public void FailureIncludesOptionalMessageWhenProvided()
{
AssertionFailure failure = AssertionConditionEvaluator.Eval(() => true, false, "Expected {0}", "true");
Assert.IsNotNull(failure);
Assert.AreEqual("Expected true", failure.Message);
}
public void FailureExcludesOptionalMessageWhenOmitted()
{
AssertionFailure failure = AssertionConditionEvaluator.Eval(() => true, false, null);
Assert.IsNotNull(failure);
Assert.IsNull(failure.Message);
}
public void FailureIncludesStackTrace()
{
AssertionFailure failure = AssertionConditionEvaluator.Eval(() => true, false, null);
Assert.IsNotNull(failure);
Assert.Contains(failure.StackTrace.ToString(), "FailureIncludesStackTrace");
}
/// <summary>
/// Verifies that a particular condition holds true.
/// </summary>
/// <remarks>
/// <para>
/// If the condition evaluates to false, the assertion failure message will
/// describe in detail the intermediate value of relevant sub-expressions within
/// the condition. Consequently the assertion failure will include more diagnostic
/// information than if <see cref="Assert.IsTrue(bool, string, object[])" /> were used instead.
/// </para>
/// </remarks>
/// <param name="condition">The conditional expression to evaluate.</param>
/// <param name="messageFormat">The custom assertion message format, or null if none.</param>
/// <param name="messageArgs">The custom assertion message arguments, or null if none.</param>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="condition"/> is null.</exception>
/// <exception cref="AssertionException">Thrown if the verification failed unless the current <see cref="AssertionContext.AssertionFailureBehavior" /> indicates otherwise.</exception>
public static void That(Expression <System.Func <bool> > condition, string messageFormat, params object[] messageArgs)
{
if (condition == null)
{
throw new ArgumentNullException("condition");
}
AssertionFailure failure = AssertionConditionEvaluator.Eval(condition, true, messageFormat, messageArgs);
AssertionHelper.Fail(failure);
}
public void FailureDescribesExpectedResultAndConditionAndParameters(bool expectedResult)
{
AssertionFailure failure = AssertionConditionEvaluator.Eval(() => !expectedResult, expectedResult, null);
Assert.IsNotNull(failure);
Assert.AreEqual(String.Format("Expected the condition to evaluate to {0}.", expectedResult.ToString().ToLowerInvariant()), failure.Description);
Assert.AreElementsEqual(new[] {
new AssertionFailure.LabeledValue("Condition", "! expectedResult"),
new AssertionFailure.LabeledValue("expectedResult", Formatter.Instance.Format(expectedResult)),
}, failure.LabeledValues);
}
public void FailureMessageIgnoresValueOfTopLevelNotExpression()
{
int x = 42;
AssertionFailure failure = AssertionConditionEvaluator.Eval(() => !(x.ToString() == "42"), true, null);
Assert.IsNotNull(failure);
Assert.AreElementsEqual(new[] {
new AssertionFailure.LabeledValue("Condition", "! (x.ToString() == \"42\")"),
new AssertionFailure.LabeledValue("x.ToString()", "\"42\""),
new AssertionFailure.LabeledValue("x", "42"),
}, failure.LabeledValues);
}
public void FailureDescribesException()
{
object x = null;
AssertionFailure failure = AssertionConditionEvaluator.Eval(() => x.Equals(null), true, null);
Assert.IsNotNull(failure);
Assert.AreEqual("Expected the condition to evaluate to true but it threw an exception.", failure.Description);
Assert.AreElementsEqual(new[] {
new AssertionFailure.LabeledValue("Condition", "x.Equals(null)"),
new AssertionFailure.LabeledValue("x", "null"),
}, failure.LabeledValues);
Assert.Count(1, failure.Exceptions);
Assert.Contains(failure.Exceptions[0].ToString(), "NullReferenceException");
}
public void FailureMessageIgnoresRepeatedOccurrencesOfAVariable()
{
int x = 42;
AssertionFailure failure = AssertionConditionEvaluator.Eval(() => x * 2 == x + 1, true, null);
Assert.IsNotNull(failure);
Assert.AreElementsEqual(new[] {
new AssertionFailure.LabeledValue("Condition", "x * 2 == x + 1"),
new AssertionFailure.LabeledValue("x * 2", "84"),
new AssertionFailure.LabeledValue("x + 1", "43"),
new AssertionFailure.LabeledValue("x", "42")
}, failure.LabeledValues);
}
public void ReturnsNullIfTheConditionEvaluatesAsExpected(bool expectedResult)
{
Assert.IsNull(AssertionConditionEvaluator.Eval(() => expectedResult, expectedResult, null));
}
public void EvalThrowsIfConditionIsNull()
{
AssertionConditionEvaluator.Eval(null, true, "abc");
}
