Added tests for config

panel/tests/conftest.py

@@ -3,16 +3,20 @@
 """
 from __future__ import absolute_import, division, unicode_literals
 
+import os
 import re
 import shutil
 
 import pytest
 
+from contextlib import contextmanager
+
 from bokeh.document import Document
 from bokeh.client import pull_session
 from pyviz_comms import Comm
 
 from panel.pane import HTML, Markdown
+from panel.io import state
 
 
 @pytest.fixture
@@ -45,6 +49,20 @@ def hv_bokeh():
     hv.Store.current_backend = prev_backend
 
 
+@pytest.yield_fixture
+def get_display_handle():
+    cleanup = []
+    def display_handle(model):
+        cleanup.append(model.ref['id'])
+        handle = {}
+        state._handles[model.ref['id']] = (handle, [])
+        return handle
+    yield display_handle
+    for ref in cleanup:
+        if ref in state._handles:
+            del state._handles[ref]
+
+
 @pytest.yield_fixture
 def hv_mpl():
     import holoviews as hv
@@ -97,3 +115,15 @@ def markdown_server_session():
         server.stop()
     except AssertionError:
         pass  # tests may already close this
+
+
+@contextmanager
+def set_env_var(env_var, value):
+    old_value = os.environ.get(env_var)
+    os.environ[env_var] = value
+    yield
+    if old_value is None:
+        del os.environ[env_var]
+    else:
+        os.environ[env_var] = old_value
+

panel/tests/test_config.py

@@ -0,0 +1,127 @@
+"""
+Tests pn.config variables
+"""
+from __future__ import absolute_import, division, unicode_literals
+
+from panel import config, state
+from panel.pane import HTML
+
+from panel.tests.conftest import set_env_var
+
+
+def test_env_var_debug():
+    with set_env_var('PANEL_DEBUG', 'disable'):
+        assert config.debug == 'disable'
+    with set_env_var('PANEL_DEBUG', 'replace'):
+        assert config.debug == 'replace'
+    with set_env_var('PANEL_DOC_BUILD', 'true'):
+        assert config.debug == 'disable'
+
+
+def test_debug_replace_stdout(document, comm, get_display_handle):
+    pane = HTML()
+    with set_env_var('PANEL_DEBUG', 'replace'):
+        model = pane.get_root(document, comm)
+        handle = get_display_handle(model)
+
+        pane._on_stdout(model.ref['id'], ['print output'])
+        assert handle == {'text/html': 'print output</br>', 'raw': True}
+
+        pane._on_stdout(model.ref['id'], ['new output'])
+        assert handle == {'text/html': 'new output</br>', 'raw': True}
+
+        pane._cleanup(model)
+        assert model.ref['id'] not in state._handles
+
+
+def test_debug_accumulate_stdout(document, comm, get_display_handle):
+    pane = HTML()
+    model = pane.get_root(document, comm)
+    handle = get_display_handle(model)
+
+    pane._on_stdout(model.ref['id'], ['print output'])
+    assert handle == {'text/html': 'print output</br>', 'raw': True}
+
+    pane._on_stdout(model.ref['id'], ['new output'])
+    assert handle == {'text/html': 'print output</br>\nnew output</br>', 'raw': True}
+
+    pane._cleanup(model)
+    assert model.ref['id'] not in state._handles
+
+
+def test_debug_disable_stdout(document, comm, get_display_handle):
+    pane = HTML()
+    with set_env_var('PANEL_DEBUG', 'disable'):
+        model = pane.get_root(document, comm)
+        handle = get_display_handle(model)
+
+        pane._on_stdout(model.ref['id'], ['print output'])
+        assert handle == {}
+
+        pane._cleanup(model)
+        assert model.ref['id'] not in state._handles
+
+
+def test_debug_replace_error(document, comm, get_display_handle):
+    pane = HTML()
+    with set_env_var('PANEL_DEBUG', 'replace'):
+        model = pane.get_root(document, comm)
+        handle = get_display_handle(model)
+
+        try:
+            1/0
+        except Exception as e:
+            pane._on_error(model.ref['id'], e)
+        assert 'text/html' in handle
+        assert 'ZeroDivisionError' in handle['text/html']
+
+        try:
+            1 + '2'
+        except Exception as e:
+            pane._on_error(model.ref['id'], e)
+        assert 'text/html' in handle
+        assert 'ZeroDivisionError' not in handle['text/html']
+        assert 'TypeError' in handle['text/html']
+
+        pane._cleanup(model)
+        assert model.ref['id'] not in state._handles
+
+
+def test_debug_accumulate_error(document, comm, get_display_handle):
+    pane = HTML()
+    model = pane.get_root(document, comm)
+    handle = get_display_handle(model)
+
+    try:
+        1/0
+    except Exception as e:
+        pane._on_error(model.ref['id'], e)
+    assert 'text/html' in handle
+    assert 'ZeroDivisionError' in handle['text/html']
+
+    try:
+        1 + '2'
+    except Exception as e:
+        pane._on_error(model.ref['id'], e)
+    assert 'text/html' in handle
+    assert 'ZeroDivisionError' in handle['text/html']
+    assert 'TypeError' in handle['text/html']
+
+    pane._cleanup(model)
+    assert model.ref['id'] not in state._handles
+
+
+def test_debug_disable_error(document, comm, get_display_handle):
+    pane = HTML()
+    with set_env_var('PANEL_DEBUG', 'disable'):
+        model = pane.get_root(document, comm)
+        handle = get_display_handle(model)
+
+        try:
+            1/0
+        except Exception as e:
+            pane._on_error(model.ref['id'], e)
+        assert handle == {}
+
+        pane._cleanup(model)
+        assert model.ref['id'] not in state._handles

panel/viewable.py

@@ -693,12 +693,13 @@ def _on_error(self, ref, error):
         if ref not in state._handles or config.debug in [None, 'disable']:
             return
         handle, accumulator = state._handles[ref]
-        formatted = '\n<PRE>'+escape(traceback.format_exc())+'</PRE>\n'
+        formatted = '\n<pre>'+escape(traceback.format_exc())+'</pre>\n'
         if config.debug == 'accumulate':
             accumulator.append(formatted)
         elif config.debug == 'replace':
             accumulator[:] = [formatted]
-        handle.update({'text/html': '\n'.join(accumulator)}, raw=True)
+        if accumulator:
+            handle.update({'text/html': '\n'.join(accumulator)}, raw=True)
 
     def _on_stdout(self, ref, stdout):
         if ref not in state._handles or config.debug is [None, 'disable']:
@@ -709,7 +710,8 @@ def _on_stdout(self, ref, stdout):
             accumulator.extend(formatted)
         elif config.debug == 'replace':
             accumulator[:] = formatted
-        handle.update({'text/html': '\n'.join(accumulator)}, raw=True)
+        if accumulator:
+            handle.update({'text/html': '\n'.join(accumulator)}, raw=True)
 
     def _link_props(self, model, properties, doc, root, comm=None):
         ref = root.ref['id']