diff --git a/lib/reducers/message-reducer.js b/lib/reducers/message-reducer.js
--- a/lib/reducers/message-reducer.js
+++ b/lib/reducers/message-reducer.js
@@ -112,7 +112,7 @@
   return threads;
 }
 
-function threadIsWatched(
+function isThreadWatched(
   threadID: string,
   threadInfo: ?RawThreadInfo,
   watchedIDs: $ReadOnlyArray<string>,
@@ -162,7 +162,7 @@
     const threadInfo = threadInfos[threadID];
     if (
       threads[threadID] ||
-      !threadIsWatched(threadID, threadInfo, watchedIDs)
+      !isThreadWatched(threadID, threadInfo, watchedIDs)
     ) {
       continue;
     }
@@ -289,7 +289,7 @@
   const unshimmedNewMessages = unshimMessageInfos(newMessageInfos);
   const unshimmedNewMessagesOfWatchedThreads = unshimmedNewMessages.filter(
     msg =>
-      threadIsWatched(
+      isThreadWatched(
         msg.threadID,
         threadInfos[msg.threadID],
         watchedThreadIDs,
@@ -579,7 +579,7 @@
   messageStoreOperations.push(...reassignMessagesOps);
   const watchedIDs = [...threadWatcher.getWatchedIDs(), ...reassignedThreadIDs];
   const watchedThreadInfos = _pickBy((threadInfo: RawThreadInfo) =>
-    threadIsWatched(threadInfo.id, threadInfo, watchedIDs),
+    isThreadWatched(threadInfo.id, threadInfo, watchedIDs),
   )(threadInfos);
 
   const filteredThreads = _pick(Object.keys(watchedThreadInfos))(
@@ -601,7 +601,7 @@
   for (const threadID in threadInfos) {
     const threadInfo = threadInfos[threadID];
     if (
-      threadIsWatched(threadID, threadInfo, watchedIDs) &&
+      isThreadWatched(threadID, threadInfo, watchedIDs) &&
       !filteredThreads[threadID]
     ) {
       filteredThreads[threadID] = {