Modify flow loop cache key to include all inputs

Author: weswigham

src/compiler/checker.ts

@@ -15418,21 +15418,21 @@ namespace ts {
         // The result is undefined if the reference isn't a dotted name. We prefix nodes
         // occurring in an apparent type position with '@' because the control flow type
         // of such nodes may be based on the apparent type instead of the declared type.
-        function getFlowCacheKey(node: Node): string | undefined {
+        function getFlowCacheKey(node: Node, declaredType: Type, initialType: Type, flowContainer: Node | undefined): string | undefined {
             switch (node.kind) {
                 case SyntaxKind.Identifier:
                     const symbol = getResolvedSymbol(<Identifier>node);
-                    return symbol !== unknownSymbol ? (isConstraintPosition(node) ? "@" : "") + getSymbolId(symbol) : undefined;
+                    return symbol !== unknownSymbol ? `${flowContainer ? getNodeId(flowContainer) : "-1"}|${getTypeId(declaredType)}|${getTypeId(initialType)}|${isConstraintPosition(node) ? "@" : ""}${getSymbolId(symbol)}` : undefined;
                 case SyntaxKind.ThisKeyword:
                     return "0";
                 case SyntaxKind.NonNullExpression:
                 case SyntaxKind.ParenthesizedExpression:
-                    return getFlowCacheKey((<NonNullExpression | ParenthesizedExpression>node).expression);
+                    return getFlowCacheKey((<NonNullExpression | ParenthesizedExpression>node).expression, declaredType, initialType, flowContainer);
                 case SyntaxKind.PropertyAccessExpression:
                 case SyntaxKind.ElementAccessExpression:
                     const propName = getAccessedPropertyName(<AccessExpression>node);
                     if (propName !== undefined) {
-                        const key = getFlowCacheKey((<AccessExpression>node).expression);
+                        const key = getFlowCacheKey((<AccessExpression>node).expression, declaredType, initialType, flowContainer);
                         return key && key + "." + propName;
                     }
             }
@@ -16367,7 +16367,7 @@ namespace ts {
                 const id = getFlowNodeId(flow);
                 const cache = flowLoopCaches[id] || (flowLoopCaches[id] = createMap<Type>());
                 if (!key) {
-                    key = getFlowCacheKey(reference);
+                    key = getFlowCacheKey(reference, declaredType, initialType, flowContainer);
                     // No cache key is generated when binding patterns are in unnarrowable situations
                     if (!key) {
                         return declaredType;