From fcf2e2a64fa3770c1c3c3dcfcea25168ed18e7fe Mon Sep 17 00:00:00 2001
From: Ben Newman <ben@apollographql.com>
Date: Fri, 7 Feb 2020 14:55:25 -0500
Subject: [PATCH] Support delivering initial cache.watch results immediately,
 if requested.

I needed this functionality for some tests of cache.modify, but I think I
can expand it into a version of cache.watch that returns an async iterator
if you do not supply a callback.
---
 src/cache/core/types/Cache.ts       | 1 +
 src/cache/inmemory/inMemoryCache.ts | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/cache/core/types/Cache.ts b/src/cache/core/types/Cache.ts
index 911e15c2d66..596a4cd5ceb 100644
--- a/src/cache/core/types/Cache.ts
+++ b/src/cache/core/types/Cache.ts
@@ -21,6 +21,7 @@ export namespace Cache {
   }
 
   export interface WatchOptions extends ReadOptions {
+    immediate?: boolean;
     callback: WatchCallback;
   }
 
diff --git a/src/cache/inmemory/inMemoryCache.ts b/src/cache/inmemory/inMemoryCache.ts
index bb5016247fc..5a55cc2eeb8 100644
--- a/src/cache/inmemory/inMemoryCache.ts
+++ b/src/cache/inmemory/inMemoryCache.ts
@@ -165,7 +165,9 @@ export class InMemoryCache extends ApolloCache<NormalizedCacheObject> {
 
   public watch(watch: Cache.WatchOptions): () => void {
     this.watches.add(watch);
-
+    if (watch.immediate) {
+      this.maybeBroadcastWatch(watch);
+    }
     return () => {
       this.watches.delete(watch);
     };