From ffac4cb05f5c5a8f91074c846b74fc1dd0c5faf3 Mon Sep 17 00:00:00 2001
From: Echo <ChaosExAnima@users.noreply.github.com>
Date: Mon, 6 Oct 2025 11:31:10 +0200
Subject: [PATCH] Emoji: Link Replacement (#36341)

---
 .../mastodon/components/account_bio.tsx       |  40 ++++--
 .../mastodon/components/emoji/html.tsx        |  99 +++++++++------
 .../status/handled_link.stories.tsx           |  65 ++++++++++
 .../components/status/handled_link.tsx        |  79 ++++++++++++
 .../mastodon/components/status_content.jsx    |  49 ++++++--
 .../mastodon/utils/__tests__/html-test.ts     |  14 ++-
 app/javascript/mastodon/utils/html.ts         | 116 ++++++++++--------
 7 files changed, 346 insertions(+), 116 deletions(-)
 create mode 100644 app/javascript/mastodon/components/status/handled_link.stories.tsx
 create mode 100644 app/javascript/mastodon/components/status/handled_link.tsx

diff --git a/app/javascript/mastodon/components/account_bio.tsx b/app/javascript/mastodon/components/account_bio.tsx
index b5ff686f8..64e5cc045 100644
--- a/app/javascript/mastodon/components/account_bio.tsx
+++ b/app/javascript/mastodon/components/account_bio.tsx
@@ -6,9 +6,10 @@ import { useLinks } from 'mastodon/hooks/useLinks';
 
 import { useAppSelector } from '../store';
 import { isModernEmojiEnabled } from '../utils/environment';
+import type { OnElementHandler } from '../utils/html';
 
-import { AnimateEmojiProvider } from './emoji/context';
 import { EmojiHTML } from './emoji/html';
+import { HandledLink } from './status/handled_link';
 
 interface AccountBioProps {
   className: string;
@@ -24,13 +25,37 @@ export const AccountBio: React.FC<AccountBioProps> = ({
   const handleClick = useLinks(showDropdown);
   const handleNodeChange = useCallback(
     (node: HTMLDivElement | null) => {
-      if (!showDropdown || !node || node.childNodes.length === 0) {
+      if (
+        !showDropdown ||
+        !node ||
+        node.childNodes.length === 0 ||
+        isModernEmojiEnabled()
+      ) {
         return;
       }
       addDropdownToHashtags(node, accountId);
     },
     [showDropdown, accountId],
   );
+
+  const handleLink = useCallback<OnElementHandler>(
+    (element, { key, ...props }) => {
+      if (element instanceof HTMLAnchorElement) {
+        return (
+          <HandledLink
+            {...props}
+            key={key as string} // React requires keys to not be part of spread props.
+            href={element.href}
+            text={element.innerText}
+            hashtagAccountId={accountId}
+          />
+        );
+      }
+      return undefined;
+    },
+    [accountId],
+  );
+
   const note = useAppSelector((state) => {
     const account = state.accounts.get(accountId);
     if (!account) {
@@ -48,13 +73,14 @@ export const AccountBio: React.FC<AccountBioProps> = ({
   }
 
   return (
-    <AnimateEmojiProvider
+    <EmojiHTML
+      htmlString={note}
+      extraEmojis={extraEmojis}
       className={classNames(className, 'translate')}
-      onClickCapture={handleClick}
+      onClickCapture={isModernEmojiEnabled() ? undefined : handleClick}
       ref={handleNodeChange}
-    >
-      <EmojiHTML htmlString={note} extraEmojis={extraEmojis} />
-    </AnimateEmojiProvider>
+      onElement={handleLink}
+    />
   );
 };
 
diff --git a/app/javascript/mastodon/components/emoji/html.tsx b/app/javascript/mastodon/components/emoji/html.tsx
index a6ecc869c..73ad5fa23 100644
--- a/app/javascript/mastodon/components/emoji/html.tsx
+++ b/app/javascript/mastodon/components/emoji/html.tsx
@@ -1,60 +1,79 @@
 import { useMemo } from 'react';
-import type { ComponentPropsWithoutRef, ElementType } from 'react';
 
 import classNames from 'classnames';
 
 import type { CustomEmojiMapArg } from '@/mastodon/features/emoji/types';
 import { isModernEmojiEnabled } from '@/mastodon/utils/environment';
+import type { OnElementHandler } from '@/mastodon/utils/html';
 import { htmlStringToComponents } from '@/mastodon/utils/html';
+import { polymorphicForwardRef } from '@/types/polymorphic';
 
 import { AnimateEmojiProvider, CustomEmojiProvider } from './context';
 import { textToEmojis } from './index';
 
