JSON

If you want to use the --json flag to return JSON output to the user, then you can set the enableJsonFlag property on the Command class.

When this property is set and the user supplies the --json flag, the command will suppress all logs and instead log the return value to the console in JSON format. Note log suppression will only work if you use the logging methods on the Command class instance. In other words, this.log will be automatically suppressed but console.log will not be.

import {Command} from '@oclif/core'
export class HelloCommand extends Command {
  public static enableJsonFlag = true
  public async run(): Promise<{ message: string }> {
    this.log('hello, world!')
    return { message: 'hello, world!' }
  }
}

$ my-cli hello
hello, world!

$ my-cli hello --json
{
  "message": "hello, world!"
}