From 894deeb97b8131f028d41e67d97b5f96b8114be7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Golder?= <lukasz.golder@tsh.io>
Date: Fri, 11 May 2018 15:07:21 +0200
Subject: [PATCH] fix(allowEmpty): return empty string also when value is empty
 string

---
 src/__tests__/createNumberMask.test.js | 10 ++++++++++
 src/createNumberMask.js                |  2 +-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/__tests__/createNumberMask.test.js b/src/__tests__/createNumberMask.test.js
index ab05116..5d1db7a 100644
--- a/src/__tests__/createNumberMask.test.js
+++ b/src/__tests__/createNumberMask.test.js
@@ -139,6 +139,16 @@ describe('Number mask', () => {
     expect(mask.format()).toBe('');
   });
 
+  it('should be formatting as empty string when the value on the store is empty string and allowEmpty is true', () => {
+    const mask = createNumberMask({
+      prefix: 'p',
+      suffix: 's',
+      allowEmpty: true,
+    });
+
+    expect(mask.format('')).toBe('');
+  });
+
   it('should update the stored value correctly', () => {
     const prefix = 'prefix 1@,.';
     const suffix = '1@,. suffix';
diff --git a/src/createNumberMask.js b/src/createNumberMask.js
index 87bb7f8..1206545 100644
--- a/src/createNumberMask.js
+++ b/src/createNumberMask.js
@@ -23,7 +23,7 @@ export default options => {
 
   const format = storeValue => {
     let number = storeValue;
-    if (number === undefined) {
+    if (number === undefined || number === '') {
       if (allowEmpty) {
         return '';
       }