Unify Printer and SchemaPrinter output for block strings

src/Language/BlockString.php

@@ -12,6 +12,8 @@
 use function mb_strlen;
 use function mb_substr;
 use function preg_split;
+use function str_replace;
+use function strpos;
 
 class BlockString
 {
@@ -103,4 +105,46 @@ public static function getIndentation(string $value): int
 
         return $commonIndent ?? 0;
     }
+
+    /**
+     * Print a block string in the indented block form by adding a leading and
+     * trailing blank line. However, if a block string starts with whitespace and is
+     * a single-line, adding a leading blank line would strip that whitespace.
+     */
+    public static function print(
+        string $value,
+        string $indentation = '',
+        bool $preferMultipleLines = false
+    ): string {
+        $valueLength          = mb_strlen($value);
+        $isSingleLine         = strpos($value, "\n") === false;
+        $hasLeadingSpace      = $value[0] === ' ' || $value[0] === '\t';
+        $hasTrailingQuote     = $value[$valueLength - 1] === '"';
+        $hasTrailingSlash     = $value[$valueLength - 1] === '\\';
+        $printAsMultipleLines =
+            ! $isSingleLine
+            || $hasTrailingQuote
+            || $hasTrailingSlash
+            || $preferMultipleLines;
+
+        $result = '';
+        // Format a multi-line block quote to account for leading space.
+        if (
+            $printAsMultipleLines
+            && ! ($isSingleLine && $hasLeadingSpace)
+        ) {
+            $result .= "\n" . $indentation;
+        }
+
+        $result .= $indentation !== ''
+            ? str_replace("\n", "\n" . $indentation, $value)
+            : $value;
+        if ($printAsMultipleLines) {
+            $result .= "\n";
+        }
+
+        return '"""'
+            . str_replace('"""', '\\"""', $result)
+            . '"""';
+    }
 }

src/Language/Printer.php

@@ -55,7 +55,6 @@
 use function count;
 use function implode;
 use function json_encode;
-use function preg_replace;
 use function str_replace;
 use function strlen;
 use function strpos;
@@ -408,7 +407,7 @@ protected function p(?Node $node, bool $isDescription = false): string
 
             case $node instanceof StringValueNode:
                 if ($node->block) {
-                    return $this->printBlockString($node->value, $isDescription);
+                    return BlockString::print($node->value, $isDescription ? '' : '  ');
                 }
 
                 return json_encode($node->value);
@@ -518,27 +517,4 @@ protected function join(array $parts, string $separator = ''): string
     {
         return implode($separator, array_filter($parts));
     }
-
-    /**
-     * Print a block string in the indented block form by adding a leading and
-     * trailing blank line. However, if a block string starts with whitespace and is
-     * a single-line, adding a leading blank line would strip that whitespace.
-     */
-    protected function printBlockString(string $value, bool $isDescription): string
-    {
-        $escaped = str_replace('"""', '\\"""', $value);
-
-        $startsWithWhitespace  = $value[0] === ' ' || $value[0] === "\t";
-        $doesNotEndWithNewline = strpos($value, "\n") === false;
-
-        if ($startsWithWhitespace && $doesNotEndWithNewline) {
-            return '"""' . preg_replace('/"$/', "\"\n", $escaped) . '"""';
-        }
-
-        $content = $isDescription
-            ? $escaped
-            : $this->indent($escaped);
-
-        return '"""' . "\n" . $content . "\n" . '"""';
-    }
 }

src/Utils/SchemaPrinter.php

@@ -5,6 +5,7 @@
 namespace GraphQL\Utils;
 
 use GraphQL\Error\Error;
+use GraphQL\Language\BlockString;
 use GraphQL\Language\Printer;
 use GraphQL\Type\Definition\Directive;
 use GraphQL\Type\Definition\EnumType;
@@ -34,7 +35,6 @@
 use function sprintf;
 use function str_replace;
 use function strlen;
-use function substr;
 
 /**
  * Given an instance of Schema, prints it in schema definition language.
@@ -167,46 +167,17 @@ protected static function printDescription(array $options, $def, string $indenta
             return '';
         }
 
