Sagui is the single development dependency that provides the tooling required to build, test and develop modern JavaScript applications.
Its main goal is to kill the need of global CLIs and boilerplates, making a reproducible and easily updated environment across projects.
It follows an opinionated convention over configuration approach, providing a solid foundation so that you can focus on writing your code and not your tooling.
Quick start in 3 steps!
Let’s create a new front-end project from scratch.
In a new folder, create a new npm project:
npm init -y
Install Sagui locally as a development dependency:
npm install --save-dev sagui
Start the development server:
npm start
Done! Sagui is an auto-bootstraping library, so during the install process (in a fresh npm project) it automatically creates a basic project scaffolding:
├── .babelrc
├── .editorconfig
├── .eslintignore
├── .eslintrc
├── .gitignore
├── node_modules
│ └── sagui
├── package.json
├── sagui.config.js
└── src
├── index.html
├── index.js
├── index.css
└── index.spec.js
Just start writing the code inside the src/ folder.
npm scripts
Sagui manages the package.json scripts for you:
npm run build: build a development version of the project;npm run dist: build an optimized (ready for deployment) version of the project;npm run start: spin up a development server with live-reload and HMR;npm run test: run all test related scripts below;npm run test:lint: run static analysis in the code;npm run test:unit: run the unit tests;npm run test:typecheck: run the static type analysis in the code;npm run test:unit:watch: run a test watcher (great for development and debugging).
If you don’t change the scripts, they will be automatically updated on new Sagui releases.
Features
As stated earlier, Sagui strives to provide all the basic needs to create modern JavaScript applications.
Development server
The development server out-of-the-box has live reloading and hot-module replacement.
ReactJS has first-class support via react-transform, so updating components’ source reflects instantly (without full refresh) in the browser.
Build
Sagui uses Webpack as its underlying bundling tool. The biggest feature that Webpack provides is that everything is a module. Sagui supports the following module types by default:
- Fonts (
.woff,.woff2,.ttf,.eot,.otf) - Images (
.png,.jpg,.jpeg,.gif,.svg) - JavaScript (
.js,.es6,.jsx) via Babel) - JSON
- Styles in CSS Modules in either plain CSS or Sass lang
- Text (
.txt) files loaded without any processing - Video (
.ogg,.mp4) - YAML
During build, optimizations and special processing are also performed in the output bundle:
- Autoprefixer for CSS properties for cross-browser support;
- Commons code splitting if there is more than a single entry-point;
- Extract styles as separated files to style the page before the JavaScript is loaded and parsed;
- Minification and code dedupication.
Testing and quality
Test automation in Sagui is achieved by creating .spec.js files inside the src/ folder using the Jasmine framework.
A simple example would be:
src/components/button.jssrc/components/button.spec.js
Sagui will automatically run every test file that follows this convention.
Under the hood it uses Karma test runner to allow running the tests in the most diverse browsers and even through Selenium (not natively).
By default Sagui uses PhantomJS to run the tests headlessly. To speed up installing the dependencies (npm install) it is advisable to have PhantomJS installed globally in the machine.
To open the tests in a browser (or in multiple browsers!), simply follow the link Karma outputs when you start running the script test:unit:watch. Running them in a browser allows you to set breakpoints and debug your code properly. Note watch mode is necessary, else tests will stop running when finished.
Linting
Static code analysis is also performed on the code following the JavaScript Standard Style convention.
Static type checking
Flowtype static type analysis is available as part of the testing suite. By default the flowtype checker only runs on files with the // @flow comment at the beginning, so no static type analysis will be actually performed unless you add that. See the docs for an more in depth explanation of why it is a good idea to have it like this.
Sagui bundles loose lib interface declarations for the Jasmine APIs used in the tests. You might want to look into the more complete flow-typed repo to get already made interfaces for common project dependencies such as React, Redux, Ramda, …
Configuration
The Sagui configuration is all performed via the single sagui.config.js that is bootstraped in the project root folder once Sagui is first installed. At its simplest it could be just:
module.exports = {
pages: ['index']
}
Then we can add extra configuration on top of it:
pages
These are static applications that can be built around multiple pages. Each page is the combination of an html and a js file.
module.exports = {
pages: ['index', 'about']
}
The previous configuration will expect and build the files:
src/about.html=>dist/about.htmlsrc/about.js=>dist/about.jssrc/index.html=>dist/index.htmlsrc/index.js=>dist/index.js
libraries
Create reusable libraries that can be shared across applications. Sagui will take care of the build process so that external libraries are not bundled and that you have a CommonJS module as the output.
