fix: improve cache handling and error recovery

src/core/render/embed.js

@@ -122,7 +122,7 @@ function walkFetchEmbed({ embedTokens, compile, fetch }, cb) {
  };
 
  if (currentToken.embed.url) {
- get(currentToken.embed.url).then(next);
+ get(currentToken.embed.url).then(next, () => next());
  } else {
  next(currentToken.embed.html);
  }
@@ -205,7 +205,7 @@ export function prerenderEmbed({ compiler, raw = '', fetch }, done) {
  walkFetchEmbed(
  { compile, embedTokens, fetch },
  ({ embedToken, token, rowIndex, cellIndex, tokenRef }) => {
- if (token) {
+ if (token && embedToken) {
  Object.assign(links, embedToken.links);
 
  if (typeof rowIndex === 'number' && typeof cellIndex === 'number') {
@@ -269,7 +269,7 @@ export function prerenderEmbed({ compiler, raw = '', fetch }, done) {
  });
  }
  }
- } else {
+ } else if (!token) {
  cached[raw] = tokens.concat();
  tokens.links = cached[raw].links = links;
  done(tokens);

src/core/util/core.js

@@ -10,8 +10,11 @@ export function cached(fn) {
  const cache = Object.create(null);
  return function (str) {
  const key = isPrimitive(str) ? str : JSON.stringify(str);
- const hit = cache[key];
- return hit || (cache[key] = fn(str));
+ if (key in cache) {
+ return cache[key];
+ }
+
+ return (cache[key] = fn(str));
  };
 }
 

test/integration/embed.test.js

@@ -262,6 +262,35 @@ Command | Description | Parameters
  expect(mainText).not.toContain("_media/second.md ':include'");
  });
 
+ test('failed embed URL does not block page render', async () => {
+ await docsifyInit({
+ markdown: {
+ homepage: `
+ # Embed Test
+
+ [missing](_media/missing.md ':include')
+
+ Text after missing embed
+
+ [ok](_media/ok.md ':include')
+ `,
+ },
+ routes: {
+ '_media/missing.md': {
+ status: 404,
+ body: 'Not Found',
+ contentType: 'text/markdown',
+ },
+ '_media/ok.md': 'reachable include content',
+ },
+ });
+
+ expect(await waitForText('#main', 'Text after missing embed')).toBeTruthy();
+ expect(
+ await waitForText('#main', 'reachable include content'),
+ ).toBeTruthy();
+ });
+
  test('embed file table cell', async () => {
  await docsifyInit({
  markdown: {

test/unit/core-util.test.js

@@ -1,12 +1,38 @@
-import { isExternal } from '../../src/core/util/index.js';
+import { cached, isExternal } from '../../src/core/util/index.js';
 
 // Core util
 // -----------------------------------------------------------------------------
 describe('core/util', () => {
+ describe('cached()', () => {
+ test('memoizes falsy return values', () => {
+ let calls = 0;
+ const fn = cached(() => {
+ calls += 1;
+ return '';
+ });
+
+ expect(fn('same-key')).toBe('');
+ expect(fn('same-key')).toBe('');
+ expect(calls).toBe(1);
+ });
+
+ test('memoizes undefined return values', () => {
+ let calls = 0;
+ const fn = cached(() => {
+ calls += 1;
+ return undefined;
+ });
+
+ expect(fn('same-key')).toBeUndefined();
+ expect(fn('same-key')).toBeUndefined();
+ expect(calls).toBe(1);
+ });
+ });
+
  // isExternal()
  // ---------------------------------------------------------------------------
  describe('isExternal()', () => {
- // cases nonexternal
+ // cases non-external
  test('non external local url with one /', () => {
  const result = isExternal(`/${location.host}/docsify/demo.md`);