feat: Add support for function prefixes

schema/firebase-config.json

@@ -279,6 +279,9 @@
                         }
                     ]
                 },
+                "prefix": {
+                    "type": "string"
+                },
                 "runtime": {
                     "enum": [
                         "nodejs18",

scripts/emulator-tests/functionsEmulator.spec.ts

@@ -19,7 +19,7 @@
 import * as secretManager from "../../src/gcp/secretManager";
 
 if ((process.env.DEBUG || "").toLowerCase().includes("spec")) {
   const dropLogLevels = (info: logform.TransformableInfo) => info.message;
   logger.add(
     new winston.transports.Console({
       level: "debug",
@@ -49,7 +49,7 @@
   // bin: path.join(MODULE_ROOT, "node_modules/.bin/ts-node"),
 };
 
 async function setupEnvFiles(envs: Record<string, string>) {
   const envFiles: string[] = [];
   for (const [filename, data] of Object.entries(envs)) {
     const envPath = path.join(FUNCTIONS_DIR, filename);
@@ -760,6 +760,48 @@
       }).timeout(TIMEOUT_MED);
     });
 
+    it("should support multiple codebases with the same source and apply prefixes", async () => {
+      const backend1: EmulatableBackend = {
+        ...TEST_BACKEND,
+        codebase: "one",
+        prefix: "prefix-one",
+      };
+      const backend2: EmulatableBackend = {
+        ...TEST_BACKEND,
+        codebase: "two",
+        prefix: "prefix-two",
+      };
+
+      emu = new FunctionsEmulator({
+        projectId: TEST_PROJECT_ID,
+        projectDir: MODULE_ROOT,
+        emulatableBackends: [backend1, backend2],
+        verbosity: "QUIET",
+        debugPort: false,
+      });
+
+      await writeSource(() => {
+        return {
+          functionId: require("firebase-functions").https.onRequest(
+            (req: express.Request, res: express.Response) => {
+              res.json({ path: req.path });
+            },
+          ),
+        };
+      });
+
+      await emu.start();
+      await emu.connect();
+
+      await supertest(emu.createHubServer())
+        .get(`/${TEST_PROJECT_ID}/us-central1/prefix-one-functionId`)
+        .expect(200);
+
+      await supertest(emu.createHubServer())
+        .get(`/${TEST_PROJECT_ID}/us-central1/prefix-two-functionId`)
+        .expect(200);
+    });
+
     describe("user-defined environment variables", () => {
       let cleanup: (() => Promise<void>) | undefined;
 

src/deploy/functions/build.spec.ts

@@ -293,3 +293,42 @@ describe("envWithType", () => {
     expect(out.WHOOPS_SECRET.asString()).to.equal("super-secret");
   });
 });
+
+describe("applyPrefix", () => {
+  const createTestBuild = (): build.Build => ({
+    endpoints: {
+      func1: {
+        region: "us-central1",
+        project: "test-project",
+        platform: "gcfv2",
+        runtime: "nodejs18",
+        entryPoint: "func1",
+        httpsTrigger: {},
+      },
+      func2: {
+        region: "us-west1",
+        project: "test-project",
+        platform: "gcfv1",
+        runtime: "nodejs16",
+        entryPoint: "func2",
+        httpsTrigger: {},
+      },
+    },
+    params: [],
+    requiredAPIs: [],
+  });
+
+  it("should update endpoint keys with prefix", () => {
+    const testBuild = createTestBuild();
+    build.applyPrefix(testBuild, "test");
+    expect(Object.keys(testBuild.endpoints).sort()).to.deep.equal(["test-func1", "test-func2"]);
+    expect(testBuild.endpoints["test-func1"].entryPoint).to.equal("func1");
+    expect(testBuild.endpoints["test-func2"].entryPoint).to.equal("func2");
+  });
+
+  it("should do nothing for an empty prefix", () => {
+    const testBuild = createTestBuild();
+    build.applyPrefix(testBuild, "");
+    expect(Object.keys(testBuild.endpoints).sort()).to.deep.equal(["func1", "func2"]);
+  });
+});

