Affects PMD Version:
7.20.0

Rule:
UnnecessaryCast

Description:

Code Sample demonstrating the issue:

long l2 = ((long) someInt & 0xFF) << 32;

The cast is necessary as the expression is immediately bit-shifted, which leads to different behavior over an int or a long. For instance, the following demonstrates the assertion is false:

	@Test
	public void testCastLongIsUseful() {
		int someInt = 1;
		long withCast = ((long) someInt & 0xFF) << 32;
		long withoutCast = (someInt & 0xFF) << 32;
		Assertions.assertThat(withCast).isEqualTo(withoutCast);
	}

The cast would be unecessary if the expression without cast was guaranteed to be a long (e.g. if 0xFF was actually a long/written as 0xFFL).

Expected outcome:

PMD reports a violation at line 0, but that's wrong. That's a false positive.

Running PMD through: [CLI | Ant | Maven | Gradle | Designer | Other]
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