From ddf5cc28098a7ce8331beeabbd2b74b36ff2aff0 Mon Sep 17 00:00:00 2001
From: Lee Byron <lee@leebyron.com>
Date: Tue, 14 Jul 2015 18:10:50 -0700
Subject: [PATCH] [RFC] standard printer uses no comma between fields

A couple issues have opened up about inconsistency in rendering graphql queries in the spec and in the ref impl - especially with respect to whitespace and commas.

Here I'm proposing that it's easier to read queries where every field is always on it's own line (eg, no `image { width, height }` one-liners) and that lines are split only by line-terminators and not also commas.

If there's agreement around this proposal, the second step will be to apply the printer to all graphql examples in the spec.
---
 src/language/__tests__/printer.js | 8 ++++----
 src/language/printer.js           | 9 +++------
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/src/language/__tests__/printer.js b/src/language/__tests__/printer.js
index a1779edaf0..a522de014c 100644
--- a/src/language/__tests__/printer.js
+++ b/src/language/__tests__/printer.js
@@ -49,12 +49,12 @@ describe('Printer', () => {
     expect(printed).to.equal(
   `query queryName($foo: ComplexType, $site: Site = MOBILE) {
   whoever123is: node(id: [123, 456]) {
-    id,
+    id
     ... on User @defer {
       field2 {
-        id,
+        id
         alias: field1(first: 10, after: $foo) @include(if: $foo) {
-          id,
+          id
           ...frag
         }
       }
@@ -75,7 +75,7 @@ fragment frag on Friend {
 }
 
 {
-  unnamed(truthy: true, falsey: false),
+  unnamed(truthy: true, falsey: false)
   query
 }
 `);
diff --git a/src/language/printer.js b/src/language/printer.js
index b5f7a21da4..bff2787e10 100644
--- a/src/language/printer.js
+++ b/src/language/printer.js
@@ -33,7 +33,9 @@ export function print(ast) {
       },
       VariableDefinition: node =>
         join([node.variable + ': ' + node.type, node.defaultValue], ' = '),
-      SelectionSet: node => blockList(node.selections, ',\n'),
+      SelectionSet: node =>
+        length(node.selections) === 0 ? null :
+        indent('{\n' + join(node.selections, '\n')) + '\n}',
       Field: node =>
         join([
           join([
@@ -94,11 +96,6 @@ export function print(ast) {
   });
 }
 
-function blockList(list, separator) {
-  return length(list) === 0 ? null :
-    indent('{\n' + join(list, separator)) + '\n}';
-}
-
 function indent(maybeString) {
   return maybeString && maybeString.replace(/\n/g, '\n  ');
 }