fix(functions): Use emulated credentials when connecting to the emulator (#2857)

* fix(functions): Use emulated credentials when connecting to the emulator

* fix tests

Author: lahirumaramba

src/functions/functions-api-client-internal.ts

@@ -54,7 +54,7 @@ export class FunctionsApiClient {
         'invalid-argument',
         'First argument passed to getFunctions() must be a valid Firebase app instance.');
     }
-    this.httpClient = new AuthorizedHttpClient(app as FirebaseApp);
+    this.httpClient = new FunctionsHttpClient(app as FirebaseApp);
   }
   /**
    * Deletes a task from a queue.
@@ -362,6 +362,19 @@ export class FunctionsApiClient {
   }
 }
 
+/**
+ * Functions-specific HTTP client which uses the special "owner" token
+ * when communicating with the Emulator.
+ */
+class FunctionsHttpClient extends AuthorizedHttpClient {
+  protected getToken(): Promise<string> {
+    if (process.env.CLOUD_TASKS_EMULATOR_HOST) {
+      return Promise.resolve('owner');
+    }
+    return super.getToken();
+  }
+}
+
 interface ErrorResponse {
   error?: Error;
 }

test/unit/functions/functions-api-client-internal.spec.ts

@@ -49,6 +49,12 @@ describe('FunctionsApiClient', () => {
     'X-Goog-Api-Client': getMetricsHeader(),
   };
 
+  const EXPECTED_HEADERS_EMULATOR = {
+    'X-Firebase-Client': `fire-admin-node/${getSdkVersion()}`,
+    'Authorization': 'Bearer owner',
+    'X-Goog-Api-Client': getMetricsHeader(),
+  };
+
   const noProjectId = 'Failed to determine project ID. Initialize the SDK with service '
     + 'account credentials or set project ID as an app option. Alternatively, set the '
     + 'GOOGLE_CLOUD_PROJECT environment variable.';
@@ -498,7 +504,7 @@ describe('FunctionsApiClient', () => {
           expect(stub).to.have.been.calledOnce.and.calledWith({
             method: 'POST',
             url: CLOUD_TASKS_URL_EMULATOR,
-            headers: EXPECTED_HEADERS,
+            headers: EXPECTED_HEADERS_EMULATOR,
             data: {
               task: expectedPayload
             }
@@ -519,7 +525,7 @@ describe('FunctionsApiClient', () => {
           expect(stub).to.have.been.calledOnce.and.calledWith({
             method: 'POST',
             url: CLOUD_TASKS_URL_EMULATOR,
-            headers: EXPECTED_HEADERS,
+            headers: EXPECTED_HEADERS_EMULATOR,
             data: {
               task: expectedPayload
             }
@@ -547,7 +553,7 @@ describe('FunctionsApiClient', () => {
           expect(stub).to.have.been.calledOnce.and.calledWith({
             method: 'POST',
             url: CLOUD_TASKS_URL_EMULATOR,
-            headers: EXPECTED_HEADERS,
+            headers: EXPECTED_HEADERS_EMULATOR,
             data: {
               task: expectedPayload
             }
@@ -603,7 +609,7 @@ describe('FunctionsApiClient', () => {
       expect(stub).to.have.been.calledWith({
         method: 'DELETE',
         url: CLOUD_TASKS_URL_EMULATOR.concat('/', 'mock-task'),
-        headers: EXPECTED_HEADERS,
+        headers: EXPECTED_HEADERS_EMULATOR,
       });
     });