-type EmojiHTMLProps<Element extends ElementType = 'div'> = Omit<
-  ComponentPropsWithoutRef<Element>,
-  'dangerouslySetInnerHTML' | 'className'
-> & {
+interface EmojiHTMLProps {
   htmlString: string;
   extraEmojis?: CustomEmojiMapArg;
-  as?: Element;
   className?: string;
-};
+  onElement?: OnElementHandler;
+}
 
-export const ModernEmojiHTML = ({
-  extraEmojis,
-  htmlString,
-  as: asProp = 'div', // Rename for syntax highlighting
-  shallow,
-  className = '',
-  ...props
-}: EmojiHTMLProps<ElementType>) => {
-  const contents = useMemo(
-    () => htmlStringToComponents(htmlString, { onText: textToEmojis }),
-    [htmlString],
-  );
+export const ModernEmojiHTML = polymorphicForwardRef<'div', EmojiHTMLProps>(
+  (
+    {
+      extraEmojis,
+      htmlString,
+      as: asProp = 'div', // Rename for syntax highlighting
+      className = '',
+      onElement,
+      ...props
+    },
+    ref,
+  ) => {
+    const contents = useMemo(
+      () =>
+        htmlStringToComponents(htmlString, { onText: textToEmojis, onElement }),
+      [htmlString, onElement],
+    );
 
-  return (
-    <CustomEmojiProvider emojis={extraEmojis}>
-      <AnimateEmojiProvider {...props} as={asProp} className={className}>
-        {contents}
-      </AnimateEmojiProvider>
-    </CustomEmojiProvider>
-  );
-};
+    return (
+      <CustomEmojiProvider emojis={extraEmojis}>
+        <AnimateEmojiProvider
+          {...props}
+          as={asProp}
+          className={className}
+          ref={ref}
+        >
+          {contents}
+        </AnimateEmojiProvider>
+      </CustomEmojiProvider>
+    );
+  },
+);
+ModernEmojiHTML.displayName = 'ModernEmojiHTML';
 
-export const LegacyEmojiHTML = <Element extends ElementType>(
-  props: EmojiHTMLProps<Element>,
-) => {
-  const { as: asElement, htmlString, extraEmojis, className, ...rest } = props;
-  const Wrapper = asElement ?? 'div';
-  return (
-    <Wrapper
-      {...rest}
-      dangerouslySetInnerHTML={{ __html: htmlString }}
-      className={classNames(className, 'animate-parent')}
-    />
-  );
-};
+export const LegacyEmojiHTML = polymorphicForwardRef<'div', EmojiHTMLProps>(
+  (props, ref) => {
+    const {
+      as: asElement,
+      htmlString,
+      extraEmojis,
+      className,
+      onElement,
+      ...rest
+    } = props;
+    const Wrapper = asElement ?? 'div';
+    return (
+      <Wrapper
+        {...rest}
+        ref={ref}
+        dangerouslySetInnerHTML={{ __html: htmlString }}
+        className={classNames(className, 'animate-parent')}
+      />
+    );
+  },
+);
+LegacyEmojiHTML.displayName = 'LegacyEmojiHTML';
 
