exceljs · guyonroche · Jan 16, 2018 · Jan 7, 2018 · Jan 7, 2018 · Jan 7, 2018
diff --git a/lib/doc/workbook.js b/lib/doc/workbook.js
@@ -29,10 +29,12 @@ var Workbook = module.exports = function() {
 
 Workbook.prototype = {
   get xlsx() {
-    return this._xlsx || (this._xlsx = new XLSX(this));
+    if (!this._xlsx) this._xlsx = new XLSX(this);
+    return this._xlsx;
   },
   get csv() {
-    return this._csv || (this._csv = new CSV(this));
+    if (!this._csv) this._csv = new CSV(this);
+    return this._csv;
   },
   get nextId() {
     // find the next unique spot to add worksheet
@@ -69,9 +71,11 @@ Workbook.prototype = {
       }
     }
 
+    var lastOrderNo = this._worksheets.reduce((acc, ws) => ((ws && ws.orderNo) > acc ? ws.orderNo : acc), 0);
     var worksheetOptions = Object.assign({}, options, {
       id: id,
       name: name,
+      orderNo: lastOrderNo + 1,
       workbook: this
     });
 
@@ -105,11 +109,11 @@ Workbook.prototype = {
 
   get worksheets() {
     // return a clone of _worksheets
-    return this._worksheets.filter(Boolean);
+    return this._worksheets.sort((a, b) => a.orderNo - b.orderNo).filter(Boolean);
   },
 
   eachSheet: function(iteratee) {
-    this._worksheets.forEach(function(sheet) {
+    this._worksheets.sort((a, b) => a.orderNo - b.orderNo).forEach((sheet) => {
       iteratee(sheet, sheet.id);
     });
   },
@@ -149,6 +153,7 @@ Workbook.prototype = {
       modified: this.modified,
       properties: this.properties,
       worksheets: this._worksheets.filter(Boolean).map(function(worksheet) { return worksheet.model; }),
+      sheets: this._worksheets.sort((a, b) => a.orderNo - b.orderNo).map(ws => ws.model).filter(Boolean),
       definedNames: this._definedNames.model,
       views: this.views,
       company: this.company,
@@ -187,9 +192,11 @@ Workbook.prototype = {
     value.worksheets.forEach(worksheetModel => {
       var id = worksheetModel.id;
       var name = worksheetModel.name;
+      var orderNo = value.sheets.findIndex(ws => ws.id === id);
       var worksheet = this._worksheets[id] = new Worksheet({
         id: id,
         name: name,
+        orderNo,
         workbook: this
       });
 

diff --git a/lib/doc/worksheet.js b/lib/doc/worksheet.js
@@ -26,6 +26,7 @@ var Worksheet = module.exports = function(options) {
 
   // in a workbook, each sheet will have a number
   this.id = options.id;
+  this.orderNo = options.orderNo;
 
   // and a name
   this.name = options.name || 'Sheet' + this.id;

diff --git a/spec/integration/data/test-issue-257.xlsx b/spec/integration/data/test-issue-257.xlsx
diff --git a/spec/integration/issues/issue-257-sheet-order.spec.js b/spec/integration/issues/issue-257-sheet-order.spec.js
@@ -0,0 +1,18 @@
+'use strict';
+
+var chai = require('chai');
+var verquire = require('../../utils/verquire');
+
+var Excel = verquire('excel');
+
+var expect = chai.expect;
+
+describe('github issues', function() {
+  it('issue 257 - worksheet order is not respected', function() {
+    var wb = new Excel.Workbook();
+    return wb.xlsx.readFile('./spec/integration/data/test-issue-257.xlsx')
+      .then(function() {
+        expect(wb.worksheets.map(ws => ws.name)).to.deep.equal(['First', 'Second']);
+      });
+  });
+});