Turing complete means that it's a simulation of a Turing machine, but not actually one. A TM is something purely abstract that was invented to prove the halting problem, and infinity of the tape is arguably the most crucial concept. Computers do not have infinite memory / power / time so the halting problem doesn't really make sense unless you talk about a pure Turing machine with infinite tape.

In most cases, you know something is wrong once your typescript compilation takes more than a few seconds. At most, it could be an interesting DOS attack, but most continuous integration systems should have a limit on how much seconds they can run the compiler for. So it's really not a problem if you have constraints on resources...