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Diffstat (limited to 'node_modules/p-locate/index.js')
-rw-r--r-- | node_modules/p-locate/index.js | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/node_modules/p-locate/index.js b/node_modules/p-locate/index.js new file mode 100644 index 0000000..7461d66 --- /dev/null +++ b/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)); +}; |