// <example>
// public event EventHandler MyEvent
// {
// add
// {
// this.ForEach(listItem => listItem.MyEvent += value;
// }
// remove
// {
// this.ForEach(listItem => listItem.MyEvent -= value;
// }
// }
// </example>
/// <remarks>
/// Event implementations are allowed to provide bodies for what to do in the add/remove cases.
/// In this case, the most appropriate action is just to forward the notification down to the contained items.
/// </remarks>
public void AppendEvent(EventInfo info, MemberMetadata eventData)
{
writer.Write($"public virtual event {eventData.HandlerType} {eventData.Name}");
using (writer.Scope) {
writer.Write("add");
using (writer.Scope) {
writer.Write($"this.ForEach(listItem => listItem.{eventData.Name} += value);");
}
writer.Write("remove");
using (writer.Scope) {
writer.Write($"this.ForEach(listItem => listItem.{eventData.Name} -= value);");
}
}
}
private void AppendConstructor(Type type, ConstructorInfo info, MemberMetadata constructorMetadata)
{
if (info.IsPrivate || info.IsStatic || info.IsFamilyAndAssembly || info.IsAssembly)
{
return;
}
var typeName = type.CreateCsName(type.Namespace);
var(basename, genericInfo) = typeName.ExtractImplementationNameParts("<");
var intermediateName = $"IntermediateStub{basename}_DoNotUse";
var stubName = $"Stub{basename}";
// for every constructor, make both a constructor and a static "DeferConstruction" method
var deferWriter = new CSharpSourceWriter(stubWriter.Indentation);
stubWriter.Write($"public {stubName}({constructorMetadata.ParameterTypesAndNames}) : base({constructorMetadata.ParameterNames})");
var outParam = $"out {stubTypeName} uninitializedStub";
var separator = constructorMetadata.ParameterTypesAndNames.Length > 0 ? ", " : string.Empty;
deferWriter.Write($"public static IDisposable DeferConstruction({constructorMetadata.ParameterTypesAndNames}{separator}{outParam})");
using (stubWriter.Scope) {
using (deferWriter.Scope) {
deferWriter.Write($"{stubTypeName} stub;");
deferWriter.Write($"var disposable = ConstructionCompletion.CreateObjectWithDeferredConstruction<{stubTypeName}>(out stub{separator}{constructorMetadata.ParameterNames});");
foreach (var member in Program.FindAllMembers(type))
{
var metadata = new MemberMetadata(member, type.Namespace);
switch (member.MemberType)
{
case MemberTypes.Method: AppendToConstructorFromMethod((MethodInfo)member, metadata, deferWriter); break;
case MemberTypes.Event: AppendToConstructorFromEvent((EventInfo)member, metadata, deferWriter); break;
case MemberTypes.Property: AppendToConstructorFromProperty((PropertyInfo)member, metadata, deferWriter); break;
default:
// the only other options are Field, Type, NestedType, and Constructor
// none of those can be virtual/abstract, so we don't need to put anything in the constructor for them.
break;
}
}
deferWriter.Write($"uninitializedStub = stub;");
deferWriter.Write($"return disposable;");
}
}
stubWriter.Write(deferWriter.ToString());
intermediateWriter.Write($"protected {intermediateName}({constructorMetadata.ParameterTypesAndNames}) : base({constructorMetadata.ParameterNames}) {{ }}");
}
public string ClassDeclaration(Type type)
{
var typeName = type.CreateCsName(type.Namespace);
string basename;
(basename, genericInfo) = typeName.ExtractImplementationNameParts("<");
constraints = MemberMetadata.GetGenericParameterConstraints(type.GetGenericArguments(), type.Namespace);
intermediateWriter.Write($"public class IntermediateStub{basename}_DoNotUse{genericInfo} : {typeName}{constraints}");
Debug.Assert(intermediateClassScope == null);
intermediateClassScope = intermediateWriter.Scope;
stubTypeName = $"Stub{basename}{genericInfo}";
return($"{stubTypeName} : IntermediateStub{basename}_DoNotUse{genericInfo}{constraints}");
}
// <example>
// public EventImplementation<EventArgs> ValueChanged = new EventImplementation<EventHandler>();
//
// event EventHandler INotifyValueChanged.ValueChanged
// {
// add
// {
// ValueChanged.add(new EventHandler<EventArgs>(value));
// }
// remove
// {
// ValueChanged.remove(new EventHandler<EventArgs>(value));
// }
// }
// </example>
// <remarks>
// Events are replaces with an EventImplementation field.
