Add state transition cycle test cases

__tests__/index/state.test.ts

@@ -0,0 +1,68 @@
+// File Dependencies
+import Sarus from "../../src/index";
+import { WS } from "jest-websocket-mock";
+import { delay } from "../helpers/delay";
+
+const url: string = "ws://localhost:1234";
+const sarusConfig = {
+  url,
+  retryConnectionDelay: 1,
+};
+
+describe("state machine", () => {
+  it("cycles through a closed connection correctly", async () => {
+    let server: WS = new WS(url);
+
+    // In the beginning, the state is "connecting"
+    const sarus: Sarus = new Sarus(sarusConfig);
+    expect(sarus.state).toBe("connecting");
+
+    // We wait until we are connected, and see a "connected" state
+    await server.connected;
+    expect(sarus.state).toBe("connected");
+
+    // When the connection drops, the state will be "closed"
+    server.close();
+    await server.closed;
+    expect(sarus.state).toBe("closed");
+
+    // Restart server
+    server = new WS(url);
+
+    // We wait a while, and the status is "connecting" again
+    await delay(1);
+    expect(sarus.state).toBe("connecting");
+
+    // When we connect in our mock server, we are "connected" again
+    await server.connected;
+    expect(sarus.state).toBe("connected");
+
+    // Cleanup
+    server.close();
+  });
+
+  it("cycles through disconnect() correctly", async () => {
+    let server: WS = new WS(url);
+
+    // Same initial state transition as above
+    const sarus: Sarus = new Sarus(sarusConfig);
+    expect(sarus.state).toBe("connecting");
+    await server.connected;
+    expect(sarus.state).toBe("connected");
+
+    // The user can disconnect and the state will be "disconnected"
+    sarus.disconnect();
+    expect(sarus.state).toBe("disconnected");
+    await server.closed;
+
+    // The user can now reconnect, and the state will be "connecting", and then
+    // "connected" again
+    sarus.connect();
+    expect(sarus.state).toBe("connecting");
+    await server.connected;
+    // XXX for some reason the test will fail without waiting 10 ms here
+    await delay(10);
+    expect(sarus.state).toBe("connected");
+    server.close();
+  });
+});