LayoutTests/storage/indexeddb/resources/cursor-leak.js

if (this.importScripts) {
    importScripts('../../../resources/js-test.js');
    importScripts('shared.js');
}

description("Verify that that cursors weakly hold script value properties");

if (window.internals) {
    indexedDBTest(prepareDatabase, onOpen);
} else {
    testFailed('This test requires access to the Internals object');
    finishJSTest();
}

function prepareDatabase(evt)
{
    db = event.target.result;
    store = db.createObjectStore('store');
    store.put({value: 'value'}, ['key']);
}

function onOpen(evt)
{
    // evalAndLog() is not used as that generates new DOM nodes.

    db = evt.target.result;
    tx = db.transaction('store');
    store = tx.objectStore('store');
    cursorRequest = store.openCursor();
    cursorRequest.onsuccess = function() {
        cursor = cursorRequest.result;
    };
    tx.oncomplete = function() {
        db.close();

        // Try and induce a leak by a reference cycle from DOM to V8 and back.
        // If the v8 value of cursor.key (etc) is only held by the cursor's
        // V8 wrapper then there will be no leak.
        cursor.key.cursor = cursor;
        cursor.primaryKey.cursor = cursor;
        cursor.value.cursor = cursor;

        cursorObserver = internals.observeGC(cursor);

        cursorRequest = null;
        cursor = null;

        gc();

        shouldBeTrue("cursorObserver.wasCollected");
        finishJSTest();
    };
}