1537768 - Make it easier to start the remote agent from tests

Status: RESOLVED FIXED

(Remote Protocol :: Agent, enhancement, P1)

Description

[Alexandre Poirot [:ochameau]]

For now, tests have to do the following in order to start a remote server:
https://searchfox.org/mozilla-central/rev/7c20ad925005fbad7b8e08813115f1ec7fa1c248/remote/test/browser/browser_cdp.js#30-33

  // Start the CDP server
  const RemoteAgent = Cc["@mozilla.org/remote/agent"].getService(Ci.nsISupports).wrappedJSObject;
  RemoteAgent.tabs.start();
  RemoteAgent.listen(Services.io.newURI("http://localhost:9222"));

The first line, to retrieve the RemoteAgent singleton is going to be simplified in bug 1536888. But there will still be the second line, where the tests have to know that internally, the remote agent has to start its TabsObserver.
It would be helpful if that step can be done as part of listen or something.

Comment 1

[Alexandre Poirot [:ochameau]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=276e7d66564c7045eb8ed36224a26a783811765c

Comment 2

[Alexandre Poirot [:ochameau]]

Attachment: Bug 1537768 - Simplify RemoteAgent initialization.

Start the TabObserver from RemoteAgent.listen in order to prevent
having the tests to manually start it.
Start it from listen instead of init as we do stop the TabObserver from
stop and stop is the reverse of listen, not the reverse of init.

Comment 3

[Alexandre Poirot [:ochameau]]

Attachment: Bug 1537768 - Simplify RemoteAgent initialization.

Automatically initialize the agent from listen in order to only
have to call this one method in order to start it.

Comment 4

[Alexandre Poirot [:ochameau]]

Attachment: Bug 1537768 - Override add_task to translate cdp exception from head.js.

This allows improving all tests exceptions without requiring
any specific to be done in each tests.
I'm also moving a few imports to head.js to share the most into head.js.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/216940ec115d
Simplify RemoteAgent initialization. r=remote-protocol-reviewers,ato
https://hg.mozilla.org/integration/autoland/rev/6586c6e89759
Override add_task to translate cdp exception from head.js. r=remote-protocol-reviewers,ato

Comment 6

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/216940ec115d
https://hg.mozilla.org/mozilla-central/rev/6586c6e89759