From 53d8f17344944182456a7c863ae186a7e37fb131 Mon Sep 17 00:00:00 2001
From: theobat <theophile.batoz@gmail.com>
Date: Wed, 22 Feb 2017 01:54:40 +0100
Subject: [PATCH] Fix Cannot read property 'length' of undefined (#162)

* fix(denormalizeStore): refresh empty list data properly

* test(denormalizeStore)
---
 .../__tests__/denormalizeStore-tests.js       | 23 +++++++++++++++++++
 src/normalize/denormalizeStore.js             |  8 +++++--
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/normalize/__tests__/denormalizeStore-tests.js b/src/normalize/__tests__/denormalizeStore-tests.js
index a386a39..772c67f 100644
--- a/src/normalize/__tests__/denormalizeStore-tests.js
+++ b/src/normalize/__tests__/denormalizeStore-tests.js
@@ -175,3 +175,26 @@ test('flag sendToServer = true for array of objects', t => {
   //                                    getPostById ->           keywordsMentioned ->       word
   t.true(context.operation.selectionSet.selections[0].selectionSet.selections[1].selectionSet.selections[0].sendToServer);
 });
+
+test('Same query with another argument', t => {
+  const rawQuery = `
+  query {
+    getCommentsByPostId {
+      _id
+      postId
+      content
+    }
+  }`;
+  const queryAST = parseAndInitializeQuery(rawQuery, clientSchema, idFieldName);
+  const context = buildExecutionContext(queryAST, {
+    variables: {"postId": "p126"},
+    coerceTypes,
+    getState: () => ({entities:{}, result: {getCommentsByPostId: {'"postId": "p123"':[]}}}),
+    idFieldName,
+    paginationWords,
+    schema: clientSchema
+  });
+  const actual = denormalizeStore(context);
+  const expected = {getCommentsByPostId:[{_id:null,postId:null,content:null}]}
+  t.deepEqual(actual, expected)
+});
diff --git a/src/normalize/denormalizeStore.js b/src/normalize/denormalizeStore.js
index cc85cc3..07c63a6 100644
--- a/src/normalize/denormalizeStore.js
+++ b/src/normalize/denormalizeStore.js
@@ -78,8 +78,12 @@ const visitObject = (subState = {}, reqAST, parentTypeSchema, context, reduction
         if (isPrimitive(nnFieldType.kind) || subState[fieldName] === null) {
           reduction[aliasOrFieldName] = visitScalar(fieldState, context.coerceTypes[typeSchema.name])
         } else {
-          if (nnFieldType.kind === LIST) {
-            reduction[aliasOrFieldName] = visitIterable(fieldState, field, typeSchema, context, aliasOrFieldName);
+          if ((nnFieldType.kind === LIST)) {
+            if (fieldState) {
+              reduction[aliasOrFieldName] = visitIterable(fieldState, field, typeSchema, context, aliasOrFieldName);
+            } else {
+              reduction[aliasOrFieldName] = [visitObject(fieldState, field, typeSchema, context)];
+            }
           } else {
             reduction[aliasOrFieldName] = visitObject(fieldState, field, typeSchema, context);
           }