feat: detect the underlying runtime

README.md

@@ -45,6 +45,9 @@ const { env, isDevelopment, isProduction } = require("std-env");
 - `isColorSupported`
 - `nodeVersion`
 - `nodeMajorVersion`
+- `isNode`
+- `isDeno`
+- `isBun`
 
 You can read more about how each flag works from [./src/flags.ts](./src/flags.ts).
 
@@ -55,12 +58,12 @@ You can read more about how each flag works from [./src/flags.ts](./src/flags.ts
 You can use `isCI` and `platform` exports to detect it:
 
 ```ts
-import { isCI, platform, platformInfo } from "std-env";
+import { isCI, provider, providerInfo } from "std-env";
 
 console.log({
   isCI, // true
-  platform, // "github_actions"
-  platformInfo, // { name: "github_actions", isCI: true }
+  provider, // "github_actions"
+  providerInfo, // { name: "github_actions", isCI: true }
 });
 ```
 
@@ -75,7 +78,20 @@ console.log(detectProvider({ VERCEL: "1" }));
 
 List of well known providers can be found from [./src/providers.ts](./src/providers.ts).
 
-## Platform agnotic env
+## Runtime Detection
+
+`std-env` can automatically detect the current JavaScript runtime based on global variables, following the [WinterCG Runtime Keys proposal](https://runtime-keys.proposal.wintercg.org/):
+
+```ts
+import { detectRuntime } from "std-env";
+
+// "node" | "deno" | "bun" | "workerd" | "lagon" ...
+console.log(detectRuntime());
+```
+
+You can also use `isNode`, `isDeno`, and `isBun` helper methods.
+
+## Platform agnostic env
 
 `std-env` provides a lightweight proxy to access environment variables in a platform agnostic way.
 

src/flags.ts

@@ -2,6 +2,7 @@ import { detectProvider, ProviderName } from "./providers";
 import { env, nodeENV } from "./env";
 import { toBoolean } from "./_utils";
 import { _process } from "./process";
+import { detectRuntime } from "./runtimes";
 
 /** Value of process.platform */
 export const platform = _process.platform || "";
@@ -55,3 +56,8 @@ export const isColorSupported =
 export const nodeVersion =
   (_process.versions?.node || "").replace(/^v/, "") || null;
 export const nodeMajorVersion = Number(nodeVersion?.split(".")[0]) || null;
+
+/** Detect the runtime type */
+export const isNode = detectRuntime() === "node";
+export const isDeno = detectRuntime() === "deno";
+export const isBun = detectRuntime() === "bun";

src/index.ts

@@ -2,3 +2,4 @@ export * from "./env";
 export * from "./flags";
 export * from "./process";
 export * from "./providers";
+export * from "./runtimes";

src/runtimes.ts

@@ -0,0 +1,63 @@
+/* eslint-disable no-var */
+declare global {
+  var EdgeRuntime: any;
+  var Netlify: any;
+  var Bun: any;
+  var Deno: any;
+  var __lagon__: any;
+  var fastly: any;
+}
+
+// https://runtime-keys.proposal.wintercg.org/
+export type Runtime =
+  | "workerd"
+  | "deno"
+  | "lagon"
+  | "netlify"
+  | "node"
+  | "bun"
+  | "edge-light"
+  | "fastly"
+  | "";
+
+// https://developers.cloudflare.com/workers/runtime-apis/web-standards/#navigatoruseragent
+const CLOUDFLARE_WORKERS_NAVIGATOR = "Cloudflare-Workers";
+
+// https://nodejs.org/api/process.html#processrelease
+const NODE_PROCESS_RELEASE_NAME = "node";
+
+export function detectRuntime(): Runtime {
+  if (typeof Netlify === "object") {
+    return "netlify";
+  }
+
+  if (typeof EdgeRuntime === "string") {
+    return "edge-light";
+  }
+
+  if (globalThis.navigator?.userAgent === CLOUDFLARE_WORKERS_NAVIGATOR) {
+    return "workerd";
+  }
+
+  if (globalThis.Deno) {
+    return "deno";
+  }
+
+  if (globalThis.__lagon__) {
+    return "lagon";
+  }
+
+  if (globalThis.process?.release?.name === NODE_PROCESS_RELEASE_NAME) {
+    return "node";
+  }
+
+  if (globalThis.Bun) {
+    return "bun";
+  }
+
+  if (globalThis.fastly) {
+    return "fastly";
+  }
+
+  return "";
+}