fix(exports): avoid "exports is not defined" ReferenceError

[dasa]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

• resolves "exports is not defined" ReferenceError in AMD output #5925

Description

This PR makes sure that exports is defined in AMD, IIFE, and UMD outputs when output.exports is "auto".

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Name	Status	Preview	Comments	Updated (UTC)
rollup	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 28, 2025 7:36pm

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.55%. Comparing base (cb8f815) to head (144f1de).
Report is 5 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #5934   +/-   ##
=======================================
  Coverage   98.55%   98.55%           
=======================================
  Files         270      270           
  Lines        8704     8704           
  Branches     1492     1492           
=======================================
  Hits         8578     8578           
  Misses         93       93           
  Partials       33       33           

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[lukastaegert]

Hi, thanks for the fix! I think your fix is correct, but it would be nice to have a dedicated "form" test, otherwise there is a chance that a future update might break this again. Here is a suggestion, distilled from the original reproduction:
https://rollupjs.org/repl/?version=4.40.0&shareable=JTdCJTIyZXhhbXBsZSUyMiUzQW51bGwlMkMlMjJtb2R1bGVzJTIyJTNBJTVCJTdCJTIyY29kZSUyMiUzQSUyMmxldCUyMHZhbHVlJTIwJTNEJTIwMCUzQiU1Q25jb25zb2xlLmxvZyh2YWx1ZSklNUNudmFsdWUlMjAlM0QlMjAxJTNCJTVDbiU1Q25leHBvcnQlMjAlN0IlMjB2YWx1ZSUyMGFzJTIwZGVmYXVsdCUyMCU3RCUzQiUyMiUyQyUyMmlzRW50cnklMjIlM0F0cnVlJTJDJTIybmFtZSUyMiUzQSUyMm1haW4uanMlMjIlN0QlNUQlMkMlMjJvcHRpb25zJTIyJTNBJTdCJTIyb3V0cHV0JTIyJTNBJTdCJTIyZXhwb3J0cyUyMiUzQSUyMmF1dG8lMjIlMkMlMjJmb3JtYXQlMjIlM0ElMjJhbWQlMjIlN0QlN0QlN0Q=

[dasa]

it would be nice to have a dedicated "form" test

new dedicated test added

[github-actions]

This PR has been released as part of rollup@4.40.2. You can test it via npm install rollup.