From 2d60dda93c09b0c8d7b69241833174f991d7b450 Mon Sep 17 00:00:00 2001
From: enisdenjo <badurinadenis@gmail.com>
Date: Sat, 31 Oct 2020 20:46:08 +0100
Subject: [PATCH] fix(client): Accept nullish values for `operationName` and
 `variables`

---
 src/message.ts      |  6 +++++-
 src/tests/client.ts | 25 +++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/message.ts b/src/message.ts
index b8b45c57..468d1c2d 100644
--- a/src/message.ts
+++ b/src/message.ts
@@ -101,10 +101,14 @@ export function isMessage(val: unknown): val is Message {
           hasOwnStringProperty(val, 'id') &&
           hasOwnObjectProperty(val, 'payload') &&
           (!hasOwnProperty(val.payload, 'operationName') ||
-            hasOwnStringProperty(val.payload, 'operationName')) &&
+            val.payload.operationName === undefined ||
+            val.payload.operationName === null ||
+            typeof val.payload.operationName === 'string') &&
           (hasOwnStringProperty(val.payload, 'query') || // string query or persisted query id
             hasOwnObjectProperty(val.payload, 'query')) && // document node query
           (!hasOwnProperty(val.payload, 'variables') ||
+            val.payload.variables === undefined ||
+            val.payload.variables === null ||
             hasOwnObjectProperty(val.payload, 'variables'))
         );
       case MessageType.Next:
diff --git a/src/tests/client.ts b/src/tests/client.ts
index adac6053..d817527a 100644
--- a/src/tests/client.ts
+++ b/src/tests/client.ts
@@ -170,6 +170,31 @@ describe('query operation', () => {
 
     await sub.waitForComplete();
   });
+
+  it('should accept nullish value for `operationName` and `variables`', async () => {
+    const { url } = await startTServer();
+
+    const client = createClient({ url });
+
+    // nothing
+    await tsubscribe(client, {
+      query: 'query { getValue }',
+    }).waitForComplete();
+
+    // undefined
+    await tsubscribe(client, {
+      operationName: undefined,
+      query: 'query { getValue }',
+      variables: undefined,
+    }).waitForComplete();
+
+    // null
+    await tsubscribe(client, {
+      operationName: null,
+      query: 'query { getValue }',
+      variables: null,
+    }).waitForComplete();
+  });
 });
 
 describe('subscription operation', () => {