Missing type-utils.d.ts file in @middy/util package

[Lorenzo Bevilacqua]

Describe the bug
When importing @middy/util in a TypeScript project, tsc fails with the following error

node_modules/@middy/util/index.d.ts:3:88 - error TS2834: Relative import paths need explicit file extensions in EcmaScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Consider adding an extension to the import path.

3 import { ArrayValues, Choose, DeepAwaited, IsUnknown, SanitizeKey, SanitizeKeys } from './type-utils'

if I correct the import by adding the .js extension, then tsc fails with another error

node_modules/@middy/util/index.d.ts:3:88 - error TS2307: Cannot find module './type-utils.js' or its corresponding type declarations.

3 import { ArrayValues, Choose, DeepAwaited, IsUnknown, SanitizeKey, SanitizeKeys } from './type-utils.js'

In fact, the type-utils.d.ts file is not present.

To Reproduce
How to reproduce the behaviour:

See sample at https://github.com/lbevilacqua/middy-util-issue

Expected behaviour
tsc command should not produce the above errors.

Environment (please complete the following information):

• Node.js: 18.18.0
• Middy: 5.0.0

Additional context
package.json type: module
tsconfig.json module: node16

[will Farrell]

Thanks for reporting. I see the issue, file wasn't included in the package. I can push an update shortly.

[will Farrell]

v5.0.1 now releasing. Please let us know if that resolves the issue.

[Lorenzo Bevilacqua]

Thank you for the prompt reply.

I updated my test repository using the newly released version.
However, the first error is still present.

Since type-utils is only a type declaration, you could fix the issue by importing it using the type modifier and .d.ts file extension, as in

import type { ArrayValues, Choose, DeepAwaited, IsUnknown, SanitizeKey, SanitizeKeys } from './type-utils.d.ts'

This way it is explicit that we are only importing types and not any underlying javascript code.

[will Farrell]

When running the tests after updating the file with the .d.ts it errors out: A declaration file cannot be imported without import type. Did you mean to import an implementation file ./type-utils instead?.

cc @lmammino

[Lorenzo Bevilacqua]

When running the tests after updating the file with the .d.ts it errors out: A declaration file cannot be imported without import type. Did you mean to import an implementation file ./type-utils instead?.

cc @lmammino

Did you add the type import modifier (see #1136 (comment))?

[will Farrell]

I did not (I don't use TypeScript myself). Looks like other tests start failing once I do. We'll have to take a deeper look when we can. You're also welcome to put a PR together.

ref: https://github.com/middyjs/middy/tree/feature/ts-import-fix

[Luciano Mammino]

I see that now the type import modifier has been added to the branch. @lbevilacqua, would you be so kind to test if the changes in Will's branch solve the issue?

[Lorenzo Bevilacqua]

Thank you.

I tried copying the modified file over the existing one and I'm not experiencing the issue anymore.