CODEWITHSUNDEEP
javajunit
nano_nano
nano_nano

Reputation: 12524

Can assertEquals(Long,Integer) succeed?

Currently I am doing some code review and I found this line of code which interrupts the testcase:

assertEquals(Long.valueOf(4321), lMessage.getNumber());

getNumber returns an Integer which is also 4321. I changed it to this:

assertTrue(4321 == lSavedStoerung.getMessage());

because in my understanding of the equals method the assertEquals can never return true in the first example. With my assertTrue all test cases running fine.

Or did I understand something wrong?

Upvotes: 12

Views: 35413

Answers (2)

Akunosh
Akunosh

Reputation: 237

What is the reason behind 4321 being a long? If it's not necessary use the integer solution dasblinkenlight sugested.

assertEquals(Integer.valueOf(4321), lMessage.getNumber());

or

assertEquals(4321, lMessage.getNumber());

On the other hand, if your code allows lMessage.getNumber() return a long depending on the circumstances then you could box it into a long for your test.

assertEquals(Long.valueOf(4321), (long) lMessage.getNumber());

PS: Getting too compfortable using assertTrue & == will cause you trouble if you ever compare something that does not come in a primitive data type, but it will not in this specific example.

Upvotes: 1

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 726987

The reason why assertEquals test has failed is that equality considers not only the value of the number, but also its type. java.lang.Long object does not compare as equal to a java.lang.Integer.

Since lMessage.getNumber() returns an int, Java wraps it into Integer before passing to assertEquals. That's why you could fix the test case by using Integer.valueOf instead:

assertEquals(Integer.valueOf(4321), lMessage.getNumber());

Upvotes: 22

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