Decorate more type names

And guard from null exception in definition handler.

Author: andyleejordan

src/PowerShellEditorServices/Services/Symbols/ReferenceTable.cs

@@ -52,7 +52,7 @@ internal IEnumerable<SymbolReference> TryGetReferences(SymbolReference? symbol)
     }
 
     internal SymbolReference? TryGetSymbolAtPosition(int line, int column) => GetAllReferences()
-        .FirstOrDefault((i) => i.NameRegion.ContainsPosition(line, column));
+        .FirstOrDefault(i => i.NameRegion.ContainsPosition(line, column));
 
     internal IEnumerable<SymbolReference> GetAllReferences()
     {

src/PowerShellEditorServices/Services/Symbols/Visitors/SymbolVisitor.cs

@@ -89,8 +89,8 @@ public override AstVisitAction VisitVariableExpression(VariableExpressionAst var
         // the same function definition.
         return _action(new SymbolReference(
             SymbolType.Variable,
-            $"${variableExpressionAst.VariablePath.UserPath}",
-            $"${variableExpressionAst.VariablePath.UserPath}",
+            "$" + variableExpressionAst.VariablePath.UserPath,
+            "$" + variableExpressionAst.VariablePath.UserPath,
             variableExpressionAst.Extent,
             variableExpressionAst.Extent, // TODO: Maybe parent?
             _file,
@@ -119,7 +119,7 @@ public override AstVisitAction VisitTypeExpression(TypeExpressionAst typeExpress
         return _action(new SymbolReference(
             SymbolType.Type,
             typeExpressionAst.TypeName.Name,
-            typeExpressionAst.TypeName.Name,
+            "(type) " + typeExpressionAst.TypeName.Name,
             typeExpressionAst.Extent,
             typeExpressionAst.Extent,
             _file,
@@ -131,7 +131,7 @@ public override AstVisitAction VisitTypeConstraint(TypeConstraintAst typeConstra
         return _action(new SymbolReference(
             SymbolType.Type,
             typeConstraintAst.TypeName.Name,
-            "[" + typeConstraintAst.TypeName.Name + "]",
+            "(type) " + typeConstraintAst.TypeName.Name,
             typeConstraintAst.Extent,
             typeConstraintAst.Extent,
             _file,
@@ -184,12 +184,13 @@ public override AstVisitAction VisitMemberExpression(MemberExpressionAst memberE
             return AstVisitAction.Continue;
         }
 
+        // TODO: It's too bad we can't get the member's real symbol and reuse its display string.
         return _action(new SymbolReference(
             SymbolType.Property,
 #pragma warning disable CS8604 // Possible null reference argument.
             memberName,
 #pragma warning restore CS8604
-            memberExpressionAst.Member.Extent.Text,
+            "(method) " + memberName,
             memberExpressionAst.Member.Extent,
             memberExpressionAst.Extent,
             _file,
@@ -209,7 +210,7 @@ public override AstVisitAction VisitInvokeMemberExpression(InvokeMemberExpressio
 #pragma warning disable CS8604 // Possible null reference argument.
             memberName,
 #pragma warning restore CS8604
-            methodCallAst.Member.Extent.Text,
+            "(method) " + memberName,
             methodCallAst.Member.Extent,
             methodCallAst.Extent,
             _file,

src/PowerShellEditorServices/Services/TextDocument/Handlers/DefinitionHandler.cs

@@ -43,6 +43,11 @@ public override async Task<LocationOrLocationLinks> Handle(DefinitionParams requ
                     request.Position.Line + 1,
                     request.Position.Character + 1);
 
+            if (foundSymbol is null)
+            {
+                return new LocationOrLocationLinks();
+            }
+
             // Short-circuit if we're already on the definition.
             if (foundSymbol.IsDeclaration)
             {
@@ -57,19 +62,16 @@ public override async Task<LocationOrLocationLinks> Handle(DefinitionParams requ
             }
 
             List<LocationOrLocationLink> definitionLocations = new();
-            if (foundSymbol is not null)
+            foreach (SymbolReference foundDefinition in await _symbolsService.GetDefinitionOfSymbolAsync(
+                scriptFile, foundSymbol, cancellationToken).ConfigureAwait(false))
             {
-                foreach (SymbolReference foundDefinition in await _symbolsService.GetDefinitionOfSymbolAsync(
-                    scriptFile, foundSymbol, cancellationToken).ConfigureAwait(false))
-                {
-                    definitionLocations.Add(
-                        new LocationOrLocationLink(
-                            new Location
-                            {
-                                Uri = DocumentUri.From(foundDefinition.FilePath),
-                                Range = foundDefinition.NameRegion.ToRange()
-                            }));
-                }
+                definitionLocations.Add(
+                    new LocationOrLocationLink(
+                        new Location
+                        {
+                            Uri = DocumentUri.From(foundDefinition.FilePath),
+                            Range = foundDefinition.NameRegion.ToRange()
+                        }));
             }
 
             return new LocationOrLocationLinks(definitionLocations);