private static bool UsesValueAndMember(IfStatementSyntax ifStatement, SemanticModel semanticModel, CancellationToken cancellationToken, IParameterSymbol value, ISymbol member)
{
var usesValue = false;
var usesMember = false;
using (var pooledIdentifierNames = IdentifierNameWalker.Create(ifStatement.Condition))
{
foreach (var identifierName in pooledIdentifierNames.Item.IdentifierNames)
{
var symbol = semanticModel.GetSymbolSafe(identifierName, cancellationToken);
if (symbol == null)
{
continue;
}
if (symbol.Equals(value))
{
usesValue = true;
}
if (symbol.Equals(member))
{
usesMember = true;
}
}
}
return(usesMember && usesValue);
}
/// <inheritdoc/>
public override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
var syntaxRoot = await context.Document.GetSyntaxRootAsync(context.CancellationToken)
.ConfigureAwait(false);
var semanticModel = await context.Document.GetSemanticModelAsync(context.CancellationToken).ConfigureAwait(false);
foreach (var diagnostic in context.Diagnostics)
{
var token = syntaxRoot.FindToken(diagnostic.Location.SourceSpan.Start);
if (string.IsNullOrEmpty(token.ValueText) ||
token.IsMissing)
{
continue;
}
var ctor = syntaxRoot.FindNode(diagnostic.Location.SourceSpan).FirstAncestorOrSelf <ConstructorDeclarationSyntax>();
var invocation = syntaxRoot.FindNode(diagnostic.Location.SourceSpan).FirstAncestorOrSelf <InvocationExpressionSyntax>();
if (ctor != null &&
invocation != null &&
invocation.Expression is MemberAccessExpressionSyntax memberAccess)
{
var condition = memberAccess.Expression;
var symbol = semanticModel.GetSymbolSafe(condition, context.CancellationToken);
if (symbol is IParameterSymbol parameter)
{
using (var pooled = IdentifierNameWalker.Create(ctor))
{
foreach (var name in pooled.Item.IdentifierNames)
{
if (name.Identifier.ValueText == parameter.Name)
{
if (!condition.Contains(name))
{
return;
}
}
}
}
if (ctor.ParameterList.Parameters.TryGetFirst(p => p.Identifier.ValueText == parameter.Name, out ParameterSyntax parameterSyntax))
{
context.RegisterCodeFix(
CodeAction.Create(
"Inject negated.",
cancellationToken => ApplyInjectNegatedFixAsync(cancellationToken, context, parameterSyntax, invocation),
nameof(InjectNegatedCodeFix)),
diagnostic);
continue;
}
}
}
}
}
/// <inheritdoc/>
public override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
var syntaxRoot = await context.Document.GetSyntaxRootAsync(context.CancellationToken)
.ConfigureAwait(false);
foreach (var diagnostic in context.Diagnostics)
{
var token = syntaxRoot.FindToken(diagnostic.Location.SourceSpan.Start);
if (string.IsNullOrEmpty(token.ValueText) ||
token.IsMissing)
{
continue;
}
var assignment = syntaxRoot.FindNode(diagnostic.Location.SourceSpan)
.FirstAncestorOrSelf <AssignmentExpressionSyntax>();
if (assignment == null ||
assignment.Left == null ||
assignment.Right == null)
{
continue;
}
if (assignment.Right is ParenthesizedLambdaExpressionSyntax lambda &&
lambda.Body != null)
{
using (var pooled = IdentifierNameWalker.Create(lambda.Body))
{
var usesArg = false;
foreach (var name in pooled.Item.IdentifierNames)
{
if (name.Identifier.ValueText == lambda.ParameterList.Parameters[0]
.Identifier.ValueText)
{
return;
}
if (name.Identifier.ValueText == lambda.ParameterList.Parameters[1]
.Identifier.ValueText)
{
usesArg = true;
}
}
context.RegisterCodeFix(
CodeAction.Create(
"Observe.Event",
cancellationToken => ApplyObserveEventLamdaFixAsync(
cancellationToken, context, assignment, usesArg),
nameof(EventSubscriptionToObserveFix)),
diagnostic);
}
}
if (assignment.Right is MemberAccessExpressionSyntax memberAccess)
{
var semanticModel = await context.Document.GetSemanticModelAsync(context.CancellationToken).ConfigureAwait(false);
if (semanticModel.GetSymbolSafe(memberAccess, context.CancellationToken) is IMethodSymbol method &&
method.DeclaredAccessibility == Accessibility.Private &&
method.DeclaringSyntaxReferences.Length == 1)
{
var methodDeclaration = (MethodDeclarationSyntax)method.DeclaringSyntaxReferences[0].GetSyntax(context.CancellationToken);
context.RegisterCodeFix(
CodeAction.Create(
"Observe.Event",
cancellationToken => ApplyObserveEventMethodFixAsync(cancellationToken, context, assignment, methodDeclaration),
