Use shim copy only for Windows and revert it for unix

crates/volta-core/src/fs.rs

@@ -118,17 +118,15 @@ pub fn create_staging_dir() -> Fallible<TempDir> {
     })
 }
 
-/// Copies the file shim
-pub fn copy_shim<S, D>(src: S, dest: D) -> io::Result<()>
-where
-    S: AsRef<Path>,
-    D: AsRef<Path>,
+/// Create a file symlink. The `dst` path will be a symbolic link pointing to the `src` path.
+pub fn symlink_file<S, D>(src: S, dest: D) -> io::Result<()>
+    where
+        S: AsRef<Path>,
+        D: AsRef<Path>,
 {
-    let result = std::fs::copy(src, dest);
-    match result {
-        Ok(_v) => Ok(()),
-        Err(e) => Err(e),
-    }
+    return std::os::windows::fs::symlink_file(src, dest);
+
+    return std::os::unix::fs::symlink(src, dest);
 }
 
 /// Create a directory symlink. The `dst` path will be a symbolic link pointing to the `src` path

crates/volta-core/src/shim.rs

@@ -6,7 +6,7 @@ use std::io;
 use std::path::Path;
 
 use crate::error::{Context, ErrorKind, Fallible, VoltaError};
-use crate::fs::{copy_shim, read_dir_eager};
+use crate::fs::{read_dir_eager, symlink_file};
 use crate::layout::{volta_home, volta_install};
 use crate::sync::VoltaLock;
 use log::debug;
@@ -70,10 +70,17 @@ pub fn create(shim_name: &str) -> Fallible<ShimResult> {
     let executable = volta_install()?.shim_executable();
     let shim = volta_home()?.shim_file(shim_name);
 
+    let shim_result;
     #[cfg(windows)]
-    windows::create_git_bash_script(shim_name)?;
+    {
+        windows::create_git_bash_script(shim_name)?;
+        shim_result = std::fs::copy(executable, shim);
+    }
+
+    #[cfg(unix)]
+    shim_result = symlink_file(executable, shim);
 
-    match copy_shim(executable, shim) {
+    match shim_result {
         Ok(_) => Ok(ShimResult::Created),
         Err(err) => {
             if err.kind() == io::ErrorKind::AlreadyExists {