refactor(shell): enhance shell detection and add VP_SHELL override (#1658)

## What changed

- Replaced `VP_SHELL_NU` and `VP_SHELL_PWSH` with one env var:
`VP_SHELL`
- Added shell parsing that accepts `bash`, `zsh`, `fish`, `nu`, `pwsh`,
and `cmd`

## Why

The old approach depended on a few shell-specific flags and inherited
env vars. It could mis-detect nested shells and is harder to maintain.

The new shell detection stages:

1. `VP_SHELL`  if it is set
2. Fallback to posix or cmd

---------

Co-authored-by: MK (fengmk2) <fengmk2@gmail.com>

Author: nekomoyi

crates/vite_global_cli/src/commands/env/setup.rs

@@ -542,7 +542,7 @@ unset __vp_bin
 vp() {
     if [ "$1" = "env" ] && [ "$2" = "use" ]; then
         case " $* " in *" -h "*|*" --help "*) command vp "$@"; return; esac
-        __vp_out="$(VP_ENV_USE_EVAL_ENABLE=1 command vp "$@")" || return $?
+        __vp_out="$(VP_ENV_USE_EVAL_ENABLE=1 VP_SHELL=sh command vp "$@")" || return $?
         eval "$__vp_out"
     else
         command vp "$@"
@@ -579,7 +579,8 @@ function vp
             command vp $argv; return
         end
         set -lx VP_ENV_USE_EVAL_ENABLE 1
-        set -l __vp_out (env FISH_VERSION=$FISH_VERSION __VP_BIN__/vp $argv); or return $status
+        set -lx VP_SHELL fish
+        set -l __vp_out (command vp $argv); or return $status
         eval (string join ';' $__vp_out)
     else
         command vp $argv
@@ -611,7 +612,7 @@ def --env --wrapped vp [...args: string@"nu-complete vp"] {
             ^vp ...$args
             return
         }
-        let out = (with-env { VP_ENV_USE_EVAL_ENABLE: "1", VP_SHELL_NU: "1" } {
+        let out = (with-env { VP_ENV_USE_EVAL_ENABLE: "1", VP_SHELL: "nu" } {
             ^vp ...$args
         })
         let lines = ($out | lines)
@@ -674,7 +675,7 @@ function vp {
             & (Join-Path $__vp_bin "vp") @args; return
         }
         $env:VP_ENV_USE_EVAL_ENABLE = "1"
-        $env:VP_SHELL_PWSH = "1"
+        $env:VP_SHELL = "pwsh"
         $output = & (Join-Path $__vp_bin "vp") @args 2>&1 | ForEach-Object {
             if ($_ -is [System.Management.Automation.ErrorRecord]) {
                 Write-Host $_.Exception.Message
@@ -683,7 +684,7 @@ function vp {
             }
         }
         Remove-Item Env:VP_ENV_USE_EVAL_ENABLE -ErrorAction SilentlyContinue
-        Remove-Item Env:VP_SHELL_PWSH -ErrorAction SilentlyContinue
+        Remove-Item Env:VP_SHELL -ErrorAction SilentlyContinue
         if ($LASTEXITCODE -eq 0 -and $output) {
             Invoke-Expression ($output -join "`n")
         }
@@ -897,10 +898,6 @@ mod tests {
             nu_content.contains("VP_COMPLETE=fish"),
             "env.nu should use dynamic Fish completion delegation"
         );
-        assert!(
-            nu_content.contains("VP_SHELL_NU"),
-            "env.nu should use VP_SHELL_NU explicit marker instead of inherited NU_VERSION"
-        );
         assert!(nu_content.contains("load-env"), "env.nu should use load-env to apply exports");
     }
 
@@ -1086,10 +1083,6 @@ mod tests {
             fish_content.contains("\"$argv[2]\" = \"use\""),
             "env.fish should check for 'use' subcommand"
         );
-        assert!(
-            fish_content.contains("/vp $argv"),
-            "env.fish should use absolute path to vp for passthrough"
-        );
     }
 
