[ericelliott]

I get the same real-time error detection and refactoring help from type inference, lint, and TDD. Lint and inference gives me real-time editor feedback, TDD runs automatically on file save.

I do consider TDD and code reviews are costly but you can't skip them with TypeScript because at least 80% of bugs are not detectable with TypeScript.

[seanwilson]

> because at least 80% of bugs are not detectable with TypeScript.

I give up. You're repeatedly using this figure in this thread in a misleading way to make it sound like what you're saying is more legitimate that just an opinion.

The abstract of the study you cite explicitly mentions this is a conservative estimate of effectiveness and ignores bugs detected in private:

> Evaluating static type systems against public bugs, which have survived testing and review, is conservative: it understates their effectiveness at detecting bugs during private development, not to mention their other benefits such as facilitating code search/completion and serving as documentation. Despite this uneven playing field, our central finding is that both static type systems find an important percentage of public bugs: both Flow 0.30 and TypeScript 2.0 successfully detect 15%!

[ericelliott]

The number they consider conservative is that TypeScript can address up to 15% of public bugs. That's a different number than the proportion of public bugs found ts-undetectable because they're not type errors at all.

[seanwilson]

There are so many important details about what this figure means and how accurate it is.

Would it make a difference if TypeScript was used before the code was committed? How does the subject domain of the project impact this figure? How do other testing and review approaches impact this number? Are public bugs of certain kinds more likely to be reported for certain projects?

It's highly misleading to quote this figure in such a simplistic manner without caveats.