public async Task GetHostIdAsync_ReturnsExpectedResult()
{
// ensure that the below job method is discovered and this test
// assembly is used to generate the ID
var type = GetType();
var firstJobMethod = FunctionIndexer.GetJobMethods(type).FirstOrDefault();
Assert.NotNull(firstJobMethod);
var mockTypeLocator = new Mock <ITypeLocator>(MockBehavior.Strict);
mockTypeLocator.Setup(p => p.GetTypes()).Returns(new Type[] { type });
var idProvider = new DefaultHostIdProvider(mockTypeLocator.Object);
// as long as this test assembly name stays the same, the ID
// computed should remain static. If this test is failing
// it likely means we've changed the ID computation algorithm
// which would be a BREAKING CHANGE
string expected = "be6b3849f12290e0f182b27aa6f10fff";
var id = await idProvider.GetHostIdAsync(CancellationToken.None);
Assert.Equal(expected, id);
// ensure the same ID is returned each time
mockTypeLocator = new Mock <ITypeLocator>(MockBehavior.Strict);
mockTypeLocator.Setup(p => p.GetTypes()).Returns(new Type[] { type });
idProvider = new DefaultHostIdProvider(mockTypeLocator.Object);
Assert.Equal(expected, await idProvider.GetHostIdAsync(CancellationToken.None));
// ensure once the ID is computed, a cached result is returned
Assert.Equal(expected, await idProvider.GetHostIdAsync(CancellationToken.None));
Assert.Equal(expected, await idProvider.GetHostIdAsync(CancellationToken.None));
mockTypeLocator.Verify(p => p.GetTypes(), Times.Once);
}
public async Task GetHostIdAsync_NoJobMethodsFound_ReturnsExpectedResult()
{
// pick a type that returns no job methods
var type = typeof(FunctionNameAttribute);
var firstJobMethod = FunctionIndexer.GetJobMethods(type).FirstOrDefault();
Assert.Null(firstJobMethod);
var mockTypeLocator = new Mock <ITypeLocator>(MockBehavior.Strict);
mockTypeLocator.Setup(p => p.GetTypes()).Returns(new Type[] { type });
var idProvider = new DefaultHostIdProvider(mockTypeLocator.Object);
// as long as this test assembly name stays the same, the ID
// computed should remain static. If this test is failing
// it likely means we've changed the ID computation algorithm
// which would be a BREAKING CHANGE
string expected = "943b1888c56ce8f0c96b2e66e1c74a7e";
var id = await idProvider.GetHostIdAsync(CancellationToken.None);
Assert.Equal(expected, id);
// ensure the same ID is returned each time
mockTypeLocator = new Mock <ITypeLocator>(MockBehavior.Strict);
mockTypeLocator.Setup(p => p.GetTypes()).Returns(new Type[] { type });
idProvider = new DefaultHostIdProvider(mockTypeLocator.Object);
Assert.Equal(expected, await idProvider.GetHostIdAsync(CancellationToken.None));
}
private string ComputeHostId()
{
// Search through all types for the first job method.
// The reason we have to do this rather than attempt to use the entry assembly
// (Assembly.GetEntryAssembly) is because that doesn't work for WebApps, and the
// SDK supports both WebApp and Console app hosts.
MethodInfo firstJobMethod = null;
foreach (var type in _typeLocator.GetTypes())
{
firstJobMethod = FunctionIndexer.GetJobMethods(type).FirstOrDefault();
if (firstJobMethod != null)
{
break;
}
}
// Compute hash and map to Guid
// If the job host doesn't yet have any job methods (e.g. it's a new project)
// then a default ID is generated
string hostName = firstJobMethod?.DeclaringType.Assembly.FullName ?? "Unknown";
Guid id;
using (var md5 = MD5.Create())
{
var hash = md5.ComputeHash(Encoding.UTF8.GetBytes(hostName));
id = new Guid(hash);
}
return(id.ToString("N"));
}