From d1eeb01b016efa5485353aa6936000b4fbb4a580 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Fri, 4 Sep 2020 15:44:18 +0200
Subject: [PATCH] core-api: overload createApiFactory with a singleton helper

---
 packages/core-api/src/apis/helpers.ts | 30 +++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/packages/core-api/src/apis/helpers.ts b/packages/core-api/src/apis/helpers.ts
index e2274a20f1..95be80e541 100644
--- a/packages/core-api/src/apis/helpers.ts
+++ b/packages/core-api/src/apis/helpers.ts
@@ -14,15 +14,37 @@
  * limitations under the License.
  */
 
-import { AnyApiFactory, ApiFactory } from './types';
+import { ApiFactory } from './types';
+import { ApiRef } from './ApiRef';
 
 /**
  * Used to infer types for a standalone ApiFactory that isn't immediately passed
  * to another function.
  * This function doesn't actually do anything, it's only used to infer types.
  */
-export function createApiFactory<Api, Impl, Deps>(
-  factory: ApiFactory<Api, Impl, Deps>,
-): AnyApiFactory {
+export function createApiFactory<
+  Api,
+  Impl extends Api,
+  Deps extends { [name in string]: unknown }
+>(factory: ApiFactory<Api, Impl, Deps>): ApiFactory<Api, Impl, Deps>;
+export function createApiFactory<Api, Impl extends Api>(
+  api: ApiRef<Api>,
+  instance: Impl,
+): ApiFactory<Api, Impl, {}>;
+export function createApiFactory<
+  Api,
+  Impl extends Api,
+  Deps extends { [name in string]: unknown }
+>(
+  factory: ApiFactory<Api, Impl, Deps> | ApiRef<Api>,
+  instance?: Impl,
+): ApiFactory<Api, Impl, Deps> {
+  if ('id' in factory) {
+    return ({
+      implements: factory,
+      deps: {},
+      factory: () => instance!,
+    } as unknown) as ApiFactory<Api, Impl, Deps>;
+  }
   return factory;
 }