src/deploy/functions/build.ts

@@ -650,3 +650,17 @@ function discoverTrigger(endpoint: Endpoint, region: string, r: Resolver): backe
   }
   assertExhaustive(endpoint);
 }
+
+/**
+ * Prefixes all endpoint IDs in a build with a given prefix.
+ */
+export function applyPrefix(build: Build, prefix: string): void {
+  if (!prefix) {
+    return;
+  }
+  const newEndpoints: Record<string, Endpoint> = {};
+  for (const id of Object.keys(build.endpoints)) {
+    newEndpoints[`${prefix}-${id}`] = build.endpoints[id];
+  }
+  build.endpoints = newEndpoints;
+}

src/deploy/functions/prepare.spec.ts

@@ -1,13 +1,17 @@
 import { expect } from "chai";
-
-import * as backend from "./backend";
+import * as sinon from "sinon";
+import * as build from "./build";
 import * as prepare from "./prepare";
+import * as runtimes from "./runtimes";
+import { RuntimeDelegate } from "./runtimes";
+import { FirebaseError } from "../../error";
+import { Options } from "../../options";
+import { ValidatedConfig } from "../../functions/projectConfig";
+import * as backend from "./backend";
 import * as ensureApiEnabled from "../../ensureApiEnabled";
 import * as serviceusage from "../../gcp/serviceusage";
 import { BEFORE_CREATE_EVENT, BEFORE_SIGN_IN_EVENT } from "../../functions/events/v1";
-import * as sinon from "sinon";
 import * as prompt from "../../prompt";
-import { FirebaseError } from "../../error";
 
 describe("prepare", () => {
   const ENDPOINT_BASE: Omit<backend.Endpoint, "httpsTrigger"> = {
@@ -16,14 +20,68 @@ describe("prepare", () => {
     region: "region",
     project: "project",
     entryPoint: "entry",
-    runtime: "nodejs16",
+    runtime: "nodejs22",
   };
 
   const ENDPOINT: backend.Endpoint = {
     ...ENDPOINT_BASE,
     httpsTrigger: {},
   };
 
+  describe("loadCodebases", () => {
+    let sandbox: sinon.SinonSandbox;
+    let runtimeDelegateStub: RuntimeDelegate;
+    let discoverBuildStub: sinon.SinonStub;
+
+    beforeEach(() => {
+      sandbox = sinon.createSandbox();
+      discoverBuildStub = sandbox.stub();
+      runtimeDelegateStub = {
+        language: "nodejs",
+        runtime: "nodejs22",
+        bin: "node",
+        validate: sandbox.stub().resolves(),
+        build: sandbox.stub().resolves(),
+        watch: sandbox.stub().resolves(() => Promise.resolve()),
+        discoverBuild: discoverBuildStub,
+      };
+      discoverBuildStub.resolves(
+        build.of({
+          test: {
+            platform: "gcfv2",
+            entryPoint: "test",
+            project: "project",
+            runtime: "nodejs22",
+            httpsTrigger: {},
+          },
+        }),
+      );
+      sandbox.stub(runtimes, "getRuntimeDelegate").resolves(runtimeDelegateStub);
+    });
+
+    afterEach(() => {
+      sandbox.restore();
+    });
+
+    it("should apply the prefix to the function name", async () => {
+      const config: ValidatedConfig = [
+        { source: "source", codebase: "codebase", prefix: "my-prefix", runtime: "nodejs22" },
+      ];
+      const options = {
+        config: {
+          path: (p: string) => p,
+        },
+        projectId: "project",
+      } as unknown as Options;
+      const firebaseConfig = { projectId: "project" };
+      const runtimeConfig = {};
+
+      const builds = await prepare.loadCodebases(config, options, firebaseConfig, runtimeConfig);
+
+      expect(Object.keys(builds.codebase.endpoints)).to.deep.equal(["my-prefix-test"]);
+    });
+  });
+
   describe("inferDetailsFromExisting", () => {
     it("merges env vars if .env is not used", () => {
       const oldE = {
@@ -304,7 +362,7 @@ describe("prepare", () => {
       region: "us-central1",
       project: "project",
       entryPoint: "entry",
-      runtime: "nodejs16",
+      runtime: "nodejs22",
       httpsTrigger: {},
     };
 
