Crashes with 0d

[nesges]

Description

dice roller crashes on 0d. roller (CLI) throws a stacktrace:

root@gond:~# roller 0d20
file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:4873
  var self = Error.call(this, message);
                   ^

peg$SyntaxError: Expected "%", "*", "**", "+", "-", "/", "^", [.], [0-9], end of input, or whitespace but "d" found.
    at new peg$SyntaxError (file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:4873:20)
    at peg$buildStructuredError (file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:5387:12)
    at peg$parse (file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:7147:11)
    at Function.parse (file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:7188:12)
    at new DiceRoll (file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:7360:40)
    at file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:7911:24
    at Array.map (<anonymous>)
    at DiceRoller.roll (file:///usr/lib/node_modules/@dice-roller/cli/node_modules/@dice-roller/rpg-dice-roller/lib/esm/bundle.js:7910:37)
    at Object.default [as handler] (file:///usr/lib/node_modules/@dice-roller/cli/lib/roll.js:28:10)
    at /usr/lib/node_modules/@dice-roller/cli/node_modules/yargs/build/index.cjs:1:8993 {
  expected: [
    {
      type: 'class',
      parts: [ [ '0', '9' ] ],
      inverted: false,
      ignoreCase: false
    },
    {
      type: 'class',
      parts: [ '.' ],
      inverted: false,
      ignoreCase: false
    },
    { type: 'other', description: 'whitespace' },
    { type: 'literal', text: '**', ignoreCase: false },
    { type: 'literal', text: '*', ignoreCase: false },
    { type: 'literal', text: '^', ignoreCase: false },
    { type: 'literal', text: '%', ignoreCase: false },
    { type: 'literal', text: '/', ignoreCase: false },
    { type: 'literal', text: '+', ignoreCase: false },
    { type: 'literal', text: '-', ignoreCase: false },
    { type: 'end' }
  ],
  found: 'd',
  location: {
    source: undefined,
    start: { offset: 1, line: 1, column: 2 },
    end: { offset: 2, line: 1, column: 3 }
  }
}

Dice Roller version

v5.3.2

Bundle type

UMD

Node version

v16.20.0

Browser name and version

No response

[GreenImp]

This is actually expected behaviour, because you can't roll 0 dice. That error is the die parser failing because the syntax is invalid; The number of sides must be at least 1.

What behaviour would you expect in this situation?

[nesges]

What behaviour would you expect in this situation?

Some kind of human readable message like "you can't roll 0 dice" would be better error handling.

I'm using rpg-dice-roller in a very simple service for a mastodon dice roller bot (https://codeberg.org/nesges/rollbot-mastodon/src/branch/main/server/server.js) and users try funny things

[GreenImp]

It's nice to see someone implementing it on Mastodon! Really cool.

You make a good point about the readability. I've been having a think about it and, at the core it's difficult to make those errors really nice, because they're thrown by the grammar parser library, Peggy. And, before it's been parsed, it's not easy to reliably tell if the notation is invalid.

However, I've just been looking over the Peggy docs, and it looks like the error messages can be enhanced slightly by naming the grammar rules. Most of the rules currently aren't annotated. I've had a quick play around, but haven't got a result I'm happy with

PRs are always appreciated.