Since `objects.backend` was being set to usertypes.Backend.QtWebKit by
default some feature detection code was calling
`version.qWebKitVersion()` which was failing because the import of
`PyQt5.QtWebKit` was failing in version.
This should not change behavior where both backends are available on if
any tests fail because they are expecting their environment to say they
are on webkit when they either aren't actually using any webkit features
or all mocked webkit features then they should probably be changed to
patch `objects.backend` or not depend on it.
Also change the block scoped `window` declaration to be const because it
seemed like a good idea. The real window seems to just silently ignore
attempts to overwrite it.
I just want to return something I can refer to the attributes of via dot
syntax without having to pointlessly write the names both when I declare
the data class and when I assign the variables.
Such a stupid warning.
Since the JSCore used by WebKit 602.1 doesn't fully support Proxy and I
can't think of a way to provide isolation otherwise just revert to the
old behaviour in that case. I am checking for the specific WebKit
version because I'm pretty sure that version just happened to be
released when Proxy support was only partially done, any later release
will presumably have a newer JSCore where it works.
There I changed the indentation of a block in the jinja template which
will have inflated the diff.
I added mocking of `objects.backend` to the `webview` and
`webenginewebview` fixtures, I am pretty sure they are mutually
exclusive so don't expect any issues from that.
Because of the feature detection being at template compile time I had to
tweak the test setup to be done via a fixture instead of the setupClass
functionality that I was using before.
The implementation of Proxy in JSCore used by current QtWebkit (webkit
602.1) doesn't support the `set()` handler for whatever reason. So
instead of testing for a specific behaviour that we can't ensure on that
version let's just skip the tests and handle user complaints with
sympathy.
Apparently making a function like `function foo() {};` in block scope is
illegal. It should be named via assignment.
Switched to an IIFE anyway because it doesn't need a name.
Adds a test to codify what I think greasemonkey scripts expect from
their scope chains. Particularly that they can:
1. access the global `window` object
2. access all of the attributes of the global window object as global
objects themselves
3. see any changes the page made to the global scope
4. write to attributes of `window` and have those attributes, and changes
to existing attributes, accessable via global scope
5. do number 4 without breaking the pages expectations, that is what
`unsafeWindow` is for
There are some other points about greasemonkey scripts' environment that
I believe to be true but am not testing in this change:
* changes a page makes to `window` _after_ a greasemonkey script is
injected will still be visible to the script if it cares to check and
it hasn't already shadowed them
* said changes will not overwrite changes that the greasemonkey script
has made.
Previously scripts were failing to find attributes that they assigned to
window and then tried to use from the global scope. Eg
window.newthing = function() {...};
newthing(...); // newthing is not defined error
This wasn't the case for things that already existed in the global scope
and were just being overwritten.
This change just overrides the `Proxy.has()` function which seems to fix
it. Probably the `while` implementation was failing to pick up new
attributes because of the lack.
I also tweaked some comments and variable names and const-ness to be a
little more production ready.
Since the global namespace of javascript in the browser is accessible
there where issues with scripts clobbering things that the page expected
to be attributes of window pages clobbering things that userscripts
saved to `window`. The latter was occuring with OneeChan. OneeChan was
setting `window.$` to a function that took a css selector and the 4chan
catalog script was setting `window.$` to some object. Since OneeChan was
set to run at document-start this broke OneeChan, switching it to
document-end broke scripts on 4chan.
I used OneeChan and 4chan-X on 4chan as the test case for this and
TamperMonkey as a guide for what is the correct way to handle scoping. I
didn't manage to pick apart just how TamperMonkey does what it does (I
think it might just be the environment that Chrome provides extensions
actually) but I got close to the same behaviour.
TamperMonkey provides a `window` object that appears to be what the
global window looked like before the webpage modified it. The global
scope though does have the pages modifications accessible. If the script
assigns something to an attribute `window` it can see that attribute in
the global scope. This implementation differs from that one in that, to
the scipt, `window` and the global scope always look the same, and that
is the same as the global scope looks in the environment provided by
TamperMonkey.
I am using the ES6 `Proxy` feature to allow the `window` object to look
like the actual (unsafe) one while allowing writing to it that doesn't
clobber the unsafe one. I am then using the ES4 `with` function to make
attributes of that window (proxy) object visible in the scope chain.
There may be other ways to do this without using `with` by using nested
functions and setting `this` creatively. There are notes around
alleging `with` to be various states of uncool[1].
I also ran into an issue where a userscript calling
`window.addEventListener(...)` would fail with `TypeError: Illegal
Execution` which is apparently due to `this` not being set correctly. I
looked at the functions which threw that error and those that didn't and
am using whether they have a `prototype` attribute or not to tell
whether I need to bind them with `window` as `this`. I am not sure how
correct that is but it worked for all the cases I ran into.
[1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/with