@@ -314,7 +372,7 @@ describe("prepare", () => {
       region: "us-central1",
       project: "project",
       entryPoint: "entry",
-      runtime: "nodejs16",
+      runtime: "nodejs22",
       callableTrigger: {
         genkitAction: "action",
       },
@@ -333,7 +391,7 @@ describe("prepare", () => {
       region: "us-central1",
       project: "project",
       entryPoint: "entry",
-      runtime: "nodejs16",
+      runtime: "nodejs22",
       callableTrigger: {
         genkitAction: "action",
       },

src/deploy/functions/prepare.ts

@@ -155,7 +155,7 @@ export async function prepare(
     }
 
     for (const endpoint of backend.allEndpoints(wantBackend)) {
-      endpoint.environmentVariables = { ...wantBackend.environmentVariables } || {};
+      endpoint.environmentVariables = { ...(wantBackend.environmentVariables || {}) };
       let resource: string;
       if (endpoint.platform === "gcfv1") {
         resource = `projects/${endpoint.project}/locations/${endpoint.region}/functions/${endpoint.id}`;
@@ -475,14 +475,15 @@ export async function loadCodebases(
       "functions",
       `Loading and analyzing source code for codebase ${codebase} to determine what to deploy`,
     );
-    wantBuilds[codebase] = await runtimeDelegate.discoverBuild(runtimeConfig, {
+    const discoveredBuild = await runtimeDelegate.discoverBuild(runtimeConfig, {
       ...firebaseEnvs,
       // Quota project is required when using GCP's Client-based APIs
       // Some GCP client SDKs, like Vertex AI, requires appropriate quota project setup
       // in order for .init() calls to succeed.
       GOOGLE_CLOUD_QUOTA_PROJECT: projectId,
     });
-    wantBuilds[codebase].runtime = codebaseConfig.runtime;
+    build.applyPrefix(discoveredBuild, codebaseConfig.prefix || "");
+    wantBuilds[codebase] = discoveredBuild;
   }
   return wantBuilds;
 }

src/emulator/controller.ts

@@ -170,18 +170,16 @@ export function shouldStart(options: Options, name: Emulators): boolean {
     );
   }
 
-  // Don't start the functions emulator if we can't find the source directory
+  // Don't start the functions emulator if we can't validate the functions config
   if (name === Emulators.FUNCTIONS && emulatorInTargets) {
     try {
       normalizeAndValidate(options.config.src.functions);
       return true;
     } catch (err: any) {
       EmulatorLogger.forEmulator(Emulators.FUNCTIONS).logLabeled(
-        "WARN",
+        "ERROR",
         "functions",
-        `The functions emulator is configured but there is no functions source directory. Have you run ${clc.bold(
-          "firebase init functions",
-        )}?`,
+        `Failed to start Functions emulator: ${err.message}`,
       );
       return false;
     }
@@ -544,6 +542,7 @@ export async function startAll(
         functionsDir,
         runtime,
         codebase: cfg.codebase,
+        prefix: cfg.prefix,
         env: {
           ...options.extDevEnv,
         },

src/emulator/functionsEmulator.ts

@@ -53,8 +53,9 @@ import {
 import { functionIdsAreValid } from "../deploy/functions/validate";
 import { Extension, ExtensionSpec, ExtensionVersion } from "../extensions/types";
 import { accessSecretVersion } from "../gcp/secretManager";
-import * as runtimes from "../deploy/functions/runtimes";
 import * as backend from "../deploy/functions/backend";
+import * as build from "../deploy/functions/build";
+import * as runtimes from "../deploy/functions/runtimes";
 import * as functionsEnv from "../functions/env";
 import { AUTH_BLOCKING_EVENTS, BEFORE_CREATE_EVENT } from "../functions/events/v1";
 import { BlockingFunctionsConfig } from "../gcp/identityPlatform";
@@ -87,6 +88,7 @@ export interface EmulatableBackend {
   env: Record<string, string>;
   secretEnv: backend.SecretEnvVar[];
   codebase: string;
+  prefix?: string;
   predefinedTriggers?: ParsedTriggerDefinition[];
   runtime?: Runtime;
   bin?: string;
@@ -563,6 +565,7 @@ export class FunctionsEmulator implements EmulatorInstance {
         );
         await this.loadDynamicExtensionBackends();
       }
+      build.applyPrefix(discoveredBuild, emulatableBackend.prefix || "");
       const resolution = await resolveBackend({
         build: discoveredBuild,
         firebaseConfig: JSON.parse(firebaseConfig),

src/firebaseConfig.ts

@@ -171,6 +171,7 @@ export type FunctionConfig = {
   ignore?: string[];
   runtime?: ActiveRuntime;
   codebase?: string;
+  prefix?: string;
 } & Deployable;
 
 export type FunctionsConfig = FunctionConfig | FunctionConfig[];