Support symbol kind for union properties

Author: mhegazy

src/compiler/checker.ts

@@ -92,7 +92,8 @@ module ts {
             getContextualType: getContextualType,
             getFullyQualifiedName: getFullyQualifiedName,
             getResolvedSignature: getResolvedSignature,
-            getEnumMemberValue: getEnumMemberValue
+            getEnumMemberValue: getEnumMemberValue,
+            getUnionTypesOfUnionProperty: getUnionTypesOfUnionProperty
         };
 
         var undefinedSymbol = createSymbol(SymbolFlags.Property | SymbolFlags.Transient, "undefined");
@@ -1750,6 +1751,10 @@ module ts {
             return links.type;
         }
 
+        function getUnionTypesOfUnionProperty(symbol: Symbol): Type[] {
+            return (symbol.flags & SymbolFlags.UnionProperty) ? getSymbolLinks(symbol).unionType.types : undefined;
+        }
+
         function getTypeOfSymbol(symbol: Symbol): Type {
             if (symbol.flags & (SymbolFlags.Variable | SymbolFlags.Property)) {
                 return getTypeOfVariableOrParameterOrProperty(symbol);
@@ -3583,7 +3588,8 @@ module ts {
         }
 
         function getBestCommonType(types: Type[], contextualType?: Type): Type {
-            return contextualType && isSupertypeOfEach(contextualType, types) ? contextualType : getUnionType(types);        }
+            return contextualType && isSupertypeOfEach(contextualType, types) ? contextualType : getUnionType(types);
+        }
 
         function isTypeOfObjectLiteral(type: Type): boolean {
             return (type.flags & TypeFlags.Anonymous) && type.symbol && (type.symbol.flags & SymbolFlags.ObjectLiteral) ? true : false;

src/compiler/types.ts

@@ -657,6 +657,8 @@ module ts {
         getContextualType(node: Node): Type;
         getResolvedSignature(node: CallExpression, candidatesOutArray?: Signature[]): Signature;
 
+        getUnionTypesOfUnionProperty(symbol: Symbol): Type[];
+
         // Returns the constant value of this enum member, or 'undefined' if the enum member has a 
         // computed value.
         getEnumMemberValue(node: EnumMember): number;

src/services/services.ts

@@ -2284,8 +2284,16 @@ module ts {
             }
         }
 
+        function getConcreteSymbol(symbol: Symbol): Symbol {
+            if (symbol.flags & SymbolFlags.UnionProperty) {
+                var types = typeInfoResolver.getUnionTypesOfUnionProperty(symbol);
+                symbol = typeInfoResolver.getPropertyOfType(types[0], symbol.name);
+            }
+            return typeInfoResolver.getRootSymbol(symbol);
+        }
+
         function getSymbolKind(symbol: Symbol): string {
-            var flags = typeInfoResolver.getRootSymbol(symbol).getFlags();
+            var flags = getConcreteSymbol(symbol).getFlags();
 
             if (flags & SymbolFlags.Module) return ScriptElementKind.moduleElement;
             if (flags & SymbolFlags.Class) return ScriptElementKind.classElement;
@@ -2344,6 +2352,7 @@ module ts {
         }
 
         function getSymbolModifiers(symbol: Symbol): string {
+            symbol = getConcreteSymbol(symbol);
             return symbol && symbol.declarations && symbol.declarations.length > 0
                 ? getNodeModifiers(symbol.declarations[0])
                 : ScriptElementKindModifier.none;

tests/cases/fourslash/completionEntryForUnionProperty.ts

@@ -0,0 +1,20 @@
+///<reference path="fourslash.ts" />
+
+////interface One {
+////    commonProperty: number;
+////    commonFunction(): number;
+////}
+////
+////interface Two {
+////    commonProperty: string
+////    commonFunction(): number;
+////}
+////
+////var x : One | Two;
+////
+////x./**/
+
+goTo.marker();
+verify.memberListContains("commonProperty", "string | number", undefined, undefined, "property");
+verify.memberListContains("commonFunction", "() => number", undefined, undefined, "method");
+verify.memberListCount(2);