Runtime exception: Structural identity doesn't work for method references

Describe the bug items.stream().map(item -> item.getId()).forEach(System.out::println) ✅ items.stream().map(Item::getId).forEach(System.out::println); 🆘

To Reproduce Test project: https://github.com/marksto/manifold-cast-exception mvn clean install

Expected behavior Structural identity works for method references in Java 8+.

Desktop (please complete the following information):

• OS Type & Version: “mac os x”, version: “10.14.3”, arch: “x86_64”, family: “mac”
• Java/JDK version: Java version: 1.8.0_172, vendor: Oracle Corporation
• IntelliJ IDEA version: 2018.1.2
• Manifold version: 0.59-alpha
• Manifold IntelliJ plugin version: 0.59-alpha

Stack trace

Exception in thread "main" java.lang.ClassCastException: manifold.ext.DataBindings cannot be cast to abc.schema.Item
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
	at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
	at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
	at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
	at abc.RunMe.loadItemsArray_PlainInterface(RunMe.java:39)
	at abc.RunMe.main(RunMe.java:22)

[rsmckinney]

Fix available in release 0.65-alpha

[marksto]

Ooo-key… I managed to figure out this inconsistency between debugger interpretation and the code being executed too (regardless the error in evaluator the app itself was running fine), and in the end this last ClassCastException turned out to be an invalid JSON Schema issue. 🤦‍♂️

Product was parsed with:

{
  ...
  "category": "string-value",
  ...
}

while the schema used for loading had:

{
  ...
  "category": {
    "type": "object",
    ...
  }
  ...
}

I’ve covered this scenario with a separate test case in updated test project, but still was not able to reproduce the exact same exception (in tests it fails with manifold.internal.javac.JavaCompileIssuesException: Error compiling Java class: abc.schema.java_lang_String_structuralproxy_abc_schema_Category).