Deno creating huge error messages from auto-generated JS

[Sharpiro]

deno 0.35.0
v8 8.1.310
typescript 3.8.2

I was working with wabt.js today and trying to get it working with deno as well as the browser. When testing, I noticed deno was creating huge errors, so big in fact, I had to save them to a file to read them. It almost seems like the error contains the entire program, or one of the huge lines. wabt.js is built using emscripten, which creates pretty ugly javascript, so I'm not sure if this only occurs when deno runs something that emscripten has built.

An example of the error:

deno https://raw.githubusercontent.com/Sharpiro/bugs/0d41bbe0d3ee8cf2e052cbc76d7f00b917a933fd/deno/large_errors/index.js

add &> temp to output it to file

deno https://raw.githubusercontent.com/Sharpiro/bugs/0d41bbe0d3ee8cf2e052cbc76d7f00b917a933fd/deno/large_errors/index.js &> temp

As an aside here is a fork of WABT I got working today in deno after fixing the errors:
https://github.com/Sharpiro/wabt.js/blob/9ea629b1c31f80c70efdf9d01b489274beb0ddb1/index.js

[kevinkassimo]

We should restrict the error line to be shorter than e.g. 150 characters IMO

[kevinkassimo]

So I have a new idea: maybe we should just show nothing if the error line is too long, since it is not likely going to help anyways. Also truncation has the problem of unicode substring handling, and I am reluctant to introduce a new crate like unicode-segmentation just to deal with grapheme clusters

[kitsonk]

Given the problem with truncation (though I suspect that would be an edge case and if you mis truncated a line, we are talking about one char being mangled), I still think if the line is longer than say 120 or 150, it just doesn't make sense to output it.