feat(cli): use ticker format for addpair

[sangaman]

This modifies the addpair command to use the trading pair ticker format such as LTC/BTC used in different commands, while keeping the ability to specify currencies separately.

Related issue #1521.

[raladev]

@sangaman

1. addpair BTC/LTC works
2. I cant specify currencies separately. I think that one of the following commands should work :) :
   ./xucli -p 28886 addpair BTC LTC
   ./xucli -p 28886 addpair --base_currency BTC --quote_currency LTC
   ./xucli -p 28886 addpair -b=BTC -q=LTC
   ./xucli -p 28886 addpair -b BTC -q LTC
   bad_attempts.log
3. also I tried ./xucli -p 28886 addpair --pair=BTC/LTC but it does not work too and I dont understand why I cant use --pair option as help saids (I think its connected with previous point).

@kilrau

1. U wrote that addpair BTC LTC should work too. addpair -b BTC -q LTC is enough or should it be addpair BTC LTC? Two interfaces by default (without flags) for one command looks a bit strange.

[kilrau]

Suggested change

	export const describe = 'add a trading pair';
	export const describe = 'add a trading pair such as LTC/BTC';

[kilrau]

Let's keep it simple. This is not worth catching 10 different ways of specifiying a pair. Only the following should work:
addpair LTC/BTC
addpair lTc/bTc

But xucli addpair --help should make that clear. Please paste a screenshot of what you find confusing in this description.

I cant use --pair option as help saids (I think its connected with previous point).
Help doesn't say that, it says addpair <pair>, which means addpair ltc/btc, it does not mean addpair --pair ltc/btc (which doesn't make much sense either).

[kilrau]

Looking at the help output, you are right @raladev , these should work

addpair --base_currency LTC --quote_currency BTC
addpair -b LTC -q BTC

Please help @sangaman understand what fails by providing output/error message.

[raladev]

Help doesn't say that, it says addpair <pair>, which means addpair ltc/btc, it does not mean addpair --pair ltc/btc (which doesn't make much sense either).

it says
--pair the trading pair in ticker format such as LTC/BTC [string]
that means that --pair can be used as a flag and addpair --pair ltc/btc should work

Please help @sangaman understand what fails by providing output/error message.

They are in bad_attempts.log file. I think the problem is that param is mandatory and i cant use flags because I don't pass this parameter.
How it Should be: "pair" or --pair "pair" or -b -q (both)

[kilrau]

Gotcha. Since it's in the help it should work, but honestly if it takes longer than 5 minutes to figure it out, I am fine with removing all of these:

--pair the trading pair in ticker format such as LTC/BTC [string]
--base_currency    the currency bought and sold for this trading pair [string]
--quote_currency   the currency used to quote a price                 [string]

and just allow the ltc/btc format. @sangaman

[sangaman]

Digging into this a bit made me realize that the approach we're using across almost every cli command is somewhat misleading in that it always prints the required, positional command arguments as "Options" in the help output. If you were to actually specify the option by passing it in as a flag instead of a positional argument, such as xucli connect --node_uri 038395febbce... instead of xucli connect 038395febbce... you'd get an error.

I can clarify those other commands in a separate PR. For now I changed this so it only uses positional arguments and that both addpair LTC/BTC and addpair LTC BTC work and the help output is clear with example commands and no misleading option descriptions.

$ ./bin/xucli addpair --help
xucli addpair <pair_id|base_currency> [quote_currency]

add a trading pair

Positionals:
  pair_id, base_currency  the pair ticker id or base currency[string] [required]
  quote_currency          the currency used to quote a price            [string]

Options:
  --help             Show help                                         [boolean]
  --version          Show version number                               [boolean]
  --rpcport, -p      RPC service port                                   [number]
  --rpchost, -h      RPC service hostname                               [string]
  --tlscertpath, -c  Path to the TLS certificate of xud                 [string]
  --json, -j         Display output in json format    [boolean] [default: false]
  --xudir, -x        Data directory for xud                             [string]

Examples:
  xucli addpair LTC/BTC  add the LTC/BTC trading pair by ticker id
  xucli addpair LTC BTC  add the LTC/BTC trading pair by currencies