Modern type-safe way of building CLIs
npm install @drizzle-team/brocli``ts
import { command, string, boolean, run } from "@drizzle-team/brocli";
const push = command({
name: "push",
options: {
dialect: string().enum("postgresql", "mysql", "sqlite"),
databaseSchema: string().required(),
databaseUrl: string().required(),
strict: boolean().default(false),
},
handler: (opts) => {
...
},
});
run([push]); // parse shell arguments and run command
`--version
$3
Brocli is meant to solve a list of challenges we've faced while building
Drizzle ORM CLI companion for generating and running SQL schema migrations:
- [x] Explicit, straightforward and discoverable API
- [x] Typed options(arguments) with built in validation
- [x] Ability to reuse options(or option sets) across commands
- [x] Transformer hook to decouple runtime config consumption from command business logic
- [x] , -v as either string or callback
- [x] Command hooks to run common stuff before/after command
- [x] Explicit global params passthrough
- [x] Testability, the most important part for us to iterate without breaking
- [x] Themes, simple API to style global/command helps
- [x] Docs generation API to eliminate docs drifting
Simple echo command with positional argument:
`ts
import { run, command, positional } from "@drizzle-team/brocli";
const echo = command({
name: "echo",
options: {
text: positional().desc("Text to echo").default("echo"),
},
handler: (opts) => {
console.log(opts.text);
},
});
run([echo])
``bash
~ bun run index.ts echo
echo
~ bun run index.ts echo text
text
`
Print version with --version -v:`ts
...
run([echo], {
version: "1.0.0",
);
``bash`
~ bun run index.ts --version
1.0.0`
Version accepts async callback for you to do any kind of io if necessary before printing cli version: ts
import { run, command, positional } from "@drizzle-team/brocli";
const version = async () => {
// you can run async here, for example fetch version of runtime-dependend library
const envVersion = process.env.CLI_VERSION;
console.log(chalk.gray(envVersion), "\n");
};
const echo = command({ ... });
run([echo], {
version: version,
);
`
options
- string
- boolean
- number
- enum
- positional
- required
- alias
- desc
- default
- hidden
Brocli command declaration has:
name - command name, will be listed in help desc - optional description, will be listed in the command help shortDesc - optional short description, will be listed in the all commands/all subcommands help aliases - command name aliases hidden - flag to hide command from help help - command help text or a callback to print help text with dynamically provided config options - typed list of shell arguments to be parsed and provided to transform or handler transform - optional hook, will be called before handler to modify CLI params handler - called with either typed options or transform params, place to run your command business logic metadata - optional meta information for docs generation flow
name, desc, shortDesc and metadata are provided to docs generation step `
ts
import { command, string, boolean } from "@drizzle-team/brocli";
const push = command({
name: "push",
options: {
dialect: string().enum("postgresql", "mysql", "sqlite"),
databaseSchema: string().required(),
databaseUrl: string().required(),
strict: boolean().default(false),
},
transform: (opts) => {
},
handler: (opts) => {
...
},
});
`
`ts
import { command } from "@drizzle-team/brocli";
const cmd = command({
name: "cmd",
options: {
dialect: string().enum("postgresql", "mysql", "sqlite"),
schema: string().required(),
url: string().required(),
},
handler: (opts) => {
...