// Explicit interface implementations then call that EventImplementation.
//
// EventImplementation exposes add, remove, handlers, and +/- operators along with an Invoke method.
// This allows you to assign custom add/remove handlers to the Stub, or make decision based on the individual added handlers,
// or use +=, -=, and .Invoke as if the EventImplementation were actually an event.
//
// Note that the explicit implementation always casts added/removed delegates to EventHandler<T>.
// This is to avoid having to deal with .net's 2 types of EventHandlers separately.
// Example: RoutedEventHandler vs EventHandler<RoutedEventArgs>.
// </remarks>
public void AppendEvent(EventInfo info, MemberMetadata eventData)
{
writer.Write($"public EventImplementation<{eventData.HandlerArgsType}> {info.Name} = new EventImplementation<{eventData.HandlerArgsType}>();");
writer.Write(string.Empty);
writer.Write($"event {eventData.HandlerType} {eventData.DeclaringType}.{info.Name}");
using (writer.Scope) {
writer.Write("add");
using (writer.Scope) {
writer.Write($"{info.Name}.add(new EventHandler<{eventData.HandlerArgsType}>(value));");
}
writer.Write("remove");
using (writer.Scope) {
writer.Write($"{info.Name}.remove(new EventHandler<{eventData.HandlerArgsType}>(value));");
}
}
}
/// <summary>
/// Normally, making a stub method on a baseclass requires two overrides with the same name.
/// An override method, and a new delegate field with the same name.
/// But for generic methods, a delegate field with the same name won't work.
/// Instead, we have a generic delegate, a dictionary for overrides, a caller for the base method, an "ImplementMember" method, and an override for the method.
/// Since all of these have different names, we can put all the overrides in a single class.
/// So don't put anything in the helper intermediate class.
/// </summary>
private void AppendGenericMethod(MethodInfo info, MemberMetadata metadata)
{
var typesExtension = StubBuilder.SanitizeMethodName(metadata.ParameterTypes);
var typeofList = info.GetGenericArguments().Select(type => $"typeof({type.Name})").Aggregate((a, b) => $"{a}, {b}");
var createKey = $"var key = new Type[] {{ {typeofList} }};";
var delegateName = $"{metadata.Name}Delegate_{typesExtension}{metadata.GenericParameters}";
var dictionary = $"{metadata.Name}Delegates_{typesExtension}";
var methodName = $"{metadata.Name}{metadata.GenericParameters}";
stubWriter.Write($"public delegate {metadata.ReturnType} {delegateName}({metadata.ParameterTypesAndNames}){metadata.GenericParameterConstraints};");
stubWriter.Write($"private readonly Dictionary<Type[], object> {dictionary} = new Dictionary<Type[], object>(new EnumerableEqualityComparer<Type>());");
stubWriter.Write($"public void Implement{methodName}({delegateName} implementation){metadata.GenericParameterConstraints}");
using (stubWriter.Scope) {
stubWriter.Write(createKey);
stubWriter.Write($"{dictionary}[key] = implementation;");
}
if (!info.IsAbstract)
{
stubWriter.Write($"public {metadata.ReturnType} Base{methodName}({metadata.ParameterTypesAndNames}){metadata.GenericParameterConstraints}");
using (stubWriter.Scope) {
stubWriter.Write($"{metadata.ReturnClause}base.{methodName}({metadata.ParameterNames});");
}
}
stubWriter.Write($"{metadata.Access} override {metadata.ReturnType} {methodName}({metadata.ParameterTypesAndNames})");
using (stubWriter.Scope) {
stubWriter.AssignDefaultValuesToOutParameters(info.DeclaringType.Namespace, info.GetParameters());
stubWriter.Write(createKey);
stubWriter.Write("object implementation;");
stubWriter.Write($"if ({dictionary}.TryGetValue(key, out implementation))");
using (stubWriter.Scope) {
stubWriter.Write($"{metadata.ReturnClause}(({delegateName})implementation).Invoke({metadata.ParameterNames});");
}
stubWriter.Write("else");
using (stubWriter.Scope) {
if (!info.IsAbstract)
{
stubWriter.Write($"{metadata.ReturnClause}Base{methodName}({metadata.ParameterNames});");
}
else if (metadata.ReturnType != "void")
{
stubWriter.Write($"return default({metadata.ReturnType});");
}
}
}
}
public void AppendMethod(MethodInfo info, MemberMetadata metadata)
{
if (info.IsStatic || info.IsPrivate || info.IsAssembly || info.IsFamilyAndAssembly)
{
return;
}
if (!info.IsVirtual && !info.IsAbstract)
{
if (metadata.Access == "protected")
{
// the member is protected. Make a public version.
