- Purpose and Vision
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- FAQ
Redwood provides a first-class CLI that helps you at every stage of development, from your first commit to your first deploy. And it comes with Redwood, which means no extra software to install!
Redwood uses yarn workspaces to separate your app's sides, generators to give you a smooth DX, and Prisma to manage your database. We have a generator for nearly everything, on both sides of the app, from components to functions.
Since the CLI is the entry point to Redwood, as Redwood continues to grow—especially as we add more sides and targets—so will the CLI.
Redwood's CLI is built with Yargs.
If you aren't familiar with it, we walk you through what you need to know in the Adding a Command section. But if you already are, know that we use the advanced api. This means that instead of seeing things written as a method chain, with the command method doing most of the work, like:
yargs
.command(
'get',
'make a get HTTP request',
function (yargs) {
return yargs.option('u', {
alias: 'url',
describe: 'the URL to make an HTTP request to'
})
},
function (argv) {
console.log(argv.url)
}
)
.help()
.argvyou'll see the arguments to the command method spread across exported constants, like:
export const command = 'get'
export const description = 'make a get HTTP request'
export const builder = (yargs) => {
return yargs.option('u', {
alias: 'url',
describe: 'the URL to make an HTTP request to'
})
}
export const handler = (argv) => {
console.log(argv.url)
}To get a good sense of the difference, compare redwood-tools.js to dev.js, or any other command.
Contributing to @redwoodjs/cli usually means adding a command or modifying an existing one. We've organized this doc around adding a command since if you know how to do this you'll know how to modify one too.
There's a few best practices we follow that you should be aware of:
- Use
descriptioninstead ofdescordescribe: While yargs accepts any of these, for consistency, usedescription - descriptions shouldn't end in periods: Again, just a stylistic choice—but stick to it!
buildershould be a function: This enables the positional api (more on that later)- Update the docs and test: By docs, we mean the content on redwoodjs.com. We know this can be a lot, so don't feel like you have to do it all yourself. We're more than happy to help—just ask us!
If none of these make sense yet, don't worry! You'll see them come up in the next section, where we walk you through adding a command.
You can add a command by creating a file in ./src/commands. Although it's not necessary, for consistency, the file should be named after the command that invokes it. For example, the build command, which is invoked with
yarn rw build
lives in ./src/commands/build.js.
To make a command using the advanced api, yargs requires that you export four constants:
| Constant | Type | Description |
|---|---|---|
command |
string | A yargs command definition. You specify the command's name and arguments here |
description |
string | A description of the command; shown in the help message |
builder |
function | Effectively "builds" the command's arguments/options |
handler |
function | The function invoked by the command; does all the work |
We'll continue to use the build command as an example as we discuss each of these individually.
command is a string that represents the command at the CLI and effectively maps it to the handler that does the work.
The command for build is:
export const command = 'build [side..]''build' specifies the name of the command and '[side..]' indicates that build takes an optional positional argument (named side—relevant for builder and handler). The dots (..) trailing side indicate that you can provide an array of strings (see Variadic Positional Arguments):
yarn rw build api web
See Positional Arguments for all your options when it comes specifying arguments for commands.
description is a string that's shown in the help output. build's description is
export const description = 'Build for production'Runnning yarn rw build help displays:
rw build [side..]
Build for production
...
Other than that, there's not much more to it. You should of course make the description descriptive. And for consistency, don't punctuate it. I.e., we prefer this
export const description = 'Build for production'to this
export const description = 'Build for production.'builder configures the positional arguments and options for the command.
While builder can be an object, the positional argument api is only available if builder is a function. But that doesn't mean we can't use an object to "build" builder. As you'll see in yargsDefaults, this is what we do with commands that share a lot of options.
Here's an excerpt of build's builder:
// ./src/commands/build.js
export const builder = (yargs) => {
yargs
.positional('side', {
choices: ['api', 'web'],
default: optionDefault(apiExists, webExists),
description: 'Which side(s) to build',
type: 'array',
})
...Using positional, you can configure side (which was was "defined" earlier in command): what values the user's allowed to pass (choices), what side defaults to if the user passes nothing (default), etc.
You should always specify description and type. The rest depends. But generally, if you can specify more, you should.
For the full list of what properties you can use to compose the options object, see .positional(key, opt). But know that besides alias and choices, we haven't had the occasion to use anything else.
