mediawiki-extensions-Multim.../tests/qunit/provider/mmv.provider.Image.test.js
Gilles Dubuc 28b8f5095e Use cross-origin img attribute instead of data URI
After lots of experimenting with Wireshark and
current Chrome + Firefox on Ubuntu 13.10, this is my
current understanding of the caching when preloading images
with AJAX requests:

* on Chrome, the image request always comes from browser cache
* Firefox makes two separate requests by default
* Firefox with img.crossOrigin = 'anonymous' makes two separate
  requests, but the second one is a 304 (does not load the
  image twice)
* when the image has already been cached by the browser (but not in
  this session), Chrome skips both requests; Firefox skips the AJAX
  request, but sends the normal one, and it returns with 304.

"wish I knew this when I started" things:
* the Chrome DevTools has an option to disable cache. When this is
  enabled, requests in the same document context still come from
  cache (so if I load the page, fire an AJAX request, then without
  reloading the page, fire an AJAX request to the same URL, then the
  second request will be cached), but an AJAX request - image request
  pair is an exception from this.
* when using Ctrl-F5 in Firefox, requests on that page will never hit
  the cache (even AJAX request fired after user activity; even if
  two identical requests follow each other). When using clear cache
  + normal reload, this is not the case.
* if the image does not have an Allow-Origin header and is loaded
  with crossOrigin=true, Firefox will refuse to load it. Chrome will
  log an error in the console saying it refused to load it, but will
  actually load it.
* Wireshark rocks.

Pushed some tech debt (browser + domain whitelist) into other tickets:
https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/232
https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/233

Reverted commits:
    8a8d74f01d.
    63021d0b0e.

Change-Id: I84ab2f3ac0a9706926adf7fe8726ecd9e9f843e0
Bug: 61542
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/207
2014-02-24 07:56:40 +00:00

137 lines
4.8 KiB
JavaScript

/*
* This file is part of the MediaWiki extension MultimediaViewer.
*
* MultimediaViewer is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* MultimediaViewer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MultimediaViewer. If not, see <http://www.gnu.org/licenses/>.
*/
( function ( mw, $ ) {
QUnit.module( 'mmv.provider.Image', QUnit.newMwEnvironment() );
QUnit.test( 'Image constructor sanity check', 1, function ( assert ) {
var imageProvider = new mw.mmv.provider.Image();
assert.ok( imageProvider );
} );
QUnit.test( 'Image load success test', 2, function ( assert ) {
var url = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0'
+ 'iAAAABlBMVEUAAAD///+l2Z/dAAAAM0lEQVR4nGP4/5/h/1+G/58ZDrAz3D/McH'
+ '8yw83NDDeNGe4Ug9C9zwz3gVLMDA/A6P9/AFGGFyjOXZtQAAAAAElFTkSuQmCC',
imageProvider = new mw.mmv.provider.Image();
imageProvider.performance = {
imagePreloadingSupported: function () { return false; },
recordEntry: $.noop
};
QUnit.stop();
imageProvider.get( url ).then( function( image ) {
assert.ok( image instanceof HTMLImageElement,
'success handler was called with the image element');
assert.strictEqual( image.src, url, 'image src is correct');
QUnit.start();
} );
} );
QUnit.test( 'Image caching test', 6, function ( assert ) {
var url = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0'
+ 'iAAAABlBMVEUAAAD///+l2Z/dAAAAM0lEQVR4nGP4/5/h/1+G/58ZDrAz3D/McH'
+ '8yw83NDDeNGe4Ug9C9zwz3gVLMDA/A6P9/AFGGFyjOXZtQAAAAAElFTkSuQmCC',
url2 = 'data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==',
result,
imageProvider = new mw.mmv.provider.Image();
imageProvider.performance = {
imagePreloadingSupported: function () { return false; },
recordEntry: $.noop
};
QUnit.stop();
imageProvider.get( url ).then( function( image ) {
result = image;
assert.ok( image instanceof HTMLImageElement,
'success handler was called with the image element');
assert.strictEqual( image.src, url, 'image src is correct');
QUnit.start();
} );
QUnit.stop();
imageProvider.get( url ).then( function( image ) {
assert.strictEqual( image, result, 'image element is cached and not regenerated' );
assert.strictEqual( image.src, url, 'image src is correct');
QUnit.start();
} );
QUnit.stop();
imageProvider.get( url2 ).then( function( image ) {
assert.notStrictEqual( image, result, 'image element for different url is not cached' );
assert.strictEqual( image.src, url2, 'image src is correct');
QUnit.start();
} );
} );
QUnit.asyncTest( 'Image load fail test', 1, function ( assert ) {
var imageProvider = new mw.mmv.provider.Image();
imageProvider.performance = {
imagePreloadingSupported: function () { return false; },
recordEntry: $.noop
};
imageProvider.get( 'doesntexist.png' ).fail( function() {
assert.ok( true, 'fail handler was called' );
QUnit.start();
} );
} );
QUnit.test( 'Image load test with preloading supported', 1, function ( assert ) {
var url = mw.config.get( 'wgScriptPath' ) + '/skins/vector/images/search-ltr.png',
imageProvider = new mw.mmv.provider.Image(),
endsWith = function ( a, b ) { return a.indexOf( b ) === a.length - b.length; };
imageProvider.imagePreloadingSupported = function () { return true; };
imageProvider.performance = {
record: function() { return $.Deferred().resolve(); }
};
QUnit.stop();
imageProvider.get( url ).done( function( image ) {
// can't test equality as browsers transform this to a full URL
assert.ok( endsWith( image.src, url ), 'local image loaded with correct source');
QUnit.start();
} ).fail( function () {
// do not hold up the tests if the image failed to load
assert.ok( false, 'uh-oh, couldnt load - might be a problem with the test installation' );
QUnit.start();
} );
} );
QUnit.test( 'Failed image load test with preloading supported', 1, function ( assert ) {
var url = 'nosuchimage.png',
imageProvider = new mw.mmv.provider.Image();
imageProvider.imagePreloadingSupported = function () { return true; };
imageProvider.performance = {
record: function() { return $.Deferred().resolve(); }
};
QUnit.stop();
imageProvider.get( url ).fail( function () {
assert.ok( true, 'Fail callback called for non-existing image' );
QUnit.start();
} );
} );
}( mediaWiki, jQuery ) );