Add support for empty descriptions

Author: vhenzl

src/Language/BlockString.php

@@ -118,9 +118,9 @@ public static function print(
     ): string {
         $valueLength          = mb_strlen($value);
         $isSingleLine         = strpos($value, "\n") === false;
-        $hasLeadingSpace      = $value[0] === ' ' || $value[0] === '\t';
-        $hasTrailingQuote     = $value[$valueLength - 1] === '"';
-        $hasTrailingSlash     = $value[$valueLength - 1] === '\\';
+        $hasLeadingSpace      = $value !== '' && ($value[0] === ' ' || $value[0] === '\t');
+        $hasTrailingQuote     = $value !== '' && $value[$valueLength - 1] === '"';
+        $hasTrailingSlash     = $value !== '' && $value[$valueLength - 1] === '\\';
         $printAsMultipleLines =
             ! $isSingleLine ||
             $hasTrailingQuote ||

src/Utils/ASTDefinitionBuilder.php

@@ -37,6 +37,7 @@
 use Throwable;
 
 use function array_reverse;
+use function count;
 use function implode;
 use function is_array;
 use function is_string;
@@ -137,7 +138,7 @@ private function getLeadingCommentBlock(Node $node): ?string
             $token      = $token->prev;
         }
 
-        return implode("\n", array_reverse($comments));
+        return count($comments) > 0 ? implode("\n", array_reverse($comments)) : null;
     }
 
     /**

src/Utils/SchemaPrinter.php

@@ -163,7 +163,7 @@ protected static function printDirective(Directive $directive, array $options):
      */
     protected static function printDescription(array $options, $def, string $indentation = '', bool $firstInBlock = true): string
     {
-        if ($def->description === null || $def->description === '') {
+        if ($def->description === null) {
             return '';
         }
 

tests/Language/BlockStringTest.php

@@ -255,4 +255,12 @@ public function testCorrectlyPrintsStringWithAFirstLineIndentation(): void
             BlockString::print($str)
         );
     }
+
+    public function testCorrectlyPrintsEmptyString(): void
+    {
+        $str = '';
+
+        self::assertEquals('""""""', BlockString::print($str));
+        self::assertEquals("\"\"\"\n\n\"\"\"", BlockString::print($str, '', true));
+    }
 }

tests/Utils/SchemaPrinterTest.php

@@ -824,6 +824,27 @@ public function testPrintsCustomDirectives(): void
         );
     }
 
+    /**
+     * @see it('Prints an empty description')
+     */
+    public function testPrintsAnEmptyDescription(): void
+    {
+        $output = $this->printSingleFieldSchema([
+            'type'        => Type::string(),
+            'description' => '',
+        ]);
+
+        self::assertEquals(
+            '
+type Query {
+  """"""
+  singleField: String
+}
+',
+            $output
+        );
+    }
+
     /**
      * @see it('One-line prints a short description')
      */