test: clear parent envs to prevent leakage to tests (#9976)

Running tests locally from nushell with customizations (i.e.
$env.PROMPT_COMMAND etc) may lead to failing tests as that customization
leaks to the sandboxed nu itself.

Remove `FILE_PWD` from env

# Tests + Formatting

Tests are now passing locally without issue in my case

crates/nu-protocol/src/shell_error.rs

@@ -431,7 +431,7 @@ pub enum ShellError {
     #[diagnostic(
         code(nu::shell::automatic_env_var_set_manually),
         help(
-            r#"The environment variable '{envvar_name}' is set automatically by Nushell and cannot not be set manually."#
+            r#"The environment variable '{envvar_name}' is set automatically by Nushell and cannot be set manually."#
         )
     )]
     AutomaticEnvVarSetManually {

crates/nu-test-support/src/macros.rs

@@ -158,12 +158,11 @@ macro_rules! nu {
 
         let target_cwd = $opts.cwd.unwrap_or(".".to_string());
         let locale = $opts.locale.unwrap_or("en_US.UTF-8".to_string());
+        let executable_path = $crate::fs::executable_path();
 
-        let mut command = Command::new($crate::fs::executable_path());
+        let mut command = $crate::macros::run_command(&executable_path, &target_cwd);
         command
-            .env("PWD", &target_cwd)
             .env(nu_utils::locale::LOCALE_OVERRIDE_ENV_VAR, locale)
-            .current_dir(target_cwd)
             .env(NATIVE_PATH_ENV_VAR, paths_joined)
             // .arg("--skip-plugins")
             // .arg("--no-history")
@@ -278,7 +277,7 @@ macro_rules! nu_with_std {
     (@main $opts:expr, $path:expr) => {{
         pub use std::error::Error;
         pub use std::io::prelude::*;
-        pub use std::process::{Command, Stdio};
+        pub use std::process::Stdio;
         pub use $crate::NATIVE_PATH_ENV_VAR;
 
         pub fn escape_quote_string(input: String) -> String {
@@ -319,12 +318,11 @@ macro_rules! nu_with_std {
 
         let target_cwd = $opts.cwd.unwrap_or(".".to_string());
         let locale = $opts.locale.unwrap_or("en_US.UTF-8".to_string());
+        let executable_path = $crate::fs::executable_path();
 
-        let mut command = Command::new($crate::fs::executable_path());
+        let mut command = $crate::macros::run_command(&executable_path, &target_cwd);
         command
-            .env("PWD", &target_cwd)
             .env(nu_utils::locale::LOCALE_OVERRIDE_ENV_VAR, locale)
-            .current_dir(target_cwd)
             .env(NATIVE_PATH_ENV_VAR, paths_joined)
             // .arg("--skip-plugins")
             // .arg("--no-history")
@@ -396,7 +394,7 @@ macro_rules! nu_with_plugins {
     ($cwd:expr, [$(($format:expr, $plugin_name:expr)),+$(,)?], $command:expr) => {{
         pub use std::error::Error;
         pub use std::io::prelude::*;
-        pub use std::process::{Command, Stdio};
+        pub use std::process::Stdio;
         pub use tempfile::tempdir;
         pub use $crate::{NATIVE_PATH_ENV_VAR, with_exe};
 
@@ -436,9 +434,7 @@ macro_rules! nu_with_plugins {
         if !executable_path.exists() {
             executable_path = $crate::fs::installed_nu_path();
         }
-        let mut process = match Command::new(executable_path)
+        let mut process = match $crate::macros::run_command(&executable_path, &target_cwd)
-            .current_dir(&target_cwd)
-            .env("PWD", &target_cwd) // setting PWD is enough to set cwd
             .arg("--commands")
             .arg(commands)
             .arg("--plugin-config")
@@ -470,3 +466,16 @@ pub fn read_std(std: &[u8]) -> String {
     let out = out.replace("\r\n", "");
     out.replace('\n', "")
 }
+
+use std::{path::PathBuf, process::Command};
+
+pub fn run_command(executable_path: &PathBuf, target_cwd: &str) -> Command {
+    let mut command = Command::new(executable_path);
+
+    command
+        .current_dir(target_cwd)
+        .env_remove("FILE_PWD")
+        .env("PWD", target_cwd); // setting PWD is enough to set cwd;
+
+    command
+}

tests/shell/environment/env.rs

@@ -190,7 +190,7 @@ fn hides_env_in_block() {
 #[test]
 fn env_var_not_var() {
     let actual = nu!("
-        echo $CARGO
+        echo $PWD
         ");
-    assert!(actual.err.contains("use $env.CARGO instead of $CARGO"));
+    assert!(actual.err.contains("use $env.PWD instead of $PWD"));
 }