add initial nushell support

crates/rattler_shell/src/shell/mod.rs

@@ -422,6 +422,64 @@ impl Shell for Fish {
     }
 }
 
+/// A [`Shell`] implementation for the Bash shell.
+#[derive(Debug, Clone, Copy, Default)]
+pub struct NuShell;
+
+impl Shell for NuShell {
+    fn set_env_var(&self, f: &mut impl Write, env_var: &str, value: &str) -> std::fmt::Result {
+        writeln!(f, "$env.{} = \"{}\"", env_var, value)
+    }
+
+    fn unset_env_var(&self, f: &mut impl Write, env_var: &str) -> std::fmt::Result {
+        writeln!(f, "hide-env {}", env_var)
+    }
+
+    fn run_script(&self, f: &mut impl Write, path: &Path) -> std::fmt::Result {
+        writeln!(f, "source \"{}\"", path.to_string_lossy())
+    }
+
+    fn set_path(
+        &self,
+        f: &mut impl Write,
+        paths: &[PathBuf],
+        modification_behaviour: PathModificationBehaviour,
+        _platform: &Platform,
+    ) -> std::fmt::Result {
+        let path = paths
+            .iter()
+            .map(|path| format!("\"{}\"", path.to_string_lossy().into_owned()))
+            .join(", ");
+
+        // Replace, Append, or Prepend the path variable to the paths.
+        match modification_behaviour {
+            PathModificationBehaviour::Replace => {
+                self.set_env_var(f, "PATH", &format!("[{}]", path))
+            }
+            PathModificationBehaviour::Prepend => {
+                writeln!(f, "let-env PATH = ($env.PATH | prepend [{}])", path)
+            }
+            PathModificationBehaviour::Append => {
+                writeln!(f, "let-env PATH = ($env.PATH | append [{}])", path)
+            }
+        }
+    }
+
+    fn extension(&self) -> &str {
+        "nu"
+    }
+
+    fn executable(&self) -> &str {
+        "nu"
+    }
+
+    fn create_run_script_command(&self, path: &Path) -> Command {
+        let mut cmd = Command::new(self.executable());
+        cmd.arg(path);
+        cmd
+    }
+}
+
 /// A generic [`Shell`] implementation for concrete shell types.
 #[enum_dispatch]
 #[allow(missing_docs)]
@@ -433,6 +491,7 @@ pub enum ShellEnum {
     CmdExe,
     PowerShell,
     Fish,
+    NuShell,
 }
 
 // The default shell is determined by the current OS.
@@ -509,6 +568,8 @@ impl ShellEnum {
             Some(Xonsh.into())
         } else if parent_process_name.contains("fish") {
             Some(Fish.into())
+        } else if parent_process_name.contains("nu") {
+            Some(NuShell.into())
         } else if parent_process_name.contains("powershell") || parent_process_name.contains("pwsh")
         {
             Some(
@@ -540,6 +601,7 @@ impl FromStr for ShellEnum {
             "xonsh" => Ok(Xonsh.into()),
             "fish" => Ok(Fish.into()),
             "cmd" => Ok(CmdExe.into()),
+            "nu" | "nushell" => Ok(NuShell.into()),
             "powershell" | "powershell_ise" => Ok(PowerShell::default().into()),
             _ => Err(ParseShellEnumError(format!(
                 "'{}' is an unknown shell variant",