Test final object is indeed redundant: objects must be JVM-final
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Blaisorblade
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| @Test def objectsAreFinal = { | ||
| val source = | ||
| """class Test { | ||
| | object Foo |
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I would test a few more cases (top-level object, object in object, object in local block).
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Scalac sometimes *forgets* the final bytecode flag, and sometimes one cares, so people even *recommend* always writing *final object* instead of object. That's bad, since we started warning about it in scala#4973. scala/bug#11094 (comment) https://nrinaudo.github.io/scala-best-practices/adts/final_case_objects.html Why care? ========= If we forget the final flag in bytecode, Java code might then extend the class. Performance might or might not be affected - some in scala/contributors debated this for ~20 minutes (starting at https://gitter.im/scala/contributors?at=5c423c449bfa375aab21f2af).
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Scalac sometimes forgets the final bytecode flag, and sometimes one cares, so
people even recommend always writing final object instead of object. That's
bad, since we started warning about it in #4973.
scala/bug#11094 (comment)
https://nrinaudo.github.io/scala-best-practices/adts/final_case_objects.html
Why care?
If we forget the final flag in bytecode, Java code might then extend the class.
Performance might or might not be affected - some in scala/contributors
debated this for ~20 minutes (starting at
https://gitter.im/scala/contributors?at=5c423c449bfa375aab21f2af).