While side would've worked in a bare-bones sort of way if we didn't use positional, builder is the only way to let the command know about its options (only showing the relevant bits here):
// ./src/commands/build.js
export const builder = (yargs) => {
yargs
...
.option('stats', {
default: false,
description: `Use ${terminalLink(
'Webpack Bundle Analyzer',
'https://github.com/webpack-contrib/webpack-bundle-analyzer'
)}`,
type: 'boolean',
})
.option('verbose', {
alias: 'v',
default: false,
description: 'Print more',
type: 'boolean',
})
...
}These two calls to options configure this command to have options --stats and --verbose:
yarn rw build --stats
yarn rw build --verbose
For the full list of what properties you can use to compose the options object, see options(key, [opt]).
handler's what actually does the work of the command. It's where all the logic goes.
More concretely, handler's a function that gets passed the positional arguments and options specified and configured in command and builder—the parsed argv.
While build's handler is too long to reproduce here in full, to get the point across, here's the signature:
// ./src/cli/commands/build.js
export const handler = async ({
side = ['api', 'web'],
verbose = false,
stats = false,
}) => {
...
}The logic that goes in a command's handler varies too much to comment on generally. But you'll see similarities among commands that do similar things, like generators.
If you're adding a command that serves as an entry point to more commands, like db, destroy, and generate, you'll want to create
- a file for the command in
./src/commands, like in Adding a Command, and - a directory to store all the commands it serves as an entry point to.
Although it's not necessary, for consistency, the file and directory should be named after the command that invokes them. Using the generate command as an example, in ./src/commands, there's the file generate.js and the directory generate.
Files for entry-point commands typically aren't too complicated. Here's the contents of generate.js in its entirety:
export const command = 'generate <type>'
export const aliases = ['g']
export const description = 'Save time by generating boilerplate code'
import terminalLink from 'terminal-link'
export const builder = (yargs) =>
yargs
.commandDir('./generate', { recurse: true })
.demandCommand()
.epilogue(
`Also see the ${terminalLink(
'Redwood CLI Reference',
'https://redwoodjs.com/reference/command-line-interface#generate-alias-g'
)}`
)The call to commandDir is what makes this command an entry point. You can read more about commandDir here. The second argument to commandDir, { recurse: true }, is specific to the generate command because each of the commands in the generate directory is in its own directory to keep things organized—more on this in Adding a Generator.
Now all the commands in the generate directory will be arguments to the generate command:
./src/commands/generate
├── auth
├── cell
├── component
├── function
├── helpers.js
├── layout
├── page
├── README.md
├── scaffold
├── sdl
├── service
└── __tests__
There are files and directories here that aren't yargs related (README.md, helper.js, and __tests__), but because yargs will only use the files that export the appropriate constants, that's ok.
We're about to refactor generators out of @redwoodjs/cli and into their own package, so some of this section will probably change soon.
You can add a generator by creating a directory and a file in that directory in ./src/commands/generate. Although it's not necessary, for consistency, the directory and file should be named after the command that invokes them. For example, the page generator, which is invoked with
yarn redwood generate page
lives in ./src/commands/generate/page/page.js, where the page directory has the following structure:
src/commands/generate/page
├── page.js
├── templates
└── __tests__
Since a typical generator writes files, needs templates to do so, and needs tests to ensure it works, we use this command-in-a-directory structure to keep things organized.
The templates for the files created by generators go in templates. They should be named after the file they create and end in .template to avoid being compiled by Babel:
src/commands/generate/page/template
├── page.js.template
└── test.js.template
The templates are processed with lodash's template function. You can use ES template literal delimiters (${}) as interpolation delimiters:
// ./src/commands/generate/page/template/page.js.template
const ${singularPascalName}Page = () => {
...The variables referenced in the template must be named the same as what's passed to the generateTemplate function, which is usually wrapped in a few functions, but accessible via the respective generator's files function.
The files function is what actually generates the files. Every genrator has one. They use a helper, templateForComponentFiles, which takes care of the logic around creating an output path and contents.
The ...rest parameter from files gets passed to this function's templateVars parameter which gets passed to generateTemplate for interpolation:
// ./src/commands/generate/page/page.js
export const files = ({ name, ...rest }) => {
const pageFile = templateForComponentFile({
name,
suffix: COMPONENT_SUFFIX,
webPathSection: REDWOOD_WEB_PATH_NAME,
generator: 'page',
templatePath: 'page.js.template',
templateVars: rest,
})For the actual writing of files to disk, generators call on a function from src/lib/index.js: writeFilesTask.
