1681402 - Improve stability and error handling for _selection_location_helper()

Status: RESOLVED FIXED

(Core :: Layout, enhancement)

Description

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

By searching test_accessiblecaret_ on bugzilla, we have a lot of intermittent bugs of KeyError: '0' or KeyError: '-1' for various testcase on AccessibleCaret. Most of them are on macOS.

One of the failure log looks like

Marionette	DEBUG	21 -> [0,25,"WebDriver:ExecuteScript",{"script":"var sel = arguments[0].editor.selection;return sel.rangeCount;","newSandbox":true, ... 6-4254-9346-b55e-6588df576563"}],"filename":"tests/layout/base/tests/marionette/selection.py","sandbox":"system","line":178}]
Marionette	DEBUG	21 <- [1,25,null,{"value":1}]
Marionette	DEBUG	21 -> [0,26,"WebDriver:GetElementTagName",{"id":"e49c6566-4254-9346-b55e-6588df576563"}]
Marionette	DEBUG	21 <- [1,26,null,{"value":"input"}]
Marionette	DEBUG	21 -> [0,27,"WebDriver:ExecuteScript",{"script":"var sel = arguments[0].editor.selection;return sel.getRangeAt(0).getClientRects(); ... 6-4254-9346-b55e-6588df576563"}],"filename":"tests/layout/base/tests/marionette/selection.py","sandbox":"system","line":171}]
Marionette	DEBUG	21 <- [1,27,null,{"value":{"item":{},"length":0}}]
Marionette	DEBUG	21 -> [0,28,"WebDriver:GetElementTagName",{"id":"e49c6566-4254-9346-b55e-6588df576563"}]
Marionette	DEBUG	21 <- [1,28,null,{"value":"input"}]
Marionette	DEBUG	21 -> [0,29,"WebDriver:ExecuteScript",{"script":"var sel = arguments[0].editor.selection;return sel.getRangeAt(0).getClientRects(); ... 6-4254-9346-b55e-6588df576563"}],"filename":"tests/layout/base/tests/marionette/selection.py","sandbox":"system","line":171}]
Marionette	DEBUG	21 <- [1,29,null,{"value":{"0":{"x":12,"y":22,"width":0,"height":14,"top":22,"right":12,"bottom":36,"left":12},"item":{},"length":1}}]

https://treeherder.mozilla.org/logviewer?job_id=323204001&repo=autoland&lineNumber=53626-53635

This should be the log of executing

        range_count = self.range_count()
        first_rect_list = self.selection_rect_list(0)
        last_rect_list = self.selection_rect_list(range_count - 1)

https://searchfox.org/mozilla-central/rev/71621bfa47a371f2b1ccfd33c704913124afb933/layout/base/tests/marionette/selection.py#190-192

The first getClientRects() (via self.selection_rect_list()) doesn't returns a rect, but the second one does. Some of the intermittent logs show the opposite.

Comment 1

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: Bug 1681402 - Improve stability and error handling for _selection_location_helper().

This patch doesn't change the behavior, but should improve the stability
and error handling of _selection_location_helper().

Throw exceptions if we don't see any range in Selection or we cannot get
any rects out of the first range, making the error message clearer.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/63d099513042
Improve stability and error handling for _selection_location_helper(). r=emilio

Comment 3

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/63d099513042