fix: render single trailing newline in .env (#9)

* fix: render single trailing newline in .env
* refactor: update test and env fixtures for case with empty lines
* refactor: update test for case with empty lines
* Added extra test case

---------

Co-authored-by: Jack Wilkinson <[email protected]>

Author: artengin

src/Printer/EnvPrinter.php

@@ -29,6 +29,6 @@ public function render(array $ast): string
             }
         }
 
-        return $output;
+        return rtrim($output) . PHP_EOL;
     }
 }

tests/EnvFileTest.php

@@ -223,4 +223,38 @@ public function testUpdateEnvWithTrailingComment()
         $result = $env->render();
         $this->assertStringContainsString('VAR_NO_VALUE=this is a test', $result);
     }
+
+    public function testUpdateEnvWithEmptyLine()
+    {
+        $filePath = __DIR__ . '/fixtures/env/test.env';
+
+        $env = EnvFile::open($filePath);
+
+        $env->addEmptyLine();
+        $env->addEmptyLine();
+        $env->addEmptyLine();
+        $env->addEmptyLine();
+
+        $this->assertEquals(file_get_contents($filePath), $env->render());
+    }
+
+    public function testEnvComplexWithEmptyLine()
+    {
+        $env = new EnvFile('');
+
+        $env->addEmptyLine();
+        $env->addEmptyLine();
+
+        $env->set('VAR_ONE', '1');
+
+        $env->addEmptyLine();
+        $env->addEmptyLine();
+
+        $env->set('VAR_TWO', '2');
+
+        $env->addEmptyLine();
+        $env->addEmptyLine();
+
+        $this->assertEquals(sprintf('%1$s%1$sVAR_ONE=1%1$s%1$s%1$sVAR_TWO=2%1$s', PHP_EOL), $env->render());
+    }
 }