The easiest way to create a resolver is to use the `createResolver` function on `ResolveFactory`, along with one of the supplied File System implementations.
| alias | [] | A list of module alias configurations or an object which maps key to value |
| aliasFields | [] | A list of alias fields in description files |
| extensionAlias | {} | An object which maps extension to extension aliases |
| cachePredicate | function() { return true }; | A function which decides whether a request should be cached or not. An object is passed to the function with `path` and `request` properties. |
| cacheWithContext | true | If unsafe cache is enabled, includes `request.context` in the cache key |
| conditionNames | [] | A list of exports field condition names |
| descriptionFiles | ["package.json"] | A list of description files to read from |
| enforceExtension | false | Enforce that a extension from extensions must be used |
| exportsFields | ["exports"] | A list of exports fields in description files |
| extensions | [".js", ".json", ".node"] | A list of extensions which should be tried for files |
| fallback | [] | Same as `alias`, but only used if default resolving fails |
| fileSystem | | The file system which should be used |
| fullySpecified | false | Request passed to resolve is already fully specified and extensions or main files are not resolved for it (they are still resolved for internal requests) |
| mainFields | ["main"] | A list of main fields in description files |
| mainFiles | ["index"] | A list of main files in directories |
| modules | ["node_modules"] | A list of directories to resolve modules from, can be absolute path or folder name |
| plugins | [] | A list of additional resolve plugins which should be applied |
| resolver | undefined | A prepared Resolver to which the plugins are attached |
| resolveToContext | false | Resolve to a context instead of a file |
| preferRelative | false | Prefer to resolve module requests as relative request and fallback to resolving as module |
| preferAbsolute | false | Prefer to resolve server-relative urls as absolute paths before falling back to resolve in roots |
| restrictions | [] | A list of resolve restrictions |
| roots | [] | A list of root paths |
| symlinks | true | Whether to resolve symlinks to their symlinked location |
| unsafeCache | false | Use this cache object to unsafely cache the successful requests |
## Plugins
Similar to `webpack`, the core of `enhanced-resolve` functionality is implemented as individual plugins that are executed using [`tapable`](https://github.com/webpack/tapable).
These plugins can extend the functionality of the library, adding other ways for files/contexts to be resolved.
A plugin should be a `class` (or its ES5 equivalent) with an `apply` method. The `apply` method will receive a `resolver` instance, that can be used to hook in to the event system.
Plugins are executed in a pipeline, and register which event they should be executed before/after. In the example above, `source` is the name of the event that starts the pipeline, and `target` is what event this plugin should fire, which is what continues the execution of the pipeline. For an example of how these different plugin events create a chain, see `lib/ResolverFactory.js`, in the `//// pipeline ////` section.
## Escaping
It's allowed to escape `#` as `\0#` to avoid parsing it as fragment.
enhanced-resolve will try to resolve requests containing `#` as path and as fragment, so it will automatically figure out if `./some#thing` means `.../some.js#thing` or `.../some#thing.js`. When a `#` is resolved as path it will be escaped in the result. Here: `.../some\0#thing.js`.
## Tests
```javascript
yarn test
```
## Passing options from webpack
If you are using `webpack`, and you want to pass custom options to `enhanced-resolve`, the options are passed from the `resolve` key of your webpack configuration e.g.:
