diff --git a/orderBook.js b/orderBook.js
new file mode 100644
index 0000000..c7cf009
--- /dev/null
+++ b/orderBook.js
@@ -0,0 +1,37 @@
+function reconcileOrder(existingBook, incomingOrder) {
+    let updatedBook = []
+    let changedOrders = []
+
+    for (let i = 0; i < existingBook.length; i++) {
+        if (!existingBook.length) {
+            updatedBook.push(incomingOrder)
+            return updatedBook
+        }
+        if (existingBook[i].type !== incomingOrder.type &&
+            existingBook[i].price === incomingOrder.price &&
+            existingBook[i].quantity === incomingOrder.quantity) {
+            incomingOrder.price = -1
+        } else if (existingBook[i].type !== incomingOrder.type &&
+            existingBook[i].price === incomingOrder.price &&
+            existingBook[i].quantity !== incomingOrder.quantity) {
+            if (existingBook[i].quantity > incomingOrder.quantity) {
+                existingBook[i].quantity = existingBook[i].quantity - incomingOrder.quantity
+                incomingOrder.quantity = 0
+                changedOrders.push(existingBook[i])
+            } else {
+                incomingOrder.quantity = incomingOrder.quantity - existingBook[i].quantity
+            }
+        } else {
+            updatedBook.push(existingBook[i])
+        }
+    }
+    if (incomingOrder.price !== -1 && incomingOrder.quantity !== 0) {
+        updatedBook.push(incomingOrder)
+    }
+
+    return updatedBook.concat(changedOrders)
+}
+
+module.exports = {
+    reconcileOrder
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index a3ac999..643a55e 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,7 @@
   "main": ".eslintrc.js",
   "scripts": {
     "lint": "./node_modules/.bin/eslint --format codeframe .",
-    "test": "./node_modules/.bin/mocha ./tests.js"
+    "test": "./node_modules/.bin/mocha ./test/tests.js"
   },
   "repository": {
     "type": "git",
diff --git a/tests.js b/test/tests.js
similarity index 98%
rename from tests.js
rename to test/tests.js
index 4926c8a..8aaa113 100644
--- a/tests.js
+++ b/test/tests.js
@@ -1,6 +1,6 @@
 /* eslint-disable max-len */
 const { expect } = require('chai')
-const reconcileOrder = require('./orderBook')
+const reconcileOrder = require('../orderBook').reconcileOrder
 
 describe('Order Book', () => {
   describe('reconcileOrder', () => {