fix(win): prevent user PATH clobbering and normalize gateway PATH env (#459)

electron/utils/env-path.ts

@@ -0,0 +1,59 @@
+type EnvMap = Record<string, string | undefined>;
+
+function isPathKey(key: string): boolean {
+  return key.toLowerCase() === 'path';
+}
+
+function preferredPathKey(): string {
+  return process.platform === 'win32' ? 'Path' : 'PATH';
+}
+
+function pathDelimiter(): string {
+  return process.platform === 'win32' ? ';' : ':';
+}
+
+export function getPathEnvKey(env: EnvMap): string {
+  const keys = Object.keys(env).filter(isPathKey);
+  if (keys.length === 0) return preferredPathKey();
+
+  if (process.platform === 'win32') {
+    if (keys.includes('Path')) return 'Path';
+    if (keys.includes('PATH')) return 'PATH';
+    return keys[0];
+  }
+
+  if (keys.includes('PATH')) return 'PATH';
+  return keys[0];
+}
+
+export function getPathEnvValue(env: EnvMap): string {
+  const key = getPathEnvKey(env);
+  return env[key] ?? '';
+}
+
+export function setPathEnvValue(
+  env: EnvMap,
+  nextPath: string,
+): EnvMap {
+  const nextEnv: EnvMap = { ...env };
+  for (const key of Object.keys(nextEnv)) {
+    if (isPathKey(key)) {
+      delete nextEnv[key];
+    }
+  }
+
+  nextEnv[getPathEnvKey(env)] = nextPath;
+  return nextEnv;
+}
+
+export function prependPathEntry(
+  env: EnvMap,
+  entry: string,
+): { env: EnvMap; path: string } {
+  const current = getPathEnvValue(env);
+  const nextPath = current ? `${entry}${pathDelimiter()}${current}` : entry;
+  return {
+    env: setPathEnvValue(env, nextPath),
+    path: nextPath,
+  };
+}