},
});
`
- string(name?: string) - defines option as a string-type option which requires data to be passed as --option=value or --option value name
- - name by which option is passed in cli args =
If not specified, defaults to key of this option
:warning: - must not contain character, not be in --help,-h,--version,-v and be unique per each command -
:speech_balloon: - will be automatically prefixed with if one character long, -- if longer string('-longname')
If you wish to have only single hyphen as a prefix on multi character name - simply specify name with it:
- number(name?: string) - defines option as a number-type option which requires data to be passed as --option=value or --option value name
- - name by which option is passed in cli args =
If not specified, defaults to key of this option
:warning: - must not contain character, not be in --help,-h,--version,-v and be unique per each command -
:speech_balloon: - will be automatically prefixed with if one character long, -- if longer number('-longname')
If you wish to have only single hyphen as a prefix on multi character name - simply specify name with it:
- boolean(name?: string) - defines option as a boolean-type option which requires data to be passed as --option name
- - name by which option is passed in cli args =
If not specified, defaults to key of this option
:warning: - must not contain character, not be in --help,-h,--version,-v and be unique per each command -
:speech_balloon: - will be automatically prefixed with if one character long, -- if longer boolean('-longname')
If you wish to have only single hyphen as a prefix on multi character name - simply specify name with it:
- positional(displayName?: string) - defines option as a positional-type option which requires data to be passed after a command as command value displayName
- - name by which option is passed in cli args
If not specified, defaults to key of this option
:warning: - does not consume options and data that starts with
Extensions:
- .alias(...aliases: string[]) - defines aliases for option aliases
- - aliases by which option is passed in cli args =
:warning: - must not contain character, not be in --help,-h,--version,-v and be unique per each command -
:speech_balloon: - will be automatically prefixed with if one character long, -- if longer .alias('-longname')
If you wish to have only single hyphen as a prefix on multi character alias - simply specify alias with it:
- .desc(description: string) - defines description for option to be displayed in help command
- .required() - sets option as required, which means that application will print an error if it is not present in cli args
- .default(value: string | boolean) - sets default value for option which will be assigned to it in case it is not present in cli args
- .hidden() - sets option as hidden - option will be omitted from being displayed in help command
- .enum(values: [string, ...string[]]) - limits values of string to one of specified here values
- - allowed enum values
- .int() - ensures that number is an integer
- .min(value: number) - specified minimal allowed value for numbers value
- - minimal allowed value
:warning: - does not limit defaults
- .max(value: number) - specified maximal allowed value for numbers value
- - maximal allowed value
:warning: - does not limit defaults
Normally, you can write handlers right in the command() function, however there might be cases where you'd want to define your handlers separately. options
For such cases, you'd want to infer type of that will be passes inside your handler. TypeOf
You can do it using type:
`Typescript
import { string, boolean, type TypeOf } from '@drizzle-team/brocli'
const commandOptions = {
opt1: string(),
opt2: boolean('flag').alias('f'),
// And so on...
}
export const commandHandler = (options: TypeOf
// Your logic goes here...
}
`
Or by using handler(options, myHandler () => {...})
`Typescript
import { string, boolean, handler } from '@drizzle-team/brocli'
const commandOptions = {
opt1: string(),
opt2: boolean('flag').alias('f'),
// And so on...
}
export const commandHandler = handler(commandOptions, (options) => {
// Your logic goes here...
});
`
To define commands, use command() function:
`Typescript
import { command, type Command, string, boolean, type TypeOf } from '@drizzle-team/brocli'
const commandOptions = {
opt1: string(),
opt2: boolean('flag').alias('f'),
// And so on...
}
const commands: Command[] = []
commands.push(command({
name: 'command',
aliases: ['c', 'cmd'],
desc: 'Description goes here',
shortDesc: 'Short description'
hidden: false,
options: commandOptions,
transform: (options) => {
// Preprocess options here...
return processedOptions
},
handler: (processedOptions) => {
// Your logic goes here...
