public async Task Get_From_Cache_If_Cache_Miss_But_Queued_Late()
{
// Arrange
var hit = false;
var providerMock = new Mock <ICacheProvider>();
providerMock.Setup(m => m.TryGet <string>("key"))
.Returns((string _) =>
{
if (hit)
{
return(Task.FromResult(CachedValueResult <string> .Hit("cached_value")));
}
hit = true;
return(Task.FromResult(CachedValueResult <string> .Miss));
});
var lockMock = new Mock <ILock>();
var handler = new CacheHandler <ICacheProvider>(providerMock.Object, lockMock.Object);
// Act
var result = await handler.GetOrFetchAsync(
"key",
key => Task.FromResult(key + "_fetched"));
// Assert
Assert.Equal("cached_value", result);
lockMock.Verify(l => l.LockAsync(It.IsAny <object>()), Times.Once);
lockMock.Verify(l => l.LockAsync("key"), Times.Once);
providerMock.Verify(m => m.Set(It.IsAny <string>(), It.IsAny <object>()), Times.Never);
providerMock.Verify(m => m.TryGet <It.IsAnyType>(It.IsAny <string>()), Times.Exactly(2));
providerMock.Verify(m => m.TryGet <string>("key"), Times.Exactly(2));
}
public Task <CachedValueResult <T> > TryGet <T>(string key)
{
EnsureNotDisposed();
if (_memoryCache.TryGetValue(key, out object dataFromCache) && dataFromCache is T castItem)
{
return(Task.FromResult(CachedValueResult <T> .Hit(castItem)));
}
return(Task.FromResult(CachedValueResult <T> .Miss));
}
public void Create_Successful_Result_Instance_With_Matching_Value()
{
// Arrange
const string value = "abc123";
// Act
var result = CachedValueResult <string> .Hit(value);
// Assert
Assert.True(result.Succeeded);
Assert.Equal(value, result.Value);
}
public async Task Gets_Cached_Item_When_Exist()
{
// Arrange
var providerMock = new Mock <ICacheProvider>();
providerMock.Setup(m => m.TryGet <string>("key"))
.Returns(Task.FromResult(CachedValueResult <string> .Hit("cached_value")));
var lockMock = new Mock <ILock>();
var handler = new CacheHandler <ICacheProvider>(providerMock.Object, lockMock.Object);
// Act
var result = await handler.GetOrFetchAsync(
"key",
key => Task.FromResult(key + "_fetched"));
// Assert
Assert.Equal("cached_value", result);
lockMock.Verify(l => l.LockAsync(It.IsAny <object>()), Times.Never);
providerMock.Verify(m => m.TryGet <It.IsAnyType>(It.IsAny <string>()), Times.Once);
providerMock.Verify(m => m.TryGet <string>("key"), Times.Once);
providerMock.Verify(m => m.Set(It.IsAny <string>(), It.IsAny <object>()), Times.Never);
}