# Pulp [![Join the chat at https://gitter.im/bodil/pulp](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/bodil/pulp?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) A build tool for PureScript. ![Jarvis Cocker dancing](http://24.media.tumblr.com/77b76c557515a801a7e99ca5507b6548/tumblr_n5cx52oT831r4ba6to1_400.gif) - [Installation](#installation) - [Getting Started with a Pulp Project](#getting-started-with-a-pulp-project) - [What if I need something a bit more complicated?](#what-if-i-need-something-a-bit-more-complicated) - [Pulp Commands](#pulp-commands) - [Global, Command Specific and Pass-Through Options](#global-command-specific-and-pass-through-options) - [Pass-Through Options](#pass-through-options) - [Building Projects](#building-projects) - [Making a JavaScript Bundle](#making-a-javascript-bundle) - [Running Your PureScript Project](#running-your-purescript-project) - [Running Test Suites](#running-test-suites) - [Running Commands Before and After an Action](#running-commands-before-and-after-an-action) - [CommonJS Aware Builds](#commonjs-aware-builds) - [Optimising Code Size](#optimising-code-size) - [Reimporting Browserified Bundles](#reimporting-browserified-bundles) - [Building Documentation](#building-documentation) - [Launching a REPL](#launching-a-repl) - [Launching a Development Server](#launching-a-development-server) - [A Quick Example](#a-quick-example) - [I Need More](#i-need-more) - [Dependency Management](#dependency-management) - [Dependency Management Cheat Sheet](#dependency-management-cheat-sheet) - [Installing Dependencies](#installing-dependencies) - [Housekeeping](#housekeeping) - [Releasing Packages](#releasing-packages) - [Publishing Packages](#publishing-packages) - [Development](#development) - [Licence](#licence) ## Installation Assuming you already have [Node](https://nodejs.org/en/download/) set up (and we recommend you also set up NPM to [keep your global packages in your home directory](https://github.com/sindresorhus/guides/blob/master/npm-global-without-sudo.md)), all you need to do to get a working PureScript environment is: ```sh $ npm install -g purescript pulp bower ``` This installs the PureScript compiler, the Pulp build tool, and the [Bower](http://bower.io/) package manager. *Aside: if you're familiar with the JavaScript ecosystem and you're wondering why PureScript uses Bower and not npm, you might be interested to read [Why the PureScript community uses Bower](http://harry.garrood.me/blog/purescript-why-bower/). Otherwise, please ignore this and read on.* ## Getting Started with a Pulp Project The short version: ```sh $ mkdir purescript-hello $ cd purescript-hello $ pulp init $ pulp run ``` The structure of your project folder, after running `pulp init`, will look like this: ``` purescript-hello - bower.json - src/ - test/ ``` `pulp` works by convention. It expects all projects to contain a manifest file for package management (usually `bower.json`, since package management in PureScript is usually handled by [Bower](http://bower.io/)). Your project source files go in the `src` folder. Your test files go in the `test` folder. Project dependencies will be installed under the Bower standard `bower_components` folder, and are expected to have the same basic `src`/`test` structure. That's all there is to a `pulp` project. We employ the `purescript-` prefix as a convention to identify PureScript projects when they're used as dependencies. You're welcome to call your project anything you like, but without the `purescript-` prefix it won't be picked up by `pulp` as a dependency. ### What if I need something a bit more complicated? If you want to change any of these defaults, you can—`pulp` offers a number of command line flags to alter its behaviour—but try to avoid using them unless you have a good reason to. If you get fed up with having to remember long `pulp` invocations, try [using `npm` as your build tool](http://substack.net/task_automation_with_npm_run). `pulp`'s numerous command line flags make it well suited for this. If that's still not enough, you might try using a more generic build tool, such as [webpack](https://webpack.github.io/) with [purs-loader](https://github.com/ethul/purs-loader), or [gulp](http://gulpjs.com) with [gulp-purescript](https://github.com/purescript-contrib/gulp-purescript). ## Pulp Commands To get a quick overview of the things `pulp` can do, you can ask it to give you a list of its available commands: ```sh $ pulp --help ``` This will print a list of `pulp`'s global command line options, and a list of commands it will accept. To see the available options for a specific command, you can invoke the command with the `--help` flag, like this: ```sh $ pulp build --help ``` This will give you an exhaustive list of ways you can modify the basic behaviour of the command. ### Global, Command Specific and Pass-Through Options Notice that there's a distinction between _global_ command line options and command specific options. Global options must appear _before_ the name of the command, and command specific options must appear _after_ it. Thus, if you want to run the `build` command in watch mode (where it will run the command once, then wait and re-run the command whenever you change a source file) you