'$' in code duplicates code with certain matchers

[lucaswerkmeister]

Minimal example:

#!/usr/bin/node
const rainbow = require('rainbow-code');
rainbow.extend("bug", [{pattern: /'[^']*'/gm}], true);
if (rainbow.colorSync("'$'x", "bug").match(/x/g).length > 1)
    console.error("DUPLICATED");

This example adds a very simple rule for character literals: single quote, not single quotes, single quote. When it is applied to the code '$'x, the x appears in the output twice.

We discovered this in our Ceylon language (eclipse-archived/ceylon#6559); however, the Java language shipped with Rainbow suffers from the same problem:

const rainbow = require('rainbow-code')
rainbow.colorSync("'$'foobarbazfoobarbaz", "java")
// '<span class="char">\'foobarbazfoobarbaz</span>foobarbazfoobarbaz'

And in Python, the code following the dollar sign isn’t duplicated, but the dollar sign and one single quote still vanish:

rainbow.colorSync("('$')", "python")
// '(<span class="string">\'</span>)'

[lucaswerkmeister]

I have found a fix for this issue and will push it shortly.