From bug 1894994 review, there's a common pattern of testing variations of context menu patterns that can probably be more standardized https://searchfox.org/mozilla-central/search?q="contextmenu"&path=test
Bug 1895789 Comment 0 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
From bug 1894994 review https://phabricator.services.mozilla.com/D209637#inline-1161487, there's a common pattern of testing variations of context menu patterns that can probably be more standardized https://searchfox.org/mozilla-central/search?q="contextmenu"&path=test