Add query builder map method

src/Illuminate/Database/Concerns/BuildsQueries.php

@@ -7,6 +7,7 @@
 use Illuminate\Database\RecordsNotFoundException;
 use Illuminate\Pagination\LengthAwarePaginator;
 use Illuminate\Pagination\Paginator;
+use Illuminate\Support\Collection;
 
 trait BuildsQueries
 {
@@ -149,6 +150,26 @@ public function first($columns = ['*'])
         return $this->take(1)->get($columns)->first();
     }
 
+    /**
+     * Run a map over each item while chunking.
+     *
+     * @param  callable  $callback
+     * @param  int  $count
+     * @return \Illuminate\Support\Collection
+     */
+    public function map(callable $callback, $count = 1000)
+    {
+        $collection = Collection::make();
+
+        $this->chunk($count, function ($items) use ($collection, $callback) {
+            $items->each(function ($item) use ($collection, $callback) {
+                $collection->push($callback($item));
+            });
+        });
+
+        return $collection;
+    }
+
     /**
      * Execute the query and get the first result if it's the sole matching record.
      *

tests/Integration/Database/EloquentWhereTest.php

@@ -6,6 +6,7 @@
 use Illuminate\Database\Eloquent\ModelNotFoundException;
 use Illuminate\Database\MultipleRecordsFoundException;
 use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Schema;
 
 /**
@@ -134,6 +135,32 @@ public function testSoleFailsIfNoRecords()
 
         $this->assertSame(UserWhereTest::class, $exception->getModel());
     }
+
+    public function testMap()
+    {
+        UserWhereTest::create([
+            'name' => 'first-name',
+            'email' => 'first-email',
+            'address' => 'first-address',
+        ]);
+
+        UserWhereTest::create([
+            'name' => 'second-name',
+            'email' => 'second-email',
+            'address' => 'second-address',
+        ]);
+
+        DB::enableQueryLog();
+
+        $results = UserWhereTest::orderBy('id')->map(function ($user) {
+            return $user->name;
+        }, 1);
+
+        $this->assertCount(2, $results);
+        $this->assertSame('first-name', $results[0]);
+        $this->assertSame('second-name', $results[1]);
+        $this->assertCount(3, DB::getQueryLog());
+    }
 }
 
 class UserWhereTest extends Model

tests/Integration/Database/QueryBuilderTest.php

@@ -213,4 +213,18 @@ public function testPaginateWithSpecificColumns()
             (object) ['title' => 'Bar Post', 'content' => 'Lorem Ipsum.'],
         ]);
     }
+
+    public function testMap()
+    {
+        DB::enableQueryLog();
+
+        $results = DB::table('posts')->orderBy('id')->map(function ($post) {
+            return $post->title;
+        }, 1);
+
+        $this->assertCount(2, $results);
+        $this->assertSame('Foo Post', $results[0]);
+        $this->assertSame('Bar Post', $results[1]);
+        $this->assertCount(3, DB::getQueryLog());
+    }
 }