Render emoji shortcodes as icons in chat (#345) (#629)

Chat models often emit GitHub/Slack-style :shortcode: text (e.g. 😊,
🎤) instead of the actual emoji. The renderer only converted real
Unicode emoji to the monochrome line icons, so shortcodes rendered as literal
text.

Add a pure, browser-free shortcode->Unicode map (emojiShortcodes.js) and run it
inside svgifyEmoji ahead of the existing Unicode->SVG pass, skipping <code>/<pre>
so code stays literal. Covers ~430 common shortcodes plus common aliases
(+1/thumbsup, etc.).

Keep the conversion from touching anything it shouldn't:
* Scope it to chat. mdToHtml/svgifyEmoji take a { shortcodes } option (default
  on); document and email body rendering (compose, export, preview) pass it as
  false so author-typed :shortcode: text stays literal. The Unicode->SVG pass
  still runs there exactly as before.
* Only convert a :shortcode: that stands on its own. A word-boundary guard
  leaves embedded colon runs alone, so "1:100:2", "10:30:45", "16:9" and
  host:fire:port are never rewritten.

Tests: extend the node-driven unit test with the boundary/false-positive cases,
and fix the markdown-rendering test loader to resolve the new emojiShortcodes
import.

tests/markdown_codefence_placeholder_regression.mjs

@@ -16,6 +16,10 @@ src = src.replace(
   /import \{ splitTableRow \} from '\.\/markdown\/tableRow\.js';/,
   'const splitTableRow = (row) => row.split("|").filter((cell) => cell.trim() !== "");'
 );
+src = src.replace(
+  /import \{ replaceEmojiShortcodes, hasEmojiShortcode \} from '\.\/emojiShortcodes\.js';/,
+  'const hasEmojiShortcode = (t) => !!t && t.indexOf(":") !== -1 && /:[a-z0-9_+-]{1,40}:/i.test(t); const replaceEmojiShortcodes = (t) => t;'
+);
 src = src.replace(/export function /g, 'function ');
 src = src.replace(/export const /g, 'const ');
 src = src.replace(/export default markdownModule;?/g, '');