-        $lines = static::descriptionLines($def->description, 120 - strlen($indentation));
         if (isset($options['commentDescriptions'])) {
-            return static::printDescriptionWithComments($lines, $indentation, $firstInBlock);
-        }
-
-        $description = $indentation !== '' && ! $firstInBlock
-            ? "\n" . $indentation . '"""'
-            : $indentation . '"""';
+            $lines = static::descriptionLines($def->description, 120 - strlen($indentation));
 
-        // In some circumstances, a single line can be used for the description.
-        if (
-            count($lines) === 1 &&
-            mb_strlen($lines[0]) < 70 &&
-            substr($lines[0], -1) !== '"'
-        ) {
-            return $description . static::escapeQuote($lines[0]) . "\"\"\"\n";
-        }
-
-        // Format a multi-line block quote to account for leading space.
-        $hasLeadingSpace = isset($lines[0]) &&
-            (
-                substr($lines[0], 0, 1) === ' ' ||
-                substr($lines[0], 0, 1) === '\t'
-            );
-        if (! $hasLeadingSpace) {
-            $description .= "\n";
-        }
-
-        $lineLength = count($lines);
-        for ($i = 0; $i < $lineLength; $i++) {
-            if ($i !== 0 || ! $hasLeadingSpace) {
-                $description .= $indentation;
-            }
-
-            $description .= static::escapeQuote($lines[$i]) . "\n";
+            return static::printDescriptionWithComments($lines, $indentation, $firstInBlock);
         }
 
-        $description .= $indentation . "\"\"\"\n";
+        $preferMultipleLines = mb_strlen($def->description) > 70;
+        $blockString         = BlockString::print($def->description, '', $preferMultipleLines);
+        $prefix              = $indentation !== '' && ! $firstInBlock ? "\n" . $indentation : $indentation;
 
-        return $description;
+        return $prefix . str_replace("\n", "\n" . $indentation, $blockString) . "\n";
     }
 
     /**
@@ -264,11 +235,6 @@ protected static function printDescriptionWithComments(array $lines, string $ind
         return $description;
     }
 
-    protected static function escapeQuote(string $line): string
-    {
-        return str_replace('"""', '\\"""', $line);
-    }
-
     /**
      * @param array<string, bool>       $options
      * @param array<int, FieldArgument> $args

tests/Language/BlockStringTest.php

@@ -174,4 +174,85 @@ public function testDoNotTakeEmptyLinesIntoAccount(): void
         self::assertEquals(1, BlockString::getIndentation("a\n\n b"));
         self::assertEquals(2, BlockString::getIndentation("a\n \n  b"));
     }
+
+    // describe('printBlockString')
+
+    /**
+     * @see it('do not escape characters')
+     */
+    public function testDoNotEscapeCharacters(): void
+    {
+        $str = "\" \\ / \u{8} \f \n \r \t"; // \u{8} === \b
+
+        self::assertEquals("\"\"\"\n" . $str . "\n\"\"\"", BlockString::print($str));
+    }
+
+    /**
+     * @see it('by default print block strings as single line')
+     */
+    public function testByDefaultPrintBlockStringsAsSingleLine(): void
+    {
+        $str = 'one liner';
+
+        self::assertEquals('"""one liner"""', BlockString::print($str));
+        self::assertEquals("\"\"\"\none liner\n\"\"\"", BlockString::print($str, '', true));
+    }
+
+    /**
+     * @see it('correctly prints single-line with leading space')
+     */
+    public function testCorrectlyPrintsSingleLineWithLeadingSpace(): void
+    {
+        $str = '    space-led string';
+
+        self::assertEquals('"""    space-led string"""', BlockString::print($str));
+        self::assertEquals("\"\"\"    space-led string\n\"\"\"", BlockString::print($str, '', true));
+    }
+
+    /**
+     * @see it('correctly prints single-line with leading space and quotation')
+     */
+    public function testCorrectlyPrintsSingleLineWithLeadingSpaceAndQuotation(): void
+    {
+        $str = '    space-led value "quoted string"';
+
+        self::assertEquals("\"\"\"    space-led value \"quoted string\"\n\"\"\"", BlockString::print($str));
+        self::assertEquals("\"\"\"    space-led value \"quoted string\"\n\"\"\"", BlockString::print($str));
+    }
+
+    /**
+     * @see it('correctly prints single-line with trailing backslash')
+     */
+    public function testCorrectlyPrintsSingleLineWithTrailingBackslash(): void
+    {
+        $str = 'backslash \\';
+
+        self::assertEquals("\"\"\"\nbackslash \\\n\"\"\"", BlockString::print($str));
+        self::assertEquals("\"\"\"\nbackslash \\\n\"\"\"", BlockString::print($str, '', true));
+    }
+
+    /**
+     * @see it('correctly prints string with a first line indentation')
+     */
+    public function testCorrectlyPrintsStringWithAFirstLineIndentation(): void
+    {
+        $str = self::joinLines(
+            '    first  ',
+            '  line     ',
+            'indentation',
+            '     string',
+        );
+
+        self::assertEquals(
+            self::joinLines(
+                '"""',
+                '    first  ',
+                '  line     ',
+                'indentation',
+                '     string',
+                '"""',
+            ),
+            BlockString::print($str)
+        );
+    }
 }

