README.md

   1 # purs-loader
   2
   3 > [PureScript](http://www.purescript.org) loader for [webpack](http://webpack.github.io)
   4
   5 - Supports hot-reloading and rebuilding of single source files
   6 - Dead code elimination using the `bundle` option
   7 - Colorized build output using `purescript-psa` and the `psc: "psa"` option
   8
   9 ## Install
  10
  11 Install with [npm](https://npmjs.org/package/purs-loader).
  12
  13 ```
  14 // For PureScript 0.11 and newer
  15 npm install purs-loader --save-dev
  16
  17 // For PureScript 0.9 and 0.10
  18 npm install purs-loader@purescript-0.9 --save-dev
  19
  20 // For PureScript 0.8
  21 npm install purs-loader@purescript-0.8 --save-dev
  22 ```
  23
  24 ## Example
  25
  26 ```javascript
  27 const webpackConfig = {
  28   // ...
  29   loaders: [
  30     // ...
  31     {
  32       test: /\.purs$/,
  33       loader: 'purs-loader',
  34       exclude: /node_modules/,
  35       query: {
  36         psc: 'psa',
  37         src: ['bower_components/purescript-*/src/**/*.purs', 'src/**/*.purs']
  38       }
  39     }
  40     // ...
  41   ]
  42   // ...
  43 }
  44 ```
  45
  46 Refer to the [purescript-webpack-example](https://github.com/ethul/purescript-webpack-example) for a more detailed example.
  47
  48 ### Options
  49
  50 Default options:
  51
  52 ```javascript
  53 const loaderConfig = {
  54   psc: null, // purs compile
  55   pscArgs: {},
  56   pscBundle: null, // purs bundle
  57   pscBundleArgs: {},
  58   pscIde: false, // instant rebuilds using psc-ide-server (experimental)
  59   pscIdeArgs: {}, // for example, to use different psc-ide-server port: {port: 4088}
  60   pscIdeServerArgs: {}, // for example, to change the port { port: 4088 }
  61   pscIdeColors: false, // defaults to true if psc === 'psa'
  62   pscPackage: false,
  63   bundleOutput: 'output/bundle.js',
  64   bundleNamespace: 'PS',
  65   bundle: false,
  66   warnings: true,
  67   watch: false, // indicates if webpack is in watch mode
  68   output: 'output',
  69   src: [
  70     path.join('src', '**', '*.purs'),
  71     // if pscPackage = false
  72     path.join('bower_components', 'purescript-*', 'src', '**', '*.purs')
  73     // if pscPackage = true
  74     // source paths reported by `psc-package sources`
  75   ]
  76 }
  77 ```
  78
  79 ### `psc-ide` support (experimental)
  80
  81 Experimental support for instant rebuilds using `psc-ide-server` can be enabled
  82 via the `pscIde: true` option.
  83 You can use an already running `psc-ide-server` instance by specifying the port in `pscIdeArgs`,
  84 if there is no server running this loader will start one for you.
  85
  86 ### `psc-package` support (experimental)
  87
  88 Set `pscPackage` query parameter to `true` to enable `psc-package` support. The `psc-package`-supplied source paths
  89 will be appended to `src` parameter.
  90
  91 ### Troubleshooting
  92
  93 #### Slower webpack startup after enabling psc-ide support?
  94
  95 By default, the psc-ide-server will be passed the globs from query.src, this is
  96 helpful for other tools using psc-ide-server (for example IDE plugins), however
  97 it might result in a slower initial webpack startup time (rebuilds are not
  98 affected). To override the default behaviour, add:
  99 `pscIdeServerArgs: { "_": ['your/*globs/here'] }` to the loader config
 100
 101 #### Errors not being displayed in watch mode?
 102
 103 When the `watch` option is set to `true`, psc errors are appended to
 104 webpack's compilation instance errors array and not passed back as an
 105 error to the loader's callback. This may result in the error not being
 106 reported by webpack. To display errors, the following plugin may be added
 107 to the webpack config.
 108
 109 ```javascript
 110 const webpackConfig = {
 111   // ...
 112   plugins: [
 113     function(){
 114       this.plugin('done', function(stats){
 115         process.stderr.write(stats.toString('errors-only'));
 116       });
 117     }
 118   ]
 119   // ...
 120 }
 121 ```
 122
 123 #### Error `spawn ENOENT`
 124
 125 This is caused when the loader tries to spawn a binary that does not exists
 126 (`file or directory not found`). If you call webpack like `webpack` or
 127 `webpack --watch`, then ensure that all required binaries that the
 128 loader depends on are available in your `$PATH`.
 129
 130 If you run webpack through an npm script (e.g., npm run or npm start) on NixOS,
 131 then it will first attempt to find binaries in `node_packages/.bin`.
 132 If you have the compiler installed through `npm` and it finds it there, this will
 133 cause `ENOENT`on Nix, because [the binary needs to be patched first, but npm will
 134 install the binary that is linked with /lib64/ld-linux-x86-64.so.2 - a file that
 135 will not exist at that path in NixOS](https://github.com/ethul/purescript-webpack-example/issues/5#issuecomment-282492131).
 136 The solution is to simply use the compiler from `haskellPackages.purescript` and
 137 make sure that it's available in `$PATH`. For more information about how to make
 138 it work on Nix, see [Purescript Webpack Example](https://github.com/ethul/purescript-webpack-example#using-globally-installed-binaries)