Get rid of redundant env variable

Author: falahat

src/deploy/apphosting/args.ts

@@ -1,11 +1,10 @@
 import { AppHostingSingle } from "../../firebaseConfig";
-import { BuildConfig, Env } from "../../gcp/apphosting";
+import { BuildConfig } from "../../gcp/apphosting";
 
 export interface LocalBuild {
   buildConfig: BuildConfig;
   buildDir: string;
   annotations: Record<string, string>;
-  env: Env[];
 }
 
 export interface Context {

src/deploy/apphosting/deploy.spec.ts

@@ -44,7 +44,6 @@ function initializeContext(): Context {
         buildDir: "./nextjs/standalone",
         buildConfig: {},
         annotations: {},
-        env: [],
       },
     },
   };

src/deploy/apphosting/prepare.spec.ts

@@ -14,7 +14,6 @@ import * as managementApps from "../../management/apps";
 import * as experiments from "../../experiments";
 import { FirebaseError } from "../../error";
 import * as projectUtils from "../../getProjectNumber";
-import * as experiments from "../../experiments";
 
 const BASE_OPTS = {
   cwd: "/",
@@ -111,7 +110,6 @@ describe("apphosting", () => {
         buildConfig,
         annotations,
       });
-      sinon.stub(experiments, "assertEnabled").returns();
       listBackendsStub.onFirstCall().resolves({
         backends: [
           {
@@ -133,7 +131,6 @@ describe("apphosting", () => {
         buildDir: "./next/standalone",
         buildConfig,
         annotations,
-        env: [],
       });
       expect(backend.ensureAppHostingServiceAgentRoles).to.have.been.called;
     });
@@ -211,9 +208,7 @@ describe("apphosting", () => {
       };
       const context = initializeContext();
 
-      sinon
-        .stub(experiments, "assertEnabled")
-        .throws(new Error("Experiment 'apphostinglocalbuilds' is not enabled."));
+      assertEnabledStub.throws(new Error("Experiment 'apphostinglocalbuilds' is not enabled."));
       listBackendsStub.onFirstCall().resolves({
         backends: [
           {

src/deploy/apphosting/prepare.ts

@@ -196,12 +196,10 @@ export default async function (context: Context, options: Options): Promise<void
           managementApps.AppPlatform.WEB,
         )) as WebConfig;
         const autoinitVars = getAutoinitEnvVars(webappConfig);
-        buildEnv[cfg.backendId] = {
-          ...buildEnv[cfg.backendId],
-          ...Object.fromEntries(
-            Object.entries(autoinitVars).map(([key, value]) => [key, { value }]),
-          ),
-        };
+        // TODO: confirm the correct priority of auto-init variables
+        for (const [key, value] of Object.entries(autoinitVars)) {
+          buildEnv[cfg.backendId][key] = { value };
+        }
       } catch (e) {
         logLabeledWarning(
           "apphosting",
@@ -221,11 +219,12 @@ export default async function (context: Context, options: Options): Promise<void
         );
       }
       context.backendLocalBuilds[cfg.backendId] = {
-        // TODO(9114): This only works for nextjs.
         buildDir: outputFiles[0],
-        buildConfig,
+        buildConfig: {
+          ...buildConfig,
+          env: mergeEnvVars(buildConfig.env || [], runtimeEnv[cfg.backendId] || []),
+        },
         annotations,
-        env: runtimeEnv[cfg.backendId] || [],
       };
     } catch (e: unknown) {
       const errorMsg = e instanceof Error ? e.message : String(e);
@@ -268,3 +267,21 @@ export function getBackendConfigs(options: Options): AppHostingMultiple {
   }
   return backendConfigs.filter((cfg) => backendIds.includes(cfg.backendId));
 }
+
+/**
+ * Merges two lists of environment variables, giving precedence to the values in overrides.
+ */
+function mergeEnvVars(base: Env[], overrides: Env[]): Env[] {
+  const merged = new Map<string, Env>();
+  for (const env of base) {
+    if (env.variable) {
+      merged.set(env.variable, env);
+    }
+  }
+  for (const env of overrides) {
+    if (env.variable) {
+      merged.set(env.variable, env);
+    }
+  }
+  return Array.from(merged.values());
+}

src/deploy/apphosting/release.ts

@@ -51,13 +51,7 @@ export default async function (context: Context, options: Options): Promise<void
       location: context.backendLocations[backendId],
       buildInput: {
         // TODO: Confirm this config behavior
-        config: {
-          ...context.backendLocalBuilds[backendId]?.buildConfig,
-          env: [
-            ...(context.backendLocalBuilds[backendId]?.buildConfig?.env || []),
-            ...(context.backendLocalBuilds[backendId]?.env || []),
-          ],
-        },
+        config: context.backendLocalBuilds[backendId]?.buildConfig || {},
         source: {
           archive: {
             userStorageUri: context.backendStorageUris[backendId],