util/mock-server.js

/* eslint-disable @typescript-eslint/no-require-imports */
/* eslint-disable functional/immutable-data */
/* eslint-disable no-console */
/* eslint-disable functional/no-let */
// Very simple mocking server for mimicking IDAPI

/* eslint-env node */
const bodyParser = require('body-parser');
const express = require('express');
const PORT = 9000;

const DEFAULT_RESPONSE = {
	status: 500,
	payload: 'Mock Server Error: No mock requests in queue',
};

const app = express();

const responses = [];
const permanent = new Map();
let permanentPatterns = [];

const findPattern = (path) =>
	permanentPatterns.find(({ pattern }) => new RegExp(pattern).test(path));

const payloads = [];

app.use(bodyParser.json({ strict: false }));
app.use(express.urlencoded({ extended: true }));

app.get('/healthcheck', (_, res) => {
	console.log('healthcheck OK');
	res.sendStatus(204);
});

// Reset all mocks, including permanent
app.get('/mock/purge', (_, res) => {
	console.log('purging all mocks');
	responses.length = 0;
	permanent.clear();
	permanentPatterns = [];
	payloads.length = 0;
	res.sendStatus(204);
});

// Push mock onto mock stack
app.post('/mock', (req, res) => {
	responses.unshift({
		status: req.get('X-status'),
		payload: req.body,
	});
	res.sendStatus(204);
});

// Mock an endpoint with a pattern
app.post('/mock/permanent-pattern', (req, res) => {
	permanentPatterns.push(req.body);
	res.sendStatus(204);
});

// Always mock supplied endpoint
app.post('/mock/permanent', (req, res) => {
	const { path, body: payload, status = 200 } = req.body;
	permanent.set(path, { payload, status });
	res.sendStatus(204);
});

// Return last POST or PATCH'd request payload
app.get('/mock/payload', (_, res) => {
	res.json(payloads[payloads.length - 1]);
});

// Return all POST or PATCH'd request payloads
app.get('/mock/payloads', (_, res) => {
	res.json(payloads);
});

// For any request, if permanent, return permanent mock, otherwise pop from mock stack.
app.all('*', (req, res) => {
	const origin = req.header('Origin');
	if (origin) {
		res.set('Access-Control-Allow-Origin', origin);
	}

	const { method } = req;
	if (method === 'POST' || method === 'PATCH') {
		payloads.push(req.body);
	}

	if (permanent.has(req.path)) {
		const { status, payload } = permanent.get(req.path);
		res.status(status).json(payload);
		// console.log(`Mocking: ${req.originalUrl}: ${status} ${inspect(payload)}`);
		return;
	}

	const patternResponse = findPattern(req.path);
	if (patternResponse) {
		// eslint-disable-next-line @typescript-eslint/no-unused-vars
		const { status, body, pattern } = patternResponse;
		res.status(status).json(body);
		// console.log(
		//   `Mocking for pattern ${pattern}: ${req.originalUrl}: ${status} ${body}`,
		// );
		return;
	}

	if (responses.length === 0) {
		res.status(DEFAULT_RESPONSE.status).json(DEFAULT_RESPONSE.body);
	} else {
		const { status, payload } = responses.pop();
		// console.log(`Mocking: ${req.originalUrl}: ${status} ${inspect(payload)}`);
		res.status(status).json(payload);
	}
});

app.listen(PORT);
console.log('mock server running on port:', PORT);