private SyntaxNode CreateConditionalAccessExpression(
ISyntaxFactsService syntaxFacts, SyntaxGenerator generator,
SyntaxNode whenPart, SyntaxNode match, SyntaxNode currentConditional)
{
var memberAccess = match.Parent as TMemberAccessExpression;
if (memberAccess != null)
{
return(whenPart.ReplaceNode(memberAccess,
generator.ConditionalAccessExpression(
match,
generator.MemberBindingExpression(
syntaxFacts.GetNameOfMemberAccessExpression(memberAccess)))));
}
var elementAccess = match.Parent as TElementAccessExpression;
if (elementAccess != null)
{
return(whenPart.ReplaceNode(elementAccess,
generator.ConditionalAccessExpression(
match,
generator.ElementBindingExpression(
syntaxFacts.GetArgumentListOfElementAccessExpression(elementAccess)))));
}
return(currentConditional);
}
private static bool TryAnalyzeInvocationCondition(
SyntaxNodeAnalysisContext context,
ISyntaxFactsService syntaxFacts,
IMethodSymbol?referenceEqualsMethodOpt,
TInvocationExpression invocation,
[NotNullWhen(true)] out SyntaxNode?conditionPartToCheck,
out bool isEquals)
{
conditionPartToCheck = null;
isEquals = true;
var expression = syntaxFacts.GetExpressionOfInvocationExpression(invocation);
var nameNode = syntaxFacts.IsIdentifierName(expression)
? expression
: syntaxFacts.IsSimpleMemberAccessExpression(expression)
? syntaxFacts.GetNameOfMemberAccessExpression(expression)
: null;
if (!syntaxFacts.IsIdentifierName(nameNode))
{
return(false);
}
syntaxFacts.GetNameAndArityOfSimpleName(nameNode, out var name, out _);
if (!syntaxFacts.StringComparer.Equals(name, nameof(ReferenceEquals)))
{
return(false);
}
var arguments = syntaxFacts.GetArgumentsOfInvocationExpression(invocation);
if (arguments.Count != 2)
{
return(false);
}
var conditionLeft = syntaxFacts.GetExpressionOfArgument(arguments[0]);
var conditionRight = syntaxFacts.GetExpressionOfArgument(arguments[1]);
if (conditionLeft == null || conditionRight == null)
{
return(false);
}
conditionPartToCheck = GetConditionPartToCheck(syntaxFacts, conditionLeft, conditionRight);
if (conditionPartToCheck == null)
{
return(false);
}
var semanticModel = context.SemanticModel;
var cancellationToken = context.CancellationToken;
var symbol = semanticModel.GetSymbolInfo(invocation, cancellationToken).Symbol;
return(referenceEqualsMethodOpt != null && referenceEqualsMethodOpt.Equals(symbol));
}
private bool IsValidFormatMethod(ISyntaxFactsService syntaxFacts, SyntaxNode expression)
{
// When calling string.Format(...), the expression will be MemberAccessExpressionSyntax
if (syntaxFacts.IsSimpleMemberAccessExpression(expression))
{
var nameOfMemberAccessExpression = syntaxFacts.GetNameOfMemberAccessExpression(expression);
return(!syntaxFacts.IsGenericName(nameOfMemberAccessExpression) &&
syntaxFacts.GetIdentifierOfSimpleName(nameOfMemberAccessExpression).ValueText
== (nameof(string.Format)));
}
// When using static System.String and calling Format(...), the expression will be
// IdentifierNameSyntax
if (syntaxFacts.IsIdentifierName(expression))
{
return(syntaxFacts.GetIdentifierOfSimpleName(expression).ValueText
== (nameof(string.Format)));
}
return(false);
}
internal List <Match <TAssignmentStatementSyntax, TMemberAccessExpressionSyntax, TExpressionSyntax> > Analyze()
{
if (_syntaxFacts.GetObjectCreationInitializer(_objectCreationExpression) != null)
{
// Don't bother if this already has an initializer.
return(null);
}
_containingStatement = _objectCreationExpression.FirstAncestorOrSelf <TStatementSyntax>();
if (_containingStatement == null)
{
return(null);
}
if (!TryInitializeVariableDeclarationCase() &&
!TryInitializeAssignmentCase())
{
return(null);
}
var containingBlock = _containingStatement.Parent;
var foundStatement = false;
List <Match <TAssignmentStatementSyntax, TMemberAccessExpressionSyntax, TExpressionSyntax> > matches = null;
HashSet <string> seenNames = null;
foreach (var child in containingBlock.ChildNodesAndTokens())
{
if (!foundStatement)
{
if (child == _containingStatement)
{
foundStatement = true;
}
continue;
}
if (child.IsToken)
{
break;
}
var statement = child.AsNode() as TAssignmentStatementSyntax;
if (statement == null)
{
break;
}
if (!_syntaxFacts.IsSimpleAssignmentStatement(statement))
{
break;
}
SyntaxNode left, right;
_syntaxFacts.GetPartsOfAssignmentStatement(statement, out left, out right);
var rightExpression = right as TExpressionSyntax;
var leftMemberAccess = left as TMemberAccessExpressionSyntax;
if (!_syntaxFacts.IsSimpleMemberAccessExpression(leftMemberAccess))
{
break;
}
var expression = (TExpressionSyntax)_syntaxFacts.GetExpressionOfMemberAccessExpression(leftMemberAccess);
if (!ValuePatternMatches(expression))
{
break;
}
// found a match!
