diff --git a/src/utils/__tests__/formatUtils.test.js b/src/utils/__tests__/formatUtils.test.js
new file mode 100644
index 00000000..b1c01d0a
--- /dev/null
+++ b/src/utils/__tests__/formatUtils.test.js
@@ -0,0 +1,48 @@
+import * as formatUtils from '../formatUtils';
+
+describe('format utils', () => {
+    it('formatAmount', () => {
+        const input = [
+            { amount: 0, coinInfo: { isBitcoin: true, currencyUnits: 'mbtc', shortcut: 'btc' } },
+            { amount: 0.5, coinInfo: { isBitcoin: true, currencyUnits: 'mbtc', shortcut: 'btc' } },
+            { amount: 1, coinInfo: { isBitcoin: false, shortcut: 'eth' } },
+            { amount: 99999, coinInfo: { isBitcoin: false, currencyUnits: 'tau' } },
+        ];
+
+        input.forEach((entry) => {
+            expect(formatUtils.formatAmount(entry.amount, entry.coinInfo)).toMatchSnapshot();
+        });
+    });
+
+    it('formatTime', () => {
+        const input = [0, 1, 2, 100, 999];
+
+        input.forEach((entry) => {
+            expect(formatUtils.formatTime(entry)).toMatchSnapshot();
+        });
+    });
+
+    it('btckb2satoshib', () => {
+        const input = [0, 1, 2, 100, 999];
+
+        input.forEach((entry) => {
+            expect(formatUtils.btckb2satoshib(entry)).toMatchSnapshot();
+        });
+    });
+
+    it('stringToHex', () => {
+        const input = ['test', '0001', 'test99999'];
+
+        input.forEach((entry) => {
+            expect(formatUtils.stringToHex(entry)).toMatchSnapshot();
+        });
+    });
+
+    it('hexToString', () => {
+        const input = [0, 'xxxtestSringtestStringaaaaaa', 30303031, 2746573743939393939, -9];
+
+        input.forEach((entry) => {
+            expect(formatUtils.hexToString(entry)).toMatchSnapshot();
+        });
+    });
+});
diff --git a/src/utils/formatUtils.js b/src/utils/formatUtils.js
index 982c9afb..986b0ee9 100644
--- a/src/utils/formatUtils.js
+++ b/src/utils/formatUtils.js
@@ -1,11 +1,9 @@
 /* @flow */
 
-
-const currencyUnits: string = 'mbtc2';
-
 // TODO: chagne currency units
+const currencyUnitsConstant: string = 'mbtc2';
 
-export const formatAmount = (n: number, coinInfo: any): string => {
+export const formatAmount = (n: number, coinInfo: any, currencyUnits = currencyUnitsConstant): string => {
     const amount = (n / 1e8);
     if (coinInfo.isBitcoin && currencyUnits === 'mbtc' && amount <= 0.1 && n !== 0) {
         const s = (n / 1e5).toString();