Allow websocket connections from browser

Summary: Gets flipper to open up a websocket server for web browser connections.

Reviewed By: passy, priteshrnandgaonkar

Differential Revision: D19501123

fbshipit-source-id: e506f35d7ddce622128932494e8bb10802d3747b

src/utils/js-client/websocketClientFlipperConnection.tsx

@@ -0,0 +1,83 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import {FlipperClientConnection} from '../../Client';
+import {Payload} from 'rsocket-types';
+import {Flowable, Single} from 'rsocket-flowable';
+import {ConnectionStatus, ISubscriber} from 'rsocket-types';
+import WebSocket from 'ws';
+
+export class WebsocketClientFlipperConnection<M>
+  implements FlipperClientConnection<string, M> {
+  websocket: WebSocket;
+  connStatusSubscribers: Set<ISubscriber<ConnectionStatus>> = new Set();
+  connStatus: ConnectionStatus;
+  app: string;
+  plugins: string[] = [];
+
+  constructor(ws: WebSocket, app: string, plugins: string[]) {
+    this.websocket = ws;
+    this.connStatus = {kind: 'CONNECTED'};
+    this.app = app;
+    this.plugins = plugins;
+  }
+
+  connectionStatus(): Flowable<ConnectionStatus> {
+    return new Flowable<ConnectionStatus>(subscriber => {
+      subscriber.onSubscribe({
+        cancel: () => {
+          this.connStatusSubscribers.delete(subscriber);
+        },
+        request: _ => {
+          this.connStatusSubscribers.add(subscriber);
+          subscriber.onNext(this.connStatus);
+        },
+      });
+    });
+  }
+
+  close(): void {
+    this.connStatus = {kind: 'CLOSED'};
+    this.connStatusSubscribers.forEach(subscriber => {
+      subscriber.onNext(this.connStatus);
+    });
+    this.websocket.send(JSON.stringify({type: 'disconnect', app: this.app}));
+  }
+
+  fireAndForget(payload: Payload<string, M>): void {
+    this.websocket.send(
+      JSON.stringify({
+        type: 'send',
+        app: this.app,
+        payload: payload.data != null ? payload.data : {},
+      }),
+    );
+  }
+
+  // TODO: fully implement and return actual result
+  requestResponse(payload: Payload<string, M>): Single<Payload<string, M>> {
+    return new Single(subscriber => {
+      const method =
+        payload.data != null ? JSON.parse(payload.data).method : 'not-defined';
+      subscriber.onSubscribe(() => {});
+      if (method != 'getPlugins') {
+        this.fireAndForget(payload);
+      }
+      subscriber.onComplete(
+        method == 'getPlugins'
+          ? {
+              data: JSON.stringify({
+                success: {plugins: this.plugins},
+              }),
+            }
+          : {data: JSON.stringify({success: null})},
+      );
+    });
+  }
+}