seenNames = seenNames ?? new HashSet <string>();
matches = matches ?? new List <Match <TAssignmentStatementSyntax, TMemberAccessExpressionSyntax, TExpressionSyntax> >();
// If we see an assignment to the same property/field, we can't convert it
// to an initializer.
var name = _syntaxFacts.GetNameOfMemberAccessExpression(leftMemberAccess);
var identifier = _syntaxFacts.GetIdentifierOfSimpleName(name);
if (!seenNames.Add(identifier.ValueText))
{
break;
}
matches.Add(new Match <TAssignmentStatementSyntax, TMemberAccessExpressionSyntax, TExpressionSyntax>(
statement, leftMemberAccess, rightExpression));
}
return(matches);
}
internal ImmutableArray <Match <TExpressionSyntax, TStatementSyntax, TMemberAccessExpressionSyntax, TAssignmentStatementSyntax> >?Analyze()
{
if (_syntaxFacts.GetObjectCreationInitializer(_objectCreationExpression) != null)
{
// Don't bother if this already has an initializer.
return(null);
}
_containingStatement = _objectCreationExpression.FirstAncestorOrSelf <TStatementSyntax>();
if (_containingStatement == null)
{
return(null);
}
if (!TryInitializeVariableDeclarationCase() &&
!TryInitializeAssignmentCase())
{
return(null);
}
var containingBlock = _containingStatement.Parent;
var foundStatement = false;
var matches = ArrayBuilder <Match <TExpressionSyntax, TStatementSyntax, TMemberAccessExpressionSyntax, TAssignmentStatementSyntax> > .GetInstance();
HashSet <string> seenNames = null;
foreach (var child in containingBlock.ChildNodesAndTokens())
{
if (!foundStatement)
{
if (child == _containingStatement)
{
foundStatement = true;
continue;
}
continue;
}
if (child.IsToken)
{
break;
}
var statement = child.AsNode() as TAssignmentStatementSyntax;
if (statement == null)
{
break;
}
if (!_syntaxFacts.IsSimpleAssignmentStatement(statement))
{
break;
}
_syntaxFacts.GetPartsOfAssignmentStatement(
statement, out var left, out var right);
var rightExpression = right as TExpressionSyntax;
var leftMemberAccess = left as TMemberAccessExpressionSyntax;
if (!_syntaxFacts.IsSimpleMemberAccessExpression(leftMemberAccess))
{
break;
}
var expression = (TExpressionSyntax)_syntaxFacts.GetExpressionOfMemberAccessExpression(leftMemberAccess);
if (!ValuePatternMatches(expression))
{
break;
}
// Don't offer this fix if the value we're initializing is itself referenced
// on the RHS of the assignment. For example:
//
// var v = new X();
// v.Prop = v.Prop.WithSomething();
//
// Or with
//
// v = new X();
// v.Prop = v.Prop.WithSomething();
//
// In the first case, 'v' is being initialized, and so will not be available
// in the object initializer we create.
//
// In the second case we'd change semantics because we'd access the old value
// before the new value got written.
if (ExpressionContainsValuePattern(rightExpression))
{
break;
}
// If we have code like "x.v = .Length.ToString()"
// then we don't want to change this into:
//
// var x = new Whatever() With { .v = .Length.ToString() }
//
// The problem here is that .Length will change it's meaning to now refer to the
// object that we're creating in our object-creation expression.
if (ImplicitMemberAccessWouldBeAffected(rightExpression))
{
break;
}
// found a match!
seenNames = seenNames ?? new HashSet <string>();
// If we see an assignment to the same property/field, we can't convert it
// to an initializer.
var name = _syntaxFacts.GetNameOfMemberAccessExpression(leftMemberAccess);
var identifier = _syntaxFacts.GetIdentifierOfSimpleName(name);
if (!seenNames.Add(identifier.ValueText))
{
break;
}
matches.Add(new Match <TExpressionSyntax, TStatementSyntax, TMemberAccessExpressionSyntax, TAssignmentStatementSyntax>(
statement, leftMemberAccess, rightExpression));
}
return(matches.ToImmutableAndFree());
}
private static void RemoveAwaitFromCallerIfPresent(
SyntaxEditor editor, ISyntaxFactsService syntaxFacts,
SyntaxNode root, ReferenceLocation referenceLocation,
CancellationToken cancellationToken)
{
if (referenceLocation.IsImplicit)
{
return;
}
var location = referenceLocation.Location;
var token = location.FindToken(cancellationToken);
var nameNode = token.Parent;
if (nameNode == null)
{
return;
}
// Look for the following forms:
// await M(...)
// await <expr>.M(...)
// await M(...).ConfigureAwait(...)
