Add basic interoperability with other Observable implementations (#196)

Closes #149.

package.json

@@ -49,7 +49,8 @@
     "lodash.isobject": "^3.0.2",
     "lodash.isstring": "^4.0.1",
     "lodash.isundefined": "^3.0.1",
-    "redux": "^3.3.1"
+    "redux": "^3.3.1",
+    "symbol-observable": "^0.2.4"
   },
   "devDependencies": {
     "async": "^1.5.2",
@@ -77,6 +78,7 @@
     "tslint": "^3.6.0",
     "typescript": "^1.8.9",
     "typings": "^0.7.9",
-    "uglify-js": "^2.6.2"
+    "uglify-js": "^2.6.2",
+    "rxjs": "^5.0.0-beta.7"
   }
 }

src/util/Observable.ts

@@ -1,6 +1,8 @@
 // This simplified polyfill attempts to follow the ECMAScript Observable proposal.
 // See https://github.com/zenparsing/es-observable
 
+import * as $$observable from 'symbol-observable'
+
 export type CleanupFunction = () => void;
 export type SubscriberFunction<T> = (observer: Observer<T>) => (Subscription | CleanupFunction);
 
@@ -15,6 +17,10 @@ export class Observable<T> {
     this.subscriberFunction = subscriberFunction;
   }
 
+  public [$$observable]() {
+    return this
+  }
+
   public subscribe(observer: Observer<T>): Subscription {
     let subscriptionOrCleanupFunction = this.subscriberFunction(observer);
 

test/QueryManager.ts

@@ -25,6 +25,10 @@ import {
   Document,
 } from 'graphql';
 
+import * as Rx from 'rxjs';
+
+import assign = require('lodash.assign');
+
 import mockNetworkInterface from './mocks/mockNetworkInterface';
 
 describe('QueryManager', () => {
@@ -391,6 +395,57 @@ describe('QueryManager', () => {
     done();
   });
 
+  it('supports interoperability with other Observable implementations like RxJS', (done) => {
+    const query = gql`
+      query people {
+        allPeople(first: 1) {
+          people {
+            name
+          }
+        }
+      }
+    `;
+
+    const data = {
+      allPeople: {
+        people: [
+          {
+            name: 'Luke Skywalker',
+          },
+        ],
+      },
+    };
+
+    const networkInterface = mockNetworkInterface(
+      {
+        request: { query },
+        result: { data },
+      }
+    );
+
+    const queryManager = new QueryManager({
+      networkInterface,
+      store: createApolloStore(),
+      reduxRootKey: 'apollo',
+    });
+
+    const handle = queryManager.watchQuery({
+      query,
+    });
+
+    const observable = Rx.Observable.from(handle);
+
+    observable
+      .map(result => (assign({ fromRx: true }, result)))
+      .subscribe({
+      next(result) {
+        const expectedResult = assign({ fromRx: true }, result);
+        assert.deepEqual(result, expectedResult);
+        done();
+      },
+    });
+  });
+
   it('allows you to refetch queries', (done) => {
     const query = gql`
       query fetchLuke($id: String) {