Kotlin: minimize the usage of 'JvmSuppressWildcards'#1793
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pwrobeldev merged 7 commits intomasterfrom Jan 26, 2026
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The annotation was used for each parameter type of collections. This was not needed. The annotation only needs to be used for open types which are: - open classes - interfaces - lambdas (generated as fun interfaces in Kotlin) Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
Hsilgos
previously approved these changes
Jan 22, 2026
Add test cases that pass. Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
The new test experiences compilation error because of missing
'JvmSuppressWildcards'.
```
gluecodium/functional-tests/functional/android/src/test/java/com/here/android/test/KotlinInteropTest.java:82:
error: incompatible types: List<CAP#1> cannot be converted to List<SomeDummyEnum>
assertEquals(0, someJavaFunctionThatTakesListOfEnums(someStruct.enumList));
^
where CAP#1 is a fresh type-variable:
CAP#1 extends SomeDummyEnum from capture of ? extends SomeDummyEnum
```
Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
Signed-off-by: Patryk Wrobel <183546751+pwrobeldev@users.noreply.github.com>
Hsilgos
approved these changes
Jan 26, 2026
pwrobeldev
deleted the
pwrobeldev/kotlin-minimize-the-usage-of-jvm-suppress-wildcards
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---------- Motivation ----------
The annotation mentioned in the title of the commit was used
for parameter types of collections (List, Map, Set) to avoid
interoperability problems when the generated code is accessed
from Java.
The problematic case is checked in
KotlinInteropTest.java.However, it turns out that the mentioned annotation needs to be
only used for enums and open types, because if the type is final
then wildcard is not generated.
---------- Solution ----------
KotlinNameResolver class is adjusted to generate the annotation for
parameter type of collection only when it is enum or the type is open.
Smoke tests are adjusted to showcase that this change minimizes the
usage of 'JvmSuppressWildcards' annotation.
The functional test called 'KotlinInteropTest.java' passes without problems after the change.