fix(remote-config, getAll): init with empty config

previously if you incorrectly called getAll before setting defaults or fetching any
remote config, we would crash.

Now we initialize values as an empty object, so we have a graceful failure

confirmed via code inspection that this matches expecations from firebase-js-sdk
https://github.com/firebase/firebase-js-sdk/blob/acc58102d4429ce0593ec22192e76018e9d16ed7/packages/remote-config/test/remote_config.test.ts#L333-L335

Fixes #5854

packages/remote-config/__tests__/remote-config.test.ts

@@ -81,20 +81,6 @@ describe('remoteConfig()', function () {
     });
   });
 
-  // TODO set up a mock for getAll from issue 5854 and probe if result is empty
-  // describe('getAll() with remote', function () {
-  //   it('should return an object of all available values', function () {
-  //     const config = firebase.remoteConfig().getAll();
-  //     config.number.asNumber().should.equal(1337);
-  //     config.number.getSource().should.equal('remote');
-  //     // firebase console stores as a string
-  //     config.float.asNumber().should.equal(123.456);
-  //     config.float.getSource().should.equal('remote');
-  //     config.prefix_1.asNumber().should.equal(1);
-  //     config.prefix_1.getSource().should.equal('remote');
-  //   });
-  // });
-
   describe('setDefaults()', function () {
     it('it throws if defaults object not provided', function () {
       expect(() => {
@@ -112,4 +98,12 @@ describe('remoteConfig()', function () {
       }).toThrow('must be a string value');
     });
   });
+
+  describe('getAll() should not crash', function () {
+    it('should return an empty object pre-fetch, pre-defaults', function () {
+      const config = firebase.remoteConfig().getAll();
+      expect(config).toBeDefined();
+      expect(config).toEqual({});
+    });
+  });
 });

packages/remote-config/lib/index.js

@@ -58,6 +58,7 @@ class FirebaseConfigModule extends FirebaseModule {
       minimumFetchIntervalMillis: 43200000,
     };
     this._lastFetchTime = -1;
+    this._values = {};
   }
 
   getValue(key) {
@@ -89,9 +90,7 @@ class FirebaseConfigModule extends FirebaseModule {
 
   getAll() {
     const values = {};
-
     Object.keys(this._values).forEach(key => (values[key] = this.getValue(key)));
-
     return values;
   }