tests=0;
testPass=0;

function testreg(regex, matches, index) {
  tests++;
  if (regex==matches) {
    if (matches==null || regex.index==index)
      return testPass++;
  }
  console.log("Test "+tests+" failed, got ",regex);
}
function test(a, b) {
  tests++;
  if (a==b) {
    return testPass++;
  }
  console.log("Test "+tests+" failed - ",a,"vs",b);
}

print("0.5=",(1)/2); // test for parsing something that isn't a regexp

testreg(new RegExp("a").exec("bc"), null);
testreg(/a/.exec("abcdef"),"a",0);
testreg(/a/.exec("bcdaef"),"a",3);
testreg(/a-c/.exec('=abc='), null); // no range set
testreg(/a(b)c/.exec("abc"),"abc,b",0);
testreg(/\sWorld/.exec("Hello World")," World",5);
testreg(/world/i.exec("Hello World"),"World",6);
testreg(/a*b/.exec("Helloaaabc"),"aaab", 5);
testreg(/[bac]*d/.exec("Hello abcd"),"abcd", 6);
testreg(/[bac]*d/i.exec("Hello aBcD"),"aBcD", 6);
testreg(/X[\/\?\-]+/.exec('==X/?/-X'), "X/?/-", 2);
testreg(/[a-z\-0-5]+/.exec('==ab-1289=='), "ab-12", 2);
testreg(/[a-d]+/i.exec('=ybC-='), "bC", 2);
testreg(/[\x00-\t]+/.exec('==\03\t\06\n=='), "\03\t\06", 2);
testreg(/[\0-Z]+/.exec('~=\0\n\x06=~'), "=\x00\n\x06=", 1);
testreg(/^X[^X]+/.exec('X-------X'), "X-------", 0);
testreg(/^X[^X]+/.exec('X---------------------------------------X'), "X---------------------------------------", 0);

var re = /\s*;\s*/g
var names = 'Harry Trump ;Fred Barney; Helen Rigby ; Bill Abel ;Chris Hand ';
testreg(re.exec(names)," ;",11);
test(re.lastIndex, 13);
testreg(re.exec(names),"; ",24);
test(re.lastIndex, 26);
testreg(re.exec(names)," ; ",37);
test(re.lastIndex, 40);
testreg(re.exec(names)," ;",49);
test(re.lastIndex, 51);
testreg(re.exec(names),null);
test(re.lastIndex, 0);
test(names.split(re), "Harry Trump,Fred Barney,Helen Rigby,Bill Abel,Chris Hand ");

test("Hellowa worldssaaa a a a".replace(/a/,""),"Hellow worldssaaa a a a");
test("Hellowa worldssaaa a a a".replace(/a/g,""),"Hellow worldss   ");
test("Hello".replace(/(l)/g,"[$1]"), "He[l][l]o");
test("Hello".replace(/e(l)/g,"[$1]"), "H[l]lo");

test("Hello".replace(/l/g, x=>"Boop"), "HeBoopBoopo");
test("Hello".replace(/l/g,(match,idx)=>idx), "He23o");
test("Hello".replace(/(l)/g,(match,l,idx)=>`[${l}]`), "He[l][l]o");

test("dddd".replace(/d/g, "d"), "dddd");
test("dddd".replace(/d/g, "dd"), "dddddddd");
test("dddd".replace(/[de]/g, "ee"), "eeeeeeee");
test("dddd".replace(/d/g, x=>"dd"), "dddddddd");

test("5c6F".replace(/(\d+)([^\d])/g, (m, r, c) => new Array(+r + 1).join(c)), "cccccFFFFFF")

test(/\s+/.test(" "), true);
test(/\S+/.test(" "), false);

test(/\S+/.test(" "), false);

test(/^foo.*/.test("foo123"), true);
test(/^fox.*/.test("foo123"), false);


test("abcde".split(/d|b/).join(","), "a,c,e");
test("abcde|f".split(/d|\||b/).join(","), "a,c,e,f");
test('Some text\nAnd some more\r\nAnd yet\rThis is the end'.split(/\r\n|\r|\n/).join(","),
     "Some text,And some more,And yet,This is the end");

result = tests==testPass;
console.log(result?"Pass":"Fail",":",tests,"tests total");