need to put the `--watch` flag _before_ the command itself, like so: ```sh $ pulp --watch build ``` On the other hand, if you want to tell the build command to produce optimised code (performing dead code elimination), using the command specific option `--optimise`, the flag needs to come _after_ the command name: ```sh $ pulp build --optimise ``` #### Pass-Through Options Finally, `pulp` commands sometimes allows you to pass flags through to the `purs` compiler. Any options appearing after `--` will be passed through to the compiler, or whichever process a `pulp` command spawns. For instance, if you want to tell `purs` to skip applying tail call optimisations, you would invoke `pulp build` like this: ```sh $ pulp build -- --no-tco ``` ## Building Projects At heart, `pulp` is just a frontend for the PureScript compiler, `purs`. Its basic function is to compile your project, which you can do by running `pulp build`. This will simply run `purs compile` with all your source files, leaving the compiled JavaScript files in the `output` folder. These files will all be CommonJS modules, which you can `require()` using anything which supports CommonJS, such as `node`. However, you will usually want to do more with your project than just compile your PureScript code into a jumble of CommonJS modules. `pulp` provides a number of commands and options for the most common use cases. ### Making a JavaScript Bundle `pulp build` can also call `purs bundle` for you, which is a compiler tool whose job it is to take the output from `purs compile`, remove the code which isn't actually being used by your program, and bundle it all up into a single compact JavaScript file. There are two command line options you can give `pulp build` to accomplish this, depending on where you want the resulting code. You can use the `--optimise` flag (or its shorthand alias, `-O`), which will send the bundled result to standard output, or you can use the `--to` (or `-t`) option, passing it a file name, and `pulp` will store the bundle in a file of that name. So, you can use either of these methods, which in this example will both have the same effect: ```sh $ pulp build --optimise > hello.js $ pulp build --to hello.js ``` Note that using both options (`pulp build --optimise --to hello.js`) is superfluous. The presence of `--to` implies the presence of `--optimise`. ### Running Your PureScript Project If you're developing a Node project using PureScript, you can tell `pulp` to run it after compiling using the `pulp run` command. This command will first run `pulp build` for you, if necessary, then launch your compiled code using `node`. If you have used any pass-through command line options, these will be passed to the `node` process. So, to run the hello world project you get from `pulp init`, you would simply: ```sh $ pulp run ``` If you want to pass command line arguments to your application, `pulp` lets you do that too: ```sh $ pulp run -- file1.txt file2.txt file3.txt ``` If you want to run your application using something other than `node`, `pulp` lets you do that too, with the `--runtime` option. For instance, if you've written an application which runs on PhantomJS, you might launch it like this: ```sh $ pulp run --runtime phantomjs ``` ### Running Test Suites `pulp` has a command `pulp test`, which works much like `pulp run`, except it will also compile the code you've placed in your `test` folder, and instead of running the `main` function in your `Main` module, it will use `Test.Main`. This module should be located in your `test` folder. `pulp` doesn't care what test framework you've chosen, as long as there's a `main` function in your `Test.Main` module to be run. If the process exits with a non-zero return code, that means your test suite failed, as far as `pulp` is concerned, and it will itself exit with an error. In short, to run your tests: ```sh $ pulp test ``` To continuously run your tests when you change the source code: ```sh $ pulp --watch test ``` ### Running Commands Before and After an Action It's sometimes useful to kick off a command before or after an action, particularly in combination with the `--watch` option above. To do this, you can use `--before`, or `--then` and `--else` for successful or failing actions respectively: ```sh $ pulp --watch --before clear build # Clears the screen before builds. $ pulp --watch --then 'say Done' build # On OS X, announces 'Done' after a successful build. $ pulp --watch --else 'say Failed' build # Announces 'Failed' if a build failed. # A more long-winded example combining the three: $ pulp --watch --before clear --then "say $(basename `pwd`) succeeded." --else 'say $(basename `pwd`) failed.' build ``` ### CommonJS Aware Builds Often, you'll want to go outside PureScript and leverage some of the enormous body of JavaScript code available on [NPM](https://www.npmjs.com/). This is such a common use case that `pulp` provides a command for it: `pulp browserify`. As the name suggests, this uses [Browserify](http://browserify.org/) to bundle up your PureScript code with Node style CommonJS dependencies. For instance, the majority of web UI libraries for PureScript these days depend on either [virtual-dom](https://github.com/Matt-Esch/virtual-dom) or [React](https://facebook.github.io/react/) as a CommonJS dependency. Here is how you would add React to your project and build a JS bundle with React included (assuming your PureScript code `require`s it): ```sh $ npm install react $ pulp browserify --to hello.js ``` Essentially, `pulp browserify --to` works exactly like `pulp build --to`, except it also resolves CommonJS dependencies and includes them in the bundle. The resulting JS file can now be loaded directly into the browser, and everything you need to run your application should be included. If you omit the `--to` option, the bundle is piped to standard output. This would thus have the same effect as the example above: ```sh $ pulp browserify > hello.js ``` #### Optimising Code Size `pulp browserify` will pull code in at the module level by default, so every file `require`d from your entry point will appear in the bundle. The PureScript compiler, as we know, is able to perform dead code elimination on your compiled PureScript code, and we can leverage this in `pulp browserify` using the `--optimise` flag. ```sh $ pulp browserify --optimise --to hello.js ``` Note that, unlike `pulp build`, `--to` doesn't automatically imply `--optimise`. In fact, if you omit `--optimise`, `pulp browserify` will not only omit the dead code elimination step, it will also run Browserify as an incremental build, which means it will run considerably faster. You should use `--optimise` only when you're building production code—when you're developing, you'll probably prefer the much faster compile times provided by Browserify's incremental mode. #### Reimporting Browserified Bundles While browserified bundles are intended to be consumed directly by browsers, you may sometimes prefer to access the bundle from some external code. While it's generally preferable to consume CommonJS modules directly, there are use cases where you might want to provide a single JS file ready to be `require`d by a consumer without needing to deal with installing and resolving dependencies. Browserify provides the `--standalone` mechanism for that, and `pulp browserify` supports it: ```sh $ pulp browserify --standalone myBundle --to myBundle.js ``` This makes a bundle which comes wrapped in a UMD header (meaning it supports both CommonJS and AMD, and will install itself in the global namespace under the name you provided if neither is present), and the exports it provides will be the same as those you export in your `Main` module. So, given the example above produces a bundle where a PureScript function `Main.main` exists, you can access it from JavaScript via CommonJS like this: ```javascript var myBundle = require("./myBundle"); myBundle.main(); ``` ### Building Documentation PureScript has an inline syntax for documentation, which can be extracted into Markdown or HTML files using the `purs docs` command. `pulp` provides the `pulp docs` command to make this process easy: ```sh $ pulp docs [--with-dependencies] ``` This extracts the documentation from your source files, and places it in the `generated-docs` folder under your project's root folder. By default, dependencies are not included, but this can be enabled with the `--with-dependencies` flag. You can also extract documentation from your tests, if you like: ```sh $ pulp docs --with-tests ``` The `purs docs` command itself also accepts some options to modify its behaviour, which can be specified by using pass-through options. The `--format` option is particularly useful, as it allows you to specify the desired output format. In particular, you can generate nice hyperlinked Pursuit-style HTML docs with the following command: ```sh $ pulp docs -- --format html ``` It is a good idea to run this command and browse the generated HTML documentation before publishing a library to Pursuit, as doing so will allow you to spot any formatting issues or any declarations which are missing documentation. ### Launching a REPL The `purs repl` interactive shell for PureScript is fantastically useful, but setting it up can be a bit of a chore, especially with a large number of dependencies. That's where `pulp repl` comes in. `pulp repl` will generate a `.purs-repl` file for your project automatically whenever you invoke it, and launch `purs repl` for you directly. It's as simple as: ```sh $ pulp repl ``` ### Launching a Development Server A common need when developing client side web apps is a tightly integrated development web server, which takes care of compilation for you on the fly. This is what `pulp server` is for: whenever you make a change to your source files, you just switch to your browser and hit the refresh button, and the server will compile and deliver your assets on the fly. No need to wait for the PureScript compiler to finish before switching to the browser. `pulp server` only provides the most basic functionality: it will serve static assets from your project root, and it will serve your compiled JS bundle from `/app.js`. #### A Quick Example To see how this works, let's set up a project for serving the default hello world app through `pulp server`. ```sh $ mkdir hello-server $ cd hello-server $ pulp init ``` We need an `index.html` file to load our compiled PureScript code. Place this in your new `hello-server` folder: ```html