From 5eebdd38b7e20b4c267484602dc2fb57ba547994 Mon Sep 17 00:00:00 2001
From: Kevin Sullivan <kevin.sullivan@axolotl.industries>
Date: Fri, 5 Oct 2018 23:04:14 -0500
Subject: [PATCH 1/2] Fix error when printing a `FieldDefinition` AST node
 without arguments

---
 src/language/printer.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/language/printer.js b/src/language/printer.js
index 949f7c22c7..66783a87f9 100644
--- a/src/language/printer.js
+++ b/src/language/printer.js
@@ -134,7 +134,7 @@ const printDocASTReducer = {
   ),
 
   FieldDefinition: addDescription(
-    ({ name, arguments: args, type, directives }) =>
+    ({ name, arguments: args = [], type, directives }) =>
       name +
       (args.every(arg => arg.indexOf('\n') === -1)
         ? wrap('(', join(args, ', '), ')')

From 16fdfd7f7dc0c6bbc7c20f8e48a96d8eb1c3aab2 Mon Sep 17 00:00:00 2001
From: Ivan Goncharov <ivan.goncharov.ua@gmail.com>
Date: Tue, 9 Oct 2018 17:56:11 +0300
Subject: [PATCH 2/2] Generalize solution

---
 src/language/printer.js | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/language/printer.js b/src/language/printer.js
index 66783a87f9..6ade5f6235 100644
--- a/src/language/printer.js
+++ b/src/language/printer.js
@@ -134,11 +134,11 @@ const printDocASTReducer = {
   ),
 
   FieldDefinition: addDescription(
-    ({ name, arguments: args = [], type, directives }) =>
+    ({ name, arguments: args, type, directives }) =>
       name +
-      (args.every(arg => arg.indexOf('\n') === -1)
-        ? wrap('(', join(args, ', '), ')')
-        : wrap('(\n', indent(join(args, '\n')), '\n)')) +
+      (hasMultilineItems(args)
+        ? wrap('(\n', indent(join(args, '\n')), '\n)')
+        : wrap('(', join(args, ', '), ')')) +
       ': ' +
       type +
       wrap(' ', join(directives, ' ')),
@@ -184,9 +184,9 @@ const printDocASTReducer = {
     ({ name, arguments: args, locations }) =>
       'directive @' +
       name +
-      (args.every(arg => arg.indexOf('\n') === -1)
-        ? wrap('(', join(args, ', '), ')')
-        : wrap('(\n', indent(join(args, '\n')), '\n)')) +
+      (hasMultilineItems(args)
+        ? wrap('(\n', indent(join(args, '\n')), '\n)')
+        : wrap('(', join(args, ', '), ')')) +
       ' on ' +
       join(locations, ' | '),
   ),
@@ -264,6 +264,14 @@ function indent(maybeString) {
   return maybeString && '  ' + maybeString.replace(/\n/g, '\n  ');
 }
 
+function isMultiline(string) {
+  return string.indexOf('\n') !== -1;
+}
+
+function hasMultilineItems(maybeArray) {
+  return maybeArray && maybeArray.some(isMultiline);
+}
+
 /**
  * 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
@@ -271,7 +279,7 @@ function indent(maybeString) {
  */
 function printBlockString(value, isDescription) {
   const escaped = value.replace(/"""/g, '\\"""');
-  return (value[0] === ' ' || value[0] === '\t') && value.indexOf('\n') === -1
-    ? `"""${escaped.replace(/"$/, '"\n')}"""`
-    : `"""\n${isDescription ? escaped : indent(escaped)}\n"""`;
+  return isMultiline(value) || (value[0] !== ' ' && value[0] !== '\t')
+    ? `"""\n${isDescription ? escaped : indent(escaped)}\n"""`
+    : `"""${escaped.replace(/"$/, '"\n')}"""`;
 }