Handle rate limit exceeded error

Closes #71. Fixes #51.

bin/can-merge

@@ -176,7 +176,7 @@ function outputStatus(response) {
 			}
 		});
 	}
-	console.error(`API Points: used - ${response.rateLimit.cost}\tremaining - ${response.rateLimit.remaining}`);
+	console.error(chalk.gray(`API Points: ${response.rateLimit.cost} used\t${response.rateLimit.remaining} remaining`));
 }
 const { repo, pr, sha } = args;
 

utils/watch.js

@@ -1,10 +1,28 @@
 'use strict';
 
+const chalk = require('chalk');
 const evaluatePending = require('../utils/evaluatePending');
 
+async function delay(ms) {
+	return new Promise((resolve) => {
+		setTimeout(resolve, ms);
+	});
+}
+
 module.exports = async function watch(retryDelay, getResponse) {
 	const response = await getResponse();
 
+	const { remaining: remAPIPoints, cost: lastReqCost, resetAt } = response.rateLimit;
+	const currentTime = new Date();
+	const resetTime = new Date(resetAt);
+	const milliSecondsLeft = resetTime - currentTime;
+	const secondsLeft = Math.ceil(milliSecondsLeft / 1000);
+
+	if ((remAPIPoints < lastReqCost) && (retryDelay < milliSecondsLeft)) {
+		console.error(chalk.grey(`API points exhausted. Command will run again in ${secondsLeft} seconds...`));
+		await delay(milliSecondsLeft);
+	}
+
 	const isPendingChecks = evaluatePending(response);
 
 	if (!isPendingChecks) {