From 5f0a23d8deaaa745a2210e2fd42d3d7dfc7ffcee Mon Sep 17 00:00:00 2001
From: Joseph Savona <joesavona@fb.com>
Date: Fri, 27 Nov 2015 16:17:16 -0800
Subject: [PATCH] Skip printing empty fragments

---
 .../__tests__/printRelayOSSQuery-test.js      | 24 +++++++++++++++++++
 src/traversal/printRelayOSSQuery.js           | 19 +++++++++++----
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/src/__forks__/traversal/__tests__/printRelayOSSQuery-test.js b/src/__forks__/traversal/__tests__/printRelayOSSQuery-test.js
index c1554173781c8..d4aa3c56919e1 100644
--- a/src/__forks__/traversal/__tests__/printRelayOSSQuery-test.js
+++ b/src/__forks__/traversal/__tests__/printRelayOSSQuery-test.js
@@ -288,6 +288,30 @@ describe('printRelayOSSQuery', () => {
       `);
       expect(variables).toEqual({});
     });
+
+    it('omits empty inline fragments', () => {
+      var fragment = getNode(Relay.QL`
+        fragment on Viewer {
+          actor {
+            id
+          }
+          ... on Viewer {
+            actor @include(if: $false) {
+              name
+            }
+          }
+        }
+      `, {false: false});
+      var {text} = printRelayOSSQuery(fragment);
+      expect(text).toEqualPrintedQuery(`
+        fragment PrintRelayOSSQuery on Viewer {
+          actor {
+            id,
+            __typename
+          }
+        }
+      `);
+    });
   });
 
   describe('fields', () => {
diff --git a/src/traversal/printRelayOSSQuery.js b/src/traversal/printRelayOSSQuery.js
index b5e82df856191..6e8b34ab7eb7d 100644
--- a/src/traversal/printRelayOSSQuery.js
+++ b/src/traversal/printRelayOSSQuery.js
@@ -160,7 +160,10 @@ function printFragment(
 function printInlineFragment(
   node: RelayQuery.Fragment,
   printerState: PrinterState
-): string {
+): ?string {
+  if (!node.getChildren().length) {
+    return null;
+  }
   var fragmentID = node.getFragmentID();
   var {fragmentMap} = printerState;
   if (!(fragmentID in fragmentMap)) {
@@ -210,9 +213,11 @@ function printChildren(
   node: RelayQuery.Node,
   printerState: PrinterState
 ): string {
-  var children = node.getChildren().map(node => {
+  let children;
+  node.getChildren().forEach(node => {
     if (node instanceof RelayQuery.Field) {
-      return printField(node, printerState);
+      children = children || [];
+      children.push(printField(node, printerState));
     } else {
       invariant(
         node instanceof RelayQuery.Fragment,
@@ -220,10 +225,14 @@ function printChildren(
         '`Fragment`, got `%s`.',
         node.constructor.name
       );
-      return printInlineFragment(node, printerState);
+      const printedFragment = printInlineFragment(node, printerState);
+      if (printedFragment) {
+        children = children || [];
+        children.push(printedFragment);
+      }
     }
   });
-  if (!children.length) {
+  if (!children) {
     return '';
   }
   return '{' + children.join(',') + '}';