Merge pull request #5 from swisnl/feature/covering

Add getCoveringDateRange method on DateRangeSet

Author: rolfvandekrol

CHANGELOG.md

@@ -7,7 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
-* Nothing yet.
+* Add `DateRangeSet::getCoveringDateRange()` method to get the minimal date 
+  range covering all ranges in the set.
 
 ## [1.1.0] - 2025-11-21
 

src/DateRangeSet.php

@@ -344,6 +344,29 @@ public function isNotEmpty(): bool
         return ! $this->isEmpty();
     }
 
+    /**
+     * Get the smallest DateRange that covers all date ranges in the set.
+     *
+     * This method returns a DateRange that covers the entire span of the date
+     * ranges in the set. If the set is empty, it will return null.
+     */
+    public function getCoveringDateRange(): ?DateRange
+    {
+        if ($this->isEmpty()) {
+            return null;
+        }
+
+        /** @var \Swis\DateRange\DateRange $firstRange */
+        $firstRange = $this->dateRanges->first();
+        /** @var \Swis\DateRange\DateRange $lastRange */
+        $lastRange = $this->dateRanges->last();
+
+        return DateRange::make(
+            $firstRange->getStartDate(),
+            $lastRange->getEndDate(),
+        );
+    }
+
     /**
      * Convert the set to a collection of CarbonImmutable dates.
      *

tests/DateRangeSetTest.php

@@ -297,3 +297,28 @@
         ],
     ],
 ]);
+
+it('gets the covering date range', function (array $ranges, ?array $coveringRange) {
+    $dateRangeSet = DateRangeSet::fromArray($ranges);
+
+    expect($dateRangeSet->getCoveringDateRange()?->toArray())->toEqual($coveringRange);
+})->with([
+    'simple' => [
+        [
+            ['2021-01-01', '2021-02-15'],
+            ['2021-03-01', '2021-03-31'],
+        ],
+        ['2021-01-01', '2021-03-31'],
+    ],
+    'with nulls' => [
+        [
+            [null, '2021-02-15'],
+            ['2021-03-01', null],
+        ],
+        [null, null],
+    ],
+    'empty set' => [
+        [],
+        null,
+    ],
+]);