LayoutTests/js/script-tests/toString-prefix-postfix-preserve-parens.js

description(
"This test checks that toString() round-trip on a function that has a typeof operator applied to a group expression will not remove the grouping."
);

// if these return a variable (such as y) instead of
// the result of typeof, this means that the parenthesis
// got lost somewhere.
function typeof_should_preserve_parens(x, y, z) {
    return typeof (x, y);
}

function typeof_should_preserve_parens1(x, y, z) {
    return typeof ((x, y));
}

function typeof_should_preserve_parens2(x, y, z) {
    var z = 33;
    return typeof (z, (x, y));
}

function typeof_should_preserve_parens_multi(x, y, z) {
    var z = 33;
    return typeof ((z,(((x, y)))));
}

unevalf = function(x) { return '(' + x.toString() + ')'; };

function testToString(fn) {
    // check that toString result evaluates to code that can be evaluated
    // this doesn't actually reveal the bug that this test is testing
    shouldBe("unevalf(eval(unevalf("+fn+")))", "unevalf(" + fn + ")");

    // check that grouping operator is still there (this test reveals the bug
    // but will create possible false negative if toString output changes in
    // the future)
    shouldBeTrue("/.*\\(+x\\)*, y\\)/.test(unevalf("+fn+"))");

}

function testToStringAndReturn(fn, p1, p2, retval)
{

    testToString(fn);

    // check that function call produces correct result
    shouldBe("" + fn + "(" + p1 + ", " + p2 +");", retval);

    // check that function call produces correct result after eval(unevalf)
    shouldBe("eval(unevalf("+fn+ "))" + "(" + p1 + ", " + p2 +");", retval);
}

testToStringAndReturn("typeof_should_preserve_parens", "'a'", 1, "'number'");
testToStringAndReturn("typeof_should_preserve_parens1", "'a'", 1, "'number'");
testToStringAndReturn("typeof_should_preserve_parens2", "'a'", 1, "'number'");
testToStringAndReturn("typeof_should_preserve_parens_multi", "'a'", 1, "'number'");