Don't show Bokeh Model class messages in plots pane (#4598)

Addresses #4597

This PR overrides the `_repr_html_` method on the `GlyphRenderer` and other `Model` class objects so they don't output html that gets shown in the plots pane.
This commonly happens when running line-by-line while making a bokeh
plot.

### Testing

Running the following (making sure the `p.line(...)` line is last.)

```python
from bokeh.plotting import figure, show
p = figure(title="Simple line example", x_axis_label='x', y_axis_label='y')
p.line([1, 2, 3, 4, 5], [6, 7, 2, 4, 5], legend_label="Temp.", line_width=2)
```
Should no longer print an ugly `GlyphRenderer(...)` message to the plots
pane.


---------

Signed-off-by: Nick Strayer <[email protected]>
Co-authored-by: seem <[email protected]>

extensions/positron-python/python_files/positron/positron_ipykernel/patch/bokeh.py

@@ -30,19 +30,27 @@ def patch_bokeh_no_access():
 
 def handle_bokeh_output(session_mode: SessionMode) -> None:
     """
-    Override the bokeh notebook display function to add a flag that the front-end can pick up on to
-    know that the data coming over should be replayed in multiple steps.
+    Make various patches to improve the experience of using bokeh plots in console sessions.
 
     Args:
         session_mode: The mode that the kernel application was started in.
-        logger: A logger function.
     """
     if session_mode == SessionMode.NOTEBOOK:
         # Don't do anything if we're in a notebook
         return
 
+    hide_glyph_renderer_output()
+    add_preload_mime_type()
+
+
+def add_preload_mime_type():
+    """
+    Override the bokeh notebook display function to add a flag that the front-end can pick up on to
+    know that the data coming over should be replayed in multiple steps.
+    """
     try:
         from bokeh.io import notebook
+
     except ImportError:
         return
 
@@ -63,3 +71,17 @@ def new_publish_display_data(*args, **kwargs) -> None:
 
     logger.debug("Overrode bokeh.notebook.publish_display_data")
     notebook.publish_display_data = new_publish_display_data
+
+
+def hide_glyph_renderer_output():
+    """
+    Disable the `_repr_html_` method on the Model class to prevent it from being called when the
+    model is displayed and thus confusing positron into thinking it's a plot to show.
+    """
+    try:
+        from bokeh.models import Model
+
+        del Model._repr_html_
+
+    except ImportError:
+        return

extensions/positron-python/python_files/positron/positron_ipykernel/tests/conftest.py

@@ -8,8 +8,10 @@
 
 import comm
 import pytest
+from jupyter_client.session import Session
 from traitlets.config import Config
 
+import positron_ipykernel.utils as utils
 from positron_ipykernel.connections import ConnectionsService
 from positron_ipykernel.positron_ipkernel import (
     PositronIPKernelApp,
@@ -18,7 +20,6 @@
 )
 from positron_ipykernel.session_mode import SessionMode
 from positron_ipykernel.variables import VariablesService
-import positron_ipykernel.utils as utils
 
 utils.TESTING = True
 
@@ -50,6 +51,21 @@ def handle_msg(self, msg, raise_errors=True):
                     raise AssertionError(error["message"])
 
 
+class TestSession(Session):
+    """
+    A session that records sent messages for testing purposes.
+    """
+
+    def __init__(self, *args, **kwargs):
+        self.messages = []
+        super().__init__(*args, **kwargs)
+
+    def send(self, *args, **kwargs):
+        msg = super().send(*args, **kwargs)
+        self.messages.append(msg)
+        return msg
+
+
 # Enable autouse so that all comms are created as DummyComms.
 @pytest.fixture(autouse=True)
 def patch_create_comm(monkeypatch: pytest.MonkeyPatch) -> None:
@@ -92,8 +108,11 @@ def kernel() -> PositronIPyKernel:
     # Positron-specific attributes:
     app.session_mode = SessionMode.CONSOLE
 
+    # Use a test session to capture sent messages.
+    session = TestSession()
+
     try:
-        kernel = PositronIPyKernel.instance(parent=app)
+        kernel = PositronIPyKernel.instance(parent=app, session=session)
     except Exception:
         print(
             "Error instantiating PositronIPyKernel. Did you import IPython.conftest, "
@@ -124,6 +143,16 @@ def shell(kernel) -> Iterable[PositronShell]:
         del shell.user_ns[key]
 
 
+@pytest.fixture
+def session(kernel) -> TestSession:
+    session: TestSession = kernel.session
+
+    # Clear all messages from previous tests.
+    session.messages.clear()
+
+    return session
+
+
 @pytest.fixture
 def mock_connections_service(shell: PositronShell, monkeypatch: pytest.MonkeyPatch) -> Mock:
     mock = Mock()

extensions/positron-python/python_files/positron/positron_ipykernel/tests/test_patch/test_bokeh.py

@@ -7,6 +7,8 @@
 
 from positron_ipykernel.positron_ipkernel import PositronShell
 
+from ..conftest import TestSession
+
 MIME_TYPE_POSITRON_WEBVIEW_FLAG = "application/positron-webview-load.v0+json"
 
 
@@ -36,3 +38,22 @@ def test_bokeh_mime_tagging(
         and "text/html" in call.kwargs["data"]
         for call in calls
     )
+
+
+def test_model_repr_html_disabled(shell: PositronShell, session: TestSession):
+    """
+    Test to make sure that the text/html mime type is excluded from Bokeh Model subclass instances.
+    This is used to prevent the awkward behavior of simple text showing up in the plots pane when a
+    user builds a bokeh plot command line-by-line in the console.
+    """
+
+    shell.run_cell(
+        """\
+from bokeh.plotting import figure, show
+p = figure(title="Simple line example", x_axis_label='x', y_axis_label='y')
+p
+"""
+    )
+
+    # Assert that none of the messages have a text/html mime type
+    assert not any("text/html" in message["content"]["data"] for message in session.messages)

extensions/positron-python/python_files/positron/positron_ipykernel/tests/utils.py

@@ -119,6 +119,7 @@ def json_rpc_request(
             },
             **content,
         },
+        "header": {},
     }
 
 

extensions/positron-python/python_files/pyproject.toml

@@ -69,3 +69,8 @@ docstring-code-format = true
 
 [tool.ruff.lint.pydocstyle]
 convention = "pep257"
+# --- Start Positron ---
+[tool.pytest.ini_options]
+# Enable colors in the VSCode Test Results pane.
+addopts = "--color=yes"
+# --- End Positron ---