Fix backward compatibility for usePDF hook

packages/renderer/src/dom/usePDF.js

@@ -5,8 +5,19 @@ import { useState, useRef, useEffect, useCallback } from 'react';
 
 import { pdf } from '../index';
 
+const useCommittedRef = value => {
+  const ref = useRef();
+
+  useEffect(() => {
+    ref.current = value;
+  });
+
+  return ref;
+};
+
 export const usePDF = ({ document } = {}) => {
   const pdfInstance = useRef(null);
+  const committedDocument = useCommittedRef(document);
 
   const [state, setState] = useState({
     url: null,
@@ -65,8 +76,15 @@ export const usePDF = ({ document } = {}) => {
     };
   }, [state.url]);
 
-  const update = useCallback(newDoc => {
-    pdfInstance.current.updateContainer(newDoc);
+  // make update function stable
+  const update = useCallback((...args) => {
+    if (args.length === 0) {
+      // TODO: add warning that no args update would be removed in next versions
+      pdfInstance.current.updateContainer(committedDocument.current);
+    } else {
+      const [newDoc] = args;
+      pdfInstance.current.updateContainer(newDoc);
+    }
   }, []);
 
   return [state, update];

packages/renderer/tests/usePDF.test.js

@@ -3,6 +3,7 @@
  */
 
 /* eslint-disable import/no-extraneous-dependencies */
+import { useEffect, useState } from 'react';
 import { renderHook, waitFor, act } from '@testing-library/react';
 import { usePDF, Document, Page, Text } from '../src/dom';
 
@@ -57,3 +58,27 @@ it('updates document', async () => {
 
   expect(result.current[0].blob.size).not.toEqual(pdfSize);
 });
+
+it('backward compatible with previous hook', async () => {
+  const { result } = renderHook(() => {
+    const [document, setDoc] = useState(() => <TestDocument />);
+    const [instance, update] = usePDF({ document });
+
+    useEffect(update, [document]);
+
+    return [
+      instance,
+      () => setDoc(<TestDocument title="Long long long title" />),
+    ];
+  });
+
+  await waitFor(() => expect(result.current[0].loading).toBeFalsy());
+
+  const pdfSize = result.current[0].blob.size;
+
+  act(() => result.current[1]());
+
+  await waitFor(() => expect(result.current[0].loading).toBeFalsy());
+
+  expect(result.current[0].blob.size).not.toEqual(pdfSize);
+});