feat(self-update): add with_saved_reg_value()

Author: rami3l

src/cli/self_update/test.rs

@@ -40,6 +40,15 @@ fn restore_path(p: Option<RegValue>) {
     restore_reg_value(&RegKey::predef(HKEY_CURRENT_USER), "Environment", "PATH", p)
 }
 
+#[cfg(windows)]
+pub fn with_saved_reg_value(root: &RegKey, subkey: &str, name: &str, f: &mut dyn FnMut()) {
+    with_saved_global_state(
+        || get_reg_value(root, subkey, name),
+        |p| restore_reg_value(root, subkey, name, p),
+        f,
+    )
+}
+
 #[cfg(windows)]
 fn get_reg_value(root: &RegKey, subkey: &str, name: &str) -> io::Result<Option<RegValue>> {
     let subkey = root.open_subkey_with_flags(subkey, KEY_READ | KEY_WRITE)?;

src/test.rs

@@ -19,6 +19,9 @@ pub use crate::cli::self_update::test::{get_path, with_saved_global_state, with_
 use crate::currentprocess;
 use crate::dist::dist::TargetTriple;
 
+#[cfg(windows)]
+pub use crate::cli::self_update::test::with_saved_reg_value;
+
 // Things that can have environment variables applied to them.
 pub trait Env {
     fn env<K, V>(&mut self, key: K, val: V)