It works similarly to pages, allowing a list of “library entry points” to be built. The only difference here is that each library points to a single JavaScript file. Taking the example of a UI toolkit project, it could have the following libraries:
module.exports = {
libraries: ['button', 'field', 'select']
}
And these will build the files:
src/button.js=>dist/button.jssrc/field.js=>dist/field.jssrc/select.js=>dist/select.js
Regarding external dependencies, Sagui will use the peerDependencies information in the project’s package.json to determine what are the external dependencies of the library that shouldn’t be bundled in the final build.
As an example, given a project with the package.json:
{
"name": "library-project",
"version": "1.0.0",
"main": "index.js",
"dependencies": {
"left-pad": "1.1.0"
},
"peerDependencies": {
"react": "^0.14.7"
}
}
And somewhere in the source there are the following imports:
import React from 'react'
import leftPad from 'left-pad'
When building the project, react won’t actually be bundled in the output but left-pad will, so your project won’t blow up once left-pad is unpublished again.
Publishing libraries as UMD
If you need to build your library targeting UMD, you can use a slightly different configuration. For UMD you need to provide a umdName for the library, which is going to be the name that it will use to add itself to the window object when loaded as a global in the browser.
module.exports = {
libraries: [
{
main: 'button',
umdName: 'MyUIButton'
}
]
}
style.cssModules
By default, styles compiled with Sagui will be output as CSS Modules, meaning they won’t be global.
It is possible to disable this behavior and have regular CSS styles:
module.exports = {
style: {
cssModules: false
}
}
style.sourceMaps
Source maps are never generated for styles, but it is possible to enable it.
module.exports = {
style: {
sourceMaps: true
}
}
style.extract
By default, when building pages, Sagui extracts the CSS definitions into separated .css files. It is possible to disable this behavior and have the CSS inlined in the same JavaScript bundle.
module.exports = {
style: {
extract: false
}
}
javaScript.transpileDependencies
Dependencies installed through npm are not transpiled with Babel by default. If you have a dependency that needs to be transpiled it is very easy, just add its name to the list:
module.exports = {
javaScript: {
transpileDependencies: ['dependency-to-be-transpiled']
}
}
javaScript.typeCheckAll
By default, Flowtype ignores files that don’t start with the // @flow comment line. If you want all your files to be statically type checked, you can enable that feature in the sagui config:
module.exports = {
javaScript: {
typeCheckAll: true
}
}
develop.proxy
Allow proxying requests to a separate, possible external, backend server.
module.exports = {
develop: {
proxy: {
'/some/path*': {
target: 'https://other-server.example.com',
secure: false
}
}
}
}
Please check node-http-proxy documentation for the available configuration options.
webpack
If a build requirement can’t be achieved via the previous configuration options, first open an issue so that we can add official support, and if you can’t wait or is something very specific to your project, there is an escape hatch to allow extending the internal Webpack configuration.
As an example, let’s add an extra loader to load HTML files. In the sagui.config.js file:
module.exports = {
webpack: {
module: {
loaders: [{
test: /\.html$/,
loader: 'html'
}]
}
}
}
For more information about configuring Webpack, check the Webpack documentation.
For more information on how the merging of Webpack configurations work, check webpack-merge.
disabledLoaders
Disable internal Sagui loaders in order to implement custom behavior via the webpack configuration.
module.exports = {
disabledLoaders: ['yaml']
}
Possible values:
fontimagejavaScriptjsonstyletxtvideoyaml
karma
If a test automation requirement can’t be achieved via the previous configuration options, first open an issue so that we can add official support, and if you can’t wait or is something very specific to your project, there is an escape hatch to allow extending the internal Karma configuration.
As an example, let’s change the default browser used to execute the tests from PhantomJS to Chrome. In the sagui.config.js file:
module.exports = {
karma: {
browsers: ['Chrome']
}
}
For more information about configuring Karma, check the Karma documentation.
Gotchas
React Router
For react-router to work on the development server, an absolute static path for the output has to be configured on Webpack. You can do that by adding this configuration to sagui.config.js:
webpack: {
output: {
publicPath: '/'
}
}
Logo
Monkey artwork created by Ryan Spiering from the Noun Project.
Contributing and development
To develop the tool locally, we will need to resort to a combination of a global npm link and local links in projects.
You can start by linking Sagui globally. While at its folder:
npm link
The environment variable is to inform Sagui that it is working in a “linked environment”.
Then, in the project you intend to use Sagui, link it locally:
npm link sagui
Now, the project is set to use your development copy of Sagui. Unfortunately, you will need to run any command in the project providing the environment variable SAGUI_LINK:
SAGUI_LINK=true npm start