More complicated generators, like auth, will have a little more logic in their directories:
src/commands/generate/auth
├── auth.js
├── providers
├── templates
└── __tests__
There's another helper you'll see being used fairly often: createYargsForComponentGeneration.
This function takes care of some of the boilerplate around yargs commands by creating the four constants—command, description, builder, and handler—for you.
It has three parameters:
componentName: a string, like'page'filesFn: a function, usually the one calledfilesbuilderObj: an object, used to constructbuilder. Defaults to yargsDefaults
The idea here's to export as many constants as you can straight from createYargsForComponentGeneration's returns:
// src/commands/generate/cell/cell.js
export const {
command,
description,
builder,
handler,
} = createYargsForComponentGeneration({
componentName: 'cell',
filesFn: files,
})But you can use createYargsForComponentGeneration even if you don't plan on using all its return values. For example, the component generator uses command, builder, and handler, but doesn't destructure description and exports its own instead:
// ./src/commands/generate/component/component.js
export const description = 'Generate a component'
export const { command, builder, handler } = createYargsForComponentGeneration({
componentName: 'component',
filesFn: files,
})If you find yourself not using the builder from createYargsForComponentGeneration (or just not using createYargsForComponentGeneration at all), you should use yargsDefaults.
yargsDefaults is an object that contains all the options common to generate commands. It's defined in generate.js, the generator entry-point command. So importing it usually looks like:
import { yargsDefaults } from '../../generate'We use yargsDefaults to "build" the builder. The generate sdl command is a good example. In sdl.js (which is in the generate directory in ./src/commands) yargsDefault is spread into another object, defaults (the name of this object is another convention):
// ./src/commands/generate/sdl/sdl.js
export const defaults = {
...yargsDefaults,
crud: {
default: false,
description: 'Also generate mutations',
type: 'boolean',
},
}This way we can define an option specific to the sdl generator (crud) while still getting all the options common to generators.
But defaults isn't builder—builder has to be a function (and named builder), so in builder, you can use the following pattern to incorporate defaults:
export const builder = (yargs) => {
yargs
.positional('model', {
description: 'Model to generate the sdl for',
type: 'string',
})
.epilogue(
`Also see the ${terminalLink(
'Redwood CLI Reference',
'https://redwoodjs.com/reference/command-line-interface#generate-sdl'
)}`
)
Object.entries(defaults).forEach(([option, config]) => {
yargs.option(option, config)
})
}If you're adding a generator or modifying an existing one, you're gonna wanna test it. (Well, at least we want you to.)
Along with a command file and a templates directory, most generators have a __tests__ directory:
src/commands/generate/page
├── page.js
├── templates
└── __tests__
Generally, __tests__ has at least one test file and a fixtures directory. For example, pages/__tests__ has page.test.js and fixtures:
src/commands/generate/page/__tests__
├── page.test.js
└── fixtures
Fixtures are necessary because generators create files, and to test commands that create files, we need something to compare them to.
You can use loadGeneratorFixture to load the appropriate fixture to test against.
It takes two arguments: the name of the generator and the name of the fixture. We usually use it to check to see that the files are equal:
// ./src/packages/cli/src/commands/generate/page/__tests__/page.test.js
test('creates a page component', () => {
expect(
singleWordFiles[
path.normalize('/path/to/project/web/src/pages/HomePage/HomePage.js')
]
).toEqual(loadGeneratorFixture('page', 'singleWordPage.js'))
})If you're adding a generator, it'd be great if you added its evil twin, a destroyer, too.
Destroyers rollback the changes made by generators. They're one-to-one, in that, for a cell generator there's a cell destroyer.
Just like generators, destroyers have helpers that minimize the amount of boilerplate you have to write so you can get straight to the custom, creative logic. They're similarly named too: createYargsForComponentDestroy is one that, like for generators, you should use if permitting. And you probably will for builder at least, since, so far, destroyers don't have any options.
And just like generators, destoyers have tests. Right now, the way we test destroyers is by comparing the files that the generator produces with the files the destroyer attempts to delete. But because we don't actually want to write files to disk, we mock the api required to run the generator's files function, which is what you'll see going in the top-level __mocks__ directory. To do this, we use Jest's manual mocking to mock NodeJS's fs module.
