• JS version has no sample tests
• inputs from description should be used in tests too...

This seems to be a duplicate of other katas which are themselves flagged as duplicates or combinations as Voile noted below, for example :

• https://www.codewars.com/kata/morse-code-translate-text-to-and-from-morse-code/discuss/javascript

There are a bunch of them with the same description of same problem with minor variations

• different word breaks
• some are numbers only, some are numbers and letters

There is also a full series on morse code which extends into much harder kata :

• https://www.codewars.com/kata/decode-the-morse-code

Seems too similar to the Decode the Morse Code. I just ran into this myself, creating a kata before realizing it really is almost an exact duplicate of another kata, albeit with stricter performance requirements and thorough random tests etc. Looks like you're in a similar situation.. a better test layout but still the same basic thing. Maybe morph it into something different? Not morse code but Cyrillic or something? Or your own invention, and then add a twist? (We do already have quite a few 'translate the...' katas.)

The test case is checking for an uppercase as the first character eventhough the discription states case insensitive. As this was noted three months ago and has yet to be fixed this is another reminder.

It is really necessary for us to make the whole dictionary ourselves? That's very annoying and is a big pile of hot garbage.

Please provide something in Preloaded.

Example test has I can write in morse code as expected result but the spec says the decode will always decode to lower case.

Also, there is no test on the case insensitiveness of the encoder in the actual tests.