grpc-js: Client waitForReady callback fix. Fixes #1352

packages/grpc-js/src/channel.ts

@@ -381,9 +381,9 @@ export class ChannelImplementation implements Channel {
     const watchersCopy = this.connectivityStateWatchers.slice();
     for (const watcherObject of watchersCopy) {
       if (newState !== watcherObject.currentState) {
-        watcherObject.callback();
         clearTimeout(watcherObject.timer);
         this.removeConnectivityStateWatcher(watcherObject);
+        watcherObject.callback();
       }
     }
   }

packages/grpc-js/test/test-client.ts

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+import * as assert from 'assert';
+
+import * as grpc from '../src';
+import { Server, ServerCredentials } from '../src';
+import { Client } from '../src';
+import { ConnectivityState } from '../src/channel';
+
+const clientInsecureCreds = grpc.credentials.createInsecure();
+const serverInsecureCreds = ServerCredentials.createInsecure();
+
+describe('Client', () => {
+  let server: Server;
+  let client: Client;
+
+  before(done => {
+    server = new Server();
+
+    server.bindAsync(
+      'localhost:0',
+      serverInsecureCreds,
+      (err, port) => {
+        assert.ifError(err);
+        client = new Client(
+          `localhost:${port}`,
+          clientInsecureCreds
+        );
+        server.start();
+        done();
+      }
+    );
+  });
+
+  after(done => {
+    client.close();
+    server.tryShutdown(done);
+  });
+
+  it('should call the waitForReady callback only once, when channel connectivity state is READY', done => {
+    const deadline = Date.now() + 100;
+    let calledTimes = 0;
+    client.waitForReady(deadline, err => {
+      assert.ifError(err);
+      assert.equal(
+        client.getChannel().getConnectivityState(true),
+        ConnectivityState.READY
+      );
+      calledTimes += 1;
+    });
+    setTimeout(() => {
+      assert.equal(calledTimes, 1);
+      done();
+    }, deadline - Date.now());
+  });
+});