[7.x] Add skipUntil and skipWhile methods to the collections (#32672

)

* Add `skipUntil` and `skipWhile` methods to the collections

* Use the new `negate` method in `takeWhile`

* Add typehint

src/Illuminate/Support/Collection.php

@@ -978,6 +978,28 @@ public function skip($count)
         return $this->slice($count);
     }
 
+    /**
+     * Skip items in the collection until the given condition is met.
+     *
+     * @param  mixed  $value
+     * @return static
+     */
+    public function skipUntil($value)
+    {
+        return new static($this->lazy()->skipUntil($value)->all());
+    }
+
+    /**
+     * Skip items in the collection while the given condition is met.
+     *
+     * @param  mixed  $value
+     * @return static
+     */
+    public function skipWhile($value)
+    {
+        return new static($this->lazy()->skipWhile($value)->all());
+    }
+
     /**
      * Slice the underlying collection array.
      *

src/Illuminate/Support/LazyCollection.php

@@ -947,6 +947,44 @@ public function skip($count)
         });
     }
 
+    /**
+     * Skip items in the collection until the given condition is met.
+     *
+     * @param  mixed  $value
+     * @return static
+     */
+    public function skipUntil($value)
+    {
+        $callback = $this->useAsCallable($value) ? $value : $this->equality($value);
+
+        return $this->skipWhile($this->negate($callback));
+    }
+
+    /**
+     * Skip items in the collection while the given condition is met.
+     *
+     * @param  mixed  $value
+     * @return static
+     */
+    public function skipWhile($value)
+    {
+        $callback = $this->useAsCallable($value) ? $value : $this->equality($value);
+
+        return new static(function () use ($callback) {
+            $iterator = $this->getIterator();
+
+            while ($iterator->valid() && $callback($iterator->current(), $iterator->key())) {
+                $iterator->next();
+            }
+
+            while ($iterator->valid()) {
+                yield $iterator->key() => $iterator->current();
+
+                $iterator->next();
+            }
+        });
+    }
+
     /**
      * Get a slice of items from the enumerable.
      *
@@ -1145,9 +1183,7 @@ public function takeWhile($value)
     {
         $callback = $this->useAsCallable($value) ? $value : $this->equality($value);
 
-        return $this->takeUntil(function ($item, $key) use ($callback) {
-            return ! $callback($item, $key);
-        });
+        return $this->takeUntil($this->negate($callback));
     }
 
     /**

src/Illuminate/Support/Traits/EnumeratesValues.php

@@ -3,6 +3,7 @@
 namespace Illuminate\Support\Traits;
 
 use CachingIterator;
+use Closure;
 use Exception;
 use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Contracts\Support\Jsonable;
@@ -965,7 +966,7 @@ protected function valueRetriever($value)
     /**
      * Make a function to check an item's equality.
      *
-     * @param  \Closure|mixed  $value
+     * @param  mixed  $value
      * @return \Closure
      */
     protected function equality($value)
@@ -974,4 +975,17 @@ protected function equality($value)
             return $item === $value;
         };
     }
+
+    /**
+     * Make a function using another function, by negating its result.
+     *
+     * @param  \Closure  $callback
+     * @return \Closure
+     */
+    protected function negate(Closure $callback)
+    {
+        return function (...$params) use ($callback) {
+            return ! $callback(...$params);
+        };
+    }
 }

tests/Support/SupportCollectionTest.php

@@ -212,6 +212,42 @@ public function testSkipMethod($collection)
         $this->assertSame([5, 6], $data->all());
     }
 
+    /**
+     * @dataProvider collectionClassProvider
+     */
+    public function testSkipUntil($collection)
+    {
+        $data = new $collection([1, 1, 2, 2, 3, 3, 4, 4]);
+
+        $data = $data->skipUntil(3)->values();
+
+        $this->assertSame([3, 3, 4, 4], $data->all());
+
+        $data = $data->skipUntil(function ($value, $key) {
+            return $value > 3;
+        })->values();
+
+        $this->assertSame([4, 4], $data->all());
+    }
+
+    /**
+     * @dataProvider collectionClassProvider
+     */
+    public function testSkipWhile($collection)
+    {
+        $data = new $collection([1, 1, 2, 2, 3, 3, 4, 4]);
+
+        $data = $data->skipWhile(1)->values();
+
+        $this->assertSame([2, 2, 3, 3, 4, 4], $data->all());
+
+        $data = $data->skipWhile(function ($value, $key) {
+            return $value < 3;
+        })->values();
+
+        $this->assertSame([3, 3, 4, 4], $data->all());
+    }
+
     /**
      * @dataProvider collectionClassProvider
      */

tests/Support/SupportLazyCollectionIsLazyTest.php

@@ -850,6 +850,40 @@ public function testSkipIsLazy()
         });
     }
 
+    public function testSkipUntilIsLazy()
+    {
+        $this->assertDoesNotEnumerate(function ($collection) {
+            $collection->skipUntil(INF);
+        });
+
+        $this->assertEnumerates(10, function ($collection) {
+            $collection->skipUntil(10)->first();
+        });
+
+        $this->assertEnumerates(10, function ($collection) {
+            $collection->skipUntil(function ($item) {
+                return $item === 10;
+            })->first();
+        });
+    }
+
+    public function testSkipWhileIsLazy()
+    {
+        $this->assertDoesNotEnumerate(function ($collection) {
+            $collection->skipWhile(1);
+        });
+
+        $this->assertEnumerates(2, function ($collection) {
+            $collection->skipWhile(1)->first();
+        });
+
+        $this->assertEnumerates(10, function ($collection) {
+            $collection->skipWhile(function ($item) {
+                return $item < 10;
+            })->first();
+        });
+    }
+
     public function testSliceIsLazy()
     {
         $this->assertDoesNotEnumerate(function ($collection) {