     #[tokio::test]

crates/vite_global_cli/src/commands/env/use.rs

@@ -181,72 +181,43 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_detect_shell_pwsh() {
+    fn test_detect_shell_vp_shell_powershell() {
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            vp_shell_pwsh: true,
+            vp_shell: Some("powershell".into()),
             ..vite_shared::EnvConfig::for_test()
         });
         let shell = detect_shell();
-        assert!(matches!(shell, Shell::PowerShell));
+        assert_eq!(shell, Shell::PowerShell);
     }
 
     #[test]
-    fn test_detect_shell_fish() {
+    fn test_detect_shell_vp_shell_fish() {
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            fish_version: Some("3.7.0".into()),
+            vp_shell: Some("fish".into()),
             ..vite_shared::EnvConfig::for_test()
         });
         let shell = detect_shell();
-        assert!(matches!(shell, Shell::Fish));
+        assert_eq!(shell, Shell::Fish);
     }
 
     #[test]
-    fn test_detect_shell_fish_and_nushell() {
-        // Fish takes priority over Nu shell signal
+    fn test_detect_shell_vp_shell_nu() {
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            fish_version: Some("3.7.0".into()),
-            vp_shell_nu: true,
+            vp_shell: Some("nu".into()),
             ..vite_shared::EnvConfig::for_test()
         });
         let shell = detect_shell();
-        assert!(matches!(shell, Shell::Fish));
+        assert_eq!(shell, Shell::NuShell);
     }
 
     #[test]
     fn test_detect_shell_posix_default() {
-        // All shell detection fields None → defaults
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig::for_test());
         let shell = detect_shell();
         #[cfg(not(windows))]
-        assert!(matches!(shell, Shell::Posix));
+        assert_eq!(shell, Shell::Posix);
         #[cfg(windows)]
-        assert!(matches!(shell, Shell::Cmd));
-    }
-
-    #[test]
-    fn test_detect_shell_nushell() {
-        let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            vp_shell_nu: true,
-            ..vite_shared::EnvConfig::for_test()
-        });
-        let shell = detect_shell();
-        assert!(matches!(shell, Shell::NuShell));
-    }
-
-    #[test]
-    fn test_detect_shell_inherited_nu_version_is_posix() {
-        // NU_VERSION alone (inherited from parent Nushell) must NOT trigger Nu detection.
-        // Only the explicit VP_SHELL_NU marker set by env.nu wrapper counts.
-        let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            nu_version: Some("0.111.0".into()),
-            vp_shell_nu: false,
-            ..vite_shared::EnvConfig::for_test()
-        });
-        let shell = detect_shell();
-        #[cfg(not(windows))]
-        assert!(matches!(shell, Shell::Posix));
-        #[cfg(windows)]
-        let _ = shell;
+        assert_eq!(shell, Shell::Cmd);
     }
 
     #[test]
@@ -346,7 +317,7 @@ mod tests {
         let cwd = AbsolutePathBuf::new(temp_dir.path().to_path_buf()).unwrap();
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
             env_use_eval_enable: true,
-            vp_shell_pwsh: true,
+            vp_shell: Some("powershell".into()),
             ..vite_shared::EnvConfig::for_test_with_home(temp_dir.path())
         });
 

crates/vite_global_cli/src/commands/shell.rs

@@ -1,5 +1,7 @@
 //! Shared shell detection and profile helpers.
 
+use std::str::FromStr;
+
 use directories::BaseDirs;
 use vite_path::{AbsolutePath, AbsolutePathBuf};
 use vite_str::Str;
@@ -19,21 +21,37 @@ pub enum Shell {
     Cmd,
 }
 
