implement Server#unregister(handlerName)

packages/grpc-js/src/server.ts

@@ -458,6 +458,10 @@ export class Server {
     return true;
   }
 
+  unregister(name: string): boolean {
+    return this.handlers.delete(name);
+  }
+
   start(): void {
     if (
       this.http2ServerList.length === 0 ||

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

@@ -220,6 +220,61 @@ describe('Server', () => {
     });
   });
 
+  describe('unregister', () => {
+
+    let server: Server;
+    let client: ServiceClient;
+
+    const mathProtoFile = path.join(__dirname, 'fixtures', 'math.proto');
+    const mathClient = (loadProtoFile(mathProtoFile).math as any).Math;
+    const mathServiceAttrs = mathClient.service;
+
+    beforeEach(done => {
+      server = new Server();
+      server.addService(mathServiceAttrs, {
+        div(call: ServerUnaryCall<any, any>, callback: sendUnaryData<any>) {
+          callback(null, {quotient: '42'});
+        },
+      });
+      server.bindAsync(
+        'localhost:0',
+        ServerCredentials.createInsecure(),
+        (err, port) => {
+          assert.ifError(err);
+          client = new mathClient(
+            `localhost:${port}`,
+            grpc.credentials.createInsecure()
+          );
+          server.start();
+          done();
+        }
+      );
+    });
+
+    afterEach(done => {
+      client.close();
+      server.tryShutdown(done);
+    });
+
+    it('removes handler by name and returns true', done => {
+      const name = mathServiceAttrs['Div'].path;
+      assert.strictEqual(server.unregister(name), true, 'Server#unregister should return true on success');
+
+      client.div(
+        { divisor: 4, dividend: 3 },
+        (error: ServiceError, response: any) => {
+          assert(error);
+          assert.strictEqual(error.code, grpc.status.UNIMPLEMENTED);
+          done();
+        }
+      );
+    });
+
+    it('returns false for unknown handler', () => {
+      assert.strictEqual(server.unregister('noOneHere'), false, 'Server#unregister should return false on failure');
+    });
+  });
+
   it('throws when unimplemented methods are called', () => {
     const server = new Server();