fix: avoid set_env panic on Windows doctor

Author: justjavac

src/commands/doctor.rs

@@ -11,20 +11,20 @@ pub fn exec(meta: &mut DvmMeta) -> Result<()> {
   // Init enviroments if need
   // actually set DVM_DIR env var if not exist.
   let home_path = dvm_root();
-  set_env::check_or_set("DVM_DIR", home_path.to_str().unwrap()).unwrap();
-  let path = set_env::get("PATH").unwrap();
+  check_or_set_env("DVM_DIR", home_path.to_str().unwrap())?;
+  let path = get_env("PATH")?;
   let looking_for = deno_bin_path().parent().unwrap().to_str().unwrap().to_string();
   let current = which::which("deno");
 
   if let Ok(current) = current {
     if current.to_str().unwrap().starts_with(&looking_for) {
       println!("{}", "DVM deno bin is already set correctly.".green());
     } else {
-      set_env::prepend("PATH", looking_for.as_str()).unwrap();
+      prepend_env_path(looking_for.as_str())?;
       println!("{}", "Please restart your shell of choice to take effects.".red());
     }
-  } else if !path.contains(looking_for.as_str()) {
-    set_env::prepend("PATH", looking_for.as_str()).unwrap();
+  } else if !env_path_contains(&path, looking_for.as_str()) {
+    prepend_env_path(looking_for.as_str())?;
     println!("{}", "Please restart your shell of choice to take effects.".red());
   }
 
@@ -65,3 +65,133 @@ pub fn exec(meta: &mut DvmMeta) -> Result<()> {
   println!("{}", "All fixes applied, DVM is ready to use.".green());
   Ok(())
 }
+
+#[cfg(not(windows))]
+fn check_or_set_env(name: &str, value: &str) -> Result<()> {
+  set_env::check_or_set(name, value).map_err(Into::into)
+}
+
+#[cfg(not(windows))]
+fn get_env(name: &str) -> Result<String> {
+  set_env::get(name).map_err(Into::into)
+}
+
+#[cfg(not(windows))]
+fn prepend_env_path(value: &str) -> Result<()> {
+  set_env::prepend("PATH", value).map_err(Into::into)
+}
+
+#[cfg(not(windows))]
+fn env_path_contains(path: &str, value: &str) -> bool {
+  path.contains(value)
+}
+
+#[cfg(windows)]
+fn check_or_set_env(name: &str, value: &str) -> Result<()> {
+  if std::env::var_os(name).is_none() {
+    set_user_env(name, value)?;
+  }
+  Ok(())
+}
+
+#[cfg(windows)]
+fn get_env(name: &str) -> Result<String> {
+  std::env::var(name).map_err(Into::into)
+}
+
+#[cfg(windows)]
+fn prepend_env_path(value: &str) -> Result<()> {
+  let user_path = get_user_env("Path")?.unwrap_or_default();
+  let new_user_path = prepend_path_value(&user_path, value);
+
+  set_user_env("Path", &new_user_path)?;
+
+  let process_path = std::env::var("PATH").unwrap_or_default();
+  std::env::set_var("PATH", prepend_path_value(&process_path, value));
+
+  Ok(())
+}
+
+#[cfg(windows)]
+fn get_user_env(name: &str) -> Result<Option<String>> {
+  let output = std::process::Command::new("powershell.exe")
+    .arg("-NoLogo")
+    .arg("-NoProfile")
+    .arg("-NonInteractive")
+    .arg("-Command")
+    .arg("[Environment]::GetEnvironmentVariable($args[0], 'User')")
+    .arg(name)
+    .output()?;
+
+  if !output.status.success() {
+    anyhow::bail!("Failed to read user environment variable {}", name);
+  }
+
+  let value = String::from_utf8(output.stdout)?.trim().to_string();
+  Ok((!value.is_empty()).then_some(value))
+}
+
+#[cfg(windows)]
+fn set_user_env(name: &str, value: &str) -> Result<()> {
+  let status = std::process::Command::new("powershell.exe")
+    .arg("-NoLogo")
+    .arg("-NoProfile")
+    .arg("-NonInteractive")
+    .arg("-Command")
+    .arg("[Environment]::SetEnvironmentVariable($args[0], $args[1], 'User')")
+    .arg(name)
+    .arg(value)
+    .status()?;
+
+  if !status.success() {
+    anyhow::bail!("Failed to set user environment variable {}", name);
+  }
+
+  std::env::set_var(name, value);
+  Ok(())
+}
+
+#[cfg(windows)]
+fn path_contains(path: &str, value: &str) -> bool {
+  path.split(';').any(|item| item.eq_ignore_ascii_case(value))
+}
+
+#[cfg(windows)]
+fn env_path_contains(path: &str, value: &str) -> bool {
+  path_contains(path, value)
+}
+
+#[cfg(windows)]
+fn prepend_path_value(path: &str, value: &str) -> String {
+  let rest = path
+    .split(';')
+    .filter(|item| !item.is_empty() && !item.eq_ignore_ascii_case(value))
+    .collect::<Vec<_>>()
+    .join(";");
+
+  if rest.is_empty() {
+    value.to_string()
+  } else {
+    format!("{};{}", value, rest)
+  }
+}
+
+#[cfg(all(test, windows))]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn prepend_path_value_moves_existing_entry_to_front() {
+    assert_eq!(
+      prepend_path_value(
+        "C:\\Windows;C:\\Users\\me\\.dvm\\bin;C:\\Tools",
+        "C:\\Users\\me\\.dvm\\bin"
+      ),
+      "C:\\Users\\me\\.dvm\\bin;C:\\Windows;C:\\Tools"
+    );
+    assert_eq!(
+      prepend_path_value("C:\\Windows;C:\\Tools", "C:\\Users\\me\\.dvm\\bin"),
+      "C:\\Users\\me\\.dvm\\bin;C:\\Windows;C:\\Tools"
+    );
+  }
+}