stubWriter.Write($"public new {metadata.ReturnType} {metadata.Name}{metadata.GenericParameters}({metadata.ParameterTypesAndNames}){metadata.GenericParameterConstraints}");
using (stubWriter.Scope) {
stubWriter.Write($"{metadata.ReturnClause}base.{metadata.Name}({metadata.ParameterNames});");
}
}
return;
}
if (info.IsGenericMethodDefinition)
{
AppendGenericMethod(info, metadata);
return;
}
var delegateName = GetDelegateName(metadata.ReturnType, metadata.ParameterTypes);
var typesExtension = StubBuilder.SanitizeMethodName(metadata.ParameterTypes);
var methodsWithMatchingNameButNotSignature = implementedMethods.Where(name => name.Split('(')[0] == metadata.Name && name != $"{metadata.Name}({metadata.ParameterTypes})");
string localImplementationName = methodsWithMatchingNameButNotSignature.Any() ? $"{metadata.Name}_{typesExtension}" : metadata.Name;
if (info.GetParameters().Any(p => p.ParameterType.IsByRef))
{
delegateName = $"{metadata.Name}Delegate_{typesExtension}";
stubWriter.Write($"public delegate {metadata.ReturnType} {delegateName}({metadata.ParameterTypesAndNames});" + Environment.NewLine);
}
stubWriter.Write($"public new {delegateName} {localImplementationName};");
WriteHelperBaseMethod(info, metadata);
WriteHelperMethod(info, metadata, stubTypeName, localImplementationName);
implementedMethods.Add($"{metadata.Name}({metadata.ParameterTypes})");
}
private void AppendToConstructorFromMethod(MethodInfo info, MemberMetadata metadata, CSharpSourceWriter deferWriter)
{
if (info.IsSpecialName || info.IsStatic || info.IsPrivate || !info.IsVirtual || info.IsAbstract || info.IsAssembly || info.IsFamilyAndAssembly || info.IsGenericMethod)
{
return;
}
if (info.IsVirtual && info.Name == "Finalize")
{
return; // Finalize is special in C#. Use a destructor instead.
}
var typesExtension = StubBuilder.SanitizeMethodName(metadata.ParameterTypes);
var methodsWithMatchingNameButNotSignature = implementedMethods.Where(name => name.Split('(')[0] == metadata.Name && name != $"{metadata.Name}({metadata.ParameterTypes})");
string localImplementationName = methodsWithMatchingNameButNotSignature.Any() ? $"{metadata.Name}_{typesExtension}" : metadata.Name;
stubWriter.Write($"if ({localImplementationName} == null) {localImplementationName} = Base{metadata.Name};");
deferWriter.Write($"stub.{localImplementationName} = stub.Base{metadata.Name};");
implementedMethods.Add($"{metadata.Name}({metadata.ParameterTypes})");
}
private void WriteHelperMethod(MethodInfo info, MemberMetadata metadata, string stubTypeName, string localImplementationName)
{
intermediateWriter.Write($"{metadata.Access} override {metadata.ReturnType} {metadata.Name}({metadata.ParameterTypesAndNames}){metadata.GenericParameterConstraints}");
using (intermediateWriter.Scope) {
var call = $"(({stubTypeName})this).{localImplementationName}";
intermediateWriter.AssignDefaultValuesToOutParameters(info.DeclaringType.Namespace, info.GetParameters());
intermediateWriter.Write($"if ({call} != null)");
using (intermediateWriter.Scope) {
intermediateWriter.Write($"{metadata.ReturnClause}{call}({metadata.ParameterNames});");
}
if (metadata.ReturnType != "void")
{
intermediateWriter.Write("else");
using (intermediateWriter.Scope) {
intermediateWriter.Write($"return default({metadata.ReturnType});");
}
}
}
}
private void AppendPropertyCommon(PropertyInfo info, MemberMetadata property, string listItem)
{
using (writer.Scope) {
if (info.CanRead)
{
writer.Write("get");
using (writer.Scope) {
writer.Write($"var results = this.Select<{property.DeclaringType}, {property.ReturnType}>(listItem => {listItem}).ToList();");
writer.Write($"return results.Count > 0 && results.All(result => result.Equals(results[0])) ? results[0] : default({property.ReturnType});");
}
}
if (info.CanWrite)
{
writer.Write("set");
using (writer.Scope) {
writer.Write($"this.ForEach(listItem => {listItem} = value);");
}
}
}
}
// <example>
// public void DoThing(int arg)
// {
// for (int i = 0; i < base.Count; i++)
// {
// base[i].DoThing(arg);
// }
// }
// </example>
/// <remarks>
/// Composite methods with return types are a bit strange.