tests/test_emoji_shortcodes_js.py

@@ -0,0 +1,101 @@
+"""Pin the pure emoji shortcode → Unicode helpers in emojiShortcodes.js.
+
+Driven through `node --input-type=module` so we exercise the real JS without a
+full Vitest/Jest setup (same approach as test_reply_recipients_js.py / test_compare_js.py).
+Skips when `node` is not installed rather than failing.
+
+Regression for issue #345: chat models emit GitHub-style :shortcode: text
+(e.g. :blush:, :microphone:) instead of the actual emoji, and nothing in the
+render pipeline translated them, so they showed up as literal ":blush:" text.
+"""
+import json
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+_REPO = Path(__file__).resolve().parent.parent
+_HELPER = _REPO / "static" / "js" / "emojiShortcodes.js"
+_HAS_NODE = shutil.which("node") is not None
+
+
+def _run(js: str) -> str:
+    proc = subprocess.run(
+        ["node", "--input-type=module"],
+        input=js, capture_output=True, text=True, cwd=str(_REPO), timeout=30,
+    )
+    assert proc.returncode == 0, proc.stderr
+    return proc.stdout.strip()
+
+
+def _replace(text: str) -> str:
+    js = f"""
+    import {{ replaceEmojiShortcodes }} from '{_HELPER.as_posix()}';
+    console.log(JSON.stringify(replaceEmojiShortcodes({json.dumps(text)})));
+    """
+    return json.loads(_run(js))
+
+
+@pytest.mark.skipif(not _HAS_NODE, reason="node binary not on PATH")
+def test_issue_345_examples_convert():
+    # The exact shortcodes the issue reported as showing up as literal text.
+    assert _replace("visit today? :blush:") == "visit today? \U0001f60a"
+    assert _replace("hobbies? **:microphone:**") == "hobbies? **\U0001f3a4**"
+
+
+@pytest.mark.skipif(not _HAS_NODE, reason="node binary not on PATH")
+def test_common_shortcodes_and_aliases():
+    assert _replace(":fire:") == "\U0001f525"
+    assert _replace(":tada:") == "\U0001f389"
+    assert _replace(":thinking:") == "\U0001f914"
+    # +1 / thumbsup are aliases for the same glyph.
+    assert _replace(":+1:") == "\U0001f44d"
+    assert _replace(":thumbsup:") == "\U0001f44d"
+    # Multiple in one string, mixed with surrounding text.
+    assert _replace("nice :fire: work :100:") == "nice \U0001f525 work \U0001f4af"
+
+
+@pytest.mark.skipif(not _HAS_NODE, reason="node binary not on PATH")
+def test_unknown_and_nonshortcodes_untouched():
+    # Unknown shortcode left verbatim (incl. the :emoji: placeholder).
+    assert _replace(":definitely_not_an_emoji:") == ":definitely_not_an_emoji:"
+    assert _replace(":emoji:") == ":emoji:"
+    # Time ranges / ratios must not be mangled.
+    assert _replace("meet at 10:30:45 today") == "meet at 10:30:45 today"
+    assert _replace("ratio 16:9 vs 4:3") == "ratio 16:9 vs 4:3"
+    # No colons at all → returned as-is.
+    assert _replace("plain text") == "plain text"
+
+
+@pytest.mark.skipif(not _HAS_NODE, reason="node binary not on PATH")
+def test_known_shortcode_embedded_in_token_is_not_converted():
+    # Regression: a KNOWN shortcode that happens to sit inside a longer run of
+    # digits/letters is literal text, not an emoji. The classic trap is a numeric
+    # range whose middle segment spells a real shortcode (`:100:` → 💯):
+    assert _replace("1:100:2") == "1:100:2"
+    assert _replace("scale 3:100:7 ok") == "scale 3:100:7 ok"
+    # Glued to a word on either side → left alone (e.g. `key:value:` style text,
+    # URL authorities like `host:fire:port`).
+    assert _replace("host:fire:port") == "host:fire:port"
+    assert _replace("status:fire:") == "status:fire:"
+    assert _replace(":fire:done") == ":fire:done"
+    # But a standalone shortcode flanked by whitespace/punctuation still converts,
+    # including back-to-back shortcodes and the leading `:100:` once delimited.
+    assert _replace("we hit :100: today") == "we hit \U0001f4af today"
+    assert _replace("see :fire:!") == "see \U0001f525!"
+    assert _replace(":fire::tada:") == "\U0001f525\U0001f389"
+
+
+@pytest.mark.skipif(not _HAS_NODE, reason="node binary not on PATH")
+def test_has_emoji_shortcode_detector():
+    js = f"""
+    import {{ hasEmojiShortcode }} from '{_HELPER.as_posix()}';
+    const out = [
+      hasEmojiShortcode(':blush:'),
+      hasEmojiShortcode('no shortcodes here'),
+      hasEmojiShortcode('a single : colon'),
+    ];
+    console.log(JSON.stringify(out));
+    """
+    assert json.loads(_run(js)) == [True, False, False]

tests/test_markdown_rendering_js.py

@@ -41,6 +41,18 @@ def _run_markdown_case(markdown: str, render_expr: str = "mod.mdToHtml(input)"):
             return (row || '').replace(/^\\s*\\|/, '').replace(/\\|\\s*$/, '').split('|').map(c => c.trim());
           }`
         );
+        // markdown.js imports the emoji-shortcode helpers relatively (issue #345),
+        // which a data: URL module can't resolve. Inline the REAL helpers (minus
+        // their export keywords) so the renderer's shortcode pass behaves exactly
+        // as it does in the browser.
+        const emojiSource = fs.readFileSync('./static/js/emojiShortcodes.js', 'utf8')
+          .replace(/^export default .*$/m, '')
+          .replace(/export const /g, 'const ')
+          .replace(/export function /g, 'function ');
+        source = source.replace(
+          /import \{ replaceEmojiShortcodes, hasEmojiShortcode \} from ['"]\.\/emojiShortcodes\.js['"];/,
+          () => emojiSource
+        );
         source = source.replace(
           /var escapeHtml = uiModule\.esc;/,
           `var escapeHtml = (value) => String(value ?? '')