From 0354ec99a576e81efbbefad77e18a5d28b92f5b5 Mon Sep 17 00:00:00 2001
From: Bohuslav Stanishevskyy
 <bohuslavstanishevskyy@MacBook-Pro-Bohuslav.local>
Date: Wed, 1 Jul 2026 13:47:45 +0300
Subject: [PATCH] feat: complete date formatter

---
 .github/workflows/test.yml-template | 23 +++++++++++
 package-lock.json                   |  9 +++--
 package.json                        |  2 +-
 src/formatDate.js                   | 60 +++++++++++++++++++++++++++++
 4 files changed, 89 insertions(+), 5 deletions(-)
 create mode 100644 .github/workflows/test.yml-template

diff --git a/.github/workflows/test.yml-template b/.github/workflows/test.yml-template
new file mode 100644
index 000000000..bb13dfc45
--- /dev/null
+++ b/.github/workflows/test.yml-template
@@ -0,0 +1,23 @@
+name: Test
+
+on:
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [20.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+    - run: npm test
diff --git a/package-lock.json b/package-lock.json
index 5794158b4..83e6357ac 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,7 +11,7 @@
       "license": "GPL-3.0",
       "devDependencies": {
         "@mate-academy/eslint-config": "latest",
-        "@mate-academy/scripts": "^1.8.6",
+        "@mate-academy/scripts": "^2.1.3",
         "eslint": "^8.57.0",
         "eslint-plugin-jest": "^28.6.0",
         "eslint-plugin-node": "^11.1.0",
@@ -1467,10 +1467,11 @@
       }
     },
     "node_modules/@mate-academy/scripts": {
-      "version": "1.8.6",
-      "resolved": "https://registry.npmjs.org/@mate-academy/scripts/-/scripts-1.8.6.tgz",
-      "integrity": "sha512-b4om/whj4G9emyi84ORE3FRZzCRwRIesr8tJHXa8EvJdOaAPDpzcJ8A0sFfMsWH9NUOVmOwkBtOXDu5eZZ00Ig==",
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/@mate-academy/scripts/-/scripts-2.1.3.tgz",
+      "integrity": "sha512-a07wHTj/1QUK2Aac5zHad+sGw4rIvcNl5lJmJpAD7OxeSbnCdyI6RXUHwXhjF5MaVo9YHrJ0xVahyERS2IIyBQ==",
       "dev": true,
+      "license": "MIT",
       "dependencies": {
         "@octokit/rest": "^17.11.2",
         "@types/get-port": "^4.2.0",
diff --git a/package.json b/package.json
index 0df4c1ec0..33f22fea8 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
   "license": "GPL-3.0",
   "devDependencies": {
     "@mate-academy/eslint-config": "latest",
-    "@mate-academy/scripts": "^1.8.6",
+    "@mate-academy/scripts": "^2.1.3",
     "eslint": "^8.57.0",
     "eslint-plugin-jest": "^28.6.0",
     "eslint-plugin-node": "^11.1.0",
diff --git a/src/formatDate.js b/src/formatDate.js
index 769e27661..b7ff0991e 100644
--- a/src/formatDate.js
+++ b/src/formatDate.js
@@ -9,6 +9,66 @@
  */
 function formatDate(date, fromFormat, toFormat) {
   // write code here
+  const oldSeparator = fromFormat[fromFormat.length - 1];
+  const newSeparator = toFormat[toFormat.length - 1];
+  let oldYearPosition = fromFormat.indexOf('YYYY');
+  let newYearPosition = toFormat.indexOf('YYYY');
+  const oldMonthPosition = fromFormat.indexOf('MM');
+  const newMonthPosition = toFormat.indexOf('MM');
+  const oldDayPosition = fromFormat.indexOf('DD');
+  const newDayPosition = toFormat.indexOf('DD');
+  const dateParts = date.split(oldSeparator);
+  let year = dateParts[oldYearPosition];
+  const month = dateParts[oldMonthPosition];
+  const day = dateParts[oldDayPosition];
+  const newDateArray = [];
+
+  if (oldYearPosition === -1) {
+    oldYearPosition = fromFormat.indexOf('YY');
+    year = dateParts[oldYearPosition];
+
+    if (newYearPosition !== -1) {
+      if (year < 30) {
+        year = '20' + year;
+      } else {
+        year = '19' + year;
+      }
+    }
+  }
+
+  if (newYearPosition === -1) {
+    newYearPosition = toFormat.indexOf('YY');
+
+    if (year.length === 4) {
+      year = year.slice(2);
+    }
+  }
+
+  newDateArray[newYearPosition] = year;
+  newDateArray[newMonthPosition] = month;
+  newDateArray[newDayPosition] = day;
+
+  const newDate = newDateArray.join(newSeparator);
+
+  return newDate;
 }
 
 module.exports = formatDate;
+
+// Create a `formatDate` function that accepts the `date` string,
+// the old `fromFormat` array and the new `toFormat` array.
+//  Function returns given date in new format.
+
+// The function can change a separator, reorder the date parts
+//  of convert a year from `4` digits to `2` digits and back.
+
+// - When converting from `YYYY` to `YY` just
+//  use `2` last digit (`1997` -> `97`).
+// - When converting from `YY` to `YYYY` use `20YY`
+// if `YY < 30` and `19YY` otherwise.
+
+// formatDate(
+//   '20/02/18',
+//   ['YY', 'MM', 'DD', '/'],
+//   ['YYYY', 'MM', 'DD', '.'],
+// ); // '2020.02.18'