Exposing NewAllocator and AllocatorOption was unnecessary, and it made
the API more complex to use and understand.
Instead, have users call NewExecAllocator directly. This removes some
code, and simplifies the examples and tests.
We were doing this for extra open tabs, since NewContext was taking care
of detaching and closing the respective target.
And cancelling an entire allocator also properly waited for all the
resources, such as processes and temporary directories, to be cleaned
up.
However, this didn't work for a browser's first context; cancelling it
should wait for that one browser's resources to be cleaned up, but that
wasn't implemented. Do that, fixing the TODO in TestExecAllocator.
It's Run that actually starts a Browser, not NewContext. If the browser
is closed or crashes, the browser handler will fail to read from the
websocket, and its goroutines will stop.
However, the target handler's goroutines may not stop. The browser
handler uses a separate cancel function to stop itself when encountering
a websocket error, so that doesn't propagate to the original context
children, like the target handler.
To fix this, make it so that NewContext can keep the cancel function
around, for Run to use it in this scenario. And add a test case that
tests this very edge case, which used to time out before the fix.
Fixes#289.
For all contexts except the first browser context, as in that case the
allocator and browser handler already take care of shutting down the
process and goroutines, respectively.
Fixes#293.
Chrome already starts with a blank page, so use that for the first
target context instead of creating a new tab.
Add the first version of the Targets API, which is useful to test this
feature.
Fixes#291.
Remove the log option lines from testAllocate; right now, we don't have
these options for Target, and Target doesn't log much anyway. We can
always revisit this in the future.
While at it, simplify some code.
This can simplify some common use cases, like running a few actions
directly, or running no actions at all. It's also an almost entirely
backwards compatible change, as all Run call sites should continue to
compile and work.
Leave Tasks, as it can still be useful for functions to return complex
sequences of actions as a single Action.
That way, we avoid the racy map access via Browser.executorForTarget. If
a context is attached to a target, the Target field must be non-nil.
The Browser.pages map is still racy, since multiple tabs can be created
concurrently; we'll fix this other data race in another commit.
First, collapse Browser.Start with NewBrowser. There's no reason to
split them up.
Second, unexport Browser.userDataDir, since it's only needed for a test.
It's also a bad precedent, as only the ExecAllocator will control the
user data directory.
Third, export Context.Browser, since we were already exporting
Context.Allocator.
Finally, remove the Executor interface, a duplicate of cdp.Executor.
All it did was wait on the entire allocator, which is confusing. From
the user's perspective, this wait method should instead wait for the
resources for its own browser, and not any other browsers sharing the
same allocator.
We haven't decided how to integrate that into our API, so simply replace
it with Allocator.Wait.
Use a single websocket connection per browser, removing the need for an
extra websocket connection per target.
This is thanks to the Target.sendMessageToTarget command to send
messages to each target, and the Target.receivedMessageFromTarget event
to receive messages back.
The browser handles activity via a single worker goroutine, and the same
technique is used for each target. This means that commands and events
are dealt with in order, and we can do away with some complexity like
mutexes and extra go statements.
First, we want all of the functionality in a single package; this means
collapsing whatever is useful into the root chromedp package.
The runner package is being replaced by the Allocator interface, with a
default implementation which starts browser processes.
The client package doesn't really have a place in the new design. The
context, allocator, and browser types will handle the connection with
each browser.
Finally, the new API is context-based, hence the addition of context.go.
The tests have been modified to build and run against the new API.
