Confusing error message when a prefab is needed

[neboskreb]

Confusing error message when a prefab is needed

When object factory fails to construct a prefab automatically (e.g. because the type is abstract or non-instantiable), an exception is thrown which explains very little about the problem and difficult to enterpret.

Receiver class nl.jqno.equalsverifier.internal.reflection.PublicKey$$DynamicSubclass$41294f8$ does not define or inherit an implementation of the resolved method 'abstract byte[] getEncoded()' of interface java.security.Key.
java.lang.AbstractMethodError: Receiver class nl.jqno.equalsverifier.internal.reflection.PublicKey$$DynamicSubclass$41294f8$ does not define or inherit an implementation of the resolved method 'abstract byte[] getEncoded()' of interface java.security.Key.
    at core.security.PublicKeyEncoding.encodeX509(PublicKeyEncoding.java:47)
    at core.state.EncryptionKeysMapper.encodePublicKey(EncryptionKeysMapper.java:34)
    at core.state.EncryptionKeysMapperImpl.encryptionKeysToPublicKeyEntity(EncryptionKeysMapperImpl.java:52)
    at core.state.EncryptionKeysMapperImpl.toEntity(EncryptionKeysMapperImpl.java:25)
    at core.state.EndpointAppKeysMapperImpl.toEntity(EndpointAppKeysMapperImpl.java:29)
    at state.EndpointAppKeysMapperTest.testTransitive(EndpointAppKeysMapperTest.java:33)

Such exception should be wrapped into a higher-level exception explaining the problem and possible solution (i.e., Consider introducing a prefab for PublicKey)

Minimal reproducible example

public class EndpointAppKeys {
  private CipherSuite cipherSuite;
  private EncryptionKeys clientKeys;
}

public class EncryptionKeys {
  private PublicKey publicKey;  // <-- PublicKey is interface. It declares but never defines `public byte[] getEncoded()`, hence the failure to instantiate the mock
}

@ExtendWith(RedAndBlueExtension.class)
public class EndpointAppKeysMapperTest {

    @Test
    void testTransitive(@RedInstance EndpointAppKeys red, @BlueInstance EndpointAppKeys blue) {
       ...
    }
}