Only apply vars once

crates/nu-cli/src/env/directory_specific_environment.rs

@@ -3,9 +3,11 @@ use commands::autoenv;
 use indexmap::{IndexMap, IndexSet};
 use nu_errors::ShellError;
 use sha2::{Digest, Sha256};
+use std::io::Write;
 use std::{
     ffi::OsString,
     fmt::Debug,
+    fs::OpenOptions,
     path::{Path, PathBuf},
 };
 
@@ -14,7 +16,7 @@ type EnvVal = OsString;
 #[derive(Debug, Default)]
 pub struct DirectorySpecificEnvironment {
     trusted: Option<Trusted>,
-
+    last_seen_directory: PathBuf,
     //Directory -> Env key. If an environment var has been added from a .nu in a directory, we track it here so we can remove it when the user leaves the directory.
     added_env_vars: IndexMap<PathBuf, IndexSet<EnvKey>>,
 }
@@ -27,6 +29,7 @@ impl DirectorySpecificEnvironment {
         };
         DirectorySpecificEnvironment {
             trusted,
+            last_seen_directory: PathBuf::from("/"),
             added_env_vars: IndexMap::new(),
         }
     }
@@ -54,13 +57,35 @@ impl DirectorySpecificEnvironment {
         Err(ShellError::untagged_runtime_error("No trusted directories"))
     }
 
+    fn is_parent_or_same(&self, parent: &PathBuf, child: &PathBuf) -> bool {
+        let mut child = Some(child.as_path());
+        while let Some(c) = child {
+            if c == parent {
+                return true;
+            }
+            child = child.expect("Can't be none").parent();
+        }
+        return false;
+    }
+
     pub fn env_vars_to_add(&mut self) -> Result<IndexMap<EnvKey, EnvVal>, ShellError> {
         let current_dir = std::env::current_dir()?;
         let mut working_dir = Some(current_dir.as_path());
         let mut vars_to_add = IndexMap::new();
 
+        //If we are in the last seen directory, do nothing
+        //If we are in a parent directory to last_seen_directory, just return without applying .nu-env in the parent directory - they were already applied earlier.
+        if self.is_parent_or_same(&current_dir, &self.last_seen_directory) {
+            return Ok(vars_to_add);
+        }
+
         //Start in the current directory, then traverse towards the root with working_dir to see if we are in a subdirectory of a valid directory.
         while let Some(wdir) = working_dir {
+            //If we are in a subdirectory to last_seen_directory, we should apply all .nu-envs up until last_seen_directory
+            if wdir == self.last_seen_directory {
+                self.last_seen_directory = current_dir;
+                return Ok(vars_to_add);
+            }
             let wdirenv = wdir.join(".nu-env");
             if wdirenv.exists() {
                 let toml_doc = self.toml_if_directory_is_trusted(&wdirenv)?;
@@ -99,6 +124,7 @@ impl DirectorySpecificEnvironment {
                 .parent();
         }
 
+        self.last_seen_directory = current_dir;
         Ok(vars_to_add)
     }