Add support for union properties in goto def

src/services/services.ts

@@ -2563,6 +2563,25 @@ module ts {
                 return false;
             }
 
+            function getDefinitionFromSymbol(symbol: Symbol, location: Node, result: DefinitionInfo[]): void {
+                var declarations = symbol.getDeclarations();
+                if (declarations) {
+                    var symbolName = typeInfoResolver.symbolToString(symbol, location);
+                    var symbolKind = getSymbolKind(symbol);
+                    var containerSymbol = symbol.parent;
+                    var containerName = containerSymbol ? typeInfoResolver.symbolToString(containerSymbol, location) : "";
+                    var containerKind = containerSymbol ? getSymbolKind(symbol) : "";
+
+                    if (!tryAddConstructSignature(symbol, location, symbolKind, symbolName, containerName, result) &&
+                        !tryAddCallSignature(symbol, location, symbolKind, symbolName, containerName, result)) {
+                        // Just add all the declarations. 
+                        forEach(declarations, declaration => {
+                            result.push(getDefinitionInfo(declaration, symbolKind, symbolName, containerName));
+                        });
+                    }
+                }
+            }
+
             synchronizeHostData();
 
             filename = TypeScript.switchToForwardSlashes(filename);
@@ -2601,26 +2620,20 @@ module ts {
 
             // Could not find a symbol e.g. node is string or number keyword,
             // or the symbol was an internal symbol and does not have a declaration e.g. undefined symbol
-            if (!symbol || !(symbol.getDeclarations())) {
+            if (!symbol) {
                 return undefined;
             }
 
             var result: DefinitionInfo[] = [];
 
-            var declarations = symbol.getDeclarations();
-            var symbolName = typeInfoResolver.symbolToString(symbol, node);
-            var symbolKind = getSymbolKind(symbol);
-            var containerSymbol = symbol.parent;
-            var containerName = containerSymbol ? typeInfoResolver.symbolToString(containerSymbol, node) : "";
-            var containerKind = containerSymbol ? getSymbolKind(symbol) : "";
-
-            if (!tryAddConstructSignature(symbol, node, symbolKind, symbolName, containerName, result) &&
-                !tryAddCallSignature(symbol, node, symbolKind, symbolName, containerName, result)) {
-                // Just add all the declarations. 
-                forEach(declarations, declaration => {
-                    result.push(getDefinitionInfo(declaration, symbolKind, symbolName, containerName));
+            if (symbol.flags & SymbolFlags.UnionProperty) {
+                forEach(typeInfoResolver.getUnionTypesOfUnionProperty(symbol), t => {
+                    getDefinitionFromSymbol(typeInfoResolver.getPropertyOfType(t, symbol.name), node, result);
                 });
             }
+            else {
+                getDefinitionFromSymbol(symbol, node, result);
+            }
 
             return result;
         }

tests/cases/fourslash/goToDefinitionUnionTypeProperty.ts

@@ -0,0 +1,24 @@
+/// <reference path='fourslash.ts' />
+
+////interface One {
+////    /*propertyDefinition1*/commonProperty: number;
+////    commonFunction(): number;
+////}
+////
+////interface Two {
+////    /*propertyDefinition2*/commonProperty: string
+////    commonFunction(): number;
+////}
+////
+////var x : One | Two;
+////
+////x./*propertyReference*/commonProperty;
+////x./*3*/commonFunction;
+
+goTo.marker("propertyReference");
+goTo.definition(0);
+verify.caretAtMarker("propertyDefinition1");
+
+goTo.marker("propertyReference");
+goTo.definition(1);
+verify.caretAtMarker("propertyDefinition2");

tests/cases/fourslash/goToDefinitionUnionTypeProperty2.ts

@@ -0,0 +1,25 @@
+/// <reference path='fourslash.ts' />
+////interface HasAOrB {
+////    /*propertyDefinition1*/a: string;
+////    b: string;
+////}
+////
+////interface One {
+////    common: { /*propertyDefinition2*/a : number; };
+////}
+////
+////interface Two {
+////    common: HasAOrB;
+////}
+////
+////var x : One | Two;
+////
+////x.common./*propertyReference*/a;
+
+goTo.marker("propertyReference");
+goTo.definition(0);
+verify.caretAtMarker("propertyDefinition1");
+
+goTo.marker("propertyReference");
+goTo.definition(1);
+verify.caretAtMarker("propertyDefinition2");