Update Teact from MyTonWallet

src/lib/teact/teact-dom.ts

@@ -12,7 +12,6 @@ import type {
 } from './teact';
 
 import { DEBUG } from '../../config';
-import { unique } from '../../util/iteratees';
 import { addEventListener, removeAllDelegatedListeners, removeEventListener } from './dom-events';
 import {
   captureImmediateEffects,
@@ -59,6 +58,8 @@ const headsByElement = new WeakMap<Element, VirtualDomHead>();
 const extraClasses = new WeakMap<Element, Set<string>>();
 const extraStyles = new WeakMap<Element, Record<string, string>>();
 
+const uniqueChildKeysCache = new WeakMap<VirtualElementChildren, (keyof any)[]>();
+
 let DEBUG_virtualTreeSize = 1;
 
 function render($element: VirtualElement | undefined, parentEl: HTMLElement) {
@@ -459,10 +460,6 @@ function renderChildren(
   forceMoveToEnd = false,
   namespace?: string,
 ) {
-  if (DEBUG) {
-    DEBUG_checkKeyUniqueness($new.children);
-  }
-
   if (('props' in $new) && $new.props.teactFastList) {
     renderFastListChildren($current, $new, currentContext, currentEl);
     return;
@@ -532,52 +529,31 @@ function renderFastListChildren(
   const currentChildren = $current.children;
   const newChildren = $new.children;
 
-  const newKeys = new Set();
-  for (const $newChild of newChildren) {
-    const key = 'props' in $newChild ? $newChild.props.key : undefined;
-
-    if (DEBUG && isParentElement($newChild)) {
-      // eslint-disable-next-line no-null/no-null
-      if (key === undefined || key === null) {
-        // eslint-disable-next-line no-console
-        console.warn('Missing `key` in `teactFastList`');
-      }
+  // Clear out duplicated keys to avoid incorrect elements matching
+  const currentKeysByIndex = getChildKeysByIndex(currentChildren);
+  const newKeysByIndex = getChildKeysByIndex(newChildren);
+  const newKeys = new Set(newKeysByIndex);
 
+  if (DEBUG) {
+    for (const $newChild of newChildren) {
       if ($newChild.type === VirtualType.Fragment) {
         throw new Error('[Teact] Fragment can not be child of container with `teactFastList`');
       }
     }
-
-    newKeys.add(key);
   }
 
   // Build a collection of old children that also remain in the new list
   let currentRemainingIndex = 0;
-  const remainingByKey: Record<string, { $element: VirtualElement; index: number; orderKey?: number }> = {};
+  const remainingByKey: Record<keyof any, { $element: VirtualElement; index: number; orderKey?: number }> = {};
   for (let i = 0, l = currentChildren.length; i < l; i++) {
     const $currentChild = currentChildren[i];
-
-    let key = 'props' in $currentChild ? $currentChild.props.key : undefined;
-    // eslint-disable-next-line no-null/no-null
-    const isKeyPresent = key !== undefined && key !== null;
+    const key = currentKeysByIndex[i];
 
     // First we process removed children
-    if (isKeyPresent && !newKeys.has(key)) {
+    if (!newKeys.has(key)) {
       renderWithVirtual(currentEl, $currentChild, undefined, $new, currentContext, -1);
 
       continue;
-    } else if (!isKeyPresent) {
-      const $newChild = newChildren[i];
-      const newChildKey = ($newChild && 'props' in $newChild) ? $newChild.props.key : undefined;
-      // If a non-key element remains at the same index we preserve it with a virtual `key`
-      if ($newChild && !newChildKey) {
-        key = `${INDEX_KEY_PREFIX}${i}`;
-        // Otherwise, we just remove it
-      } else {
-        renderWithVirtual(currentEl, $currentChild, undefined, $new, currentContext, -1);
-
-        continue;
-      }
     }
 
     // Then we build up info about remaining children
@@ -595,7 +571,7 @@ function renderFastListChildren(
 
   for (let i = 0, l = newChildren.length; i < l; i++) {
     const $newChild = newChildren[i];
-    const key = 'props' in $newChild ? $newChild.props.key : `${INDEX_KEY_PREFIX}${i}`;
+    const key = newKeysByIndex[i];
     const currentChildInfo = remainingByKey[key];
 
     if (!currentChildInfo) {
@@ -932,23 +908,57 @@ function DEBUG_addToVirtualTreeSize($current: VirtualElementParent | VirtualDomH
   });
 }
 
-function DEBUG_checkKeyUniqueness(children: VirtualElementChildren) {
-  const firstChild = children[0];
-  if (firstChild && 'props' in firstChild && firstChild.props.key !== undefined) {
-    const keys = children.reduce((acc: any[], child) => {
-      if ('props' in child && child.props.key) {
-        acc.push(child.props.key);
+/** Returns unique and not missing key for each child */
+function getChildKeysByIndex(children: VirtualElementChildren) {
+  // The caching makes sense, because each children list is handled at least twice (as the new and the current children)
+  let uniqueKeysByIndex = uniqueChildKeysCache.get(children);
+  if (uniqueKeysByIndex) return uniqueKeysByIndex;
+
+  const seenKeys = new Set<any>();
+  const DEBUG_duplicatedKeys = new Set<any>();
+
+  uniqueKeysByIndex = children.map(($child, index) => {
+    let key = getElementKey($child);
+
+    if (isNullable(key)) {
+      if (DEBUG && isParentElement($child)) {
+        // eslint-disable-next-line no-console
+        console.warn('Missing `key` in `teactFastList`');
       }
 
-      return acc;
-    }, []);
+      key = `${INDEX_KEY_PREFIX}${index}`;
+    } else {
+      if (seenKeys.has(key)) {
+        if (DEBUG) {
+          DEBUG_duplicatedKeys.add(key);
+        }
 
-    if (keys.length !== unique(keys).length) {
-      // eslint-disable-next-line no-console
-      console.warn('[Teact] Duplicated keys:', keys.filter((e, i, a) => a.indexOf(e) !== i), children);
-      throw new Error('[Teact] Children keys are not unique');
+        key = `${INDEX_KEY_PREFIX}${index}`;
+      } else {
+        seenKeys.add(key);
+      }
     }
+
+    return key;
+  });
+
+  if (DEBUG && DEBUG_duplicatedKeys.size) {
+    // eslint-disable-next-line no-console
+    console.warn('[Teact] Duplicated keys:', [...DEBUG_duplicatedKeys], children);
+    throw new Error('[Teact] Children keys are not unique');
   }
+
+  uniqueChildKeysCache.set(children, uniqueKeysByIndex);
+  return uniqueKeysByIndex;
+}
+
+function getElementKey($element: VirtualElement) {
+  return 'props' in $element ? $element.props.key : undefined;
+}
+
+function isNullable(value: unknown): value is undefined | null {
+  // eslint-disable-next-line no-null/no-null
+  return value === undefined || value === null;
 }
 
 const TeactDOM = { render };

src/lib/teact/teact.ts

@@ -1,4 +1,3 @@
-/* eslint-disable react-x/no-unnecessary-use-prefix */
 import type { ReactElement } from 'react';
 
 import { DEBUG, DEBUG_MORE } from '../../config';
@@ -137,6 +136,7 @@ export type TeactNode =
   | string
   | number
   | boolean
+  | undefined
   | TeactNode[];
 
 type Effect = () => (NoneToVoidFunction | void);