escalade

A tiny (183B to 210B) and fast utility to ascend parent directories
With 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:
- the callback returns a truthy value
escaladehas reached the system root directory (eg,/)
Important:
Please note thatescaladeonly deals with direct ancestry – it will not dive into parents’ sibling directories.
Notice: As of v3.1.0, escalade now
includes Deno support! Please
see Deno Usage 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, ES Module
This is the primary/default mode. It makes use of
async/await and util.promisify.
“sync”
Node.js: >= 6.x
Size (gzip): 183 bytes
Availability: CommonJS, ES Module
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
//~> 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);
//=> undefinedNote: To run the above example with “sync” mode, import from
escalade/syncand remove theawaitkeyword.
API
escalade(input, callback)
Returns: string|void or
Promise<string|void>
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:
Thesyncandasyncversions share the same API.
The only difference is thatsyncis 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,
inputwill be resolved fromprocess.cwd()location.
callback
Type: Function
The callback to execute for each ancestry level. It always is given two arguments:
dir- an absolute path of the current parent directorynames- a list (string[]) of contents relative to thedirparent
Note: The
nameslist 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
callbackcan be aPromise/AsyncFunctionwhen using the “async” version ofescalade.
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 is identical and that there are still two modes from which to choose:
// 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-readpermission is required!
Related
- premove - A tiny (247B) utility to remove items recursively
- totalist - A tiny (195B to 224B) utility to recursively list all (total) files in a directory
- mk-dirs - A tiny (420B) utility to make a directory and its parents, recursively
License
MIT © Luke Edwards