Implement strict mode in std

[kitsonk]

Deno runs in non-strict mode, in the Deno core though, we enforce strict mode. I think we should enforce that for std. I am seeing a lot of code in here that is not compliant with strict mode, which allows a lot of unsafe assignments around null and undefined as well as quite a few other violations which make the code unsound.

We also have quite a few linting violations too, which we catch in core, which are not being caught in our code review, like unused variables, lets where no reassignment occurs, etc...

My opinion is we need to find a way to enforce these as part of the CI process before it gets too far out of hand.

[ry]

Yes - we need TSLint here.

[kitsonk]

Actually, ESLint. See denoland/deno#1824... TSLint is moving itself into ESLint.

[bartlomieju]

With ESLing in CI pipeline can we close this issue?

[kitsonk]

No, this is more than that. Now that tsconfig.json is support on the CLI, we would want to change the CI to run Deno in strict mode in addition to linting. I haven't tried it yet, but I suspect it will throw out a huge amount of errors.

[bartlomieju]

Thanks for comment @kitsonk, I'll look into it