From db37cea0b6d3235ec9db63391e5e78f64627f560 Mon Sep 17 00:00:00 2001
From: Ryan Cavanaugh <RyanCavanaugh@users.noreply.github.com>
Date: Thu, 10 Aug 2017 16:38:24 -0700
Subject: [PATCH] Use the function stack!

---
 src/services/refactors/extractMethod.ts | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/src/services/refactors/extractMethod.ts b/src/services/refactors/extractMethod.ts
index 893cc875963..93a7c2e3410 100644
--- a/src/services/refactors/extractMethod.ts
+++ b/src/services/refactors/extractMethod.ts
@@ -890,7 +890,6 @@ namespace ts.refactor.extractMethod {
             errorsPerScope.push([]);
         }
         const seenUsages = createMap<Usage>();
-        let valueUsage = Usage.Read;
         const target = isReadonlyArray(targetRange.range) ? createBlock(<Statement[]>targetRange.range) : targetRange.range;
         const containingLexicalScopeOfExtraction = isBlockScope(scopes[0], scopes[0].parent) ? scopes[0] : getEnclosingBlockScopeContainer(scopes[0]);
 
@@ -926,31 +925,22 @@ namespace ts.refactor.extractMethod {
 
         return { target, usagesPerScope, errorsPerScope };
 
-        function collectUsages(node: Node) {
+        function collectUsages(node: Node, valueUsage = Usage.Read) {
             if (isDeclaration(node) && node.symbol) {
                 visibleDeclarationsInExtractedRange.push(node.symbol);
             }
 
             if (isAssignmentExpression(node)) {
-                const savedValueUsage = valueUsage;
                 // use 'write' as default usage for values
-                valueUsage = Usage.Write;
-                collectUsages(node.left);
-                valueUsage = savedValueUsage;
+                collectUsages(node.left, Usage.Write);
                 collectUsages(node.right);
             }
             else if (isUnaryExpressionWithWrite(node)) {
-                const savedValueUsage = valueUsage;
-                valueUsage = Usage.Write;
-                collectUsages(node.operand);
-                valueUsage = savedValueUsage;
+                collectUsages(node.operand, Usage.Write);
             }
             else if (isPropertyAccessExpression(node) || isElementAccessExpression(node)) {
-                const savedValueUsage = valueUsage;
                 // use 'write' as default usage for values
-                valueUsage = Usage.Read;
                 forEachChild(node, collectUsages);
-                valueUsage = savedValueUsage;
             }
             else if (isIdentifier(node)) {
                 if (!node.parent) {