-/// Detect the current shell from environment variables.
+impl FromStr for Shell {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "sh" | "bash" | "zsh" => Ok(Shell::Posix),
+            "fish" => Ok(Shell::Fish),
+            "nu" | "nushell" => Ok(Shell::NuShell),
+            "pwsh" | "powershell" => Ok(Shell::PowerShell),
+            "cmd" => Ok(Shell::Cmd),
+            _ => Err(()),
+        }
+    }
+}
+
+/// Detect the current shell:
+/// 1. `VP_SHELL` environment variable
+/// 2. Platform default
 #[must_use]
 pub fn detect_shell() -> Shell {
     let config = vite_shared::EnvConfig::get();
-    if config.fish_version.is_some() {
-        Shell::Fish
-    } else if config.vp_shell_nu {
-        Shell::NuShell
-    } else if config.vp_shell_pwsh {
-        Shell::PowerShell
-    } else if cfg!(windows) {
-        Shell::Cmd
-    } else {
-        Shell::Posix
+
+    // 1. Check VP_SHELL environment variable
+    if let Some(vp_shell) = &config.vp_shell {
+        if let Ok(shell) = Shell::from_str(vp_shell) {
+            return shell;
+        }
     }
+
+    // 2. Platform default
+    if cfg!(windows) { Shell::Cmd } else { Shell::Posix }
 }
 
 /// All shell profile files that interactive terminal sessions may source.
@@ -235,53 +253,98 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_detect_shell_pwsh() {
+    fn test_shell_from_str() {
+        // POSIX shells
+        assert_eq!(Shell::from_str("sh"), Ok(Shell::Posix));
+        assert_eq!(Shell::from_str("bash"), Ok(Shell::Posix));
+        assert_eq!(Shell::from_str("zsh"), Ok(Shell::Posix));
+
+        // Other shells
+        assert_eq!(Shell::from_str("fish"), Ok(Shell::Fish));
+        assert_eq!(Shell::from_str("nu"), Ok(Shell::NuShell));
+        assert_eq!(Shell::from_str("nushell"), Ok(Shell::NuShell));
+        assert_eq!(Shell::from_str("powershell"), Ok(Shell::PowerShell));
+        assert_eq!(Shell::from_str("pwsh"), Ok(Shell::PowerShell));
+        assert_eq!(Shell::from_str("cmd"), Ok(Shell::Cmd));
+
+        // Case insensitive
+        assert_eq!(Shell::from_str("SH"), Ok(Shell::Posix));
+        assert_eq!(Shell::from_str("BASH"), Ok(Shell::Posix));
+        assert_eq!(Shell::from_str("Fish"), Ok(Shell::Fish));
+        assert_eq!(Shell::from_str("POWERSHELL"), Ok(Shell::PowerShell));
+        assert_eq!(Shell::from_str("Nu"), Ok(Shell::NuShell));
+
+        // Invalid
+        assert!(Shell::from_str("posix").is_err());
+        assert!(Shell::from_str("invalid").is_err());
+        assert!(Shell::from_str("").is_err());
+    }
+
+    #[test]
+    fn test_detect_shell_vp_shell_explicit() {
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            vp_shell_pwsh: true,
+            vp_shell: Some("nu".into()),
             ..vite_shared::EnvConfig::for_test()
         });
         let shell = detect_shell();
-        assert!(matches!(shell, Shell::PowerShell));
+        assert_eq!(shell, Shell::NuShell);
     }
 
     #[test]
-    fn test_detect_shell_fish() {
+    fn test_detect_shell_vp_shell_case_insensitive() {
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            fish_version: Some("3.7.0".into()),
+            vp_shell: Some("POWERSHELL".into()),
             ..vite_shared::EnvConfig::for_test()
         });
         let shell = detect_shell();
-        assert!(matches!(shell, Shell::Fish));
+        assert_eq!(shell, Shell::PowerShell);
     }
 
     #[test]
-    fn test_detect_shell_nushell() {
+    fn test_detect_shell_vp_shell_pwsh_alias() {
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            vp_shell_nu: true,
+            vp_shell: Some("pwsh".into()),
             ..vite_shared::EnvConfig::for_test()
         });
         let shell = detect_shell();
-        assert!(matches!(shell, Shell::NuShell));
+        assert_eq!(shell, Shell::PowerShell);
     }
 
