switch between modes at runtime and apply on process.env

Author: james-elicx

packages/cloudflare/src/cli/build/patches/investigated/copy-package-cli-files.ts

@@ -22,7 +22,9 @@ export async function copyPackageCliFiles(
 
   fs.cpSync(sourceDir, destinationDir, { recursive: true });
 
-  const envVars = extractProjectEnvVars(openNextConfig);
+  const devEnvVars = extractProjectEnvVars("development", openNextConfig);
+  const prodEnvVars = extractProjectEnvVars("production", openNextConfig);
+
   await build({
     entryPoints: [path.join(packageDistDir, "cli", "templates", "worker.ts")],
     outfile: path.join(openNextConfig.outputDir, "worker.js"),
@@ -31,7 +33,8 @@ export async function copyPackageCliFiles(
     bundle: false,
     minify: false,
     define: {
-      __OPENNEXT_BUILD_TIME_ENV: JSON.stringify(envVars),
+      __OPENNEXT_BUILD_TIME_DEV_ENV: JSON.stringify(devEnvVars),
+      __OPENNEXT_BUILD_TIME_PROD_ENV: JSON.stringify(prodEnvVars),
     },
   });
 }

packages/cloudflare/src/cli/build/utils/extract-project-env-vars.spec.ts

@@ -23,7 +23,7 @@ describe("extractProjectEnvVars", () => {
   afterEach(() => mockFs.restore());
 
   it("should extract production env vars", () => {
-    const result = extractProjectEnvVars(options);
+    const result = extractProjectEnvVars("production", options);
     expect(result).toEqual({
       ENV_LOCAL_VAR: "value",
       ENV_PROD_LOCAL_VAR: "value",
@@ -35,7 +35,7 @@ describe("extractProjectEnvVars", () => {
   it("should extract development env vars", () => {
     writeFileSync(".dev.vars", 'NEXTJS_ENV = "development"');
 
-    const result = extractProjectEnvVars(options);
+    const result = extractProjectEnvVars("development", options);
     expect(result).toEqual({
       ENV_LOCAL_VAR: "value",
       ENV_DEV_LOCAL_VAR: "value",
@@ -47,7 +47,7 @@ describe("extractProjectEnvVars", () => {
   it("should override env vars with those in a local file", () => {
     writeFileSync(".env.production.local", "ENV_PROD_VAR=overridden");
 
-    const result = extractProjectEnvVars(options);
+    const result = extractProjectEnvVars("production", options);
     expect(result).toEqual({
       ENV_LOCAL_VAR: "value",
       ENV_PROD_VAR: "overridden",

packages/cloudflare/src/cli/build/utils/extract-project-env-vars.ts

@@ -29,10 +29,6 @@ function readEnvFiles(fileNames: string[], { monorepoRoot, appPath }: BuildOptio
  * In a monorepo, the env files in an app's directory will take precedence over
  * the env files at the root of the monorepo.
  */
-export function extractProjectEnvVars(options: BuildOptions) {
-  const wranglerDevVars = readEnvFiles([".dev.vars"], options);
-
-  const mode = wranglerDevVars["NEXTJS_ENV"] ?? "production";
-
+export function extractProjectEnvVars(mode: "development" | "production", options: BuildOptions) {
   return readEnvFiles([".env", `.env.${mode}`, ".env.local", `.env.${mode}.local`], options);
 }

packages/cloudflare/src/cli/templates/worker.ts

@@ -21,13 +21,20 @@ const cloudflareContextALS = new AsyncLocalStorage<CloudflareContext>();
   }
 );
 
-declare const __OPENNEXT_BUILD_TIME_ENV: Record<string, string>;
+declare const __OPENNEXT_BUILD_TIME_DEV_ENV: Record<string, string>;
+declare const __OPENNEXT_BUILD_TIME_PROD_ENV: Record<string, string>;
+
+function applyBuildTimeEnv(mode?: string) {
+  const secrets = mode === "development" ? __OPENNEXT_BUILD_TIME_DEV_ENV : __OPENNEXT_BUILD_TIME_PROD_ENV;
+
+  for (const key in secrets) {
+    process.env[key] = secrets[key];
+  }
+}
 
 export default {
   async fetch(request, env, ctx) {
-    const combinedEnv = { ...__OPENNEXT_BUILD_TIME_ENV, ...env };
-
-    return cloudflareContextALS.run({ env: combinedEnv, ctx, cf: request.cf }, async () => {
+    return cloudflareContextALS.run({ env, ctx, cf: request.cf }, async () => {
       // Set the default Origin for the origin resolver.
       const url = new URL(request.url);
       process.env.OPEN_NEXT_ORIGIN = JSON.stringify({
@@ -38,16 +45,18 @@ export default {
         },
       });
 
+      applyBuildTimeEnv(env["NEXTJS_ENV"]);
+
       // The Middleware handler can return either a `Response` or a `Request`:
       // - `Response`s should be returned early
       // - `Request`s are handled by the Next server
-      const reqOrResp = await middlewareHandler(request, combinedEnv, ctx);
+      const reqOrResp = await middlewareHandler(request, env, ctx);
 
       if (reqOrResp instanceof Response) {
         return reqOrResp;
       }
 
-      return serverHandler(reqOrResp, combinedEnv, ctx);
+      return serverHandler(reqOrResp, env, ctx);
     });
   },
-} as ExportedHandler<{ ASSETS: Fetcher }>;
+} as ExportedHandler<{ ASSETS: Fetcher; NEXTJS_ENV?: string }>;