/// If all the methods agree on what to return, then return that.
/// If any are different, then just return default.
/// In the case of nullables and bools, this default seems appropriate.
/// But it can be strange for numeric types.
///
/// For methods that return void, a composite simply forwards the method call down to each thing that it contains.
/// </remarks>
public void AppendMethod(MethodInfo info, MemberMetadata method)
{
// Use an explicit implementation only if the signature has already been used
// example: IEnumerable<T>, which extends IEnumerable
if (!implementedMethods.Any(name => name == $"{method.Name}({method.ParameterTypes})"))
{
writer.Write($"public virtual {method.ReturnType} {method.Name}{method.GenericParameters}({method.ParameterTypesAndNames}){method.GenericParameterConstraints}");
}
else
{
writer.Write($"{method.ReturnType} {method.DeclaringType}.{method.Name}{method.GenericParameters}({method.ParameterTypesAndNames}){method.GenericParameterConstraints}");
}
using (writer.Scope) {
writer.AssignDefaultValuesToOutParameters(info.DeclaringType.Namespace, info.GetParameters());
if (method.ReturnType == "void")
{
writer.Write("for (int i = 0; i < base.Count; i++)");
using (writer.Scope) {
writer.Write($"base[i].{method.Name}{method.GenericParameters}({method.ParameterNames});");
}
}
else
{
writer.Write($"var results = new System.Collections.Generic.List<{method.ReturnType}>();");
writer.Write("for (int i = 0; i < base.Count; i++)");
using (writer.Scope) {
writer.Write($"results.Add(base[i].{method.Name}{method.GenericParameters}({method.ParameterNames}));");
}
writer.Write("if (results.Count > 0 && results.All(result => result.Equals(results[0])))");
using (writer.Scope) {
writer.Write("return results[0];");
}
writer.Write($"return default({method.ReturnType});");
}
}
writer.Write(string.Empty);
implementedMethods.Add($"{method.Name}({method.ParameterTypes})");
}
/// <summary>
/// Creates a Builder of the given generic type to implement the given interface.
/// Output is placed in the given fileName.
/// </summary>
private static void GenerateImplementation <TPatternBuilder>(Type type)
where TPatternBuilder : IPatternBuilder
{
var writer = new CSharpSourceWriter(numberOfSpacesToIndent: 4);
var builder = (TPatternBuilder)Activator.CreateInstance(typeof(TPatternBuilder), writer);
var fileName = builder.GetDesiredOutputFileName(type);
Console.WriteLine($"Generating {fileName} ...");
writer.Write($"// this file was created by AutoImplement");
writer.Write($"namespace {type.Namespace}");
using (writer.Scope) {
writer.Write($"public class {builder.ClassDeclaration(type)}");
using (writer.Scope) {
builder.AppendExtraMembers(type);
var allMembers = FindAllMembers(type);
foreach (var member in allMembers)
{
var metadata = new MemberMetadata(member, type.Namespace);
switch (member.MemberType)
{
case MemberTypes.Method: ImplementMethod(member, metadata, builder); break;
case MemberTypes.Event: ImplementEvent(member, metadata, builder); break;
case MemberTypes.Property: ImplementProperty(member, metadata, builder); break;
default:
// the only other options are Field, Type, NestedType, and Constructor
// for classes, any of these are possible, and all can be ignored.
break;
}
}
}
builder.BuildCompleted();
}
File.WriteAllText(fileName, writer.ToString());
}
/// <remarks>
/// Since Item properties in .net have parameters, the Item property has to be handled specially.
