support latex better

src/st_demo/app.py

@@ -11,7 +11,7 @@ from uuid import uuid4
 
 from ipython_shell.jupyter import InputRequest, JupyterApp, ParsedJupyterMessage
 
-from st_demo.ui import event_to_record, preferred_mime
+from st_demo.ui import event_to_record, latex_body, preferred_mime
 
 
 @dataclass
@@ -174,7 +174,7 @@ def _render_mime(data: dict[str, object]) -> None:
     elif mime == "application/javascript":
         st.code(str(value), language="javascript")
     elif mime == "text/latex":
-        st.latex(str(value))
+        st.latex(latex_body(value))
     else:
         st.code(str(value), language="text")
 

src/st_demo/ui.py

@@ -34,6 +34,21 @@ def preferred_mime(data: Mapping[str, object]) -> tuple[str, object] | None:
     return next(iter(data.items()), None)
 
 
+def latex_body(value: object) -> str:
+    """Adapt common Jupyter LaTeX payloads to Streamlit's ``st.latex`` API.
+
+    IPython's LaTeX formatter commonly returns ``$...$`` while Streamlit
+    supplies its own delimiters around the value. Remove only the outer
+    delimiters so they are not rendered as literal dollar signs.
+    """
+    body = str(value).strip()
+    delimiters = (("$$", "$$"), ("$", "$"), (r"\[", r"\]"), (r"\(", r"\)"))
+    for opening, closing in delimiters:
+        if body.startswith(opening) and body.endswith(closing):
+            return body[len(opening) : -len(closing)].strip()
+    return body
+
+
 def _content_record(content: object) -> dict[str, object]:
     if isinstance(content, BaseModel):
         return content.model_dump(mode="json")

tests/test_info.py

@@ -5,7 +5,7 @@ from fastapi.testclient import TestClient
 from ipython_mcp.app import app as mcp_app
 from ipython_shell import App, AppInfo
 from ipython_webapp.app import app as web_app
-from langchain_demo.ipython_wrapper import get_app_info
+from ipython_agent.ipython_wrapper import get_app_info
 
 
 class AppInfoTests(unittest.IsolatedAsyncioTestCase):

tests/test_st_demo.py

@@ -8,7 +8,7 @@ from ipython_shell.jupyter.messages import (
     UnknownJupyterMessage,
 )
 from st_demo.app import visible_records
-from st_demo.ui import event_to_record, preferred_mime
+from st_demo.ui import event_to_record, latex_body, preferred_mime
 
 
 class UIDisplayTests(unittest.TestCase):
@@ -44,6 +44,24 @@ class UIDisplayTests(unittest.TestCase):
 
         self.assertEqual((mime, value), ("text/html", "<b>rich</b>"))
 
+    def test_preferred_mime_chooses_latex_before_plain_text(self):
+        latex = r"\\int_0^1 x^2\\,dx = \\frac{1}{3}"
+
+        mime, value = preferred_mime(
+            {
+                "text/plain": "integral",
+                "text/latex": latex,
+            }
+        )
+
+        self.assertEqual((mime, value), ("text/latex", latex))
+
+    def test_latex_body_unwraps_ipython_math_delimiters(self):
+        self.assertEqual(
+            latex_body(r"$\displaystyle x^{2} - x - 6$"),
+            r"\displaystyle x^{2} - x - 6",
+        )
+
     def test_execute_result_record_keeps_mime_and_repr(self):
         event = ExecuteResultMessage(
             message_id="message-1",