# escalade [![CI](https://github.com/lukeed/escalade/workflows/CI/badge.svg)](https://github.com/lukeed/escalade/actions) [![codecov](https://badgen.now.sh/codecov/c/github/lukeed/escalade)](https://codecov.io/gh/lukeed/escalade) > A tiny (183B to 210B) and [fast](#benchmarks) utility to ascend parent directories With [escalade](https://en.wikipedia.org/wiki/Escalade), you can scale parent directories until you've found what you're looking for.
Given an input file or directory, `escalade` will continue executing your callback function until either: 1) the callback returns a truthy value 2) `escalade` has reached the system root directory (eg, `/`) > **Important:**
Please note that `escalade` only deals with direct ancestry – it will not dive into parents' sibling directories. --- **Notice:** As of v3.1.0, `escalade` now includes [Deno support](http://deno.land/x/escalade)! Please see [Deno Usage](#deno) below. --- ## Install ``` $ npm install --save escalade ``` ## Modes There are two "versions" of `escalade` available: #### "async" > **Node.js:** >= 8.x
> **Size (gzip):** 210 bytes
> **Availability:** [CommonJS](https://unpkg.com/escalade/dist/index.js), [ES Module](https://unpkg.com/escalade/dist/index.mjs) This is the primary/default mode. It makes use of `async`/`await` and [`util.promisify`](https://nodejs.org/api/util.html#util_util_promisify_original). #### "sync" > **Node.js:** >= 6.x
> **Size (gzip):** 183 bytes
> **Availability:** [CommonJS](https://unpkg.com/escalade/sync/index.js), [ES Module](https://unpkg.com/escalade/sync/index.mjs) This is the opt-in mode, ideal for scenarios where `async` usage cannot be supported. ## Usage ***Example Structure*** ``` /Users/lukeed └── oss ├── license └── escalade ├── package.json └── test └── fixtures ├── index.js └── foobar └── demo.js ``` ***Example Usage*** ```js //~> demo.js import { join } from 'path'; import escalade from 'escalade'; const input = join(__dirname, 'demo.js'); // or: const input = __dirname; const pkg = await escalade(input, (dir, names) => { console.log('~> dir:', dir); console.log('~> names:', names); console.log('---'); if (names.includes('package.json')) { // will be resolved into absolute return 'package.json'; } }); //~> dir: /Users/lukeed/oss/escalade/test/fixtures/foobar //~> names: ['demo.js'] //--- //~> dir: /Users/lukeed/oss/escalade/test/fixtures //~> names: ['index.js', 'foobar'] //--- //~> dir: /Users/lukeed/oss/escalade/test //~> names: ['fixtures'] //--- //~> dir: /Users/lukeed/oss/escalade //~> names: ['package.json', 'test'] //--- console.log(pkg); //=> /Users/lukeed/oss/escalade/package.json // Now search for "missing123.txt" // (Assume it doesn't exist anywhere!) const missing = await escalade(input, (dir, names) => { console.log('~> dir:', dir); return names.includes('missing123.txt') && 'missing123.txt'; }); //~> dir: /Users/lukeed/oss/escalade/test/fixtures/foobar //~> dir: /Users/lukeed/oss/escalade/test/fixtures //~> dir: /Users/lukeed/oss/escalade/test //~> dir: /Users/lukeed/oss/escalade //~> dir: /Users/lukeed/oss //~> dir: /Users/lukeed //~> dir: /Users //~> dir: / console.log(missing); //=> undefined ``` > **Note:** To run the above example with "sync" mode, import from `escalade/sync` and remove the `await` keyword. ## API ### escalade(input, callback) Returns: `string|void` or `Promise` When your `callback` locates a file, `escalade` will resolve/return with an absolute path.
If your `callback` was never satisfied, then `escalade` will resolve/return with nothing (undefined). > **Important:**
The `sync` and `async` versions share the same API.
The **only** difference is that `sync` is not Promise-based. #### input Type: `string` The path from which to start ascending. This may be a file or a directory path.
However, when `input` is a file, `escalade` will begin with its parent directory. > **Important:** Unless given an absolute path, `input` will be resolved from `process.cwd()` location. #### callback Type: `Function` The callback to execute for each ancestry level. It always is given two arguments: 1) `dir` - an absolute path of the current parent directory 2) `names` - a list (`string[]`) of contents _relative to_ the `dir` parent > **Note:** The `names` list can contain names of files _and_ directories. When your callback returns a _falsey_ value, then `escalade` will continue with `dir`'s parent directory, re-invoking your callback with new argument values. When your callback returns a string, then `escalade` stops iteration immediately.
If the string is an absolute path, then it's left as is. Otherwise, the string is resolved into an absolute path _from_ the `dir` that housed the satisfying condition. > **Important:** Your `callback` can be a `Promise/AsyncFunction` when using the "async" version of `escalade`. ## Benchmarks > Running on Node.js v10.13.0 ``` # Load Time find-up 3.891ms escalade 0.485ms escalade/sync 0.309ms # Levels: 6 (target = "foo.txt"): find-up x 24,856 ops/sec ±6.46% (55 runs sampled) escalade x 73,084 ops/sec ±4.23% (73 runs sampled) find-up.sync x 3,663 ops/sec ±1.12% (83 runs sampled) escalade/sync x 9,360 ops/sec ±0.62% (88 runs sampled) # Levels: 12 (target = "package.json"): find-up x 29,300 ops/sec ±10.68% (70 runs sampled) escalade x 73,685 ops/sec ± 5.66% (66 runs sampled) find-up.sync x 1,707 ops/sec ± 0.58% (91 runs sampled) escalade/sync x 4,667 ops/sec ± 0.68% (94 runs sampled) # Levels: 18 (target = "missing123.txt"): find-up x 21,818 ops/sec ±17.37% (14 runs sampled) escalade x 67,101 ops/sec ±21.60% (20 runs sampled) find-up.sync x 1,037 ops/sec ± 2.86% (88 runs sampled) escalade/sync x 1,248 ops/sec ± 0.50% (93 runs sampled) ``` ## Deno As of v3.1.0, `escalade` is available on the Deno registry. Please note that the [API](#api) is identical and that there are still [two modes](#modes) from which to choose: ```ts // Choose "async" mode import escalade from 'https://deno.land/escalade/async.ts'; // Choose "sync" mode import escalade from 'https://deno.land/escalade/sync.ts'; ``` > **Important:** The `allow-read` permission is required! ## Related - [premove](https://github.com/lukeed/premove) - A tiny (247B) utility to remove items recursively - [totalist](https://github.com/lukeed/totalist) - A tiny (195B to 224B) utility to recursively list all (total) files in a directory - [mk-dirs](https://github.com/lukeed/mk-dirs) - A tiny (420B) utility to make a directory and its parents, recursively ## License MIT © [Luke Edwards](https://lukeed.com)