 export const EmojiHTML = isModernEmojiEnabled()
   ? ModernEmojiHTML
diff --git a/app/javascript/mastodon/components/status/handled_link.stories.tsx b/app/javascript/mastodon/components/status/handled_link.stories.tsx
new file mode 100644
index 000000000..a45e33626
--- /dev/null
+++ b/app/javascript/mastodon/components/status/handled_link.stories.tsx
@@ -0,0 +1,65 @@
+import type { Meta, StoryObj } from '@storybook/react-vite';
+
+import { HashtagMenuController } from '@/mastodon/features/ui/components/hashtag_menu_controller';
+import { accountFactoryState } from '@/testing/factories';
+
+import { HoverCardController } from '../hover_card_controller';
+
+import type { HandledLinkProps } from './handled_link';
+import { HandledLink } from './handled_link';
+
+const meta = {
+  title: 'Components/Status/HandledLink',
+  render(args) {
+    return (
+      <>
+        <HandledLink {...args} mentionAccountId='1' hashtagAccountId='1' />
+        <HashtagMenuController />
+        <HoverCardController />
+      </>
+    );
+  },
+  args: {
+    href: 'https://example.com/path/subpath?query=1#hash',
+    text: 'https://example.com',
+  },
+  parameters: {
+    state: {
+      accounts: {
+        '1': accountFactoryState(),
+      },
+    },
+  },
+} satisfies Meta<Pick<HandledLinkProps, 'href' | 'text'>>;
+
+export default meta;
+
+type Story = StoryObj<typeof meta>;
+
+export const Default: Story = {};
+
+export const Hashtag: Story = {
+  args: {
+    text: '#example',
+  },
+};
+
+export const Mention: Story = {
+  args: {
+    text: '@user',
+  },
+};
+
+export const InternalLink: Story = {
+  args: {
+    href: '/about',
+    text: 'About',
+  },
+};
+
+export const InvalidURL: Story = {
+  args: {
+    href: 'ht!tp://invalid-url',
+    text: 'ht!tp://invalid-url -- invalid!',
+  },
+};
diff --git a/app/javascript/mastodon/components/status/handled_link.tsx b/app/javascript/mastodon/components/status/handled_link.tsx
new file mode 100644
index 000000000..ee4132128
--- /dev/null
+++ b/app/javascript/mastodon/components/status/handled_link.tsx
@@ -0,0 +1,79 @@
+import type { ComponentProps, FC } from 'react';
+
+import { Link } from 'react-router-dom';
+
+export interface HandledLinkProps {
+  href: string;
+  text: string;
+  hashtagAccountId?: string;
+  mentionAccountId?: string;
+}
+
+export const HandledLink: FC<HandledLinkProps & ComponentProps<'a'>> = ({
+  href,
+  text,
+  hashtagAccountId,
+  mentionAccountId,
+  ...props
+}) => {
+  // Handle hashtags
+  if (text.startsWith('#')) {
+    const hashtag = text.slice(1).trim();
+    return (
+      <Link
+        {...props}
+        className='mention hashtag'
+        to={`/tags/${hashtag}`}
+        rel='tag'
+        data-menu-hashtag={hashtagAccountId}
+      >
+        #<span>{hashtag}</span>
+      </Link>
+    );
+  } else if (text.startsWith('@')) {
+    // Handle mentions
+    const mention = text.slice(1).trim();
+    return (
+      <Link
+        {...props}
+        className='mention'
+        to={`/@${mention}`}
+        title={`@${mention}`}
+        data-hover-card-account={mentionAccountId}
+      >
+        @<span>{mention}</span>
+      </Link>
+    );
+  }
+
+  // Non-absolute paths treated as internal links.
+  if (href.startsWith('/')) {
+    return (
+      <Link {...props} className='unhandled-link' to={href}>
+        {text}
+      </Link>
+    );
+  }
+
+  try {
+    const url = new URL(href);
+    const [first, ...rest] = url.pathname.split('/').slice(1); // Start at 1 to skip the leading slash.
+    return (
+      <a
+        {...props}
+        href={href}
+        title={href}
+        className='unhandled-link'
+        target='_blank'
+        rel='noreferrer noopener'
+        translate='no'
+      >
+        <span className='invisible'>{url.protocol + '//'}</span>
+        <span className='ellipsis'>{`${url.hostname}/${first ?? ''}`}</span>
+        <span className='invisible'>{'/' + rest.join('/')}</span>
+      </a>
+    );
+  } catch {
+    return text;
+  }
+};
diff --git a/app/javascript/mastodon/components/status_content.jsx b/app/javascript/mastodon/components/status_content.jsx
index d766793d8..93c0e77bd 100644
--- a/app/javascript/mastodon/components/status_content.jsx
+++ b/app/javascript/mastodon/components/status_content.jsx
@@ -18,6 +18,7 @@ import { languages as preloadedLanguages } from 'mastodon/initial_state';
 import { isModernEmojiEnabled } from '../utils/environment';
 
 import { EmojiHTML } from './emoji/html';
+import { HandledLink } from './status/handled_link';
 
 const MAX_HEIGHT = 706; // 22px * 32 (+ 2px padding at the top)
 