/// Instead of using a PropertyImplementation object, two separate delegates are exposed, named get_Item and set_Item.
/// The get and set of the Item property forward to these two public fields.
/// If no implementation is provided, get_Item will just return default.
/// </remarks>
public void AppendItemProperty(PropertyInfo info, MemberMetadata property)
{
// define the backing get/set_Item methods if this property hasn't been implemented yet
if (!implementedProperties.Contains(property.Name))
{
if (info.CanRead)
{
writer.Write($"public Func<{property.ParameterTypes}, {property.ReturnType}> get_Item = ({property.ParameterNames}) => default({property.ReturnType});" + Environment.NewLine);
}
if (info.CanWrite)
{
writer.Write($"public Action<{property.ParameterTypes}, {property.ReturnType}> set_Item = ({property.ParameterNames}, value) => {{}};" + Environment.NewLine);
}
implementedProperties.Add(property.Name);
}
// define the explicit interface implementation
// this may run multiple times if the same property is defined on multiple interfaces (example, IReadOnlyList and IList)
writer.Write($"{property.ReturnType} {property.DeclaringType}.this[{property.ParameterTypesAndNames}]");
using (writer.Scope) {
if (info.CanRead)
{
writer.Write("get");
using (writer.Scope) {
writer.Write($"return get_Item({property.ParameterNames});");
}
}
if (info.CanWrite)
{
writer.Write("set");
using (writer.Scope) {
writer.Write($"set_Item({property.ParameterNames}, value);");
}
}
}
}
public void AppendExtraMembers(Type type)
{
// add in constructors
var constructors = type.GetConstructors(BindingFlags.Instance | BindingFlags.NonPublic)
.Concat(type.GetConstructors(BindingFlags.Instance | BindingFlags.Public));
foreach (var constructor in constructors)
{
var metadata = new MemberMetadata(constructor, type.Namespace);
AppendConstructor(type, constructor, metadata);
}
implementedMethods.Clear();
// add in fields
var protectedFields = type.GetFields(BindingFlags.Instance | BindingFlags.NonPublic).Where(field => field.IsFamily || field.IsFamilyOrAssembly);
foreach (var field in protectedFields)
{
var metadata = new MemberMetadata(field, type.Namespace);
AppendField(type, field, metadata);
}
}
public void AppendItemProperty(PropertyInfo info, MemberMetadata metadata)
{
var methodInfo = info.GetMethod ?? info.SetMethod;
if (methodInfo.IsStatic || methodInfo.IsPrivate || methodInfo.IsAssembly || methodInfo.IsFamilyAndAssembly)
{
return;
}
if (!methodInfo.IsVirtual && !methodInfo.IsAbstract)
{
// the member is protected. Make a public version.
