CLOUDP-306578: IPA-123: Enums

[yelizhenden-mdb]

Proposed changes

Jira ticket: CLOUDP-306578

   xgen-IPA-123-allowable-enum-values-should-not-exceed-20:
    description: |
      Allowable enum values should not exceed 20 entries.

      ##### Implementation details
      Rule checks for the following conditions:
        - Applies to inline enum values
        - Validates that each enum array has 20 or fewer values
        - Reusable enum schemas will be ignored
        - Skips validation if the schema has an exception defined for this rule

Found 61 violations to fix

Checklist

• I have signed the MongoDB CLA
• I have added tests that prove my fix is effective or that my feature works

Changes to Spectral

• I have read the README file for Spectral Updates

Further comments

[yelizhenden-mdb]

FYI: drive-by fix, not to duplicate the check for referenced schemas. The rule validates only the root component

[lovisaberggren]

Suggested change

	const ERROR_MESSAGE = 'Enum arrays should not exceed 20 values. Current count: ';
	const ERROR_MESSAGE = 'Enum arrays should not exceed 20 values, consider opting for a string instead. Current count: ';

[yelizhenden-mdb]

I also thought about including it, but not sure if producers would understand the difference, because type is already string. What do you think?

[lovisaberggren]

Yeah I took it right from the IPAs, so if it's unclear we should probably update the IPA too to explain. No string opinion though, I think in the context it makes sense

[yelizhenden-mdb]

Until the investigation for the reusable enum schemas are finalized, I think we should not give any suggestions here. I will note that the relevant IPA and error message here should be refined according to the investigation results

[wtrocki]

IMHO it is premature to put recomendation for using string. We moving problem to area we also want to fix (long strings).

[yelizhenden-mdb]

Ticket created: https://jira.mongodb.org/browse/CLOUDP-310775

[wtrocki]

To be clear - I agree that each IPA should have a clear message how to workaround the problem.
For this IPA we agreed that we're going to delegate it outside this PR as more investigation is required.

[Copilot]

Pull Request Overview

This pull request implements a new validation rule ensuring that enum arrays in the OpenAPI schema do not exceed 20 values. The key changes include:

• Adding a new rule function (IPA123EnumValuesShouldNotExceed20.js) that checks the enum value count.
• Updating documentation (README.md) to include the new rule.
• Modifying the Spectral ruleset configuration (IPA-123.yaml) to register the new rule.
• Providing comprehensive tests for the new rule in IPA123EnumValuesShouldNotExceed20.test.js.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
tools/spectral/ipa/rulesets/functions/IPA123EnumValuesShouldNotExceed20.js	New function to enforce the maximum allowed enum values
tools/spectral/ipa/rulesets/README.md	Documentation update for the new rule
tools/spectral/ipa/rulesets/IPA-123.yaml	Rule configuration update to include the new rule
tools/spectral/ipa/tests/IPA123EnumValuesShouldNotExceed20.test.js	Added tests covering various scenarios for the new rule

[yelizhenden-mdb]

FYI: Reusable enum schemas are ignored now

[wtrocki]

❤️

[wtrocki]

LGTM althought strong recomendation to keep enum size as parameter for rule inputs

[wtrocki]

LGTM!

[wtrocki]

In driveby next time cover parameter in rule description