Add unittest

holoviews/tests/plotting/bokeh/test_plot.py

@@ -1,16 +1,19 @@
+import numpy as np
 import pyviz_comms as comms
 
 from param import concrete_descendents
 
 from holoviews.core.element import Element
 from holoviews.core.options import Store
 from holoviews.element.comparison import ComparisonTestCase
+from holoviews import Curve
 
 from bokeh.models import (
-    ColumnDataSource, LinearColorMapper, LogColorMapper, HoverTool
+    ColumnDataSource, CustomJS, LinearColorMapper, LogColorMapper, HoverTool
 )
 from holoviews.plotting.bokeh.callbacks import Callback
 from holoviews.plotting.bokeh.element import ElementPlot
+
 bokeh_renderer = Store.renderers['bokeh']
 
 from .. import option_intersections
@@ -76,3 +79,21 @@ def _test_hover_info(self, element, tooltips, line_policy='nearest', formatters=
         print(renderers, hover)
         for renderer in renderers:
             self.assertTrue(any(renderer in h.renderers for h in hover))
+
+
+def test_sync_legends():
+    curve = lambda i: Curve(np.arange(10) * i, label="ABC"[i])
+    plot1 = curve(0) * curve(1)
+    plot2 = curve(0) * curve(1) * curve(2)
+    combined_plot = plot1 + plot2
+
+    grid_bkplot = bokeh_renderer.get_plot(combined_plot).handles["plot"]
+    for p, *_ in grid_bkplot.children:
+        for r in p.renderers:
+            if r.name == "C":
+                assert r.js_property_callbacks == {}
+            else:
+                k, v = next(iter(r.js_property_callbacks.items()))
+                assert k == "change:muted"
+                assert isinstance(v[0], CustomJS)
+                assert v[0].code == "dst.muted = src.muted"