add an error for if the custom_palette supplied is a dict but no labels were supplied

Author: JAnns98

dabest/forest_plot.py

@@ -177,6 +177,8 @@ def check_for_errors(
     # Custom palette
     if custom_palette is not None and not isinstance(custom_palette, (dict, list, str, type(None))):
         raise TypeError("The `custom_palette` must be either a dictionary, list, string, or `None`.")
+    if isinstance(custom_palette, dict) and labels is None:
+        raise ValueError("The `labels` argument must be provided if `custom_palette` is a dictionary.")
 
 
     # Halfviolin alpha and desat

nbs/API/forest_plot.ipynb

@@ -236,6 +236,8 @@
     "    # Custom palette\n",
     "    if custom_palette is not None and not isinstance(custom_palette, (dict, list, str, type(None))):\n",
     "        raise TypeError(\"The `custom_palette` must be either a dictionary, list, string, or `None`.\")\n",
+    "    if isinstance(custom_palette, dict) and labels is None:\n",
+    "        raise ValueError(\"The `labels` argument must be provided if `custom_palette` is a dictionary.\")\n",
     "\n",
     "\n",
     "    # Halfviolin alpha and desat\n",