feat: provide static process.* and import.meta.* build flags (#1331)

Author: pi0

src/rollup/config.ts

@@ -18,9 +18,10 @@ import type { Preset } from "unenv";
 import { sanitizeFilePath, resolvePath } from "mlly";
 import unimportPlugin from "unimport/unplugin";
 import { hash } from "ohash";
-import type { Nitro } from "../types";
+import type { Nitro, NitroStaticBuildFlags } from "../types";
 import { resolveAliases } from "../utils";
 import { runtimeDir } from "../dirs";
+import { version } from "../../package.json";
 import { replace } from "./plugins/replace";
 import { virtual } from "./plugins/virtual";
 import { dynamicRequire } from "./plugins/dynamic-require";
@@ -163,6 +164,7 @@ export const getRollupConfig = (nitro: Nitro): RollupConfig => {
   if (nitro.options.preset === "nitro-prerender") {
     NODE_ENV = "prerender";
   }
+
   const buildEnvVars = {
     NODE_ENV,
     prerender: nitro.options.preset === "nitro-prerender",
@@ -172,6 +174,18 @@ export const getRollupConfig = (nitro: Nitro): RollupConfig => {
     DEBUG: nitro.options.dev,
   };
 
+  const staticFlags: NitroStaticBuildFlags = {
+    dev: nitro.options.dev,
+    preset: nitro.options.preset,
+    prerender: nitro.options.preset === "nitro-prerender",
+    server: true,
+    client: false,
+    nitro: true,
+    // @ts-expect-error
+    "versions.nitro": version,
+    "versions?.nitro": version,
+  };
+
   // Universal import.meta
   rollupConfig.plugins.push(importMeta(nitro));
 
@@ -208,6 +222,18 @@ export const getRollupConfig = (nitro: Nitro): RollupConfig => {
             JSON.stringify(val),
           ])
         ),
+        ...Object.fromEntries(
+          Object.entries(staticFlags).map(([key, val]) => [
+            `process.${key}`,
+            JSON.stringify(val),
+          ])
+        ),
+        ...Object.fromEntries(
+          Object.entries(staticFlags).map(([key, val]) => [
+            `import.meta.${key}`,
+            JSON.stringify(val),
+          ])
+        ),
         ...nitro.options.replace,
       },
     })

src/types/global.ts

@@ -0,0 +1,24 @@
+import type { NitroOptions } from "./nitro";
+
+export interface NitroStaticBuildFlags {
+  dev?: boolean;
+  client?: boolean;
+  nitro?: boolean;
+  prerender?: boolean;
+  preset?: NitroOptions["preset"];
+  server?: boolean;
+  versions?: {
+    nitro?: string;
+  };
+}
+
+declare global {
+  // eslint-disable-next-line @typescript-eslint/no-namespace
+  namespace NodeJS {
+    interface Process extends NitroStaticBuildFlags {}
+  }
+
+  interface ImportMeta extends NitroStaticBuildFlags {}
+}
+
+export {};

src/types/index.ts

@@ -1,4 +1,5 @@
 export * from "./fetch";
+export * from "./global";
 export * from "./serialize";
 export * from "./nitro";
 export * from "./handler";

test/fixture/routes/static-flags.ts

@@ -0,0 +1,13 @@
+// eslint-disable-next-line require-await
+export default eventHandler(async (event) => {
+  return {
+    dev: [process.dev, import.meta.dev],
+    preset: [process.preset, import.meta.preset],
+    prerender: [process.prerender, import.meta.prerender],
+    server: [process.server, import.meta.server],
+    client: [process.client, import.meta.client],
+    nitro: [process.nitro, import.meta.nitro],
+    "versions.nitro": [process.versions.nitro, import.meta.versions.nitro],
+    "versions?.nitro": [process.versions?.nitro, import.meta.versions?.nitro],
+  };
+});

test/tests.ts

@@ -371,4 +371,21 @@ export function testNitro(
       expect(headers["server-timing"]).toMatch(/-;dur=\d+;desc="Generate"/);
     });
   }
+
+  it("static build flags", async () => {
+    const { data } = await callHandler({ url: "/static-flags" });
+    expect(data).toMatchObject({
+      dev: [ctx.isDev, ctx.isDev],
+      preset: [ctx.preset, ctx.preset],
+      prerender: [
+        ctx.preset === "nitro-prerenderer",
+        ctx.preset === "nitro-prerenderer",
+      ],
+      client: [false, false],
+      nitro: [true, true],
+      server: [true, true],
+      "versions.nitro": [expect.any(String), expect.any(String)],
+      "versions?.nitro": [expect.any(String), expect.any(String)],
+    });
+  });
 }