From 1e2bff1f2f3014903d1bc9302412930bbe62f927 Mon Sep 17 00:00:00 2001
From: Nathaniel Tucker <me@ntucker.me>
Date: Mon, 27 Jan 2020 01:50:06 -0800
Subject: [PATCH] enhance: Remove lodash dependency, reducing total bundle size
 (#250)

---
 packages/rest-hooks/package.json              |  4 +-
 .../rest-hooks/src/state/NetworkManager.ts    | 67 ++++++++++---------
 .../src/state/SubscriptionManager.ts          | 41 ++++++------
 3 files changed, 57 insertions(+), 55 deletions(-)

diff --git a/packages/rest-hooks/package.json b/packages/rest-hooks/package.json
index 953cd0de469..b6c7a227ee4 100644
--- a/packages/rest-hooks/package.json
+++ b/packages/rest-hooks/package.json
@@ -67,9 +67,7 @@
   "dependencies": {
     "@babel/runtime": "^7.7.2",
     "@rest-hooks/normalizr": "^4.3.2",
-    "@types/lodash": "^4.14.149",
-    "flux-standard-action": "^2.1.1",
-    "lodash": "^4.17.15"
+    "flux-standard-action": "^2.1.1"
   },
   "peerDependencies": {
     "@types/react": "^16.8.2",
diff --git a/packages/rest-hooks/src/state/NetworkManager.ts b/packages/rest-hooks/src/state/NetworkManager.ts
index 48387ce7e0f..84060153b99 100644
--- a/packages/rest-hooks/src/state/NetworkManager.ts
+++ b/packages/rest-hooks/src/state/NetworkManager.ts
@@ -1,5 +1,3 @@
-import { memoize } from 'lodash';
-
 import RIC from './RIC';
 import { createReceive, createReceiveError } from './actionCreators';
 
@@ -7,6 +5,7 @@ import {
   FetchAction,
   ReceiveAction,
   MiddlewareAPI,
+  Middleware,
   Manager,
   Dispatch,
 } from '~/types';
@@ -35,9 +34,40 @@ export default class NetworkManager implements Manager {
   protected rejectors: { [k: string]: (value?: any) => void } = {};
   declare readonly dataExpiryLength: number;
   declare readonly errorExpiryLength: number;
+  protected declare middleware: Middleware;
+
   constructor(dataExpiryLength = 60000, errorExpiryLength = 1000) {
     this.dataExpiryLength = dataExpiryLength;
     this.errorExpiryLength = errorExpiryLength;
+
+    this.middleware = <R extends React.Reducer<any, any>>({
+      dispatch,
+    }: MiddlewareAPI<R>) => {
+      return (next: Dispatch<R>) => (
+        action: React.ReducerAction<R>,
+      ): Promise<void> => {
+        switch (action.type) {
+          case FETCH_TYPE:
+            this.handleFetch(action, dispatch);
+            if (process.env.NODE_ENV !== 'production') action.meta.nm = true;
+            return next(action);
+          case RECEIVE_DELETE_TYPE:
+          case RECEIVE_MUTATE_TYPE:
+          case RECEIVE_TYPE:
+            // only receive after new state is computed
+            return next(action).then(() => {
+              if (action.meta.url in this.fetched) {
+                this.handleReceive(action);
+              }
+            });
+          case RESET_TYPE:
+            this.cleanup();
+            return next(action);
+          default:
+            return next(action);
+        }
+      };
+    };
   }
 
   /** Ensures all promises are completed by rejecting remaining. */
@@ -112,36 +142,9 @@ export default class NetworkManager implements Manager {
    * Resolve/rejects a request when matching 'rest-hooks/receive' event
    * is seen.
    */
-  getMiddleware = memoize(function<T extends NetworkManager>(this: T) {
-    return <R extends React.Reducer<any, any>>({
-      dispatch,
-    }: MiddlewareAPI<R>) => {
-      return (next: Dispatch<R>) => (
-        action: React.ReducerAction<R>,
-      ): Promise<void> => {
-        switch (action.type) {
-          case FETCH_TYPE:
-            this.handleFetch(action, dispatch);
-            if (process.env.NODE_ENV !== 'production') action.meta.nm = true;
-            return next(action);
-          case RECEIVE_DELETE_TYPE:
-          case RECEIVE_MUTATE_TYPE:
-          case RECEIVE_TYPE:
-            // only receive after new state is computed
-            return next(action).then(() => {
-              if (action.meta.url in this.fetched) {
-                this.handleReceive(action);
-              }
-            });
-          case RESET_TYPE:
-            this.cleanup();
-            return next(action);
-          default:
-            return next(action);
-        }
-      };
-    };
-  });
+  getMiddleware<T extends NetworkManager>(this: T) {
+    return this.middleware;
+  }
 
   /** Ensures only one request for a given url is in flight at any time
    *
diff --git a/packages/rest-hooks/src/state/SubscriptionManager.ts b/packages/rest-hooks/src/state/SubscriptionManager.ts
index 2173ebc3f50..83d1f82ac10 100644
--- a/packages/rest-hooks/src/state/SubscriptionManager.ts
+++ b/packages/rest-hooks/src/state/SubscriptionManager.ts
@@ -1,7 +1,6 @@
-import { memoize } from 'lodash';
-
 import {
   MiddlewareAPI,
+  Middleware,
   SubscribeAction,
   UnsubscribeAction,
   Manager,
@@ -44,10 +43,27 @@ export default class SubscriptionManager<S extends SubscriptionConstructable>
   } = {};
 
   protected declare readonly Subscription: S;
+  protected declare middleware: Middleware;
 
   constructor(Subscription: S) {
     this.Subscription = Subscription;
-    this.getMiddleware = memoize(this.getMiddleware);
+
+    this.middleware = <R extends React.Reducer<any, any>>({
+      dispatch,
+    }: MiddlewareAPI<R>) => {
+      return (next: Dispatch<R>) => (action: React.ReducerAction<R>) => {
+        switch (action.type) {
+          case SUBSCRIBE_TYPE:
+            this.handleSubscribe(action, dispatch);
+            return Promise.resolve();
+          case UNSUBSCRIBE_TYPE:
+            this.handleUnsubscribe(action, dispatch);
+            return Promise.resolve();
+          default:
+            return next(action);
+        }
+      };
+    };
   }
 
   /** Ensures all subscriptions are cleaned up. */
@@ -104,22 +120,7 @@ export default class SubscriptionManager<S extends SubscriptionConstructable>
    * Will possibly dispatch 'rest-hooks/fetch' or 'rest-hooks/receive' to keep resources fresh
    *
    */
-  getMiddleware<T extends SubscriptionManager<S>>(this: T) {
-    return <R extends React.Reducer<any, any>>({
-      dispatch,
-    }: MiddlewareAPI<R>) => {
-      return (next: Dispatch<R>) => (action: React.ReducerAction<R>) => {
-        switch (action.type) {
-          case SUBSCRIBE_TYPE:
-            this.handleSubscribe(action, dispatch);
-            return Promise.resolve();
-          case UNSUBSCRIBE_TYPE:
-            this.handleUnsubscribe(action, dispatch);
-            return Promise.resolve();
-          default:
-            return next(action);
-        }
-      };
-    };
+  getMiddleware<T extends SubscriptionManager<any>>(this: T) {
+    return this.middleware;
   }
 }