fix: use autoguessing of the shell in the shell hook

docs/cli.md

@@ -376,8 +376,8 @@ exit
 This command prints the activation script of an environment.
 
 ##### Options
-- `--shell`: The shell for which the activation script should be printed. Defaults to the current shell.
-    Currently supported variants: [`Bash`,  `Zsh`,  `Xonsh`,  `CmdExe`,  `PowerShell`,  `Fish`,  `NuShell`]
+- `--shell <SHELL> (-s)`: The shell for which the activation script should be printed. Defaults to the current shell.
+    Currently supported variants: [`bash`,  `zsh`,  `xonsh`,  `cmd`,  `powershell`,  `fish`,  `nushell`]
 - `--manifest-path`: the path to `pixi.toml`, by default it searches for one in the parent directories.
 - `--frozen`: install the environment as defined in the lockfile. Without checking the status of the lockfile. It can also be controlled by the `PIXI_FROZEN` environment variable (example: `PIXI_FROZEN=true`).
 - `--locked`: only install if the `pixi.lock` is up-to-date with the `pixi.toml`[^1]. It can also be controlled by the `PIXI_LOCKED` environment variable (example: `PIXI_LOCKED=true`). Conflicts with `--frozen`.
@@ -387,6 +387,7 @@ This command prints the activation script of an environment.
 pixi shell-hook
 pixi shell-hook --shell bash
 pixi shell-hook --shell zsh
+pixi shell-hook -s powershell
 pixi shell-hook --manifest-path ~/myproject/pixi.toml
 pixi shell-hook --frozen
 pixi shell-hook --locked

src/cli/shell_hook.rs

@@ -18,7 +18,7 @@ use crate::{
 /// Print the activation script so users can source it in their shell, without needing the pixi executable.
 #[derive(Parser, Debug)]
 pub struct Args {
-    /// Sets the shell
+    /// Sets the shell, options: [`bash`,  `zsh`,  `xonsh`,  `cmd`,  `powershell`,  `fish`,  `nushell`]
     #[arg(short, long)]
     shell: Option<ShellEnum>,
 
@@ -39,7 +39,12 @@ async fn generate_activation_script(
     shell: Option<ShellEnum>,
     environment: &Environment<'_>,
 ) -> miette::Result<String> {
-    let shell = shell.unwrap_or_default();
+    // Get shell from the arguments or from the current process or use default if all fails
+    let shell = shell.unwrap_or_else(|| {
+        ShellEnum::from_parent_process()
+            .unwrap_or_else(|| ShellEnum::from_env().unwrap_or_default())
+    });
+
     let activator = get_activator(environment, shell).into_diagnostic()?;
 
     let path = std::env::var("PATH")
@@ -88,20 +93,55 @@ pub async fn execute(args: Args) -> miette::Result<()> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use rattler_shell::shell::{Bash, CmdExe, Fish, NuShell, PowerShell, Xonsh, Zsh};
 
     #[tokio::test]
     async fn test_shell_hook() {
         let project = Project::discover().unwrap();
         let environment = project.default_environment();
-        let script = generate_activation_script(None, &environment)
+        let script = generate_activation_script(Some(ShellEnum::Bash(Bash)), &environment)
+            .await
+            .unwrap();
+        assert!(script.contains("export PATH="));
+        assert!(script.contains("export CONDA_PREFIX="));
+
+        let script = generate_activation_script(
+            Some(ShellEnum::PowerShell(PowerShell::default())),
+            &environment,
+        )
+        .await
+        .unwrap();
+        assert!(script.contains("${Env:PATH}"));
+        assert!(script.contains("${Env:CONDA_PREFIX}"));
+
+        let script = generate_activation_script(Some(ShellEnum::Zsh(Zsh)), &environment)
+            .await
+            .unwrap();
+        assert!(script.contains("export PATH="));
+        assert!(script.contains("export CONDA_PREFIX="));
+
+        let script = generate_activation_script(Some(ShellEnum::Fish(Fish)), &environment)
+            .await
+            .unwrap();
+        assert!(script.contains("set -gx PATH "));
+        assert!(script.contains("set -gx CONDA_PREFIX "));
+
+        let script = generate_activation_script(Some(ShellEnum::Xonsh(Xonsh)), &environment)
+            .await
+            .unwrap();
+        assert!(script.contains("$PATH = "));
+        assert!(script.contains("$CONDA_PREFIX = "));
+
+        let script = generate_activation_script(Some(ShellEnum::CmdExe(CmdExe)), &environment)
+            .await
+            .unwrap();
+        assert!(script.contains("@SET \"PATH="));
+        assert!(script.contains("@SET \"CONDA_PREFIX="));
+
+        let script = generate_activation_script(Some(ShellEnum::NuShell(NuShell)), &environment)
             .await
             .unwrap();
-        if cfg!(unix) {
-            assert!(script.contains("export PATH="));
-            assert!(script.contains("export CONDA_PREFIX="));
-        } else {
-            assert!(script.contains("@SET \"PATH="));
-            assert!(script.contains("@SET \"CONDA_PREFIX="));
-        }
+        assert!(script.contains("$env.PATH = "));
+        assert!(script.contains("$env.CONDA_PREFIX = "));
     }
 }