Fix SqlServerAdapter returning empty string instead of null for colum…

…n default (#2090)

src/Phinx/Db/Adapter/SqlServerAdapter.php

@@ -488,11 +488,18 @@ public function getColumns($tableName)
     }
 
     /**
-     * @param string $default Default
+     * @param string|null $default Default
      * @return int|string|null
      */
     protected function parseDefault($default)
     {
+        // if a column is non-nullable and has no default, the value of column_default is null,
+        // otherwise it should be a string value that we parse below, including "(NULL)" which
+        // also stands for a null default
+        if ($default === null) {
+            return null;
+        }
+
         $result = preg_replace(["/\('(.*)'\)/", "/\(\((.*)\)\)/", "/\((.*)\)/"], '$1', $default);
 
         if (strtoupper($result) === 'NULL') {

tests/Phinx/Db/Adapter/SqlServerAdapterTest.php

@@ -426,6 +426,21 @@ public function testAddColumnWithDefaultNull()
         }
     }
 
+    public function testAddColumnWithNotNullableNoDefault()
+    {
+        $table = new \Phinx\Db\Table('table1', [], $this->adapter);
+        $table
+            ->addColumn('col', 'string', ['null' => false])
+            ->create();
+
+        $columns = $this->adapter->getColumns('table1');
+        $this->assertCount(2, $columns);
+        $this->assertArrayHasKey('id', $columns);
+        $this->assertArrayHasKey('col', $columns);
+        $this->assertFalse($columns['col']->isNull());
+        $this->assertNull($columns['col']->getDefault());
+    }
+
     public function testAddColumnWithDefaultBool()
     {
         $table = new \Phinx\Db\Table('table1', [], $this->adapter);