add node modules to repo

node_modules/p-locate/index.js

@@ -0,0 +1,31 @@
+'use strict';
+const pLimit = require('p-limit');
+
+class EndError extends Error {
+	constructor(value) {
+		super();
+		this.value = value;
+	}
+}
+
+// the input can also be a promise, so we `Promise.all()` them both
+const finder = el => Promise.all(el).then(val => val[1] === true && Promise.reject(new EndError(val[0])));
+
+module.exports = (iterable, tester, opts) => {
+	opts = Object.assign({
+		concurrency: Infinity,
+		preserveOrder: true
+	}, opts);
+
+	const limit = pLimit(opts.concurrency);
+
+	// start all the promises concurrently with optional limit
+	const items = Array.from(iterable).map(el => [el, limit(() => Promise.resolve(el).then(tester))]);
+
+	// check the promises either serially or concurrently
+	const checkLimit = pLimit(opts.preserveOrder ? 1 : Infinity);
+
+	return Promise.all(items.map(el => checkLimit(() => finder(el))))
+		.then(() => {})
+		.catch(err => err instanceof EndError ? err.value : Promise.reject(err));
+};