fix: remove legacy React.render() from the editor (#5893)

src/components/ImageExportDialog.tsx

@@ -1,9 +1,7 @@
 import React, { useEffect, useRef, useState } from "react";
-import { render, unmountComponentAtNode } from "react-dom";
 import { probablySupportsClipboardBlob } from "../clipboard";
 import { canvasToBlob } from "../data/blob";
 import { NonDeletedExcalidrawElement } from "../element/types";
-import { CanvasError } from "../errors";
 import { t } from "../i18n";
 import { getSelectedElements, isSomeElementSelected } from "../scene";
 import { exportToCanvas } from "../scene/export";
@@ -33,19 +31,6 @@ export const ErrorCanvasPreview = () => {
   );
 };
 
-const renderPreview = (
-  content: HTMLCanvasElement | Error,
-  previewNode: HTMLDivElement,
-) => {
-  unmountComponentAtNode(previewNode);
-  previewNode.innerHTML = "";
-  if (content instanceof HTMLCanvasElement) {
-    previewNode.appendChild(content);
-  } else {
-    render(<ErrorCanvasPreview />, previewNode);
-  }
-};
-
 export type ExportCB = (
   elements: readonly NonDeletedExcalidrawElement[],
   scale?: number,
@@ -99,6 +84,7 @@ const ImageExportModal = ({
   const [exportSelected, setExportSelected] = useState(someElementIsSelected);
   const previewRef = useRef<HTMLDivElement>(null);
   const { exportBackground, viewBackgroundColor } = appState;
+  const [renderError, setRenderError] = useState<Error | null>(null);
 
   const exportedElements = exportSelected
     ? getSelectedElements(elements, appState, true)
@@ -119,15 +105,16 @@ const ImageExportModal = ({
       exportPadding,
     })
       .then((canvas) => {
+        setRenderError(null);
         // if converting to blob fails, there's some problem that will
         // likely prevent preview and export (e.g. canvas too big)
         return canvasToBlob(canvas).then(() => {
-          renderPreview(canvas, previewNode);
+          previewNode.replaceChildren(canvas);
         });
       })
       .catch((error) => {
         console.error(error);
-        renderPreview(new CanvasError(), previewNode);
+        setRenderError(error);
       });
   }, [
     appState,
@@ -140,7 +127,9 @@ const ImageExportModal = ({
 
   return (
     <div className="ExportDialog">
-      <div className="ExportDialog__preview" ref={previewRef} />
+      <div className="ExportDialog__preview" ref={previewRef}>
+        {renderError && <ErrorCanvasPreview />}
+      </div>
       {supportsContextFilters &&
         actionManager.renderAction("exportWithDarkMode")}
       <div style={{ display: "grid", gridTemplateColumns: "1fr" }}>