Upgrade to TypeScript 3.9

[sindresorhus]

No description provided.

[sindresorhus]

I think this is caused by microsoft/TypeScript#38540

[BenSjoberg]

The linked TypeScript bug also causes the current version of got to fail when using TS 3.9. The issue occurs when you mix the default import with type imports (i.e. import got, { HTTPError } from 'got') or when using a dynamic import (i.e. await import('got'))

A workaround I found is to add module.exports.__esModule = true after this line. TypeScript sets __esModule to true on the exported module by default, but setting module.exports = got overwrites it.

The right answer might be to just wait for TypeScript to fix the problem, but no one from the team has commented on the bug yet, so it might be a while. :( (Edit: nvm, looks like someone from the TS team accepted the bug earlier today. So hopefully it'll be fixed soon!)

[DanielRosenwasser]

We should have a fix at microsoft/TypeScript#38808. If you can pick up the build that will be produced at the bottom of the page and try it out, that'd really help give us some confidence that we can back-port it to 3.9.

[sindresorhus]

I tried it in d6dae82, and seems like it doesn't fix our issue, but it doesn't cause any other problems either.

[szmarczak]

This too?

[sindresorhus]

I have no idea how to fix it. I just punted it as it's more important to get TS upgraded:

source/create.ts:201:51 - error TS2345: Argument of type 'Merge<Options, PaginationOptions<T, R>> | undefined' is not assignable to parameter of type 'Options | undefined'.
  Type 'Merge<Options, PaginationOptions<T, R>>' is not assignable to type 'Options | undefined'.
    Type 'Merge<Options, PaginationOptions<T, R>>' is not assignable to type 'Options'.
      Types of property 'pagination' are incompatible.
        Type '{ transform?: ((response: Response<R>) => T[] | Promise<T[]>) | undefined; filter?: ((item: T, allItems: T[], currentItems: T[]) => boolean) | undefined; ... 4 more ...; stackAllItems?: boolean | undefined; } | undefined' is not assignable to type '{ transform?: ((response: Response<unknown>) => unknown[] | Promise<unknown[]>) | undefined; filter?: ((item: unknown, allItems: unknown[], currentItems: unknown[]) => boolean) | undefined; paginate?: ((response: Response<unknown>, allItems: unknown[], currentItems: unknown[]) => false | Options) | undefined; should...'.
          Type '{ transform?: ((response: Response<R>) => T[] | Promise<T[]>) | undefined; filter?: ((item: T, allItems: T[], currentItems: T[]) => boolean) | undefined; ... 4 more ...; stackAllItems?: boolean | undefined; }' is not assignable to type '{ transform?: ((response: Response<unknown>) => unknown[] | Promise<unknown[]>) | undefined; filter?: ((item: unknown, allItems: unknown[], currentItems: unknown[]) => boolean) | undefined; paginate?: ((response: Response<unknown>, allItems: unknown[], currentItems: unknown[]) => false | Options) | undefined; should...'.
            Types of property 'transform' are incompatible.
              Type '((response: Response<R>) => T[] | Promise<T[]>) | undefined' is not assignable to type '((response: Response<unknown>) => unknown[] | Promise<unknown[]>) | undefined'.
                Type '(response: Response<R>) => T[] | Promise<T[]>' is not assignable to type '(response: Response<unknown>) => unknown[] | Promise<unknown[]>'.
                  Types of parameters 'response' and 'response' are incompatible.
                    Type 'Response<unknown>' is not assignable to type 'Response<R>'.
                      Type 'unknown' is not assignable to type 'R'.
                        'R' could be instantiated with an arbitrary type which could be unrelated to 'unknown'.

201  	let normalizedOptions = normalizeArguments(url, options, defaults.options);
     	                                                ~~~~~~~


Found 1 error.

I'll add a TODO comment.

[sindresorhus]

TS 3.9 introduced a lot of issues, and it seems many will be fixed in TS 4, so I suggest ignoring it until then.

[szmarczak]

microsoft/TypeScript#33436

[szmarczak]

Simplest repro:

interface Options<T = unknown> {
    fn: (value: T) => void
}

const normalizeOptions = (options: Options): void => {};

function someOtherFunction<T>(options: Options<T>) {
    normalizeOptions(options);
}

[szmarczak]

Replacing unknown with any seems to fix the issue.

[szmarczak]

Interestingly the example reproduces the error on all TS 3.x versions.

[szmarczak]

Hey, you precious wizard! How have you achieved that? :P