nameof(EventSubscriptionToObserveFix)),
diagnostic);
}
}
}
}
private static async Task <Document> ApplyObserveEventMethodFixAsync(
CancellationToken cancellationToken,
CodeFixContext context,
AssignmentExpressionSyntax assignment,
MethodDeclarationSyntax methodDeclaration)
{
var usesArg = false;
if (methodDeclaration.ParameterList.Parameters.Any())
{
using (var pooled = IdentifierNameWalker.Create((SyntaxNode)methodDeclaration.Body ?? methodDeclaration.ExpressionBody))
{
foreach (var name in pooled.Item.IdentifierNames)
{
if (name.Identifier.ValueText == methodDeclaration.ParameterList.Parameters[0].Identifier.ValueText)
{
if (methodDeclaration.ParameterList.Parameters.Count == 1)
{
usesArg = true;
continue;
}
return(context.Document);
}
if (methodDeclaration.ParameterList.Parameters.Count == 2 &&
name.Identifier.ValueText == methodDeclaration.ParameterList.Parameters[1]
.Identifier.ValueText)
{
usesArg = true;
}
}
}
}
var editor = await DocumentEditor.CreateAsync(context.Document, cancellationToken)
.ConfigureAwait(false);
var eventSymbol = (IEventSymbol)editor.SemanticModel.GetSymbolSafe(assignment.Left, cancellationToken);
var observeSubscribe = GetObservableFromEventString(eventSymbol)
.Replace("HANDLERTYPE", eventSymbol.Type.ToDisplayString())
.Replace("ARGTYPE", ArgType(eventSymbol))
.Replace("LEFT", assignment.Left.ToString())
.Replace("LAMBDA", Lambda(methodDeclaration, usesArg));
editor.ReplaceNode(
assignment,
SyntaxFactory.ParseExpression(observeSubscribe)
.WithLeadingTrivia(assignment.GetLeadingTrivia())
.WithAdditionalAnnotations(Simplifier.Annotation));
if (methodDeclaration.ParameterList.Parameters.Count == 2)
{
editor.RemoveNode(methodDeclaration.ParameterList.Parameters[0]);
}
if (!usesArg &&
methodDeclaration.ParameterList.Parameters.Any())
{
editor.RemoveNode(methodDeclaration.ParameterList.Parameters.Last());
}
return(editor.GetChangedDocument());
}
private static void HandleAssignment(SyntaxNodeAnalysisContext context)
{
var assignment = (AssignmentExpressionSyntax)context.Node;
if (assignment?.IsMissing != false ||
assignment.FirstAncestorOrSelf <ConstructorDeclarationSyntax>() != null ||
assignment.FirstAncestorOrSelf <InitializerExpressionSyntax>() != null)
{
return;
}
var block = assignment.FirstAncestorOrSelf <BlockSyntax>();
if (block == null)
{
return;
}
var typeDeclaration = assignment.FirstAncestorOrSelf <TypeDeclarationSyntax>();
var typeSymbol = context.SemanticModel.GetDeclaredSymbolSafe(typeDeclaration, context.CancellationToken);
if (!typeSymbol.Is(KnownSymbol.INotifyPropertyChanged))
{
return;
}
var field = context.SemanticModel.GetSymbolSafe(assignment.Left, context.CancellationToken) as IFieldSymbol;
if (field == null || !typeSymbol.Equals(field.ContainingType))
{
return;
}
foreach (var member in typeDeclaration.Members)
{
var propertyDeclaration = member as PropertyDeclarationSyntax;
if (propertyDeclaration == null)
{
continue;
}
var property = context.SemanticModel.GetDeclaredSymbolSafe(propertyDeclaration, context.CancellationToken);
var getter = Getter(propertyDeclaration);
if (getter == null || property == null || property.DeclaredAccessibility != Accessibility.Public)
{
continue;
}
using (var pooled = IdentifierNameWalker.Create(getter))
{
foreach (var identifierName in pooled.Item.IdentifierNames)
{
var component = context.SemanticModel.GetSymbolSafe(identifierName, context.CancellationToken);
var componentField = component as IFieldSymbol;
if (componentField == null)
{
var propertySymbol = component as IPropertySymbol;
if (propertySymbol == null)
{
continue;
}
if (!Property.TryGetBackingField(propertySymbol, context.SemanticModel, context.CancellationToken, out componentField))
{
continue;
}
}
if (!field.Equals(componentField))
{
continue;
}
if (PropertyChanged.InvokesPropertyChangedFor(assignment, property, context.SemanticModel, context.CancellationToken) == PropertyChanged.InvokesPropertyChanged.No)
{
var properties = ImmutableDictionary.CreateRange(new[] { new KeyValuePair <string, string>(PropertyNameKey, property.Name), });
context.ReportDiagnostic(Diagnostic.Create(Descriptor, assignment.GetLocation(), properties, property.Name));
}
}
}
}
}