src/third_party/mozjs-45/js/src/jit-test/tests/self-test/inJit.js

// Test that inJit eventually becomes truthy.
// This code should never timeout.

function callInJit() {
    return inJit();
};

function test() {
    // Test with OSR.
    while(!inJit());

    // Test with inlining.
    while(!callInJit());

    // Test with zealous gc preventing compilation.
    while(!inJit()) gc();
};

test();