From 52b956f697ffee0a0faa54f4793c96e395a526f3 Mon Sep 17 00:00:00 2001
From: Nater Jorde <nater@iamnater.com>
Date: Sun, 24 Mar 2019 13:09:41 -0500
Subject: [PATCH 1/2] issue 269 fix. change Object lookup to Map

---
 source/lib/workbook/workbook.js | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/source/lib/workbook/workbook.js b/source/lib/workbook/workbook.js
index e83d4d2..f124927 100644
--- a/source/lib/workbook/workbook.js
+++ b/source/lib/workbook/workbook.js
@@ -90,9 +90,9 @@ class Workbook {
 
         this.sheets = [];
         this.sharedStrings = [];
-        this.sharedStringLookup = {};
+        this.sharedStringLookup = new Map();
         this.styles = [];
-        this.stylesLookup = {};
+        this.stylesLookup = new Map();
         this.dxfCollection = new DXFCollection(this);
         this.mediaCollection = new MediaCollection();
         this.definedNameCollection = new DefinedNameCollection();
@@ -242,11 +242,11 @@ class Workbook {
         const lookupKey = JSON.stringify(thisStyle.toObject());
 
         // Use existing style if one exists
-        if (this.stylesLookup[lookupKey]) {
-            return this.stylesLookup[lookupKey];
+        if (this.stylesLookup.get(lookupKey)) {
+            return this.stylesLookup.get(lookupKey);
         }
 
-        this.stylesLookup[lookupKey] = thisStyle;
+        this.stylesLookup.set(lookupKey, thisStyle);
         const index = this.styles.push(thisStyle) - 1;
         this.styles[index].ids.cellXfs = index;
         return this.styles[index];
@@ -258,10 +258,10 @@ class Workbook {
      * @returns {Number} index of the string in the shared strings array
      */
     getStringIndex(val) {
-        const target = this.sharedStringLookup[val];
+        const target = this.sharedStringLookup.get(val);
         if (_isUndefined(target)) {
             const index = this.sharedStrings.push(val) - 1;
-            this.sharedStringLookup[val] = index;
+            this.sharedStringLookup.set(val, index);
             return index;
         } else {
             return target;

From 37a09c6012ad243366d25b7bf4a60a9b955dc9a4 Mon Sep 17 00:00:00 2001
From: Nater Jorde <nater@iamnater.com>
Date: Mon, 25 Mar 2019 16:18:57 -0500
Subject: [PATCH 2/2] use JSON.stringify for lookup keys of complex strings

---
 source/lib/workbook/workbook.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/source/lib/workbook/workbook.js b/source/lib/workbook/workbook.js
index f124927..cc171e9 100644
--- a/source/lib/workbook/workbook.js
+++ b/source/lib/workbook/workbook.js
@@ -258,10 +258,11 @@ class Workbook {
      * @returns {Number} index of the string in the shared strings array
      */
     getStringIndex(val) {
-        const target = this.sharedStringLookup.get(val);
+        const lookupKey = typeof val === "string" ? val : JSON.stringify(val);
+        const target = this.sharedStringLookup.get(lookupKey);
         if (_isUndefined(target)) {
             const index = this.sharedStrings.push(val) - 1;
-            this.sharedStringLookup.set(val, index);
+            this.sharedStringLookup.set(lookupKey, index);
             return index;
         } else {
             return target;