The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/js/src/tests/ecma_5/extensions/watch-value-prop-becoming-setter.js	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,43 @@
     1.4 +/*
     1.5 + * Any copyright is dedicated to the Public Domain.
     1.6 + * http://creativecommons.org/licenses/publicdomain/
     1.7 + */
     1.8 +
     1.9 +/* A stock watcher function. */
    1.10 +var watcherCount;
    1.11 +function watcher(id, old, newval) {
    1.12 +    watcherCount++;
    1.13 +    return newval; 
    1.14 +}
    1.15 +
    1.16 +/* Create an object with a value property. */
    1.17 +var o = { w:2, x:3 };
    1.18 +
    1.19 +/*
    1.20 + * Place a watchpoint on the value property. The watchpoint structure holds
    1.21 + * the original JavaScript setter, and a pointer to the shape.
    1.22 + */
    1.23 +o.watch('x', watcher);
    1.24 +
    1.25 +/*
    1.26 + * Put the object in dictionary mode, so that JSObject::putProperty will 
    1.27 + * mutate its shapes instead of creating new ones.
    1.28 + */
    1.29 +delete o.w;
    1.30 +
    1.31 +/*
    1.32 + * Replace the value property with a setter.
    1.33 + */
    1.34 +var setterCount;
    1.35 +o.__defineSetter__('x', function() { setterCount++; });
    1.36 +
    1.37 +/*
    1.38 + * Trigger the watchpoint. The watchpoint handler should run, and then the
    1.39 + * setter should run.
    1.40 + */
    1.41 +watcherCount = setterCount = 0;
    1.42 +o.x = 4;
    1.43 +assertEq(watcherCount, 1);
    1.44 +assertEq(setterCount, 1);
    1.45 +
    1.46 +reportCompare(true, true);