"Because a wise man once said your source code should be transpiled with same tool as your tests to avoid any hidden bugs."
Don't know where he got his wisdom. But I can't see why your tests should be even written in the same language. Its convenient if they are written in the same language, but on the other hand using different transpilers, languages etc will also highlight errors in the transpilers and languages themselves which might else have made their way into production.
Imagine a transpiler which by accident transpiles a number value always to 1 then the test "result equals 5" will always succeed (also when result equals 7) whereas 2 different transpilers might catch the error as 1 of them might do the right thing (or at least make different mistakes :-))