},
help: () => 'This command works like this: ...',
subcommands: [
command(
// You can define subcommands like this
)
]
}));
`
Parameters:
- name - name by which command is searched in cli args -
:warning: - must not start with character, be equal to [true, false, 0, 1] (case-insensitive) and be unique per command collection
- aliases - aliases by which command is searched in cli args -
:warning: - must not start with character, be equal to [true, false, 0, 1] (case-insensitive) and be unique per command collection
- desc - description for command to be displayed in help command
- shortDesc - short description for command to be displayed in help command
- hidden - sets command as hidden - if true, command will be omitted from being displayed in help command
- options - object containing command options created using string and boolean functions
- transform - optional function to preprocess options before they are passed to handler
:warning: - type of return mutates type of handler's input
- handler - function, which will be executed in case of successful option parse
:warning: - must be present if your command doesn't have subcommands
If command has subcommands but no handler, help for this command is going to be called instead of handler
- help - function or string, which will be executed or printed when help is called for this command commandHelp
:warning: - if passed, takes prevalence over theme's event
- subcommands - subcommands for command positional
:warning: - command can't have subcommands and options at the same time
- metadata - any data that you want to attach to command to later use in docs generation step
After defining commands, you're going to need to execute run function to start command execution
`Typescript
import { command, type Command, run, string, boolean, type TypeOf } from '@drizzle-team/brocli'
const commandOptions = {
opt1: string(),
opt2: boolean('flag').alias('f'),
// And so on...
}
const commandHandler = (options: TypeOf
// Your logic goes here...
}
const commands: Command[] = []
commands.push(command({
name: 'command',
aliases: ['c', 'cmd'],
desc: 'Description goes here',
hidden: false,
options: commandOptions,
handler: commandHandler,
}));
// And so on...
run(commands, {
name: 'mysoft',
description: 'MySoft CLI',
omitKeysOfUndefinedOptions: true,
argSource: customEnvironmentArgvStorage,
version: '1.0.0',
help: () => {
console.log('Command list:');
commands.forEach(c => console.log('This command does ... and has options ...'));
},
theme: async (event) => {
if (event.type === 'commandHelp') {
await myCustomUniversalCommandHelp(event.command);
return true;
}
if (event.type === 'unknownError') {
console.log('Something went wrong...');
return true;
}
return false;
},
globals: {
flag: boolean('gflag').description('Global flag').default(false)
},
hook: (event, command, globals) => {
if(event === 'before') console.log(Command '${command.name}' started with flag ${globals.flag})Command '${command.name}' succesfully finished it's work with flag ${globals.flag}
if(event === 'after') console.log()`
}
})
Parameters:
- name - name that's used to invoke your application from cli. app do-task --help
Used for themes that print usage examples, example: results in Usage: app do-task undefined
Default:
- description - description of your app myapp --help
Used for themes, example: results in `
MyApp CLI
Usage: myapp [command]...
` undefined
Default:
- omitKeysOfUndefinedOptions - flag that determines whether undefined options will be passed to transform\handler or not false
Default:
- argSource - location of array of args in your environment process.argv
:warning: - first two items of this storage will be ignored as they typically contain executable and executed file paths
Default:
- version - string or handler used to print your app version
:warning: - if passed, takes prevalence over theme's version event
- help - string or handler used to print your app's global help globalHelp
:warning: - if passed, takes prevalence over theme's event
- theme(event: BroCliEvent) - function that's used to customize messages that are printed on various events true
Return:
| Promise if you consider event processed false
| Promise to redirect event to default theme
- globals - global options that could be processed in hook globals
:warning: - positionals are not allowed in
:warning: - names and aliases must not overlap with options of commands
- hook(event: EventType, command: Command, options: TypeOf - function that's used to execute code before and after every command's transform and handler execution
- commandsInfo(commands: Command[]) - get simplified representation of your command collection
Can be used to generate docs
- test(command: Command, args: string) - test behaviour for command with specified arguments transform
:warning: - if command has , it will get called, however handler won't
- getCommandNameWithParents(command: Command) - get subcommand's name with parent command names
In BroCLI, command doesn't have to be the first argument, instead it may be passed in any order. --verbose true
To make this possible, hovewer, option that's passed right before command should have an explicit value, even if it is a flag: (does not apply to reserved flags: [ --help | -h | --version | -v`])
Options are parsed in strict mode, meaning that having any unrecognized options will result in an error.