Change type to &str

src/cli/self_update/windows.rs

@@ -457,11 +457,11 @@ pub(crate) fn wait_for_parent() -> Result<()> {
 
 pub(crate) fn do_add_to_path(process: &Process) -> Result<()> {
     let new_path = _with_path_cargo_home_bin(_add_to_path, process)?;
-    _apply_new_path(new_path)?;
+    _apply_new_path(new_path.as_deref())?;
     do_add_to_programs(process)
 }
 
-fn _apply_new_path(new_path: Option<String>) -> Result<()> {
+fn _apply_new_path(new_path: Option<&str>) -> Result<()> {
     use std::ptr;
     use windows_sys::Win32::Foundation::*;
     use windows_sys::Win32::UI::WindowsAndMessaging::{
@@ -478,7 +478,7 @@ fn _apply_new_path(new_path: Option<String>) -> Result<()> {
     if new_path.is_empty() {
         environment.remove_value("PATH")?;
     } else {
-        environment.set_string("PATH", &new_path)?;
+        environment.set_string("PATH", new_path)?;
     }
 
     // Tell other processes to update their environment
@@ -515,22 +515,22 @@ fn get_windows_path_var() -> Result<Option<String>> {
 
 // Returns None if the existing old_path does not need changing, otherwise
 // prepends the path_str to old_path, handling empty old_path appropriately.
-fn _add_to_path(old_path: String, path_str: String) -> Option<String> {
+fn _add_to_path(old_path: &str, path_str: &str) -> Option<String> {
     if old_path.is_empty() {
-        Some(path_str)
-    } else if old_path.contains(&path_str) {
+        Some(path_str.to_owned())
+    } else if old_path.contains(path_str) {
         None
     } else {
-        let mut new_path = path_str;
+        let mut new_path = path_str.to_owned();
         new_path.push(';');
-        new_path += &old_path;
+        new_path += old_path;
         Some(new_path)
     }
 }
 
 // Returns None if the existing old_path does not need changing
-fn _remove_from_path(old_path: String, path_str: String) -> Option<String> {
-    let idx = old_path.find(&path_str)?;
+fn _remove_from_path(old_path: &str, path_str: &str) -> Option<String> {
+    let idx = old_path.find(path_str)?;
     // If there's a trailing semicolon (likely, since we probably added one
     // during install), include that in the substring to remove. We don't search
     // for that to find the string, because if it's the last string in the path,
@@ -552,17 +552,18 @@ fn _remove_from_path(old_path: String, path_str: String) -> Option<String> {
 
 fn _with_path_cargo_home_bin<F>(f: F, process: &Process) -> Result<Option<String>>
 where
-    F: FnOnce(String, String) -> Option<String>,
+    F: FnOnce(&str, &str) -> Option<String>,
 {
-    let windows_path = get_windows_path_var()?;
+    let path = get_windows_path_var()?;
+    let windows_path = path.as_deref();
     let mut path_str = process.cargo_home()?;
     path_str.push("bin");
-    Ok(windows_path.and_then(|old_path| f(old_path, path_str.to_string_lossy().to_string())))
+    Ok(windows_path.and_then(|old_path| f(old_path, &path_str.to_string_lossy())))
 }
 
 pub(crate) fn do_remove_from_path(process: &Process) -> Result<()> {
     let new_path = _with_path_cargo_home_bin(_remove_from_path, process)?;
-    _apply_new_path(new_path)?;
+    _apply_new_path(new_path.as_deref())?;
     do_remove_from_programs()
 }
 
@@ -760,8 +761,8 @@ mod tests {
         assert_eq!(
             None,
             super::_add_to_path(
-                r"c:\users\example\.cargo\bin;foo".to_string(),
-                r"c:\users\example\.cargo\bin".to_string()
+                r"c:\users\example\.cargo\bin;foo",
+                r"c:\users\example\.cargo\bin"
             )
         );
     }
@@ -796,7 +797,7 @@ mod tests {
             {
                 // Can't compare the Results as Eq isn't derived; thanks error-chain.
                 #![allow(clippy::unit_cmp)]
-                assert_eq!((), super::_apply_new_path(Some("foo".to_string())).unwrap());
+                assert_eq!((), super::_apply_new_path(Some("foo")).unwrap());
             }
             let environment = CURRENT_USER.create("Environment").unwrap();
             let path = environment.get_string("PATH").unwrap();
@@ -815,7 +816,7 @@ mod tests {
             {
                 // Can't compare the Results as Eq isn't derived; thanks error-chain.
                 #![allow(clippy::unit_cmp)]
-                assert_eq!((), super::_apply_new_path(Some(String::new())).unwrap());
+                assert_eq!((), super::_apply_new_path(Some("")).unwrap());
             }
             let reg_value = environment.get_string("PATH");
             match reg_value {
@@ -868,8 +869,8 @@ mod tests {
         assert_eq!(
             "foo",
             super::_remove_from_path(
-                r"c:\users\example\.cargo\bin;foo".to_string(),
-                r"c:\users\example\.cargo\bin".to_string(),
+                r"c:\users\example\.cargo\bin;foo",
+                r"c:\users\example\.cargo\bin",
             )
             .unwrap()
         )
@@ -880,8 +881,8 @@ mod tests {
         assert_eq!(
             "foo",
             super::_remove_from_path(
-                r"foo;c:\users\example\.cargo\bin".to_string(),
-                r"c:\users\example\.cargo\bin".to_string(),
+                r"foo;c:\users\example\.cargo\bin",
+                r"c:\users\example\.cargo\bin",
             )
             .unwrap()
         )