How an Anti-TypeScript “JavaScript developer” like me became a TypeScript fan

Re:How an Anti-TypeScript “JavaScript developer” like me bec... by kipple on Tuesday March 02, 2021 @01:12PM (#26318366)

This particular example is close to my heart: the definition files for things like JSON.parse() were written before the "unknown" type was introduced as an alternative to "any"

And because this "any" is coming from an external definition file, it can't be caught by tsc's --noImplicitAny nor eslint's no-explicit-any

Those two rules allow us to protect us from our own code, but not external definitions/libraries. Relevant GitHub issue here — https://github.com/microsoft/TypeScript/issues/26188

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Re:How an Anti-TypeScript “JavaScript developer” like me bec... by kipple on Tuesday March 02, 2021 @01:28PM (#26318595)

Looks like eslint is working on a new set of rules that would help with these currently-unprotected any cases: https://github.com/typescript-eslint/typescript-eslint/issue...

> Create a rule which uses type information to determine when you're inadvertently breaking type safety by using an any, potentially without knowing.

> Often libraries (or even the typescript defs themselves) can have weak(/lazy) types which return any. If you're not careful, you can inadvertently introduce anys within your codebase, leading to bugs that aren't caught by the compiler.

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