/// <summary>
/// Gets a metadata entry with the specified key.
/// </summary>
/// <param name="descriptor">The <see cref="CommandDescriptor"/>.</param>
/// <param name="key">The metadata key.</param>
/// <typeparam name="T">The type of the metadata value.</typeparam>
/// <returns>The metadata value.</returns>
/// <exception cref="InvalidCastException">The metadata value is not of the specified type.</exception>
/// <exception cref="KeyNotFoundException">The metadata entry was not found.</exception>
public static T GetMetadata <T>(this CommandDescriptor descriptor, string key)
{
if (!TryGetMetadata(descriptor, key, out T value))
{
throw new KeyNotFoundException($"Metadata value with key {key} is unknown.");
}
return(value);
}
/// <summary>
/// Gets a metadata entry with the specified key. Returns the <paramref name="defaultValue"/> if not found.
/// </summary>
/// <param name="descriptor">The <see cref="CommandDescriptor"/>.</param>
/// <param name="key">The metadata key.</param>
/// <param name="defaultValue">The metadata default value.</param>
/// <typeparam name="T">The type of the metadata value.</typeparam>
/// <returns>The metadata value if the entry was found; <paramref name="defaultValue"/> otherwise.</returns>
/// <exception cref="InvalidCastException">The metadata value is not of the specified type.</exception>
public static T GetMetadata <T>(this CommandDescriptor descriptor, string key, T defaultValue)
{
if (!TryGetMetadata(descriptor, key, out T result))
{
result = defaultValue;
}
return(result);
}
public void TryGetMetadataReturnsFalseIfNotFound()
{
string testKey = "test";
var metadata = new Dictionary <string, object>();
var descriptor = new CommandDescriptor(typeof(TestCommand), metadata);
descriptor.TryGetMetadata(testKey, out int value)
.Should()
.BeFalse();
}
public void GetMetadataReturnsDefaultValueIfNotFound()
{
int defaultValue = 123;
string testKey = "test";
var metadata = new Dictionary <string, object>();
var descriptor = new CommandDescriptor(typeof(TestCommand), metadata);
descriptor.GetMetadata(testKey, defaultValue)
.Should()
.Be(defaultValue);
}
public void GetMetadataThrowsIfNotFound()
{
var metadata = new Dictionary <string, object>();
var descriptor = new CommandDescriptor(typeof(TestCommand), metadata);
Action action = () =>
{
descriptor.GetMetadata <int>("key");
};
action.Should()
.Throw <KeyNotFoundException>();
}
public void GetMetadataReturnsValue()
{
string testKey = "test";
int testValue = 1;
var metadata = new Dictionary <string, object> {
{ testKey, testValue }
};
var descriptor = new CommandDescriptor(typeof(TestCommand), metadata);
descriptor.GetMetadata <int>(testKey)
.Should()
.Be(testValue);
}
public void TryGetMetadataThrowsIfOfWrongType()
{
string testKey = "test";
int testValue = 1;
var metadata = new Dictionary <string, object> {
{ testKey, testValue }
};
var descriptor = new CommandDescriptor(typeof(TestCommand), metadata);
Action action = () =>
{
descriptor.TryGetMetadata(testKey, out string wrongTypeValue);
};
action.Should()
.Throw <InvalidCastException>();
}
/// <summary>
/// Tries to get an metadata entry with the specified key.
/// </summary>
/// <param name="descriptor">The <see cref="CommandDescriptor"/>.</param>
/// <param name="key">The metadata key.</param>
/// <param name="value">The metadata value.</param>
/// <typeparam name="T">The type of the metadata value.</typeparam>
/// <returns><c>true</c> if the metadata entry was found; <c>false</c> otherwise.</returns>
/// <exception cref="InvalidCastException">The metadata value is not of the specified type.</exception>
public static bool TryGetMetadata <T>(this CommandDescriptor descriptor, string key, out T value)
{
Ensure.Arg.NotNull(descriptor, nameof(descriptor));
Ensure.Arg.NotEmpty(key, nameof(key));
if (!descriptor.Metadata.TryGetValue(key, out object tmp))
{
value = default;
return(false);
}
if (!(tmp is T))
{
throw new InvalidCastException(
$"Metadata value with key {key} is not of the expected type {typeof(T).GetDisplayName()}");
}
value = (T)tmp;
return(true);
}
public void PopulatesCommandDescriptorWithMetadata()
{
var provider1 = Substitute.For <ICommandMetadataProvider>();
provider1.When(p => p.GetMetadata(Arg.Any <Type>(), Arg.Any <IDictionary <string, object> >()))
.Do(
ci =>
{
var metadata = ci.ArgAt <IDictionary <string, object> >(1);
metadata.Add("1", 1);
});
var provider2 = Substitute.For <ICommandMetadataProvider>();
provider2.When(p => p.GetMetadata(Arg.Any <Type>(), Arg.Any <IDictionary <string, object> >()))
.Do(
ci =>
{
var metadata = ci.ArgAt <IDictionary <string, object> >(1);
metadata.Add("2", 2);
});
var factory = new CommandDescriptorFactory(
new[]
{
provider1,
provider2
});
CommandDescriptor descriptor = factory.CreateDescriptor(typeof(TestCommand));
descriptor.Metadata.Should()
.BeEquivalentTo(
new KeyValuePair <string, object>("1", 1),
new KeyValuePair <string, object>("2", 2));
}