Replace ichwh with which and some fixes for auto-cd (canonicalization) (#1672)

* fix: absolutize path against its parent if it was a symlink.

On Linux this happens because Rust calls readlink but doesn't canonicalize the resultant path.

* feat: playground function to create symlinks

* fix: use playground dirs

* feat: test for #1631, shift tests names

* Creation of FilesystemShell with custom location may fail

* Replace ichwh with which

* Creation of FilesystemShell with custom location may fail

* Replace ichwh with which

* fix: add ichwh again since it cannot be completely replaced

* fix: replace one more use of which

Cargo.lock

@@ -2199,6 +2199,7 @@ dependencies = [
  "umask",
  "unicode-xid",
  "users",
+ "which",
 ]
 
 [[package]]
@@ -4084,6 +4085,16 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "which"
+version = "3.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d011071ae14a2f6671d0b74080ae0cd8ebf3a6f8c9589a2cd45f23126fe29724"
+dependencies = [
+ "failure",
+ "libc",
+]
+
 [[package]]
 name = "widestring"
 version = "0.4.0"

crates/nu-cli/Cargo.toml

@@ -84,6 +84,7 @@ toml = "0.5.6"
 typetag = "0.1.4"
 umask = "0.1"
 unicode-xid = "0.2.0"
+which = "3"
 
 trash = { version = "1.0.0", optional = true }
 clipboard = { version = "0.5", optional = true }

crates/nu-cli/src/cli.rs

@@ -6,6 +6,7 @@ use crate::commands::whole_stream_command;
 use crate::context::Context;
 #[cfg(not(feature = "starship-prompt"))]
 use crate::git::current_branch;
+use crate::path::canonicalize;
 use crate::prelude::*;
 use futures_codec::FramedRead;
 
@@ -22,7 +23,7 @@ use rustyline::{
 use std::error::Error;
 use std::io::{BufRead, BufReader, Write};
 use std::iter::Iterator;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::sync::atomic::Ordering;
 
 fn load_plugin(path: &std::path::Path, context: &mut Context) -> Result<(), ShellError> {
@@ -775,9 +776,9 @@ async fn process_line(
                             .as_ref()
                             .map(NamedArguments::is_empty)
                             .unwrap_or(true)
-                        && dunce::canonicalize(&name).is_ok()
-                        && PathBuf::from(&name).is_dir()
-                        && ichwh::which(&name).await.unwrap_or(None).is_none()
+                        && canonicalize(ctx.shell_manager.path(), name).is_ok()
+                        && Path::new(&name).is_dir()
+                        && which::which(&name).is_err()
                     {
                         // Here we work differently if we're in Windows because of the expected Windows behavior
                         #[cfg(windows)]

crates/nu-cli/src/commands/classified/external.rs

@@ -467,12 +467,12 @@ fn spawn(
 async fn did_find_command(name: &str) -> bool {
     #[cfg(not(windows))]
     {
-        ichwh::which(name).await.unwrap_or(None).is_some()
+        which::which(name).is_ok()
     }
 
     #[cfg(windows)]
     {
-        if ichwh::which(name).await.unwrap_or(None).is_some() {
+        if which::which(name).is_ok() {
             true
         } else {
             let cmd_builtins = [

crates/nu-cli/src/commands/classified/internal.rs

@@ -117,7 +117,7 @@ pub(crate) fn run_internal_command(
                     }
                     CommandAction::EnterShell(location) => {
                         context.shell_manager.insert_at_current(Box::new(
-                            FilesystemShell::with_location(location, context.registry().clone()),
+                            FilesystemShell::with_location(location, context.registry().clone())?,
                         ));
                     }
                     CommandAction::AddAlias(name, args, block) => {

crates/nu-cli/src/commands/run_external.rs

@@ -181,7 +181,7 @@ async fn maybe_autocd_dir<'a>(cmd: &ExternalCommand, ctx: &mut Context) -> Optio
         || (cmd.args.is_empty()
             && PathBuf::from(name).is_dir()
             && dunce::canonicalize(name).is_ok()
-            && ichwh::which(&name).await.unwrap_or(None).is_none())
+            && which::which(&name).is_err())
     {
         Some(name)
     } else {

crates/nu-cli/src/shell/filesystem_shell.rs

@@ -69,9 +69,15 @@ impl FilesystemShell {
         })
     }
 
-    pub fn with_location(path: String, commands: CommandRegistry) -> FilesystemShell {
+    pub fn with_location(
+        path: String,
+        commands: CommandRegistry,
+    ) -> Result<FilesystemShell, std::io::Error> {
+        let path = canonicalize(std::env::current_dir()?, &path)?;
+        let path = path.display().to_string();
         let last_path = path.clone();
-        FilesystemShell {
+
+        Ok(FilesystemShell {
             path,
             last_path,
             completer: NuCompleter {
@@ -80,7 +86,7 @@ impl FilesystemShell {
                 homedir: dirs::home_dir(),
             },
             hinter: HistoryHinter {},
-        }
+        })
     }
 }
 
@@ -978,7 +984,7 @@ impl Shell for FilesystemShell {
 
     fn set_path(&mut self, path: String) {
         let pathbuf = PathBuf::from(&path);
-        let path = match dunce::canonicalize(pathbuf.as_path()) {
+        let path = match canonicalize(self.path(), pathbuf.as_path()) {
             Ok(path) => {
                 let _ = std::env::set_current_dir(&path);
                 path