feat!: improve env polyfill

src/env.ts

@@ -1,41 +1,59 @@
-const _envShim = Object.create(null);
-
 export type EnvObject = Record<string, string | undefined>;
 
-const _getEnv = (useShim?: boolean) =>
-  globalThis.process?.env ||
-  import.meta.env ||
-  globalThis.Deno?.env.toObject() ||
-  globalThis.__env__ ||
-  (useShim ? _envShim : globalThis);
+const _envShim = Object.create(null) as EnvObject;
 
 export const env = new Proxy<EnvObject>(_envShim, {
   get(_, prop) {
-    const env = _getEnv();
-    return env[prop as any] ?? _envShim[prop];
+    return getEnvValue(prop as string);
   },
   has(_, prop) {
-    const env = _getEnv();
-    return prop in env || prop in _envShim;
+    return getEnvValue(prop as string) !== undefined;
   },
   set(_, prop, value) {
-    const env = _getEnv(true);
-    env[prop as any] = value;
-    return true;
+    return Reflect.set(getEnvObj(), prop as string, `${value}`);
   },
   deleteProperty(_, prop) {
-    if (!prop) {
-      return false;
-    }
-    const env = _getEnv(true);
-    delete env[prop as any];
-    return true;
+    return Reflect.deleteProperty(getEnvObj(), prop as string);
   },
   ownKeys() {
-    const env = _getEnv(true);
-    return Object.keys(env);
+    return Reflect.ownKeys(getEnvObj());
+  },
+  defineProperty(_, prop, descriptor) {
+    const value = descriptor.get?.() ?? descriptor.value;
+    return Reflect.set(getEnvObj(), prop as string, `${value}`);
   },
 });
 
+function getEnvObj(fallbackToGlobal?: boolean): EnvObject {
+  if (globalThis.__env__) {
+    return globalThis.__env__;
+  }
+  if (globalThis.process?.env) {
+    return globalThis.process.env;
+  }
+  if (import.meta.env) {
+    return import.meta.env;
+  }
+  return fallbackToGlobal ? (globalThis as unknown as EnvObject) : _envShim;
+}
+
+function getEnvValue(key: string): string | undefined {
+  if (globalThis.__env__ && key in globalThis.__env__) {
+    return globalThis.__env__[key];
+  }
+  if (globalThis.process?.env && key in globalThis.process.env) {
+    return globalThis.process.env[key];
+  }
+  if (import.meta?.env && key in import.meta.env) {
+    return import.meta.env[key];
+  }
+  if (globalThis.Deno?.env) {
+    return (globalThis.Deno.env as any).get(key);
+  }
+  if (key in _envShim) {
+    return _envShim[key];
+  }
+}
+
 export const nodeENV =
   (typeof process !== "undefined" && process.env && process.env.NODE_ENV) || "";