fix(java): handle formatted values in inner enum comparisons

[KannaKim]

Description

Fixes #20952.

Formatted inner enums such as type: string, format: uri can generate equalsIgnoreCase() calls on non-String Java values, causing compilation errors when useEnumCaseInsensitive=true.

This change updates 11 affected inner-enum templates to compare formatted string enum values using toString() when useEnumCaseInsensitive=true. Unformatted strings retain their existing behavior, and comparisons with the option disabled remain unchanged.

Null inputs are handled without calling toString() on them. Existing equality behavior is preserved for non-string enums and when useEnumCaseInsensitive=false.

Testing

All 26 parameterized cases pass across 13 generator/library configurations, with case-insensitive matching enabled and disabled.

Tests compile and execute generated fromValue methods in isolated enum fixtures, covering:

• Plain strings, email, and custom string formats.
• URI and UUID values.
• Unformatted and formatted numeric enums.
• Exact matches and differently cased inputs.
• Nullable and non-nullable enums, including distinguishing Java null from the literal string "null".

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---

Summary by cubic

Fixes #20952. Inner enum comparisons for string formats like uri no longer generate equalsIgnoreCase() calls on non-String values, so Java code using useEnumCaseInsensitive=true compiles.

• Updates 11 inner-enum templates to use java.util.Objects.equals() when a format is present.
• Unformatted string enums keep case-insensitive matching.
• Formatted string enums mapped to Java String now match case-sensitively.
• Adds parameterized regression tests that compile and run generated fromValue methods across 13 generator/library configurations.

^{Written for commit e0ecda9. Summary will update on new commits.}

[cubic-dev-ai]

All reported issues were addressed across 13 files

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[KannaKim]

The cubic review was probably based on my previous PR description. I’ve updated the description to accurately reflect the implementation.

[cubic-dev-ai]

No issues found across 13 files

_{Re-trigger cubic}

[wing328]

FYI. Tested with this (using the default okhttp-gson library) but the output won't compile:

[ERROR] C:\Users\User\AppData\Local\Temp\enumtest2\src\main\java\org\openapitools\client\model\Example.java:[321,18] error: no suitable method found for value(UUID)
[ERROR]     method JsonWriter.value(String) is not applicable
[ERROR]       (argument mismatch; UUID cannot be converted to String)
[ERROR]     method JsonWriter.value(boolean) is not applicable
[ERROR]       (argument mismatch; UUID cannot be converted to boolean)
[ERROR]     method JsonWriter.value(Boolean) is not applicable
[ERROR]       (argument mismatch; UUID cannot be converted to Boolean)
[ERROR]     method JsonWriter.value(float) is not applicable
[ERROR]       (argument mismatch; UUID cannot be converted to float)
[ERROR]     method JsonWriter.value(double) is not applicable
[ERROR]       (argument mismatch; UUID cannot be converted to double)
[ERROR]     method JsonWriter.value(long) is not applicable
[ERROR]       (argument mismatch; UUID cannot be converted to long)
[ERROR]     method JsonWriter.value(Number) is not applicable
[ERROR]       (argument mismatch; UUID cannot be converted to Number)
[ERROR] C:\Users\User\AppData\Local\Temp\enumtest2\src\main\java\org\openapitools\client\model\Example.java:[326,32] error: cannot find symbol
[ERROR]   symbol:   method nextUUID()
[ERROR]   location: variable jsonReader of type JsonReader
[ERROR] C:\Users\User\AppData\Local\Temp\enumtest2\src\main\java\org\openapitools\client\model\Example.java:[332,30] error: cannot find symbol
[ERROR]   symbol:   method getAsUUID()
[ERROR]   location: variable jsonElement of type JsonElement

Not related to this change. Just another edge case we need to address one day.

[KannaKim]

Noted, I can make separate PR for this.

[wing328]

thanks for the PR.

I did a test with

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g java -i https://raw.githubusercontent.com/KannaKim/openapi-generator/1a102a1226560e5c7482f2bb1714e2fff877305e/modules/openapi-generator/src/test/resources/3_0/issue_20952_inner_enum_comparison.yaml -o /tmp/enumtest2/

But don't see any change when compared with the latest master.

Are you seeing the same or I'm no testing this change correctly ?

[KannaKim]

thanks for the PR.

I did a test with

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g java -i https://raw.githubusercontent.com/KannaKim/openapi-generator/1a102a1226560e5c7482f2bb1714e2fff877305e/modules/openapi-generator/src/test/resources/3_0/issue_20952_inner_enum_comparison.yaml -o /tmp/enumtest2/

But don't see any change when compared with the latest master.

Are you seeing the same or I'm no testing this change correctly ?

Hi, thanks for testing. It looks like useEnumCaseInsensitive=true was omitted in your command. I just ran test on my end using

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g java -i https://raw.githubusercontent.com/KannaKim/openapi-generator/1a102a1226560e5c7482f2bb1714e2fff877305e/modules/openapi-generator/src/test/resources/3_0/issue_20952_inner_enum_comparison.yaml -o /tmp/enumtest2/ --additional-properties=useEnumCaseInsensitive=true

generated comparison changed from

b.value.equalsIgnoreCase(value)

to

b.value.toString().equalsIgnoreCase(value == null ? null : value.toString())

[wing328]

Ah ok. I missed that. Thanks for the details and the fix