public IEnumerable <IXunitTestCase> Discover(ITestFrameworkDiscoveryOptions discoveryOptions, ITestMethod testMethod, IAttributeInfo theoryAttribute)
{
// Special case Skip, because we want a single Skip (not one per data item); plus, a skipped test may
// not actually have any data (which is quasi-legal, since it's skipped).
var skipReason = theoryAttribute.GetInitializedArgument <string>("Skip");
if (skipReason != null)
{
return new[] { new XunitTestCase(_diagnosticMessageSink, discoveryOptions.MethodDisplayOrDefault(), testMethod) }
}
;
var vsix = testMethod.GetVsixAttribute(theoryAttribute);
var validVsVersions = vsix.VisualStudioVersions.Where(v => VsVersions.InstalledVersions.Contains(v)).ToArray();
// We always pre-enumerate theories, since that's how we build the concrete test cases.
try
{
var dataAttributes = testMethod.Method.GetCustomAttributes(typeof(DataAttribute));
var results = new List <IXunitTestCase>();
foreach (var dataAttribute in dataAttributes)
{
var discovererAttribute = dataAttribute.GetCustomAttributes(typeof(DataDiscovererAttribute)).First();
var discoverer = ExtensibilityPointFactory.GetDataDiscoverer(_diagnosticMessageSink, discovererAttribute);
if (!discoverer.SupportsDiscoveryEnumeration(dataAttribute, testMethod.Method))
{
return(CreateTestCasesForTheory(discoveryOptions, testMethod, validVsVersions, vsix).ToArray());
}
// GetData may return null, but that's okay; we'll let the NullRef happen and then catch it
// down below so that we get the composite test case.
foreach (var dataRow in discoverer.GetData(dataAttribute, testMethod.Method))
{
// Determine whether we can serialize the test case, since we need a way to uniquely
// identify a test and serialization is the best way to do that. If it's not serializable,
// this will throw and we will fall back to a single theory test case that gets its data at runtime.
if (!SerializationHelper.IsSerializable(dataRow))
{
return(CreateTestCasesForTheory(discoveryOptions, testMethod, validVsVersions, vsix).ToArray());
}
var testCases = CreateTestCasesForDataRow(discoveryOptions, testMethod, validVsVersions, vsix, dataRow);
results.AddRange(testCases);
}
}
if (results.Count == 0)
{
results.Add(new ExecutionErrorTestCase(_diagnosticMessageSink,
discoveryOptions.MethodDisplayOrDefault(),
testMethod,
$"No data found for {testMethod.TestClass.Class.Name}.{testMethod.Method.Name}"));
}
// Add invalid VS versions.
results.AddRange(vsix.VisualStudioVersions
.Where(version => !VsVersions.InstalledVersions.Contains(version))
.Select(version => new ExecutionErrorTestCase(_diagnosticMessageSink, discoveryOptions.MethodDisplayOrDefault(), testMethod,
string.Format("Cannot execute test for specified {0}={1} because there is no VSSDK installed for that version.", nameof(IVsixAttribute.VisualStudioVersions), version))));
return(results);
}
catch { } // If something goes wrong, fall through to return just the XunitTestCase
return(CreateTestCasesForTheory(discoveryOptions, testMethod, validVsVersions, vsix).ToArray());
}