Adding a provider to the auth generator is as easy as adding a file in ./src/commands/generate/auth/providers that exports the three constants: config, packages, and notes.
Note that the provider you are about to add has to have already been implemented in
@redwoodjs/auth. For example, the provider in the example below, Netlify Identity, is implemented here.So if you haven't done that yet, start with this doc, then come back to this section afterwards.
We'll use the Netlify Identity provider as an example to discuss these requirements:
// ./src/commands/generate/auth/providers/netlify.js
export const config = {
imports: [`import netlifyIdentity from 'netlify-identity-widget'`],
init: 'netlifyIdentity.init()',
authProvider: {
client: 'netlifyIdentity',
type: 'netlify',
},
}
export const packages = ['netlify-identity-widget']
export const notes = [
'You will need to enable Identity on your Netlify site and configure the API endpoint.',
'See: https://github.com/netlify/netlify-identity-widget#localhost',
]config is an object that contains everything that needs to be inserted into a Redwood app's ./web/src/index.js to setup the auth provider and make it available to the router. It has three properties: imports, init, and authProvider.
imports is an array of strings that lists any imports that need to be added to the top of ./web/src/index.js. Any initialization code that needs to go after the import statements goes in init. And authProvider is an object that contains exactly two keys, client and type that will be passed as props to <AuthProvider>.
The second required export, packages is an array of strings of the packages that need to be added to the web workspace's package.json.
Lastly, notes is an array of strings to output after the generator has finished, instructing the user through any further required setup (like setting ENV vars). Each string in the array will output on its own line.
Most of the commands in dbCommands are just wrappers around Prisma commands,
the exception being seed, which runs a Redwood app's ./api/prisma/seed.js.
Adding or modifying a command here's no different—there's still a command, descripton, builder, and handler. But there's a pattern to handler: it usually uses runCommandTask, a Redwood-defined function.
This is because most dbCommands are really just running prisma commands, so they really just have to output something like yarn prisma ....
redwood-tools is Redwood's companion CLI development tool.
You can find a list of its commands in the top-level contributing guide. If you're contributing to redwood-tools, you're contributing in a way that helps people contribute, which is pretty meta.
As mentioned, redwood-tools uses the "regular" yargs api, which is defined by method-chaining.
Adding a command here just entails adding another command method before the calls to demandCommand and strict at the end:
// ./src/commands/redwood-tools.js
...
.command(
['hello', 'h'],
'Say hi',
{},
() => console.log('hi!')
)
.demandCommand()
.strict().argvContrived example aside, any command you add here should help people contribute to Redwood.
We're in the midst of converting Redwood to TypeScript. If you're interested, we'd love your help! You can track our progress and see where you can contribute here.
If you're converting a generator, read the Goals section of tracking issue #523; it details some specs you should comply with.
Some of the generators have already been converted; use them as a reference (linking to the PRs here):
For most of the generate commands, the option (in the builder) for generating a typescript file is already there, either in the builder returned from createYargsForComponentGeneration or in yargsDefaults (the former actually uses the latter).
Because it's where most of the action is, most of this doc has been about the src/commands directory. But what about all those other files?
redwood/packages/cli
├── jest.config.js
├── __mocks__
├── package.json
├── README.md
└── src
├── commands
├── index.d.ts
├── index.js
├── lib
└── redwood-tools.js
index.js is the rw in yarn rw. It's the entry-point command to all commands, and like other entry-point commands, it's not too complicated.
But it's distinct from the others in that it's the only one that has a shebang at the top and argv at the bottom:
// ./src/index.js
#!/usr/bin/env node
...
.demandCommand()
.strict().argvWe also use methods that we want to affect all commands here, like demandCommand and strict.
colors.js provides a declarative way of coloring output to the console using chalk. You'll see it imported like:
import c from 'src/lib/colors'And used mainly in catch statements, like:
try {
await t.run()
} catch (e) {
console.log(c.error(e.message))
}We only use error right now, like in the example above, but you can use warning, green, and info as well:
Adding a new color is as simple as adding a new property to the default export:
// ./src/lib/colors.js
export default {
error: chalk.bold.red,
warning: chalk.keyword('orange'),
green: chalk.green,
info: chalk.grey,
}You're not the only one. See the discussion here.
Not yet, but we're talking about it! See the ongoing dicussions in these issues: