From 88a757cd0863d45ba81fc394d5f3ebb88ff13dd3 Mon Sep 17 00:00:00 2001
From: John Jablonski <jablonski.kce@gmail.com>
Date: Mon, 10 Jun 2024 10:45:16 +0200
Subject: [PATCH] Add Date::offsetByMonths and Date::offsetByYears methods
 (#694)

---
 lib/Date.php            | 18 +++++++++++
 tests/unit/DateTest.php | 66 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 82 insertions(+), 2 deletions(-)

diff --git a/lib/Date.php b/lib/Date.php
index ea1b0f41..add6bdb0 100644
--- a/lib/Date.php
+++ b/lib/Date.php
@@ -103,6 +103,24 @@ public function offsetByDays(int $days): self
         return $this->modify(\sprintf('%d days', $days));
     }
 
+    public function offsetByMonths(int $months): self
+    {
+        if ($months === 0) {
+            return $this;
+        }
+
+        return $this->modify(\sprintf('%d months', $months));
+    }
+
+    public function offsetByYears(int $years): self
+    {
+        if ($years === 0) {
+            return $this;
+        }
+
+        return $this->modify(\sprintf('%d years', $years));
+    }
+
     /**
      * Provides a date time representation of this date in UTC.
      */
diff --git a/tests/unit/DateTest.php b/tests/unit/DateTest.php
index b04a4fb1..7316e044 100644
--- a/tests/unit/DateTest.php
+++ b/tests/unit/DateTest.php
@@ -396,7 +396,7 @@ public function it_calculates_diff_correctly(): void
     /**
      * @return iterable<array{int}>
      */
-    public static function provideNumberOfDayOffsets(): iterable
+    public static function provideNumberOfDaysOffsets(): iterable
     {
         yield [-10];
         yield [-5];
@@ -407,7 +407,7 @@ public static function provideNumberOfDayOffsets(): iterable
         yield [10];
     }
 
-    #[DataProvider('provideNumberOfDayOffsets')]
+    #[DataProvider('provideNumberOfDaysOffsets')]
     #[Test]
     public function it_can_be_offset_by_days(int $days): void
     {
@@ -424,6 +424,68 @@ public function it_can_be_offset_by_days(int $days): void
         $this->assertTrue($expectedDate->equals($offsetDate));
     }
 
+    /**
+     * @return iterable<array{int}>
+     */
+    public static function provideNumberOfMonthsOffsets(): iterable
+    {
+        yield [-10];
+        yield [-5];
+        yield [-1];
+        yield [0];
+        yield [1];
+        yield [5];
+        yield [10];
+    }
+
+    #[DataProvider('provideNumberOfMonthsOffsets')]
+    #[Test]
+    public function it_can_be_offset_by_months(int $days): void
+    {
+        $date = Date::fromYearMonthDay(2022, 5, 1);
+
+        $offsetDate = $date->offsetByMonths($days);
+
+        $expectedDate = Date::fromDateTime($date->toDateTime()->modify(\sprintf('%d months', $days)));
+
+        if ($days !== 0) {
+            $this->assertNotSame($date, $offsetDate);
+        }
+
+        $this->assertTrue($expectedDate->equals($offsetDate));
+    }
+
+    /**
+     * @return iterable<array{int}>
+     */
+    public static function provideNumberOfYearsOffsets(): iterable
+    {
+        yield [-10];
+        yield [-5];
+        yield [-1];
+        yield [0];
+        yield [1];
+        yield [5];
+        yield [10];
+    }
+
+    #[DataProvider('provideNumberOfYearsOffsets')]
+    #[Test]
+    public function it_can_be_offset_by_years(int $days): void
+    {
+        $date = Date::fromYearMonthDay(2022, 5, 1);
+
+        $offsetDate = $date->offsetByYears($days);
+
+        $expectedDate = Date::fromDateTime($date->toDateTime()->modify(\sprintf('%d years', $days)));
+
+        if ($days !== 0) {
+            $this->assertNotSame($date, $offsetDate);
+        }
+
+        $this->assertTrue($expectedDate->equals($offsetDate));
+    }
+
     #[Test]
     public function it_can_be_constructed_from_a_number_of_years_ago(): void
     {