issue-680

.gitignore

node_modules/
yarn.lock

README.md

Test repo for issue 680

To use it, run

yarn install
yarn test

The test code is in Subscription.spec.ts

package.json

{
	"name": "issue-680",
	"version": "0.0.1",
	"license": "MIT",
	"scripts": {
		"test": "jest --detectOpenHandles --runInBand ./Subscription.spec.ts"
	},
	"dependencies": {
		"@types/jest": "^23.3.7",
		"@types/node": "^10.12.18",
		"apollo-client": "^2.4.5",
		"apollo-link-ws": "^1.0.9",
		"graphql": "^14.0.2",
		"graphql-tag": "^2.10.0",
		"jest": "^23.6.0",
		"subscriptions-transport-ws": "^0.9.15",
		"ts-jest": "^23.10.4",
		"typescript": "^3.1.3",
		"ws": "5.2.2"
	},
	"jest": {
		"roots": [
			"<rootDir>"
		],
		"transform": {
			"^.+\\.tsx?$": "ts-jest"
		},
		"globals": {
			"ts-jest": {
				"tsConfig": "./tsconfig.json"
			}
		},
		"testEnvironment": "node",
		"testRegex": ".*\\.(ts|js)?$",
		"moduleFileExtensions": [
			"ts",
			"tsx",
			"js",
			"jsx",
			"json",
			"node"
		]
	}
}

Subscription.spec.ts

import gql from 'graphql-tag';
import { WebSocketLink } from 'apollo-link-ws';
import { SubscriptionClient } from 'subscriptions-transport-ws';
import { execute } from 'apollo-link';

// This doesn't work with import. No idea why
const ws = require('ws');

// How many times to repeat doSubscription
const repetitions = 10;

// How long to wait until we get through REPETETITIONS times
// calling doSubscription (in ms). On my machine, which also runs graph-node,
// setting this to 250 leads to intermittent failures, bumping it to 2500
// lets this test pass reliably
const subscription_timeout = 2500;

// Change these two variables to match whatever you have deployed as a
// subgraph.  It does not seem to matter what is used; you will also have
// to adapt the 'expect' below.
// This is based on https://github.com/lutter/dice2win-subgraph
//const subgraph_url = 'ws://127.0.0.1:8001/subgraphs/name/dice2win';
const subgraph_url = 'wss://api.staging.thegraph.com/subgraphs/name/lutter/dice2win';
const subgraph_subscr = gql`
subscription js_test {
  beneficiaries(where: {jackpots_gt: 0}) {
    id
    winnings
    jackpots
  }
}`;

async function waitUntilTrue(f: () => boolean) {
  return new Promise((resolve, reject) => {
    (function waitForIt() {
      if (f()) { return resolve(); }
      setTimeout(waitForIt, 30);
    })();
  });
}

// Subscribe to a query and wait for the first response. Check that the
// response contains some well-known data.
async function doSubscription(step: number) {
  const client = new SubscriptionClient(subgraph_url, { reconnect: true }, ws);
  const link = new WebSocketLink(client);
  let query : string = subgraph_subscr;
  const subscriptionClient = execute(link, { query });

  let event;
  let nextWasCalled = false;
  const consumer = await subscriptionClient.subscribe(
    (eventData) => {
      // Do something on receipt of the event
      nextWasCalled = true;
      event = eventData.data;
    },
    (err) => {
      expect(true).toEqual(false);
    },
  );

  // wait until the subscription callback has been called
  await waitUntilTrue(() => nextWasCalled);
  console.log('Step #%d:\n%O', step, event);
  expect(event.beneficiaries).toContainEqual({
    id: "0xb461c1ce4b3421b9be916f8a3114865bb5bf9968",
    winnings: expect.any(String),
    jackpots: expect.any(String)
  });
  consumer.unsubscribe();
  client.close();
};

async function doSubscriptions(n: number) {
  for (let i = 1; i <= n; i++) {
    console.log('Call #%d', i);
    await doSubscription(i);
  }
};

describe('Subscriptions', () => {
    it('subscribes', async () => {
        console.log('Subscribing to %s', subgraph_url);
        await doSubscriptions(repetitions)
  }, repetitions*subscription_timeout);
});

tsconfig.json

{
  "compilerOptions": {
    "lib": [
      "es2015"
    ],
    "types": [
      "@types/jest",
      "@types/node"
    ]
  }
}