if (metadata.Access == "protected")
{
intermediateWriter.Write($"public new {metadata.ReturnType} this[{metadata.ParameterTypesAndNames}]");
using (intermediateWriter.Scope) {
if (info.CanRead)
{
intermediateWriter.Write($"get {{ return base[{metadata.ParameterNames}]; }}");
}
if (info.CanWrite)
{
intermediateWriter.Write($"set {{ base[{metadata.ParameterNames}] = value; }}");
}
}
}
return;
}
if (info.CanRead)
{
stubWriter.Write($"public new Func<{metadata.ParameterTypes}, {metadata.ReturnType}> get_Item;");
}
if (info.CanWrite)
{
stubWriter.Write($"public new Action<{metadata.ParameterTypes}, {metadata.ReturnType}> set_Item;");
}
if (methodInfo.IsVirtual && !methodInfo.IsAbstract)
{
if (info.CanRead)
{
intermediateWriter.Write($"public {metadata.ReturnType} Base_get_Item({metadata.ParameterTypesAndNames})");
using (intermediateWriter.Scope) {
intermediateWriter.Write($"return base[{metadata.ParameterNames}];");
}
}
if (info.CanWrite)
{
intermediateWriter.Write($"public void Base_set_Item({metadata.ParameterTypesAndNames}, {metadata.ReturnType} value)");
using (intermediateWriter.Scope) {
intermediateWriter.Write($"base[{metadata.ParameterNames}] = value;");
}
}
}
intermediateWriter.Write($"{metadata.Access} override {metadata.ReturnType} this[{metadata.ParameterTypesAndNames}]");
using (intermediateWriter.Scope) {
if (info.CanRead)
{
intermediateWriter.Write($"get {{ return (({stubTypeName})this).get_Item({metadata.ParameterNames}); }}");
}
if (info.CanWrite)
{
intermediateWriter.Write($"set {{ (({stubTypeName})this).set_Item({metadata.ParameterNames}, value); }}");
}
}
}
private void AppendToConstructorFromProperty(PropertyInfo info, MemberMetadata metadata, CSharpSourceWriter deferWriter)
{
var method = info.GetMethod ?? info.SetMethod;
if (method.IsAbstract && !method.IsAssembly && !method.IsFamilyAndAssembly)
{
if (info.Name == "Item" && info.GetIndexParameters().Length > 0)
{
// item property maps to two methods, get_Item and set_Item
// but since the property is abstract, we have no base implementation
// so just like methods, give no default values in the constructor (or defer construction call)
}
else
{
stubWriter.Write($"if ({metadata.Name} == null) {metadata.Name} = new PropertyImplementation<{metadata.ReturnType}>();");
deferWriter.Write($"stub.{metadata.Name} = new PropertyImplementation<{metadata.ReturnType}>();");
}
}
if (method.IsStatic || method.IsPrivate || !method.IsVirtual || method.IsAbstract || method.IsAssembly || method.IsFamilyAndAssembly)
{
return;
}
if (info.Name == "Item" && info.GetIndexParameters().Length > 0)
{
if (info.CanRead)
{
stubWriter.Write($"if (get_Item == null) get_Item = Base_get_Item;");
}
if (CanWrite(info))
{
stubWriter.Write($"if (set_Item == null) set_Item = Base_set_Item;");
}
if (info.CanRead)
{
deferWriter.Write($"stub.get_Item = stub.Base_get_Item;");
}
if (CanWrite(info))
{
deferWriter.Write($"stub.set_Item = stub.Base_set_Item;");
}
}
else
{
stubWriter.Write($"if ({metadata.Name} == null)");
using (stubWriter.Scope) {
stubWriter.Write($"{metadata.Name} = new PropertyImplementation<{metadata.ReturnType}>();");
if (info.CanRead)
{
stubWriter.Write($"{metadata.Name}.get = () => Base{metadata.Name};");
}
if (CanWrite(info))
{
stubWriter.Write($"{metadata.Name}.set = value => Base{metadata.Name} = value;");
}
}
deferWriter.Write($"stub.{metadata.Name} = new PropertyImplementation<{metadata.ReturnType}>();");
if (info.CanRead)
{
deferWriter.Write($"stub.{metadata.Name}.get = () => stub.Base{metadata.Name};");
}
if (CanWrite(info))
{
deferWriter.Write($"stub.{metadata.Name}.set = value => stub.Base{metadata.Name} = value;");
}
}
}
private static void ImplementEvent(MemberInfo info, MemberMetadata metadata, IPatternBuilder builder)
{
var eventInfo = (EventInfo)info;
builder.AppendEvent(eventInfo, metadata);
}
private void ImplementInterfaceMethod(MethodInfo info, string localImplementationName, MemberMetadata method)
{
var call = $"this.{localImplementationName}";
writer.Write($"{method.ReturnType} {method.DeclaringType}.{method.Name}({method.ParameterTypesAndNames})");
using (writer.Scope) {
writer.AssignDefaultValuesToOutParameters(info.DeclaringType.Namespace, info.GetParameters());
writer.Write($"if ({call} != null)");
using (writer.Scope) {
writer.Write($"{method.ReturnClause}{call}({method.ParameterNames});");
}
if (method.ReturnType != "void")
{
writer.Write("else");
using (writer.Scope) {
writer.Write($"return default({method.ReturnType});");
}
}
}
}