unable to determine user's default shell")]
+    UndeterminableShell,
+
+    #[error("Cannot read symlink target of : {0}")]
+    DotfilesNotFound(String),
+
+    #[error("Environent variable {0} not set")]
+    EnvVarNotSet(String),
+}

crates/omnix-health/src/lib.rs

@@ -20,7 +20,7 @@ use traits::Check;
 
 use self::check::{
     caches::Caches, flake_enabled::FlakeEnabled, max_jobs::MaxJobs, min_nix_version::MinNixVersion,
-    rosetta::Rosetta, trusted_users::TrustedUsers,
+    rosetta::Rosetta, shell::Shell, trusted_users::TrustedUsers,
 };
 
 /// Nix Health check of user's install
@@ -36,6 +36,7 @@ pub struct NixHealth {
     pub trusted_users: TrustedUsers,
     pub caches: Caches,
     pub direnv: Direnv,
+    pub shell: Shell,
 }
 
 /// Convert [NixHealth] into a generic [Vec] of checks
@@ -53,6 +54,7 @@ impl<'a> IntoIterator for &'a NixHealth {
             &self.trusted_users,
             &self.caches,
             &self.direnv,
+            &self.shell,
         ];
         items.into_iter()
     }