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   pscIdeClient: null, // purs ide client
  60   pscIdeClientArgs: {}, // for example, to use different port {port: 4088}
  61   pscIdeServer: null, // purs ide server
  62   pscIdeServerArgs: {}, // for example, to change the port { port: 4088 }
  63   pscIdeColors: false, // defaults to true if psc === 'psa'
  64   pscPackage: false,
  65   bundleOutput: 'output/bundle.js',
  66   bundleNamespace: 'PS',
  67   bundle: false,
  68   warnings: true,
  69   watch: false, // indicates if webpack is in watch mode
  70   output: 'output',
  71   src: [
  72     path.join('src', '**', '*.purs'),
  73     // if pscPackage = false
  74     path.join('bower_components', 'purescript-*', 'src', '**', '*.purs')
  75     // if pscPackage = true
  76     // source paths reported by `psc-package sources`
  77   ]
  78 }
  79 ```
  80
  81 ### `psc-ide` support (experimental)
  82
  83 Experimental support for instant rebuilds using `psc-ide-server` can be enabled
  84 via the `pscIde: true` option.
  85 You can use an already running `psc-ide-server` instance by specifying the port in `pscIdeArgs`,
  86 if there is no server running this loader will start one for you.
  87
  88 ### `psc-package` support (experimental)
  89
  90 Set `pscPackage` query parameter to `true` to enable `psc-package` support. The `psc-package`-supplied source paths
  91 will be appended to `src` parameter.
  92
  93 ### Troubleshooting
  94
  95 #### Slower webpack startup after enabling psc-ide support?
  96
  97 By default, the psc-ide-server will be passed the globs from query.src, this is
  98 helpful for other tools using psc-ide-server (for example IDE plugins), however
  99 it might result in a slower initial webpack startup time (rebuilds are not
 100 affected). To override the default behaviour, add:
 101 `pscIdeServerArgs: { "_": ['your/*globs/here'] }` to the loader config
 102
 103 #### Errors not being displayed in watch mode?
 104
 105 When the `watch` option is set to `true`, psc errors are appended to
 106 webpack's compilation instance errors array and not passed back as an
 107 error to the loader's callback. This may result in the error not being
 108 reported by webpack. To display errors, the following plugin may be added
 109 to the webpack config.
 110
 111 ```javascript
 112 const webpackConfig = {
 113   // ...
 114   plugins: [
 115     function(){
 116       this.plugin('done', function(stats){
 117         process.stderr.write(stats.toString('errors-only'));
 118       });
 119     }
 120   ]
 121   // ...
 122 }
 123 ```
 124
 125 #### Error `spawn ENOENT`
 126
 127 This is caused when the loader tries to spawn a binary that does not exists
 128 (`file or directory not found`). If you call webpack like `webpack` or
 129 `webpack --watch`, then ensure that all required binaries that the
 130 loader depends on are available in your `$PATH`.
 131
 132 If you run webpack through an npm script (e.g., npm run or npm start) on NixOS,
 133 then it will first attempt to find binaries in `node_packages/.bin`.
 134 If you have the compiler installed through `npm` and it finds it there, this will
 135 cause `ENOENT`on Nix, because [the binary needs to be patched first, but npm will
 136 install the binary that is linked with /lib64/ld-linux-x86-64.so.2 - a file that
 137 will not exist at that path in NixOS](https://github.com/ethul/purescript-webpack-example/issues/5#issuecomment-282492131).
 138 The solution is to simply use the compiler from `haskellPackages.purescript` and
 139 make sure that it's available in `$PATH`. For more information about how to make
 140 it work on Nix, see [Purescript Webpack Example](https://github.com/ethul/purescript-webpack-example#using-globally-installed-binaries)