Preserve user input in initializeTestApp (#3923)

Author: samtstern

.changeset/ninety-kings-agree.md

@@ -0,0 +1,5 @@
+---
+'@firebase/rules-unit-testing': patch
+---
+
+Do not delete uid property from user auth object in initializeTestApp()

packages/rules-unit-testing/src/api/index.ts

@@ -127,9 +127,6 @@ function createUnsecuredJwt(token: TokenOptions, projectId?: string): string {
     throw new Error("Auth must contain 'sub', 'uid', or 'user_id' field!");
   }
 
-  // Remove the uid option since it's not actually part of the token spec
-  delete token.uid;
-
   const payload: FirebaseIdToken = {
     // Set all required fields to decent defaults
     iss: `https://securetoken.google.com/${project}`,
@@ -148,6 +145,11 @@ function createUnsecuredJwt(token: TokenOptions, projectId?: string): string {
     ...token
   };
 
+  // Remove the uid option since it's not actually part of the token spec.
+  if (payload.uid) {
+    delete payload.uid;
+  }
+
   // Unsecured JWTs use the empty string as a signature.
   const signature = '';
   return [

packages/rules-unit-testing/test/database.test.ts

@@ -245,7 +245,21 @@ describe('Testing Module Tests', function () {
       wrongClaim.firestore().doc('test/test').set({ hello: 'test' })
     );
   });
-  
+
+  it('initializeTestApp() does not destroy user input', function () {
+    const options = {
+      projectId: 'fakeproject',
+      auth: {
+        uid: 'sam',
+        email: '[email protected]'
+      }
+    };
+    const optionsCopy = Object.assign({}, options);
+
+    firebase.initializeTestApp(options);
+    expect(options).to.deep.equal(optionsCopy);
+  });
+
   it('loadDatabaseRules() throws if no databaseName or rules', async function () {
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     await expect((firebase as any).loadDatabaseRules.bind(null, {})).to.throw(