Add new map method for query builder

src/mantle/database/query/class-builder.php

@@ -833,6 +833,27 @@ public function each_by_id( callable $callback, int $count = 100, string $attrib
 		}, $attribute );
 	}
 
+	/**
+	 * Map the query results to a new collection.
+	 *
+	 * @template TMapValue
+	 *
+	 * @param callable(TModel): TMapValue $callback Callback to run on each chunk.
+	 * @param int                     $count Number of items to chunk by.
+	 * @return Collection<int, TMapValue>
+	 */
+	public function map( callable $callback, int $count = 100 ) {
+		$results = new Collection();
+
+		$this->chunk( $count, function ( Collection $items ) use ( $callback, $results ): bool {
+			$results->push( ...$items->map( $callback ) );
+
+			return true;
+		} );
+
+		return $results;
+	}
+
 	/**
 	 * Magic method to proxy to the appropriate query method.
 	 *

tests/Database/Query/PostQueryBuilderTest.php

@@ -451,6 +451,21 @@ public function test_each_by_id() {
 		$this->assertNull( get_post( collect( $post_ids )->last() ) );
 	}
 
+	public function test_map() {
+		$post_ids = static::factory()->post->create_many( 100 );
+
+		$ids = Testable_Post::map( function ( Testable_Post $post ) {
+			return [ 'id' => $post->id() ];
+		} );
+
+		$this->assertEquals(
+			collect( $post_ids )->map( function ( $id ) {
+				return [ 'id' => $id ];
+			} )->sort()->values(),
+			$ids->sort()->values()
+		);
+	}
+
 	public function test_where_raw() {
 		$post_id = static::get_random_post_id();