As we noticed for a couple commands geckodriver sets default values for arguments if those are not present. Instead it should ignore those and pass-through transparently to Marionette. That would avoid us from having to maintain multiple places for default values.

Currently it looks like that only SetWindowRect, ExecuteScript, and ExecuteAsyncScript seem to send null or no longer needed values to Marionette. All other Webdriver commands are using Optional as expected.

The argument "specialPowers" is no longer used in Marionette and as such can be removed from the serialization. The default value for "newSandbox" in Marionette is false, so it doesn't need to be explicitely set in geckodriver. By removing those two properties a custom serialization is no longer neccessary. Depends on D7210

Andreas, I already uploaded the patch with a review for you. In case it looks all fine and gets your r+ maybe you can land it if you are around at the weekend. Thanks.

Comment on attachment 9012970 [details] Bug 1494637 - [geckodriver] Only serialize non null arguments for Marionette. r?ato Andreas Tolfsen ❲:ato❳ has approved the revision.

Comment on attachment 9012972 [details] Bug 1494637 - [geckodriver] Remove custom serialization of JavascriptCommandParameters for Marionette. r?ato Andreas Tolfsen ❲:ato❳ has approved the revision.

Pushed by atolfsen@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/77cf6aa75d7e [geckodriver] Only serialize non null arguments for Marionette. r=ato

Actually those are only cosmetic changes. As such I don't think that we have to uplift this patch.

So I actually missed to land the second commit of this patch which now has been made obsolete. Andreas, did you include it somewhere else? If not I will file a new bug to get it landed.

Maybe Phabricator lets you push the missing commit with Lando? It should be possible to re-open (“reclaim” in Phabricator vernacular) a review if Lando doesn’t work on obsoleted diffs. Otherwise pushing to inbound with this same bug number works too.

Pushed by hskupin@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/7b5cc9b80a3e [geckodriver] Remove custom serialization of JavascriptCommandParameters for Marionette. r=ato