/// <summary>
/// Verifies that a delegate throws a particular exception when called.
/// </summary>
/// <param name="expression">A constraint to be satisfied by the exception</param>
/// <param name="code">A TestSnippet delegate</param>
/// <param name="message">The message that will be displayed on failure</param>
/// <param name="args">Arguments to be used in formatting the message</param>
public static Exception Throws(IResolveConstraint expression, TestDelegate code, string message, params object[] args)
{
Exception caughtException = null;
#if ASYNC
if (AwaitUtils.IsAsyncVoid(code))
{
throw new ArgumentException("'async void' methods are not supported. Please use 'async Task' instead.", nameof(code));
}
#endif
using (new TestExecutionContext.IsolatedContext())
{
try
{
code();
}
catch (Exception ex)
{
caughtException = ex;
}
}
Assert.That(caughtException, expression, message, args);
return(caughtException);
}
/// <summary>
/// Executes the code and returns success if an exception is thrown.
/// </summary>
/// <param name="actual">A delegate representing the code to be tested</param>
/// <returns>True if an exception is thrown, otherwise false</returns>
public override ConstraintResult ApplyTo <TActual>(TActual actual)
{
TestDelegate code = actual as TestDelegate;
Exception caughtException = null;
if (code != null)
{
#if ASYNC
if (AwaitUtils.IsAsyncVoid(code))
{
throw new ArgumentException("'async void' methods are not supported. Please use 'async Task' instead.");
}
#endif
try
{
code();
}
catch (Exception ex)
{
caughtException = ex;
}
}
#if ASYNC
AsyncTestDelegate asyncCode = actual as AsyncTestDelegate;
if (asyncCode != null)
{
try
{
AwaitUtils.Await(asyncCode, asyncCode.Invoke());
}
catch (Exception ex)
{
caughtException = ex;
}
}
if (code == null && asyncCode == null)
#else
else
#endif
{
throw new ArgumentException(string.Format("The actual value must be a TestDelegate or AsyncTestDelegate but was {0}", actual.GetType().Name), "actual");
}
return(new ThrowsExceptionConstraintResult(this, caughtException));
}
internal static Exception Intercept(object invocation)
{
var invocationDescriptor = GetInvocationDescriptor(invocation);
#if ASYNC
if (AwaitUtils.IsAwaitable(invocationDescriptor.Delegate))
{
try
{
object result = invocationDescriptor.Invoke();
AwaitUtils.Await(invocationDescriptor.Delegate, result);
return(null);
}
catch (Exception ex)
{
return(ex);
}
}
if (AwaitUtils.IsAsyncVoid(invocationDescriptor.Delegate))
{
throw new ArgumentException("'async void' methods are not supported. Please use 'async Task' instead.");
}
#endif
using (new TestExecutionContext.IsolatedContext())
{
try
{
invocationDescriptor.Invoke();
return(null);
}
catch (Exception ex)
{
return(ex);
}
}
}
/// <summary>
/// Helper method that checks the signature of a TestMethod and
/// any supplied parameters to determine if the test is valid.
///
/// Currently, NUnitTestMethods are required to be public,
/// non-abstract methods, either static or instance,
/// returning void. They may take arguments but the _values must
/// be provided or the TestMethod is not considered runnable.
///
/// Methods not meeting these criteria will be marked as
/// non-runnable and the method will return false in that case.
/// </summary>
/// <param name="testMethod">The TestMethod to be checked. If it
/// is found to be non-runnable, it will be modified.</param>
/// <param name="parms">Parameters to be used for this test, or null</param>
/// <returns>True if the method signature is valid, false if not</returns>
/// <remarks>
/// The return value is no longer used internally, but is retained
/// for testing purposes.
/// </remarks>
private static bool CheckTestMethodSignature(TestMethod testMethod, TestCaseParameters parms)
{
if (testMethod.Method.IsAbstract)
{
return(MarkAsNotRunnable(testMethod, "Method is abstract"));
}
if (!testMethod.Method.IsPublic)
{
return(MarkAsNotRunnable(testMethod, "Method is not public"));
}
IParameterInfo[] parameters;
parameters = testMethod.Method.GetParameters();
int minArgsNeeded = 0;
foreach (var parameter in parameters)
{
// IsOptional is supported since .NET 1.1
if (!parameter.IsOptional)
{
minArgsNeeded++;
}
}
int maxArgsNeeded = parameters.Length;
object[] arglist = null;
int argsProvided = 0;
if (parms != null)
{
testMethod.parms = parms;
testMethod.RunState = parms.RunState;
arglist = parms.Arguments;
if (arglist != null)
{
argsProvided = arglist.Length;
}
if (testMethod.RunState != RunState.Runnable)
{
return(false);
}
}
ITypeInfo returnType = testMethod.Method.ReturnType;
#if ASYNC
if (AwaitUtils.IsAsyncVoid(testMethod.Method.MethodInfo))
{
return(MarkAsNotRunnable(testMethod, "Async test method must have non-void return type"));
}
if (AwaitUtils.IsAwaitable(testMethod.Method.MethodInfo))
{
var resultType = AwaitUtils.GetAwaitableResultType(testMethod.Method.MethodInfo);
if (parms != null && parms.HasExpectedResult)
{
if (resultType == typeof(void))
{
return(MarkAsNotRunnable(testMethod,
"Async test method must not return void when awaited when a result is expected"));
}
}
else
{
if (resultType != typeof(void))
{
return(MarkAsNotRunnable(testMethod,
"Async test method must return void when awaited when no result is expected"));
}
}
}
else
#endif
if (returnType.IsType(typeof(void)))
{
if (parms != null && parms.HasExpectedResult)
{
return(MarkAsNotRunnable(testMethod, "Method returning void cannot have an expected result"));
}
}
else if (parms == null || !parms.HasExpectedResult)
{
return(MarkAsNotRunnable(testMethod, "Method has non-void return value, but no result is expected"));
}
if (argsProvided > 0 && maxArgsNeeded == 0)
{
return(MarkAsNotRunnable(testMethod, "Arguments provided for method with no parameters"));
}
if (argsProvided == 0 && minArgsNeeded > 0)
{
return(MarkAsNotRunnable(testMethod, "No arguments were provided"));
}
if (argsProvided < minArgsNeeded)
{
return(MarkAsNotRunnable(testMethod, string.Format("Not enough arguments provided, provide at least {0} arguments.", minArgsNeeded)));
}
if (argsProvided > maxArgsNeeded)
{
return(MarkAsNotRunnable(testMethod, string.Format("Too many arguments provided, provide at most {0} arguments.", maxArgsNeeded)));
}
if (testMethod.Method.IsGenericMethodDefinition && arglist != null)
{
var typeArguments = new GenericMethodHelper(testMethod.Method.MethodInfo).GetTypeArguments(arglist);
foreach (Type o in typeArguments)
{
if (o == null || o == TypeHelper.NonmatchingType)
{
return(MarkAsNotRunnable(testMethod, "Unable to determine type arguments for method"));
}
}
testMethod.Method = testMethod.Method.MakeGenericMethod(typeArguments);
parameters = testMethod.Method.GetParameters();
}
if (arglist != null && parameters != null)
{
TypeHelper.ConvertArgumentList(arglist, parameters);
}
return(true);
}