@@ -99,6 +100,23 @@ class StatusContent extends PureComponent {
     }
 
     const { status, onCollapsedToggle } = this.props;
+    if (status.get('collapsed', null) === null && onCollapsedToggle) {
+      const { collapsible, onClick } = this.props;
+
+      const collapsed =
+          collapsible
+          && onClick
+          && node.clientHeight > MAX_HEIGHT
+          && status.get('spoiler_text').length === 0;
+
+      onCollapsedToggle(collapsed);
+    }
+
+    // Exit if modern emoji is enabled, as it handles links using the HandledLink component.
+    if (isModernEmojiEnabled()) {
+      return;
+    }
+
     const links = node.querySelectorAll('a');
 
     let link, mention;
@@ -128,18 +146,6 @@ class StatusContent extends PureComponent {
         link.classList.add('unhandled-link');
       }
     }
-
-    if (status.get('collapsed', null) === null && onCollapsedToggle) {
-      const { collapsible, onClick } = this.props;
-
-      const collapsed =
-          collapsible
-          && onClick
-          && node.clientHeight > MAX_HEIGHT
-          && status.get('spoiler_text').length === 0;
-
-      onCollapsedToggle(collapsed);
-    }
   }
 
   componentDidMount () {
@@ -201,6 +207,23 @@ class StatusContent extends PureComponent {
     this.node = c;
   };
 
+  handleElement = (element, {key, ...props}) => {
+    if (element instanceof HTMLAnchorElement) {
+      const mention = this.props.status.get('mentions').find(item => element.href === item.get('url'));
+      return (
+        <HandledLink
+          {...props}
+          href={element.href}
+          text={element.innerText}
+          hashtagAccountId={this.props.status.getIn(['account', 'id'])}
+          mentionAccountId={mention?.get('id')}
+          key={key}
+        />
+      );
+    }
+    return undefined;
+  }
+
   render () {
     const { status, intl, statusContent } = this.props;
 
@@ -245,6 +268,7 @@ class StatusContent extends PureComponent {
               lang={language}
               htmlString={content}
               extraEmojis={status.get('emojis')}
+              onElement={this.handleElement.bind(this)}
             />
 
             {poll}
@@ -262,6 +286,7 @@ class StatusContent extends PureComponent {
             lang={language}
             htmlString={content}
             extraEmojis={status.get('emojis')}
+            onElement={this.handleElement.bind(this)}
           />
 
           {poll}
diff --git a/app/javascript/mastodon/utils/__tests__/html-test.ts b/app/javascript/mastodon/utils/__tests__/html-test.ts
index 6aacc396d..a48a8b572 100644
--- a/app/javascript/mastodon/utils/__tests__/html-test.ts
+++ b/app/javascript/mastodon/utils/__tests__/html-test.ts
@@ -53,13 +53,19 @@ describe('html', () => {
 
     it('calls onElement callback', () => {
       const input = '<p>lorem ipsum</p>';
-      const onElement = vi.fn(
-        (element: HTMLElement, children: React.ReactNode[]) =>
-          React.createElement(element.tagName.toLowerCase(), {}, ...children),
+      const onElement = vi.fn<html.OnElementHandler>(
+        (element, props, children) =>
+          React.createElement(
+            element.tagName.toLowerCase(),
+            props,
+            ...children,
+          ),
       );
       html.htmlStringToComponents(input, { onElement });
       expect(onElement).toHaveBeenCalledExactlyOnceWith(
         expect.objectContaining({ tagName: 'P' }),
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+        expect.objectContaining({ key: expect.any(String) }),
         expect.arrayContaining(['lorem ipsum']),
         {},
       );
@@ -71,6 +77,8 @@ describe('html', () => {
       const output = html.htmlStringToComponents(input, { onElement });
       expect(onElement).toHaveBeenCalledExactlyOnceWith(
         expect.objectContaining({ tagName: 'P' }),
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+        expect.objectContaining({ key: expect.any(String) }),
         expect.arrayContaining(['lorem ipsum']),
         {},
       );
diff --git a/app/javascript/mastodon/utils/html.ts b/app/javascript/mastodon/utils/html.ts
index 971aefa6d..f37018d86 100644
--- a/app/javascript/mastodon/utils/html.ts
+++ b/app/javascript/mastodon/utils/html.ts
@@ -32,14 +32,21 @@ interface QueueItem {
   depth: number;
 }
 
