Merge pull request #116 from EriBloo/main

Implement PeriodCollection Union

README.md

@@ -231,6 +231,12 @@ Intersects given period with every period within a collection. The result is a n
 
 ![](./docs/img/collection-intersect.png)
 
+### `union(): static`
+
+Merges all periods in collection with overlapping ranges.
+
+![](./docs/img/collection-union.png)
+
 ---
 
 Finally, there are a few utility methods available on `PeriodCollection` as well:

src/PeriodCollection.php

@@ -200,4 +200,15 @@ public function sort(): PeriodCollection
 
         return $collection;
     }
+
+    public function union(): PeriodCollection
+    {
+        $boundaries = $this->boundaries();
+
+        if (!$boundaries) {
+            return static::make();
+        }
+
+        return static::make($boundaries)->subtract($boundaries->subtract(...$this));
+    }
 }

tests/PeriodCollectionTest.php

@@ -284,3 +284,24 @@
     expect($sorted[2]->equals($periods[2]))->toBeTrue();
     expect($sorted[3]->equals($periods[3]))->toBeTrue();
 });
+
+it('unions collection', function () {
+    $collection = new PeriodCollection(
+        Period::make('2018-01-30', '2018-01-31'),
+        Period::make('2018-01-30', '2018-02-2'),
+        Period::make('2018-02-04', '2018-02-05'),
+        Period::make('2018-02-07', '2018-02-09'),
+        Period::make('2018-02-12', '2018-02-14'),
+        Period::make('2018-02-08', '2018-02-13')
+    );
+
+    $unioned = $collection->union();
+
+    expect($unioned)->toHaveCount(3);
+    expect($unioned[0]->start() == $collection[0]->start())->toBeTrue();
+    expect($unioned[0]->end() == $collection[1]->end())->toBeTrue();
+    expect($unioned[1]->start() == $collection[2]->start())->toBeTrue();
+    expect($unioned[1]->end() == $collection[2]->end())->toBeTrue();
+    expect($unioned[2]->start() == $collection[3]->start())->toBeTrue();
+    expect($unioned[2]->end() == $collection[4]->end())->toBeTrue();
+});