[api-extractor] v7.57.0 no longer exports `extends/tsdoc-base.json`

[awanlin]

Summary

We use the API Extractor as part of our process in the Backstage project and with extends/tsdoc-base.json not being exported it breaks the functionality for us.

Repro steps

1. Create a new plugin in the Backstage or Community Plugins repo
2. Run yarn build:api-reports (this will run backstage-repo-tools api-reports -o ae-wrong-input-file-type,ae-undocumented --validate-release-tags)

Expected result: The API Reports should generate Markdown files or update the existing ones

Actual result: Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './extends/tsdoc-base.json' is not defined by "exports" in /home/runner/work/community-plugins/community-plugins/workspaces/catalog/node_modules/@microsoft/api-extractor/package.json

Workaround: We could pin to the older version but we have over 80+ plugins in the Community Plugins repo all under their own Yarn setup. We would need to add it and then remove int once it's been fixed.

Details

Here's the code on the Backstage side that's expecting extends/tsdoc-base.json:

https://github.com/backstage/backstage/blob/605c98ee47e509435464613c7e1dee49c6b438c2/packages/repo-tools/src/commands/api-reports/api-reports/runApiExtraction.ts#L70-L85

Standard questions

Please answer these questions to help us investigate your issue more quickly:

Question	Answer
@microsoft/api-extractor version?	7.57.0 (and .1 and .2)
Operating system?	Mac / Linux
API Extractor scenario?	reporting (.api.md)
Would you consider contributing a PR?	No
TypeScript compiler version?	5.7.3
Node.js version (node -v)?	22 and 24

[awanlin]

I think maybe this is a regression from the changes in #5628 🤔

[awanlin]

Here's an example of it failing in action: https://github.com/backstage/community-plugins/actions/runs/22260417918/job/64397774788?pr=7663

[awanlin]

Thanks for the quick turnaround on this, just curious as to when a new version will be published to NPM?

[iclanton]

@awanlin - this is fixed in 7.57.3.