In https://github.com/lightpanda-io/browser/pull/798 module caching was added.
This was necessary as the same module loaded multiple time should result in the
same v8 module instance.
To make this work, modules became cached by their full URL. The full URL of one
module was also used to determine the full URL of nested modules (full url +
specifier).
With inline scripts, the page URL was used as the full URL. While this is
correct when resolving nested modules, it's incorrect for caching the module
itself. Two inline modules on a page share the same URL, but they aren't the
same and should be cached.
To fix this, inline modules still inherit the page URL, in order to resolve the
correct URL for nested modules, but are themselves never cached.
When V8 calls the ResolveModuleCallback that we give it, it passes the specifier
which is essentially the string given to `from`:
```
import {x} from './blah.js';
```
We were taking that specifier and giving it to the page. The page knew the
currently executing script, an thus could resolve the full URL. Given the full
URL, it could either return the JS content from its module cache or fetch
the source.
At best though, this isn't efficient. If two files import the same module, yes
we cache the src, but we still ask v8 to re-compile it. At worse, it crashes
due to resource exhaustion in the case of cyclical dependencies.
ResolveModuleCallback should instead detect that it has already loaded the
module and return the previously loaded module. Essentially, we shouldn't be
caching the JavaScript source, we should be caching the v8 module.
However, in order to do this, we need more than the specifier, which might only
be a relative path (and thus isn't unique). So, in addition to a module cache,
we now also maintain an module identifier lookup. Given a module, we can get
its full path. Thankfully ResolveModuleCallback gives us the referring module,
so we can look up that modules URL, stitch it to the specifier, and get the
full url (the unique identifier) within the JS runtime.
Need more real world testing, and a fully working example before I celebrate,
but for sites with many import, this appears to improve performance by many
orders of magnitude.
Adds a dummy PerformanceObserver. Only the supportedEntryTypes static attribute
is supported, and it currently returns an empty array. This hopefully prevents
code from trying to use it. For example, before using it, reddit checks if
specific types are supported and, if not, doesn't use it.
This introduced complexity in the js runtime. Our current approach to
attributes only works with primitive types. Non-primitive types can't be
attached to a FunctionTemplate (v8 will crash saying only primitive types can
be set). Plus, all non primitive types require a context to create anyways.
We now detect "primitive" attributes and "complex" attributes. Primitive
attributes are setup as before. Complex attributes are setup per-context,
requiring another loop through our types to detect & setup on each context
creation.
Probing a union match for an possible value should rarely hard-fail. Instead,
it should return an .{.invalid = {}} response to let the prober decide how to
proceed. This fixes a hard-fail when a JS value fails to probe as an array.
Also, add :modal pseudo-class.
(both issues came up looking at github integration)
Test speed has been improved only slightly by tweaking a 2-second running tests.
Build has been improved by:
1 - moving logFunctionCallError out of js.Caller and to a standalone function
2 - removing some non-generic code from the generic portions of the logger
Caller.getter and Caller.setter have been removed in favor or calling
Caller.method. This wasn't previously possible - prior to our v8 upgrade, they
had different signatures.
Also removed a largely unused parser/str.zig file.
Currently, if there's an internal navigation event, we continue to process the
page normally. This has negative performance implication, and can result in
user-scripts producing unexpected results.
For example, imagine a page with a script that does.
```js
if (x) {
form.submit();
}
reloadProduct();
```
The call to `form.submit()` should stop the script from executing. And, if the
page has 10 other <script> tags after this, they shouldn't be loaded nor
executed.
This code terminates the execution of the current script on an internal
navigation event, and stops the rest of the page from load.
While I believe this creates a more "correct" behavior, it also introduces new
edge cases. There's no a period of time, between the termination being stopped
and then being resumed, where executing code is not safe.
This adds support for:
```
new URLSearchParams({over: 9000});
```
The spec says that any thing that produces/iterates a sequence of string pairs
is valid. By using the lower-level JsObject, this hopefully takes care of the
most common cases. But I don't think it's complete, and I don't think we
currently capture enough data to make this work. There's no way for the JS
runtime to know if a value (say, a netsurf instance, or even a Zig instance)
provides an string=>string iterator.
Automatically include the stack trace in a `console.error` output. This is
useful because code frequently does:
```
try blah();
catch (e) console.log(e);
```
Which we log, but, without this, don't get the stack.
If you look at the specification for `console` [1], you'll note that it's a
namespace, not an interface (like most things). Furthermore, MDN lists its
methods as "static".
But it's a pretty weird namespace IMO, because some of its "functions", like
`count` can have state associated with them.
This causes some problems with our current implementation. Something like:
```
[1].forEach(console.log)
```
Fails, since `this` isn't our window-attached Console instance.
This commit introducing a new `static_XYZ` naming convention which does not
have the class/Self as a receiver:
```
pub fn static_log(values: []JsObject, page: *Page) !void {
```
This turns Console into a namespace for these specific functions, while still
being used normally for those functions that require state.
We could infer this behavior from the first parameter, but that seems more
error prone. For now, I prefer having the explicit `static_` prefix.
[1] https://console.spec.whatwg.org/#console-namespace
1 - Add a custom console.lp function to make our debug logs stand out from
script logs.
2 - In some cases, significantly improve how JavaScript values are serialized
in debug logs and in console.log.
1 - Make log_level a runtime option (not a build-time)
2 - Make log_format a runtime option
3 - In Debug mode, allow for log scope filtering
Improve the general usability of scopes. Previously, the scope was more or less
based on the file that the log was in. Now they are more logically grouped.
Consider the case where you want to silence HTTP request information, previously
you'd have to filter out the `page`, `xhr` and `http_client` scopes, but that
would also elimiate other page, xhr and http_client logs. Now, you can just
filter out the `http` scope.
Instead of taking a callback function, addEventListener can take an object
that exposes a `handleEvent` function. When used this way, `this` is
automatically bound. I don't think the current behavior is correct when
`handleEvent` is defined as a property (getter), but I couldn't figure out how
to make it work the way WPT expects, and it hopefully isn't a common usage
pattern.
Also added option support to removeEventListener.
Outputs in logfmt in release and a "pretty" print in debug mode. The format
along with the log level will become arguments to the binary at some point in
the future.
Because jsValueToStruct is now used in union probing, it shouldn't fail on a
mismatch, but rather return null. It's up to the caller to decide whether that's
an error or not.
Caller is a transient object that exists only for calling Zig functions from
JS. But jsValueToZig is more generally useful and can be used outside of an
explicit JS call. The scope is a better place for these as it's generally
referenced already by any code that would need to map values (i.e. a Callback).
1 - Add a log_level build option to control the default log level from
the build (e.g. -Dlog_level=debug). Defaults to info
2 - Add a new boolean log_unknown_properties build option to enable
logging unknown properties. Defautls to false.
3 - Remove the log debug for script eval - this can be a huge value
(i.e. hundreds of KB), which makes the debug log unusable IMO.
Capture its unique properties:
1- instances are falsy, and
2- instance can be called as a function
The behavior is used for browser detection (i.e. duckduckgo treats us as a
legacy browser because we document.all != false)
1 - Named properties should not be enumerable
2 - Empty key should always result in a null/undefined (depending on the API)
even if there's an element with an empty id/name
To address the first issue, we now require PropertyAttributes to be specified
when setting an object's value.
