Add query buider 'unless' method (inverse of 'when')

src/Illuminate/Database/Concerns/BuildsQueries.php

@@ -94,6 +94,25 @@ public function when($value, $callback, $default = null)
         return $this;
     }
 
+    /**
+     * Apply the callback's query changes if the given "value" is false.
+     *
+     * @param  mixed  $value
+     * @param  callable  $callback
+     * @param  callable  $default
+     * @return mixed
+     */
+    public function unless($value, $callback, $default = null)
+    {
+        if (! $value) {
+            return $callback($this, $value) ?: $this;
+        } elseif ($default) {
+            return $default($this, $value) ?: $this;
+        }
+
+        return $this;
+    }
+
     /**
      * Create a new length-aware paginator instance.
      *

tests/Database/DatabaseQueryBuilderTest.php

@@ -189,6 +189,65 @@ public function testWhenCallbackWithDefault()
         $this->assertEquals([0 => 2, 1 => 'foo'], $builder->getBindings());
     }
 
+    public function testUnlessCallback()
+    {
+        $callback = function ($query, $condition) {
+            $this->assertFalse($condition);
+
+            $query->where('id', '=', 1);
+        };
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->unless(false, $callback)->where('email', 'foo');
+        $this->assertEquals('select * from "users" where "id" = ? and "email" = ?', $builder->toSql());
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->unless(true, $callback)->where('email', 'foo');
+        $this->assertEquals('select * from "users" where "email" = ?', $builder->toSql());
+    }
+
+    public function testUnlessCallbackWithReturn()
+    {
+        $callback = function ($query, $condition) {
+            $this->assertFalse($condition);
+
+            return $query->where('id', '=', 1);
+        };
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->unless(false, $callback)->where('email', 'foo');
+        $this->assertEquals('select * from "users" where "id" = ? and "email" = ?', $builder->toSql());
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->unless(true, $callback)->where('email', 'foo');
+        $this->assertEquals('select * from "users" where "email" = ?', $builder->toSql());
+    }
+
+    public function testUnlessCallbackWithDefault()
+    {
+        $callback = function ($query, $condition) {
+            $this->assertEquals($condition, 0);
+
+            $query->where('id', '=', 1);
+        };
+
+        $default = function ($query, $condition) {
+            $this->assertEquals($condition, 'truthy');
+
+            $query->where('id', '=', 2);
+        };
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->unless(0, $callback, $default)->where('email', 'foo');
+        $this->assertEquals('select * from "users" where "id" = ? and "email" = ?', $builder->toSql());
+        $this->assertEquals([0 => 1, 1 => 'foo'], $builder->getBindings());
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->unless('truthy', $callback, $default)->where('email', 'foo');
+        $this->assertEquals('select * from "users" where "id" = ? and "email" = ?', $builder->toSql());
+        $this->assertEquals([0 => 2, 1 => 'foo'], $builder->getBindings());
+    }
+
     public function testTapCallback()
     {
         $callback = function ($query) {