[11.x] Introduce whenWhere methods in query builder

src/Illuminate/Database/Query/Builder.php

@@ -1773,6 +1773,39 @@ protected function addDateBasedWhere($type, $column, $operator, $value, $boolean
         return $this;
     }
 
+    /**
+     * Add a whenWhere to the query.
+     *
+     * @param  mixed  $condition
+     * @param  string  $column
+     * @param  string|null  $operator
+     * @param  mixed|null  $value
+     * @param  string  $boolean
+     * @return $this
+     */
+    public function whenWhere($condition, $column, $operator = null, $value = null, string $boolean = 'and')
+    {
+        if (! $condition) {
+            return $this;
+        }
+
+        return $this->where($column, $operator, $value, $boolean);
+    }
+
+    /**
+     * Add a or whenWhere to the query.
+     *
+     * @param  mixed  $condition
+     * @param  string  $column
+     * @param  string|null  $operator
+     * @param  mixed|null  $value
+     * @return $this
+     */
+    public function orWhenWhere($condition, $column, $operator = null, $value = null)
+    {
+        return $this->whenWhere($condition, $column, $operator, $value, 'or');
+    }
+
     /**
      * Add a nested where statement to the query.
      *

tests/Integration/Database/QueryBuilderTest.php

@@ -598,6 +598,18 @@ public function testChunkMap()
         $this->assertCount(3, DB::getQueryLog());
     }
 
+    public function testWhenWhere()
+    {
+        $this->assertSame(1, DB::table('posts')->whenWhere(true, 'id', 1)->count());
+        $this->assertSame(2, DB::table('posts')->whenWhere(false, 'id', 1)->count());
+    }
+
+    public function testOrWhenWhere()
+    {
+        $this->assertSame(1, DB::table('posts')->whenWhere(true, 'id', 1)->count());
+        $this->assertSame(2, DB::table('posts')->whenWhere(false, 'id', 1)->count());
+    }
+
     public function testPluck()
     {
         // Test SELECT override, since pluck will take the first column.