56 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			56 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# `patchRequire(vol[, unixifyPaths[, Module]])`
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Patches Node's `module` module to use a given *fs-like* object `vol` for module loading.
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 - `vol` - fs-like object
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 - `unixifyPaths` *(optional)* - whether to convert Windows paths to unix style paths, defaults to `false`.
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 - `Module` *(optional)* - a module to patch, defaults to `require('module')`
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Monkey-patches the `require` function in Node, this way you can make
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Node.js to *require* modules from your custom filesystem.
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It expects an object with three filesystem methods implemented that are
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needed for the `require` function to work.
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```js
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let vol = {
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    readFileSync: () => {},
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    realpathSync: () => {},
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    statSync: () => {},
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};
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```
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If you want to make Node.js to *require* your files from memory, you
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don't need to implement those functions yourself, just use the
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[`memfs`](https://github.com/streamich/memfs) package:
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```js
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import {vol} from 'memfs';
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import {patchRequire} from 'fs-monkey';
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vol.fromJSON({'/foo/bar.js': 'console.log("obi trice");'});
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patchRequire(vol);
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require('/foo/bar'); // obi trice
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```
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Now the `require` function will only load the files from the `vol` file
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system, but not from the actual filesystem on the disk.
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If you want the `require` function to load modules from both file
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systems, use the [`unionfs`](https://github.com/streamich/unionfs) package
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to combine both filesystems into a union:
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```js
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import {vol} from 'memfs';
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import {patchRequire} from 'fs-monkey';
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import {ufs} from 'unionfs';
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import * as fs from 'fs';
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vol.fromJSON({'/foo/bar.js': 'console.log("obi trice");'});
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ufs
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    .use(vol)
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    .use(fs);
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patchRequire(ufs);
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require('/foo/bar.js'); // obi trice
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```
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