Conduitry 5 years ago
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MIT License
Copyright (c) 2018
Copyright (c) 2018 Conduitry
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal

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# cheap-watch
If it works, why use something else?
# Cheap Watch: If it works, why use something else?
[![npm version](](
**Cheap Watch** is a small, simple, dependency-free, cross-platform file system watcher for Node.js 8+.
It began life as part of [Defiler]( and was then prettied up and extracted into its own library.
## Constructor
### `new CheapWatch({ dir, filter, watch = true, debounce = 10 })``
- `dir` - The directory whose contents to watch. It's recommended, though not required, for this to be an absolute path, say one returned by `path.resolve`.
- `filter({ path, stats })` - _(optional)_ A function to decide whether a given file or directory should be watched. It's passed an object containing the file or directory's relative `path` and its `stats`. It should return `true` or `false` (or a `Promise` resolving to one of those). Returning `false` for a directory means that none of its contents will be watched. You can use `stats.isFile()` and `stats.isDirectory()` to determine whether this is a file or a directory.
- `watch` - _(optional)_ Whether to actually watch the directory for changes. Defaults to `true`. If `false`, you can retrieve all of the files within a given directory along with their `Stats` but changes will not actually be watched.
- `debounce` - _(optional)_ Length of timeout in milliseconds to use to debounce incoming events from ``. Defaults to 10. Multiple events are often emitted for a single change, and events can also be emitted before `fs.stat` reports the changes. Cheap Watch will wait until `debounce` milliseconds have passed since the last `` event for a file before reporting it. The default of 10ms Works On My Machine.
## Methods
### `cheapWatch.init()`
Initialize the watcher, traverse the directory to find the initial files, and set up watchers to look for changes.
This returns a `Promise` that resolves to an array of `{ path, stats }` object, one per file. `path` is a relative path from the `CheapWatch`'s `dir`, and `stats` is the `Stats` object for the file.
### `cheapWatch.close()`
Close all `FSWatcher` instances, and stop watching for file changes.
## Events
`CheapWatch` is a subclass of `EventEmitter`, and emits two events to report a new or update file or to report a deleted file.
### `+` `{ path, stats }`
A `+` event is emitted with an object containing a `path` string and a `stats` object whenever a watched file is created or updated.
### `-` `{ path }`
A `-` event is emitted with an object containing a `path` string whenever a watched file is deleted.
## Usage
import CheapWatch from 'cheap-watch';
const watch = new CheapWatch({ dir, /* ... */ });
const initialFiles = await watch.init();
watch.on('+', ({ path, stats }) => /* ... */ );
watch.on('-', ({ path }) => /* ... */);
## License
Copyright (c) 2018 Conduitry