Test with latest versions of iOS VoiceOver to see if numbers in strings are read out correctly

[hannalaakso]

Background

The component changes the content of at-timer with a countdown message at intervals.

Issue

When the component was tested on (See "Accessibility") VoiceOver + Safari + iOS 10.3.2 + iPhone 5s, there were issues with getting VoiceOver to read out numbers in longer strings when the content of at-timer changed.

For instance "We will reset your application if you do not respond in 2 minutes 30 seconds" was read out as "We will reset your application if you do not respond in".

To get around this we experimented with converting the numbers to letters at which point iOS read the message out correctly.

Next steps

This behaviour in iOS feels like an anomaly and was found on a c.2017 version of iOS so we should experiment removing the conversion to letters and test the component on the last couple of iOS versions to see if the problem can be replicated there.

If the problem can't be replicated we should probably just consider removing the code that converts numbers to letters. If there is an issue then bugs should be filed with browser vendors where relevant.