tests/Language/PrinterTest.php

@@ -119,67 +119,6 @@ public function testPrintsFragmentWithVariableDirectives(): void
         self::assertEquals($expected, Printer::doPrint($queryAstWithVariableDirective));
     }
 
-    /**
-     * @see it('correctly prints single-line with leading space')
-     */
-    public function testCorrectlyPrintsSingleLineBlockStringsWithLeadingSpace(): void
-    {
-        $mutationAstWithArtifacts = Parser::parse(
-            '{ field(arg: """    space-led value""") }'
-        );
-        $expected                 = '{
-  field(arg: """    space-led value""")
-}
-';
-        self::assertEquals($expected, Printer::doPrint($mutationAstWithArtifacts));
-    }
-
-    /**
-     * @see it('correctly prints string with a first line indentation')
-     */
-    public function testCorrectlyPrintsBlockStringsWithAFirstLineIndentation(): void
-    {
-        $mutationAstWithArtifacts = Parser::parse(
-            '{
-  field(arg: """
-        first
-      line
-    indentation
-  """)
-}'
-        );
-        $expected                 = '{
-  field(arg: """
-        first
-      line
-    indentation
-  """)
-}
-';
-        self::assertEquals($expected, Printer::doPrint($mutationAstWithArtifacts));
-    }
-
-    /**
-     * @see it('correctly prints single-line with leading space and quotation')
-     */
-    public function testCorrectlyPrintsSingleLineWithLeadingSpaceAndQuotation(): void
-    {
-        $mutationAstWithArtifacts = Parser::parse('
-            {
-              field(arg: """    space-led value "quoted string"
-              """)
-            }
-        ');
-        $expected                 = <<<END
-{
-  field(arg: """    space-led value "quoted string"
-  """)
-}
-
-END;
-        self::assertEquals($expected, Printer::doPrint($mutationAstWithArtifacts));
-    }
-
     /**
      * @see it('Experimental: correctly prints fragment defined variables')
      */
@@ -203,25 +142,6 @@ public function testExperimentalCorrectlyPrintsFragmentDefinedVariables(): void
         );
     }
 
-    /**
-     * @see it('correctly prints single-line with leading space and quotation')
-     */
-    public function testCorrectlyPrintsSingleLineStringsWithLeadingSpaceAndQuotation(): void
-    {
-        $mutationAstWithArtifacts = Parser::parse(
-            '{
-  field(arg: """    space-led value "quoted string"
-  """)
-}'
-        );
-        $expected                 = '{
-  field(arg: """    space-led value "quoted string"
-  """)
-}
-';
-        self::assertEquals($expected, Printer::doPrint($mutationAstWithArtifacts));
-    }
-
     /**
      * @see it('prints kitchen sink')
      */

tests/Language/SchemaPrinterTest.php

@@ -62,13 +62,9 @@ public function testPrintsKitchenSink(): void
 """
 type Foo implements Bar & Baz & Two {
   one: Type
-  """
-  This is a description of the `two` field.
-  """
+  """This is a description of the `two` field."""
   two(
-    """
-    This is a description of the `argument` argument.
-    """
+    """This is a description of the `argument` argument."""
     argument: InputType!
   ): Type
   three(argument: InputType, other: String): Int