Try to avoid link issue

Author: schmidt-sebastian

packages/firestore/exp/src/api/reference.ts

@@ -55,7 +55,7 @@ import {
   NextFn,
   PartialObserver,
   Unsubscribe
-} from '../../../src/api/observer';
+} from '../../../src/core/event_manager';
 import { getFirestoreClient } from './components';
 import { AsyncObserver } from '../../../src/util/async_observer';
 import { newQueryForPath } from '../../../src/core/query';

packages/firestore/exp/test/shim.ts

@@ -69,7 +69,10 @@ import {
   where
 } from '../../exp/index';
 import { UntypedFirestoreDataConverter } from '../../src/api/user_data_reader';
-import { isPartialObserver, PartialObserver } from '../../src/api/observer';
+import {
+  isPartialObserver,
+  PartialObserver
+} from '../../src/core/event_manager';
 import { isPlainObject } from '../../src/util/input_validation';
 
 export { GeoPoint, Blob, Timestamp } from '../index';

packages/firestore/src/api/observer.ts

@@ -23,6 +23,7 @@ import { SyncEngine, SyncEngineListener } from './sync_engine';
 import { OnlineState } from './types';
 import { ChangeType, DocumentViewChange, ViewSnapshot } from './view_snapshot';
 import { wrapInUserErrorIfRecoverable } from '../util/async_queue';
+import { JsonObject } from '../model/object_value';
 
 /**
  * Holds the listeners and the last received ViewSnapshot for a query being
@@ -41,6 +42,28 @@ export interface Observer<T> {
   error: EventHandler<Error>;
 }
 
+/**
+ * Observer/Subscribe interfaces.
+ */
+export type NextFn<T> = (value: T) => void;
+export type ErrorFn = (error: Error) => void;
+export type CompleteFn = () => void;
+
+// Allow for any of the Observer methods to be undefined.
+export interface PartialObserver<T> {
+  next?: NextFn<T>;
+  error?: ErrorFn;
+  complete?: CompleteFn;
+}
+
+export interface Unsubscribe {
+  (): void;
+}
+
+export function isPartialObserver(obj: unknown): boolean {
+  return implementsAnyMethods(obj, ['next', 'error', 'complete']);
+}
+
 /**
  * EventManager is responsible for mapping queries to query event emitters.
  * It handles "fan-out". -- Identical queries will re-use the same watch on the
@@ -357,3 +380,21 @@ export class QueryListener {
     this.queryObserver.next(snap);
   }
 }
+
+/**
+ * Returns true if obj is an object and contains at least one of the specified
+ * methods.
+ */
+function implementsAnyMethods(obj: unknown, methods: string[]): boolean {
+  if (typeof obj !== 'object' || obj === null) {
+    return false;
+  }
+
+  const object = obj as JsonObject<unknown>;
+  for (const method of methods) {
+    if (method in object && typeof object[method] === 'function') {
+      return true;
+    }
+  }
+  return false;
+}

packages/firestore/src/core/event_manager.ts

@@ -30,12 +30,11 @@ import { Deferred } from '../util/promise';
 import {
   EventManager,
   ListenOptions,
-  Observer,
-  QueryListener
+  QueryListener,
+  Unsubscribe
 } from './event_manager';
 import { SyncEngine } from './sync_engine';
 import { View } from './view';
-
 import { SharedClientState } from '../local/shared_client_state';
 import { AutoId } from '../util/misc';
 import { DatabaseId, DatabaseInfo } from './database_info';
@@ -47,7 +46,6 @@ import {
   OfflineComponentProvider,
   OnlineComponentProvider
 } from './component_provider';
-import { Unsubscribe } from '../api/observer';
 import { AsyncObserver } from '../util/async_observer';
 
 const LOG_TAG = 'FirestoreClient';

packages/firestore/src/core/firestore_client.ts

@@ -15,9 +15,8 @@
  * limitations under the License.
  */
 
-import { Observer } from '../core/event_manager';
+import { Observer, PartialObserver } from '../core/event_manager';
 import { EventHandler } from './misc';
-import { PartialObserver } from '../api/observer';
 
 /*
  * A wrapper implementation of Observer<T> that will dispatch events