Merge pull request #11 from Souler/refactor/drop-moment-dependency

Remove moment as a dependency

format.js

@@ -0,0 +1,106 @@
+const util = require('util');
+
+/**
+ * Pads the provided number into a string of 2 digits; adding leading
+ * zeros if needed.
+ * Values resulting in more than 2 digits are left untouched.
+ *
+ * @param {string} number
+ * @returns A two-digit number
+ * @throws {TypeError} if the provided value is not a valid integer
+ */
+function toTwoDigits(number) {
+  if (!Number.isInteger(number)) {
+    throw new TypeError(`Not a valid integer: ${number}`);
+  }
+
+  return number.toString().padStart(2, '0');
+}
+
+/**
+ * Look-up map of month number into month short name (in english).
+ * A month number is the value returned by Date#getMonth() and a short month name
+ * is a 3 letter representation of a month of the year.
+ */
+const shortMonthByMonthNumber = {
+  0: 'Jan',
+  1: 'Feb',
+  2: 'Mar',
+  3: 'Apr',
+  4: 'May',
+  5: 'Jun',
+  6: 'Jul',
+  7: 'Aug',
+  8: 'Sep',
+  9: 'Oct',
+  10: 'Nov',
+  11: 'Dec'
+};
+
+/**
+ * Returns a [short](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat/DateTimeFormat#month)
+ * (3-letters) representation of the given month index **in English**.
+ *
+ * @param {number} month
+ * @returns {string}
+ * @throws {TypeError} if the provided value is not a valid month number
+ */
+function toShortMonth(month) {
+  if (!(month in shortMonthByMonthNumber)) {
+    throw new TypeError(`Not a valid month value: ${month}`);
+  }
+
+  return shortMonthByMonthNumber[month];
+}
+
+/**
+ * Returns a [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) compliant
+ * offset string.
+ *
+ * @returns {string}
+ * @throws {TypeError} if the provided value is not a valid integer
+ */
+function toOffset(offsetMinutes) {
+  if (!Number.isInteger(offsetMinutes)) {
+    throw new TypeError(`Not a valid integer: ${offsetMinutes}`);
+  }
+
+  const absoluteOffset = Math.abs(offsetMinutes);
+  const hours = toTwoDigits(Math.floor(absoluteOffset / 60));
+  const minutes = toTwoDigits(absoluteOffset % 60);
+  const sign = offsetMinutes >= 0 ? '-' : '+';
+
+  return `${sign}${hours}${minutes}`;
+}
+
+/**
+ * Formats the provided date into a [Common Log Format](https://en.wikipedia.org/wiki/Common_Log_Format)
+ * compliant string.
+ *
+ * @param {Date} date
+ * @returns {string}
+ */
+function toCommonAccessLogDateFormat(date) {
+  if (!(date instanceof Date)) {
+    throw new TypeError('Not a valid date');
+  }
+
+  // e.g: 10/Oct/2000:13:55:36 -0700
+  return util.format(
+    '%s/%s/%s:%s:%s:%s %s',
+    toTwoDigits(date.getDate()),
+    toShortMonth(date.getMonth()),
+    date.getFullYear(),
+    toTwoDigits(date.getHours()),
+    toTwoDigits(date.getMinutes()),
+    toTwoDigits(date.getSeconds()),
+    toOffset(date.getTimezoneOffset())
+  );
+}
+
+module.exports = {
+  toCommonAccessLogDateFormat,
+  toOffset,
+  toShortMonth,
+  toTwoDigits
+};

index.js

@@ -1,5 +1,5 @@
 const util = require('util');
-const moment = require('moment');
+const { toCommonAccessLogDateFormat } = require('./format');
 
 module.exports = function (stream) {
   if (!stream) stream = process.stdout;
@@ -13,7 +13,7 @@ module.exports = function (stream) {
 
     // eslint-disable-next-line unicorn/explicit-length-check
     const length = ctx.length ? ctx.length.toString() : '-';
-    const date = moment().format('D/MMM/YYYY:HH:mm:ss ZZ');
+    const date = toCommonAccessLogDateFormat(new Date());
 
     stream.write(
       util.format(

package.json

@@ -30,9 +30,6 @@
     "3imed-jaberi <[email protected]> (https://www.3imed-jaberi.com)"
   ],
   "license": "MIT",
-  "dependencies": {
-    "moment": "^2.26.0"
-  },
   "devDependencies": {
     "eslint-config-xo-lass": "^1.0.3",
     "koa": "^2.12.1",

test/format.spec.js

@@ -0,0 +1,95 @@
+const {
+  toCommonAccessLogDateFormat,
+  toOffset,
+  toShortMonth,
+  toTwoDigits,
+} = require('../format')
+
+describe('toTwoDigits', () => {
+  test.each([
+    { value: 0, expected: '00' },
+    { value: 1, expected: '01' },
+    { value: 11, expected: '11' },
+    { value: 99, expected: '99' },
+    { value: 123, expected: '123' },
+  ])('returns $expected for $value', ({ value, expected }) => {
+    expect(toTwoDigits(value)).toBe(expected)
+  })
+
+  test('throws TypeError if provided value is Infinity', () => {
+    expect(() => toTwoDigits(Infinity)).toThrow(TypeError)
+  })
+
+  test('throws TypeError if provided value is NaN', () => {
+    expect(() => toTwoDigits(NaN)).toThrow(TypeError)
+  })
+
+  test('throws TypeError if provided value is a decimal number', () => {
+    expect(() => toTwoDigits(0.99)).toThrow(TypeError)
+  })
+
+  test('throws TypeError if provided value is a string', () => {
+    expect(() => toTwoDigits('0')).toThrow(TypeError)
+  })
+})
+
+describe('toOffset', () => {
+  test.each([
+    { value: 480, expected: '-0800' },
+    { value: 0, expected: '+0000' },
+    { value: -180, expected: '+0300' },
+  ])('returns $expected for $value', ({ value, expected }) => {
+    expect(toOffset(value)).toBe(expected)
+  })
+
+  test('throws TypeError if provided value is Infinity', () => {
+    expect(() => toOffset(Infinity)).toThrow(TypeError)
+  })
+
+  test('throws TypeError if provided value is NaN', () => {
+    expect(() => toOffset(NaN)).toThrow(TypeError)
+  })
+
+  test('throws TypeError if provided value is a decimal number', () => {
+    expect(() => toOffset(60.5)).toThrow(TypeError)
+  })
+
+  test('throws TypeError if provided value is a string', () => {
+    expect(() => toOffset('60')).toThrow(TypeError)
+  })
+})
+
+describe('toShortMonth', () => {
+  test.each([
+    { value: 0, expected: 'Jan' },
+    { value: 1, expected: 'Feb' },
+    { value: 2, expected: 'Mar' },
+    { value: 3, expected: 'Apr' },
+    { value: 4, expected: 'May' },
+    { value: 5, expected: 'Jun' },
+    { value: 6, expected: 'Jul' },
+    { value: 7, expected: 'Aug' },
+    { value: 8, expected: 'Sep' },
+    { value: 9, expected: 'Oct' },
+    { value: 10, expected: 'Nov' },
+    { value: 11, expected: 'Dec' },
+  ])('returns $expected for $value', ({ value, expected }) => {
+    expect(toShortMonth(value)).toBe(expected)
+  })
+
+  test('throws TypeError for a non-valid month number', () => {
+    expect(() => toShortMonth(13)).toThrow(TypeError)
+  })
+})
+
+describe('toCommonAccessLogDateFormat', () => {
+  test('correctly formats a date', () => {
+    const date = new Date('2020-01-01T12:34:56Z')
+    const expectedValue = '01/Jan/2020:10:34:56 +0200'
+    expect(toCommonAccessLogDateFormat(date)).toBe(expectedValue)
+  })
+
+  test('throws TypeError for non-Date value', () => {
+    expect(() => toCommonAccessLogDateFormat({})).toThrow(TypeError)
+  })
+})