verify options for subcommands

[itsspriyansh]

Description

This PR adds the functions for verifying the option passed with subcommands.
verifyOptions checks if the option is valid or not.
showHelp shows usage instructions for a specific subcommand.
Moves the repetitive logic of displaying subcommand's options help to a separate function.

Examples

Shows help for individual subcommand without having to check environment variables.

Throws error for unknown boolean option

Throws error for unknown valued option

If more than one main option is present then we throw an error.

If more than one main option is present then we throw the same error irrespective of any other option present. This is because we need the main option first before we can verify any other options by going one level inside.

Any valued option meant to be used with a specific main option will throw error if used with any other main option.

Everything works fine even if no value is passed along with the valued option.

[garg3133]

In the case of --help flag with a subcommand, instead of going inside the respective subcommand file and then calling verifyOptions from there, we should probably call the showHelp function from the first line of the subcommands/index.ts > run() method itself. We don't need to do any checks (like check for Java, ANDROID_HOME env, etc.) if the user just want to get the --help for the subcommand.

Also, leave a new line at the end of the help section.

[itsspriyansh]

@garg3133 I have updated the PR and the image.

[itsspriyansh]

@garg3133 I have updated the PR. Please check the updated PR description to see the example cases.

This is going to be the new interface for available subcommands:

export interface ValuedOptions {
  name: string,
  alias: string[],
  description: string,
}

export interface Subcommand {
  description: string;
  valuedOptions?: ValuedOptions[];
  options: {
    name: string;
    description: string;
    valuedOptions: ValuedOptions[];
  }[];
}

export interface AvailableSubcommands {
  [key: string]: Subcommand;
}

valuedOptions key is present twice in the Subcommand interface because there are two cases to handle.

# If valued option is passed for a subcommand
npx @nightwatch/mobile-helper android disconnect --deviceId <device_id>

# if valued option is passed for an option of a subcommand
npx @nightwatch/mobile-helper android connect --emulator --avd <avd_name>

[garg3133]

Since you're only considering the main name of the options here, wouldn't it cause the corresponding aliases to be moved to the valuedOptionsPassed instead of the mainOptionsPassed, which would result in unknown valued option passed error?

[itsspriyansh]

I don't think that should be an issue here since we haven't decided to use any aliases for the subcommand options. Aliases exists only for the flags (valued options).

[itsspriyansh]

@garg3133 PR updated.

[garg3133]

Just asking, don't make any changes: wouldn't the above block misbehave for subcommands like disconnect which does not accept any main option but only the optionFlags?

[itsspriyansh]

This function wasn't intended to be used for subcommands like disconnect. Since there is just one workflow for disconnect and no main option, so the disconnect/index.ts file itself is used for the disconnect script. Unlike other scripts where the index.ts file is used to verify options and facilitate default flow. In this case, there is just one thing we have to verify, that is, if there is any other option other than the valued flags then we will show error otherwise everything works fine.

So shall we just manually check this before calling the disconnect script (which I originally considered), or shall we made a minor addition to the verifyOptions to do this instead?

[itsspriyansh]

Right now, updating verifyOptions appears a better idea to me.

[garg3133]

Since there were a lot of things going on in this PR and it was difficult to wrap my head around it all (mostly due to the confusing naming scheme and use of "options" at contradicting places), I tried to simplify it with #64. Please review it once.

[garg3133]

Completed in #64.