     #[test]
-    fn test_detect_shell_nushell_wins_over_powershell() {
+    fn test_detect_shell_vp_shell_fish() {
         let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
-            vp_shell_nu: true,
-            ps_module_path: Some("/some/path".into()),
+            vp_shell: Some("fish".into()),
             ..vite_shared::EnvConfig::for_test()
         });
         let shell = detect_shell();
-        assert!(matches!(shell, Shell::NuShell));
+        assert_eq!(shell, Shell::Fish);
     }
 
     #[test]
-    fn test_detect_shell_posix_default() {
-        let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig::for_test());
+    fn test_detect_shell_defaults_without_vp_shell() {
+        let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
+            vp_shell: None,
+            ..vite_shared::EnvConfig::for_test()
+        });
+        let shell = detect_shell();
+        if cfg!(windows) {
+            assert_eq!(shell, Shell::Cmd);
+        } else {
+            assert_eq!(shell, Shell::Posix);
+        }
+    }
+
+    #[test]
+    fn test_detect_shell_invalid_vp_shell_falls_back_to_default() {
+        let _guard = vite_shared::EnvConfig::test_guard(vite_shared::EnvConfig {
+            vp_shell: Some("invalid".into()),
+            ..vite_shared::EnvConfig::for_test()
+        });
         let shell = detect_shell();
-        #[cfg(not(windows))]
-        assert!(matches!(shell, Shell::Posix));
-        #[cfg(windows)]
-        assert!(matches!(shell, Shell::Cmd));
+        if cfg!(windows) {
+            assert_eq!(shell, Shell::Cmd);
+        } else {
+            assert_eq!(shell, Shell::Posix);
+        }
     }
 }

crates/vite_shared/src/env_config.rs

@@ -113,33 +113,10 @@ pub struct EnvConfig {
     /// Env: `HOME` (Unix) / `USERPROFILE` (Windows)
     pub user_home: Option<PathBuf>,
 
-    /// Fish shell version (indicates running under fish).
+    /// Explicitly specify the current shell.
     ///
-    /// Env: `FISH_VERSION`
-    pub fish_version: Option<String>,
-
-    /// `PowerShell` module path (indicates running under `PowerShell` on Windows).
-    ///
-    /// Env: `PSModulePath`
-    pub ps_module_path: Option<String>,
-
-    /// Nu shell version (indicates running under Nu shell).
-    ///
-    /// Env: `NU_VERSION`
-    pub nu_version: Option<String>,
-
-    /// Explicit Nu shell eval signal set by the `env.nu` wrapper.
-    ///
-    /// Unlike `NU_VERSION`, this is not inherited by child processes — it is only
-    /// present when the Nushell wrapper explicitly passes it via `with-env`.
-    ///
-    /// Env: `VP_SHELL_NU`
-    pub vp_shell_nu: bool,
-
-    /// Explicit `PowerShell` eval signal set by the `env.ps1` wrapper.
-    ///
-    /// Env: `VP_SHELL_PWSH`
-    pub vp_shell_pwsh: bool,
+    /// Env: `VP_SHELL`
+    pub vp_shell: Option<String>,
 }
 
 impl EnvConfig {
@@ -167,11 +144,7 @@ impl EnvConfig {
                 .or_else(|_| std::env::var("USERPROFILE"))
                 .ok()
                 .map(PathBuf::from),
-            fish_version: std::env::var("FISH_VERSION").ok(),
-            ps_module_path: std::env::var("PSModulePath").ok(),
-            nu_version: std::env::var("NU_VERSION").ok(),
-            vp_shell_nu: std::env::var(env_vars::VP_SHELL_NU).is_ok(),
-            vp_shell_pwsh: std::env::var(env_vars::VP_SHELL_PWSH).is_ok(),
+            vp_shell: std::env::var(env_vars::VP_SHELL).ok(),
         }
     }
 
@@ -254,11 +227,7 @@ impl EnvConfig {
             update_task_types: None,
             node_version: None,
             user_home: None,
-            fish_version: None,
-            ps_module_path: None,
-            nu_version: None,
-            vp_shell_nu: false,
-            vp_shell_pwsh: false,
+            vp_shell: None,
         }
     }