JSTests/microbenchmarks/string-substring-length-constant.js

function shouldBe(actual, expected) {
    if (actual !== expected)
        throw new Error("bad value: " + actual);
}

function test1() {
    return "/assets/omfg".substring(0, "/assets/".length) === "/assets/";
}
noInline(test1);

var count = 0;
for (var i = 0; i < testLoopCount; ++i) {
    if (test1())
        ++count;
}
shouldBe(count, testLoopCount);