/**
* Test method for {@link DivisionExpression#evaluate(EvaluableVariableAssignment)}. Asserts that:
*
* <ul>
* <li>The method passes the assignment to the inner expressions
* <li>It returns the quotients of its inner expressions.
* <li>{@code NaN} and infinity values are handled like specified in IEEE 754.
* <li>Passing {@code null} throws an exception.
* </ul>
*/
@Test
public void evaluate() {
final EvaluableExpression dividend = mock(EvaluableExpression.class);
final EvaluableExpression divisor = mock(EvaluableExpression.class);
final EvaluableVariableAssignment assignment = new EvaluableVariableAssignment();
final DivisionExpression testedExpression = new DivisionExpression(dividend, divisor);
assertThat(() -> testedExpression.evaluate(null), throwsException(NullPointerException.class));
given(dividend.evaluate(same(assignment))).willReturn(15d);
given(divisor.evaluate(same(assignment))).willReturn(3d);
assertThat(testedExpression.evaluate(assignment), is(5d));
given(dividend.evaluate(same(assignment))).willReturn(15d);
given(divisor.evaluate(same(assignment))).willReturn(0d);
assertThat(testedExpression.evaluate(assignment), is(Double.POSITIVE_INFINITY));
given(dividend.evaluate(same(assignment))).willReturn(-15d);
given(divisor.evaluate(same(assignment))).willReturn(0d);
assertThat(testedExpression.evaluate(assignment), is(Double.NEGATIVE_INFINITY));
given(dividend.evaluate(same(assignment))).willReturn(Double.POSITIVE_INFINITY);
given(divisor.evaluate(same(assignment))).willReturn(Double.POSITIVE_INFINITY);
assertThat(testedExpression.evaluate(assignment), is(Double.NaN));
given(dividend.evaluate(same(assignment))).willReturn(0d);
given(divisor.evaluate(same(assignment))).willReturn(0d);
assertThat(testedExpression.evaluate(assignment), is(Double.NaN));
}
