ENUM lint rule (MPR001) rejects the Mendix-recommended ENUM_ prefix

[recktenwaldfabian]

Summary

The naming convention rule (MPR001) for enumerations conflicts with Mendix's
official naming best practices. The rule flags the exact naming pattern Mendix
recommends as a violation.

Details

DefaultEnumerationPattern in mdl/linter/rules/naming.go is:

var DefaultEnumerationPattern = regexp.MustCompile(`^[A-Z][a-zA-Z0-9]*$`)

This requires plain PascalCase and disallows underscores. However, the
Mendix Naming Convention Best Practices
state that enumerations should carry an ENUM_ prefix:

"Enumerations should be identified with a prefix. The name of the enumeration
should reflect its business context, for example, ENUM_ShippingStatus."
(prefix table: Enumeration → ENUM_)

As a result, the recommended name ENUM_ShippingStatus fails the pattern
(_ is not in [a-zA-Z0-9]), and the rule's toPascalCase suggestion rewrites
it to something like EnumShippingstatus — also incorrect per the convention.

Suggested fix

Allow the ENUM_ prefix, mirroring the microflow approach:

var DefaultEnumerationPattern = regexp.MustCompile(`^(ENUM_)?[A-Z][a-zA-Z0-9]*$`)

And update the suggestion helper to preserve the ENUM_ prefix.

References

• Rule source: mdl/linter/rules/naming.go
• https://docs.mendix.com/refguide/naming-convention-best-practices/
• https://docs.mendix.com/refguide/enumerations/

[ako]

Analysis + fix (implemented in b2447d1b5)

Confirmed — and the conflict is sharper than a single rule being too strict: two built-in lint subsystems contradict each other on enum naming, so no name satisfies both.

Rule	Source	ENUM_ShippingStatus	ShippingStatus
MPR001 (built-in Go)	mdl/linter/rules/naming.go — ^[A-Z][a-zA-Z0-9]*$	❌ warning (underscore)	✅ pass
CONV004 (Starlark)	.claude/lint-rules/conv004_enumeration_prefix.star	✅ pass (requires ENUM_)	❌ info ("does not start with ENUM_")

The Mendix-recommended ENUM_ShippingStatus trips MPR001; a plain ShippingStatus trips CONV004. There was no winning name. The suggestion was also wrong: toPascalCase("ENUM_ShippingStatus") splits on the _ and produces EnumShippingStatus (prefix destroyed).

Fix

Adopted the regex from the report plus the matching suggestion/message work (mirroring how microflows already handle their prefixes):

• DefaultEnumerationPattern → ^(ENUM_)?[A-Z][a-zA-Z0-9]*$
• New suggestEnumerationName preserves the ENUM_ prefix (was bare toPascalCase)
• MPR001 enum message now mentions the optional ENUM_ prefix
• CONV004 unchanged — it now agrees with a fixed MPR001

After the fix, ENUM_ShippingStatus passes both rules.

Tests

naming_test.go now asserts the pattern accepts ENUM_ShippingStatus (and still rejects ENUM_shippingStatus and a bare ENUM_), plus a TestSuggestEnumerationName that confirms the suggestion preserves the prefix (ENUM_shipping_status → ENUM_ShippingStatus). go test ./mdl/linter/... green.

[ako]

Fixed in b2447d1 (on the issues branch, merged to main). MPR001 now accepts the Mendix ENUM_ prefix and its suggestion preserves it; resolves the contradiction with the CONV004 rule.