From 96405157f05582ae91fcdca2192836b5877a45d3 Mon Sep 17 00:00:00 2001
From: William O'Beirne <wbobeirne@gmail.com>
Date: Thu, 27 Jul 2017 19:21:50 -0400
Subject: [PATCH] Fix number formatter (#99)

* Fix initialState -> INITIAL_STATE rename

* Fix number formatter for removing non-trailing zeroes, not handling zero decimals. Add tests.
---
 common/utils/formatters.js    | 14 ++++++++++---
 spec/utils/formatters.spec.js | 37 ++++++++++++++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/common/utils/formatters.js b/common/utils/formatters.js
index d5d84e17..13a60557 100644
--- a/common/utils/formatters.js
+++ b/common/utils/formatters.js
@@ -12,10 +12,18 @@ export function combineAndUpper(...args: string[]) {
 // Use in place of angular number filter
 export function formatNumber(number: Big, digits: number = 3): string {
   let parts = number.toFixed(digits).split('.');
-  parts[1] = parts[1].replace(/0+/, '');
-  if (!parts[1]) {
-    parts.pop();
+
+  // Remove trailing zeroes on decimal (If there is a decimal)
+  if (parts[1]) {
+    parts[1] = parts[1].replace(/0+$/, '');
+
+    // If there's nothing left, remove decimal altogether
+    if (!parts[1]) {
+      parts.pop();
+    }
   }
+
+  // Commafy the whole numbers
   parts[0] = parts[0].replace(/\B(?=(\d{3})+(?!\d))/g, ',');
 
   return parts.join('.');
diff --git a/spec/utils/formatters.spec.js b/spec/utils/formatters.spec.js
index 31b02d46..0e1de394 100644
--- a/spec/utils/formatters.spec.js
+++ b/spec/utils/formatters.spec.js
@@ -1,4 +1,5 @@
-import { toFixedIfLarger } from '../../common/utils/formatters';
+import Big from 'big.js';
+import { toFixedIfLarger, formatNumber } from '../../common/utils/formatters';
 
 describe('toFixedIfLarger', () => {
   it('should return same value if decimal isnt longer than default', () => {
@@ -15,3 +16,37 @@ describe('toFixedIfLarger', () => {
     expect(toFixedIfLarger(numExample, 2)).toEqual(String(7.12));
   });
 });
+
+describe('formatNumber', () => {
+  const pairs = [
+    {
+      input: new Big('0.0127491'),
+      output: '0.013'
+    },
+    {
+      input: new Big('21.87468421'),
+      output: '21.875'
+    },
+    {
+      input: new Big(0),
+      output: '0'
+    },
+    {
+      input: new Big('354.4728173'),
+      output: '354.4728',
+      digits: 4
+    },
+    {
+      input: new Big('100.48391'),
+      output: '100',
+      digits: 0
+    }
+  ];
+
+  pairs.forEach(pair => {
+    const digits = pair.digits === undefined ? 'default' : pair.digits;
+    it(`should convert ${pair.input.toString()} to ${pair.output} when using ${digits} digits`, () => {
+      expect(formatNumber(pair.input, pair.digits)).toEqual(pair.output);
+    });
+  });
+});