From fb0b1ac00407dc87682146d10aa36857418e9f12 Mon Sep 17 00:00:00 2001
From: Timo Hocker <t-hocker@web.de>
Date: Fri, 24 Apr 2020 16:57:50 +0200
Subject: [PATCH] tests, padding

---
 index.js      |  8 ++++++--
 test/index.js | 21 +++++++++++++++++++++
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 47b4157..3d9d205 100644
--- a/index.js
+++ b/index.js
@@ -50,10 +50,14 @@ function to_hex (str, encoding = '') {
  * encode a number to hex
  *
  * @param {number} n number to encode
+ * @param {number} padding minumum length of output
  * @returns {string} hex
  */
-function num_to_hex (n) {
-  return n.toString (16);
+function num_to_hex (n, padding = 0) {
+  const res = n.toString (16);
+  if (res.length < padding)
+    return '0'.repeat (padding - res.length) + res;
+  return res;
 }
 
 /**
diff --git a/test/index.js b/test/index.js
index 9c5aad6..0adc243 100644
--- a/test/index.js
+++ b/test/index.js
@@ -6,6 +6,7 @@
  */
 
 // @ts-nocheck
+/* eslint-disable no-magic-numbers */
 'use strict';
 
 const test = require ('ava');
@@ -26,3 +27,23 @@ test ('encoding to_utf8', (t) => {
   const utf = encoding.to_utf8 ('Zm9v', 'base64');
   t.is (utf, 'foo');
 });
+
+test ('convert num to hex', (t) => {
+  const res = encoding.num_to_hex (11);
+  t.is (res, 'b');
+});
+
+test ('convert num to hex padded', (t) => {
+  const res = encoding.num_to_hex (11, 2);
+  t.is (res, '0b');
+});
+
+test ('convert hex to num', (t) => {
+  const res = encoding.hex_to_num ('b');
+  t.is (res, 11);
+});
+
+test ('convert hex padded to num', (t) => {
+  const res = encoding.hex_to_num ('0b');
+  t.is (res, 11);
+});