strip-comments.js

/**
 * http://www.codewars.com/kata/51c8e37cee245da6b40000bd/
 *
 Description:

 Complete the solution so that it strips all text that follows any of a set of comment markers passed in. Any whitespace at the end of the line should also be stripped out.

 Example:

 Given an input string of:

 apples, pears # and bananas
 grapes
 bananas !apples

 The output expected would be:

 apples, pears
 grapes
 bananas

 The code would be called like so:

 var result = solution("apples, pears # and bananas\ngrapes\nbananas !apples", ["#", "!"])
 // result should == "apples, pears\ngrapes\nbananas"
 *
 */

let tests = require('./lib/framework.js');
let Test = tests.Test, describe = tests.describe, it = tests.it, before = tests.before, after = tests.after;

function escapeRegExp(str) {
    return str.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
}

function solution(input, markers) {
    let reg = new RegExp('(\s*)(' + markers.map(escapeRegExp).join('|') + ').*$', 'g');

    return input.split("\n").map(function (line) {
        return line.replace(reg, '').replace(/(\s*)$/, '');
    }).join("\n");
}

Test.assertEquals(solution("apples, pears # and bananas\ngrapes\nbananas !apples", ["#", "!"]), "apples, pears\ngrapes\nbananas", 0);
Test.assertEquals(solution("a #b\nc\nd $e f g", ['#', '$']), "a\nc\nd", 0);