-export interface HTMLToStringOptions<Arg extends Record<string, unknown>> {
+export type OnElementHandler<
+  Arg extends Record<string, unknown> = Record<string, unknown>,
+> = (
+  element: HTMLElement,
+  props: Record<string, unknown>,
+  children: React.ReactNode[],
+  extra: Arg,
+) => React.ReactNode;
+
+export interface HTMLToStringOptions<
+  Arg extends Record<string, unknown> = Record<string, unknown>,
+> {
   maxDepth?: number;
   onText?: (text: string, extra: Arg) => React.ReactNode;
-  onElement?: (
-    element: HTMLElement,
-    children: React.ReactNode[],
-    extra: Arg,
-  ) => React.ReactNode;
+  onElement?: OnElementHandler<Arg>;
   onAttribute?: (
     name: string,
     value: string,
@@ -125,9 +132,57 @@ export function htmlStringToComponents<Arg extends Record<string, unknown>>(
         const children: React.ReactNode[] = [];
         let element: React.ReactNode = undefined;
 
+        // Generate props from attributes.
+        const key = `html-${uniqueIdCounter++}`; // Get the current key and then increment it.
+        const props: Record<string, unknown> = { key };
+        for (const attr of node.attributes) {
+          let name = attr.name.toLowerCase();
+
+          // Custom attribute handler.
+          if (onAttribute) {
+            const result = onAttribute(
+              name,
+              attr.value,
+              node.tagName.toLowerCase(),
+              extraArgs,
+            );
+            if (result) {
+              const [cbName, value] = result;
+              props[cbName] = value;
+            }
+          } else {
+            // Check global attributes first, then tag-specific ones.
+            const globalAttr = globalAttributes[name];
+            const tagAttr = tagInfo.attributes?.[name];
+
+            // Exit if neither global nor tag-specific attribute is allowed.
+            if (!globalAttr && !tagAttr) {
+              continue;
+            }
+
+            // Rename if needed.
+            if (typeof tagAttr === 'string') {
+              name = tagAttr;
+            } else if (typeof globalAttr === 'string') {
+              name = globalAttr;
+            }
+
+            let value: string | boolean | number = attr.value;
+
+            // Handle boolean attributes.
+            if (value === 'true') {
+              value = true;
+            } else if (value === 'false') {
+              value = false;
+            }
+
+            props[name] = value;
+          }
+        }
+
         // If onElement is provided, use it to create the element.
         if (onElement) {
-          const component = onElement(node, children, extraArgs);
+          const component = onElement(node, props, children, extraArgs);
 
           // Check for undefined to allow returning null.
           if (component !== undefined) {
@@ -137,53 +192,6 @@ export function htmlStringToComponents<Arg extends Record<string, unknown>>(
 
         // If the element wasn't created, use the default conversion.
         if (element === undefined) {
-          const props: Record<string, unknown> = {};
-          props.key = `html-${uniqueIdCounter++}`; // Get the current key and then increment it.
-          for (const attr of node.attributes) {
-            let name = attr.name.toLowerCase();
-
-            // Custom attribute handler.
-            if (onAttribute) {
-              const result = onAttribute(
-                name,
-                attr.value,
-                node.tagName.toLowerCase(),
-                extraArgs,
-              );
-              if (result) {
-                const [cbName, value] = result;
-                props[cbName] = value;
-              }
-            } else {
-              // Check global attributes first, then tag-specific ones.
-              const globalAttr = globalAttributes[name];
-              const tagAttr = tagInfo.attributes?.[name];
-
-              // Exit if neither global nor tag-specific attribute is allowed.
-              if (!globalAttr && !tagAttr) {
-                continue;
-              }
-
-              // Rename if needed.
-              if (typeof tagAttr === 'string') {
-                name = tagAttr;
-              } else if (typeof globalAttr === 'string') {
-                name = globalAttr;
-              }
-
-              let value: string | boolean | number = attr.value;
-
-              // Handle boolean attributes.
-              if (value === 'true') {
-                value = true;
-              } else if (value === 'false') {
-                value = false;
-              }
-
-              props[name] = value;
-            }
-          }
-
           element = React.createElement(
             tagName,
             props,