Remove throttling

Author: sebmarkbage

packages/react-devtools-shared/package.json

@@ -22,8 +22,6 @@
     "jsc-safe-url": "^0.2.4",
     "json5": "^2.1.3",
     "local-storage-fallback": "^4.1.1",
-    "lodash.throttle": "^4.1.1",
-    "memoize-one": "^3.1.1",
     "react-virtualized-auto-sizer": "^1.0.23",
     "react-window": "^1.8.10"
   }

packages/react-devtools-shared/src/backend/agent.js

@@ -8,7 +8,6 @@
  */
 
 import EventEmitter from '../events';
-import throttle from 'lodash.throttle';
 import {
   SESSION_STORAGE_LAST_SELECTION_KEY,
   SESSION_STORAGE_RELOAD_AND_PROFILE_KEY,
@@ -483,7 +482,13 @@ export default class Agent extends EventEmitter<{
         this._persistedSelection = null;
         this._persistedSelectionMatch = null;
         renderer.setTrackedPath(null);
-        this._throttledPersistSelection(rendererID, id);
+        // Throttle persisting the selection.
+        this._lastSelectedElementID = id;
+        this._lastSelectedRendererID = rendererID;
+        if (!this._persistSelectionTimerScheduled) {
+          this._persistSelectionTimerScheduled = true;
+          setTimeout(this._persistSelection, 1000);
+        }
       }
 
       // TODO: If there was a way to change the selected DOM element
@@ -893,22 +898,25 @@ export default class Agent extends EventEmitter<{
     this._bridge.send('unsupportedRendererVersion', rendererID);
   }
 
-  _throttledPersistSelection: any = throttle(
-    (rendererID: number, id: number) => {
-      // This is throttled, so both renderer and selected ID
-      // might not be available by the time we read them.
-      // This is why we need the defensive checks here.
-      const renderer = this._rendererInterfaces[rendererID];
-      const path = renderer != null ? renderer.getPathForElement(id) : null;
-      if (path !== null) {
-        sessionStorageSetItem(
-          SESSION_STORAGE_LAST_SELECTION_KEY,
-          JSON.stringify(({rendererID, path}: PersistedSelection)),
-        );
-      } else {
-        sessionStorageRemoveItem(SESSION_STORAGE_LAST_SELECTION_KEY);
-      }
-    },
-    1000,
-  );
+  _persistSelectionTimerScheduled: boolean = false;
+  _lastSelectedRendererID: number = -1;
+  _lastSelectedElementID: number = -1;
+  _persistSelection: any = () => {
+    this._persistSelectionTimerScheduled = false;
+    const rendererID = this._lastSelectedRendererID;
+    const id = this._lastSelectedElementID;
+    // This is throttled, so both renderer and selected ID
+    // might not be available by the time we read them.
+    // This is why we need the defensive checks here.
+    const renderer = this._rendererInterfaces[rendererID];
+    const path = renderer != null ? renderer.getPathForElement(id) : null;
+    if (path !== null) {
+      sessionStorageSetItem(
+        SESSION_STORAGE_LAST_SELECTION_KEY,
+        JSON.stringify(({rendererID, path}: PersistedSelection)),
+      );
+    } else {
+      sessionStorageRemoveItem(SESSION_STORAGE_LAST_SELECTION_KEY);
+    }
+  };
 }

packages/react-devtools-shared/src/backend/views/Highlighter/index.js

@@ -7,8 +7,6 @@
  * @flow
  */
 
-import memoize from 'memoize-one';
-import throttle from 'lodash.throttle';
 import Agent from 'react-devtools-shared/src/backend/agent';
 import {hideOverlay, showOverlay} from './Highlighter';
 
@@ -189,18 +187,12 @@ export default function setupHighlighter(
     event.stopPropagation();
   }
 
-  const selectElementForNode = throttle(
-    memoize((node: HTMLElement) => {
-      const id = agent.getIDForHostInstance(node);
-      if (id !== null) {
-        bridge.send('selectElement', id);
-      }
-    }),
-    200,
-    // Don't change the selection in the very first 200ms
-    // because those are usually unintentional as you lift the cursor.
-    {leading: false},
-  );
+  const selectElementForNode = (node: HTMLElement) => {
+    const id = agent.getIDForHostInstance(node);
+    if (id !== null) {
+      bridge.send('selectElement', id);
+    }
+  };
 
   function getEventTarget(event: MouseEvent): HTMLElement {
     if (event.composed) {

packages/react-devtools-shared/src/devtools/views/hooks.js

@@ -7,7 +7,6 @@
  * @flow
  */
 
-import throttle from 'lodash.throttle';
 import {
   useCallback,
   useEffect,
@@ -125,10 +124,8 @@ export function useIsOverflowing(
 
     const container = ((containerRef.current: any): HTMLDivElement);
 
-    const handleResize = throttle(
-      () => setIsOverflowing(container.clientWidth <= totalChildWidth),
-      100,
-    );
+    const handleResize = () =>
+      setIsOverflowing(container.clientWidth <= totalChildWidth);
 
     handleResize();