calling viewer handler multiple times should not accidentally cause v…

…iewer to be null

Reviewed By: JenniferWang

Differential Revision: D6015530

fbshipit-source-id: 217d3ad825f75ff872e9b965c733792ce6a7d003

packages/relay-runtime/handlers/viewer/RelayViewerHandler.js

@@ -38,7 +38,8 @@ function update(store: RecordSourceProxy, payload: HandleFieldPayload): void {
   }
   const serverViewer = record.getLinkedRecord(payload.fieldKey);
   if (!serverViewer) {
-    record.setValue(null, payload.handleKey);
+    // If `serverViewer` is null, `viewer` key for `client:root` should already
+    // be null, so no need to `setValue` again.
     return;
   }
   // Server data already has viewer data at `client:root:viewer`, so link the

packages/relay-runtime/handlers/viewer/__tests__/RelayViewerHandler-test.js

@@ -60,30 +60,9 @@ describe('RelayViewerHandler', () => {
     expect(sinkData).toEqual({});
   });
 
-  it('sets the handle as deleted if the server viewer is null', () => {
-    baseSource.delete(VIEWER_ID);
-    RelayModernRecord.setLinkedRecordID(
-      baseSource.get(ROOT_ID),
-      'viewer',
-      VIEWER_ID,
-    );
-
-    const payload = {
-      dataID: ROOT_ID,
-      fieldKey: 'viewer',
-      handleKey: getRelayHandleKey('viewer', null, 'viewer'),
-    };
-    RelayViewerHandler.update(store, payload);
-    expect(sinkData).toEqual({
-      [ROOT_ID]: {
-        [ID_KEY]: ROOT_ID,
-        [TYPENAME_KEY]: ROOT_TYPE,
-        [payload.handleKey]: null,
-      },
-    });
-  });
-
-  it('sets the handle as deleted if the server viewer is undefined', () => {
+  it('links the handle to the server viewer for query data', () => {
+    const viewer = RelayModernRecord.create(VIEWER_ID, 'Viewer');
+    baseSource.set(VIEWER_ID, viewer);
     RelayModernRecord.setLinkedRecordID(
       baseSource.get(ROOT_ID),
       'viewer',
@@ -100,12 +79,13 @@ describe('RelayViewerHandler', () => {
       [ROOT_ID]: {
         [ID_KEY]: ROOT_ID,
         [TYPENAME_KEY]: ROOT_TYPE,
-        [payload.handleKey]: null,
+        viewer: null,
+        [payload.handleKey]: {[REF_KEY]: VIEWER_ID},
       },
     });
   });
 
-  it('links the handle to the server viewer for query data', () => {
+  it('links the handle to the server viewer when called multiple times', () => {
     const viewer = RelayModernRecord.create(VIEWER_ID, 'Viewer');
     baseSource.set(VIEWER_ID, viewer);
     RelayModernRecord.setLinkedRecordID(
@@ -119,6 +99,8 @@ describe('RelayViewerHandler', () => {
       fieldKey: 'viewer',
       handleKey: getRelayHandleKey('viewer', null, 'viewer'),
     };
+    // called twice should not break
+    RelayViewerHandler.update(store, payload);
     RelayViewerHandler.update(store, payload);
     expect(sinkData).toEqual({
       [ROOT_ID]: {