// await <expr>.M(...).ConfigureAwait(...)
var expressionNode = nameNode;
if (syntaxFacts.IsNameOfMemberAccessExpression(nameNode))
{
expressionNode = nameNode.Parent;
}
if (!syntaxFacts.IsExpressionOfInvocationExpression(expressionNode))
{
return;
}
// We now either have M(...) or <expr>.M(...)
var invocationExpression = expressionNode.Parent;
Debug.Assert(syntaxFacts.IsInvocationExpression(invocationExpression));
if (syntaxFacts.IsExpressionOfAwaitExpression(invocationExpression))
{
// Handle the case where we're directly awaited.
var awaitExpression = invocationExpression.Parent;
editor.ReplaceNode(awaitExpression, (currentAwaitExpression, generator) =>
syntaxFacts.GetExpressionOfAwaitExpression(currentAwaitExpression)
.WithTriviaFrom(currentAwaitExpression));
}
else if (syntaxFacts.IsExpressionOfMemberAccessExpression(invocationExpression))
{
// Check for the .ConfigureAwait case.
var parentMemberAccessExpression = invocationExpression.Parent;
var parentMemberAccessExpressionNameNode = syntaxFacts.GetNameOfMemberAccessExpression(
parentMemberAccessExpression);
var parentMemberAccessExpressionName = syntaxFacts.GetIdentifierOfSimpleName(parentMemberAccessExpressionNameNode).ValueText;
if (parentMemberAccessExpressionName == nameof(Task.ConfigureAwait))
{
var parentExpression = parentMemberAccessExpression.Parent;
if (syntaxFacts.IsExpressionOfAwaitExpression(parentExpression))
{
var awaitExpression = parentExpression.Parent;
editor.ReplaceNode(awaitExpression, (currentAwaitExpression, generator) =>
{
var currentConfigureAwaitInvocation = syntaxFacts.GetExpressionOfAwaitExpression(currentAwaitExpression);
var currentMemberAccess = syntaxFacts.GetExpressionOfInvocationExpression(currentConfigureAwaitInvocation);
var currentInvocationExpression = syntaxFacts.GetExpressionOfMemberAccessExpression(currentMemberAccess);
return(currentInvocationExpression.WithTriviaFrom(currentAwaitExpression));
});
}
}
}
}
private void RemoveAwaitFromCallerIfPresent(
SyntaxEditor editor, ISyntaxFactsService syntaxFacts,
SyntaxNode root, ReferenceLocation referenceLocation,
CancellationToken cancellationToken)
{
if (referenceLocation.IsImplicit)
{
return;
}
var location = referenceLocation.Location;
var token = location.FindToken(cancellationToken);
var nameNode = token.Parent;
if (nameNode == null)
{
return;
}
// Look for the following forms:
// await M(...)
// await <expr>.M(...)
// await M(...).ConfigureAwait(...)
// await <expr>.M(...).ConfigureAwait(...)
var expressionNode = nameNode;
if (syntaxFacts.IsNameOfMemberAccessExpression(nameNode))
{
expressionNode = nameNode.Parent;
}
if (!syntaxFacts.IsExpressionOfInvocationExpression(expressionNode))
{
return;
}
// We now either have M(...) or <expr>.M(...)
var invocationExpression = expressionNode.Parent;
Debug.Assert(syntaxFacts.IsInvocationExpression(invocationExpression));
if (syntaxFacts.IsExpressionOfAwaitExpression(invocationExpression))
{
// Handle the case where we're directly awaited.
var awaitExpression = invocationExpression.Parent;
editor.ReplaceNode(awaitExpression, (currentAwaitExpression, generator) =>
syntaxFacts.GetExpressionOfAwaitExpression(currentAwaitExpression)
.WithTriviaFrom(currentAwaitExpression));
}
else if (syntaxFacts.IsExpressionOfMemberAccessExpression(invocationExpression))
{
// Check for the .ConfigureAwait case.
var parentMemberAccessExpression = invocationExpression.Parent;
var parentMemberAccessExpressionNameNode = syntaxFacts.GetNameOfMemberAccessExpression(
parentMemberAccessExpression);
var parentMemberAccessExpressionName = syntaxFacts.GetIdentifierOfSimpleName(parentMemberAccessExpressionNameNode).ValueText;
if (parentMemberAccessExpressionName == nameof(Task.ConfigureAwait))
{
var parentExpression = parentMemberAccessExpression.Parent;
if (syntaxFacts.IsExpressionOfAwaitExpression(parentExpression))
{
var awaitExpression = parentExpression.Parent;
editor.ReplaceNode(awaitExpression, (currentAwaitExpression, generator) =>
{
var currentConfigureAwaitInvocation = syntaxFacts.GetExpressionOfAwaitExpression(currentAwaitExpression);
var currentMemberAccess = syntaxFacts.GetExpressionOfInvocationExpression(currentConfigureAwaitInvocation);
var currentInvocationExpression = syntaxFacts.GetExpressionOfMemberAccessExpression(currentMemberAccess);
return currentInvocationExpression.WithTriviaFrom(currentAwaitExpression);
});
}
}
}
}
