Add Collection::wrap method (#20055)

If the given value is not a collection, wrap it in one.

If you pass a collection or an array as the value you get a collection with data in the collection or array back. If you pass in anything else you get a collection of one containing that value.

src/Illuminate/Support/Collection.php

@@ -59,6 +59,19 @@ public static function make($items = [])
         return new static($items);
     }
 
+    /**
+     * If the given value is not a collection, wrap it in one.
+     *
+     * @param  mixed  $value
+     * @return static
+     */
+    public static function wrap($value)
+    {
+        return $value instanceof self
+            ? new static($value)
+            : new static(Arr::wrap($value));
+    }
+
     /**
      * Create a new collection by invoking the callback a given amount of times.
      *

tests/Support/SupportCollectionTest.php

@@ -1014,6 +1014,49 @@ public function testMakeMethodFromArray()
         $this->assertEquals(['foo' => 'bar'], $collection->all());
     }
 
+    public function testWrapWithScalar()
+    {
+        $collection = Collection::wrap('foo');
+        $this->assertEquals(['foo'], $collection->all());
+    }
+
+    public function testWrapWithArray()
+    {
+        $collection = Collection::wrap(['foo']);
+        $this->assertEquals(['foo'], $collection->all());
+    }
+
+    public function testWrapWithArrayable()
+    {
+        $collection = Collection::wrap($o = new TestArrayableObject);
+        $this->assertEquals([$o], $collection->all());
+    }
+
+    public function testWrapWithJsonable()
+    {
+        $collection = Collection::wrap($o = new TestJsonableObject);
+        $this->assertEquals([$o], $collection->all());
+    }
+
+    public function testWrapWithJsonSerialize()
+    {
+        $collection = Collection::wrap($o = new TestJsonSerializeObject);
+        $this->assertEquals([$o], $collection->all());
+    }
+
+    public function testWrapWithCollectionClass()
+    {
+        $collection = Collection::wrap(Collection::make(['foo']));
+        $this->assertEquals(['foo'], $collection->all());
+    }
+
+    public function testWrapWithCollectionSubclass()
+    {
+        $collection = TestCollectionSubclass::wrap(Collection::make(['foo']));
+        $this->assertEquals(['foo'], $collection->all());
+        $this->assertInstanceOf(TestCollectionSubclass::class, $collection);
+    }
+
     public function testTimesMethod()
     {
         $two = Collection::times(2, function ($number) {
@@ -2287,3 +2330,8 @@ public function __construct($value)
         $this->value = $value;
     }
 }
+
+class TestCollectionSubclass extends Collection
+{
+    //
+}