Should test that sequential calls to hashcode return the same int when object has no state

[GoogleCodeExporter]

What steps will reproduce the problem?

Given this class 

public final class VariableHash {
    @Override
    public int hashCode() {
        return (int)(1000*Math.random());
    }
}

Test the class with this unit test

@Test
public void equalsContract() {
    EqualsVerifier.forClass(VariableHash.class).verify();
}

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What is the code (equals method, hashCode method, relevant fields) that
triggers the problem?

hashcode method in a class with no fields that doesn't also override equals

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What error message does EqualsVerifier give?

No error message, but the above test passes instead of fails.

This test actually does fail as one would expect:

@Test
public void testVariableHash() {
    Object c = new VariableHash();
    assertEquals(c.hashCode(), c.hashCode());
}

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What stacktrace does EqualsVerifier print, when called with the debug()
method?

N/A

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What did you expect?

Expected the test to fail.

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What version of EqualsVerifier are you using?

1.5

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Please provide any additional information below.

See conversation in google group:
https://groups.google.com/forum/?fromgroups#!topic/equalsverifier/mflja4nNBqw

Maybe we can add a check where EV tests the hashCode of an object on itself.

Maybe we should also add a check that if hashCode is defined, so should equals 
be (and vice versa). But it would be necessary that such a check can be 
disabled, too.

Original issue reported on code.google.com by [email protected] on 26 Sep 2014 at 1:30

[GoogleCodeExporter]

Original comment by [email protected] on 27 Sep 2014 at 2:20

• Changed state: Accepted
• Added labels: ****
• Removed labels: ****

[GoogleCodeExporter]

Fixed in version 1.6.

Original comment by [email protected] on 17 Jan 2015 at 4:26

• Changed state: Fixed
• Added labels: ****
• Removed labels: ****