BREAKING: remove functions.config() implementation (#1748)

Replace functions.config() implementation with an error that provides
clear migration guidance to the params module. This removes the deprecated
API as planned for the next major release while helping developers migrate.

The error message directs users to:
https://firebase.google.com/docs/functions/config-env#migrate-config

Author: taeold

spec/v1/config.spec.ts

@@ -21,53 +21,16 @@
 // SOFTWARE.
 
 import { expect } from "chai";
-import * as fs from "fs";
-import * as process from "process";
-import * as sinon from "sinon";
 
-import { config, resetCache } from "../../src/v1/config";
+import { config } from "../../src/v1/config";
 
 describe("config()", () => {
-  let readFileSync: sinon.SinonStub;
-  let cwdStub: sinon.SinonStub;
-
-  before(() => {
-    readFileSync = sinon.stub(fs, "readFileSync");
-    readFileSync.throws("Unexpected call");
-    cwdStub = sinon.stub(process, "cwd");
-    cwdStub.returns("/srv");
-  });
-
-  after(() => {
-    sinon.verifyAndRestore();
-  });
-
-  afterEach(() => {
-    resetCache();
-    delete process.env.FIREBASE_CONFIG;
-    delete process.env.CLOUD_RUNTIME_CONFIG;
-    delete process.env.K_CONFIGURATION;
-  });
-
-  it("will never load in GCFv2", () => {
-    const json = JSON.stringify({
-      foo: "bar",
-      firebase: {},
-    });
-    readFileSync.withArgs("/srv/.runtimeconfig.json").returns(Buffer.from(json));
-
-    process.env.K_CONFIGURATION = "my-service";
-    expect(config).to.throw(Error, /transition to using environment variables/);
-  });
-
-  it("loads config values from .runtimeconfig.json", () => {
-    const json = JSON.stringify({
-      foo: "bar",
-      firebase: {},
-    });
-    readFileSync.withArgs("/srv/.runtimeconfig.json").returns(Buffer.from(json));
-    const loaded = config();
-    expect(loaded).to.not.have.property("firebase");
-    expect(loaded).to.have.property("foo", "bar");
+  it("throws an error with migration guidance", () => {
+    expect(config).to.throw(
+      Error,
+      "functions.config() has been removed in firebase-functions v7. " +
+        "Migrate to environment parameters using the params module. " +
+        "Migration guide: https://firebase.google.com/docs/functions/config-env#migrate-config"
+    );
   });
 });

src/v1/config.ts

@@ -20,63 +20,17 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-import * as fs from "fs";
-import * as path from "path";
-
 export { firebaseConfig } from "../common/config";
 
-/** @internal */
-export let singleton: Record<string, any>;
-
-/** @internal */
-export function resetCache(): void {
-  singleton = undefined;
-}
-
 /**
- * Store and retrieve project configuration data such as third-party API
- * keys or other settings. You can set configuration values using the
- * Firebase CLI as described in
- * https://firebase.google.com/docs/functions/config-env.
- *
- * @deprecated Using functions.config() is discouraged. See https://firebase.google.com/docs/functions/config-env.
+ * @deprecated `functions.config()` has been removed in firebase-functions v7.
+ * Migrate to environment parameters using the `params` module immediately.
+ * Migration guide: https://firebase.google.com/docs/functions/config-env#migrate-config
  */
 export function config(): Record<string, any> {
-  // K_CONFIGURATION is only set in GCFv2
-  if (process.env.K_CONFIGURATION) {
-    throw new Error(
-      "functions.config() is no longer available in Cloud Functions for " +
-        "Firebase v2. Please see the latest documentation for information " +
-        "on how to transition to using environment variables"
-    );
-  }
-  if (typeof singleton === "undefined") {
-    init();
-  }
-  return singleton;
-}
-
-function init() {
-  try {
-    const parsed = JSON.parse(process.env.CLOUD_RUNTIME_CONFIG);
-    delete parsed.firebase;
-    singleton = parsed;
-    return;
-  } catch (e) {
-    // Do nothing
-  }
-
-  try {
-    const configPath =
-      process.env.CLOUD_RUNTIME_CONFIG || path.join(process.cwd(), ".runtimeconfig.json");
-    const contents = fs.readFileSync(configPath);
-    const parsed = JSON.parse(contents.toString("utf8"));
-    delete parsed.firebase;
-    singleton = parsed;
-    return;
-  } catch (e) {
-    // Do nothing
-  }
-
-  singleton = {};
+  throw new Error(
+    "functions.config() has been removed in firebase-functions v7. " +
+      "Migrate to environment parameters using the params module. " +
+      "Migration guide: https://firebase.google.com/docs/functions/config-env#migrate-config"
+  );
 }