Include all options in enum error messages

altair/utils/schemapi.py

@@ -84,9 +84,14 @@ def _get_most_relevant_errors(
     if len(errors) == 0:
         return []
 
+    # Start from the first error on the top-level as we want to show
+    # an error message for one specific error only even if the chart
+    # specification might have multiple issues
+    top_level_error = errors[0]
+
     # Go to lowest level in schema where an error happened as these give
-    # the most relevant error messages
-    lowest_level = errors[0]
+    # the most relevant error messages.
+    lowest_level = top_level_error
     while lowest_level.context:
         lowest_level = lowest_level.context[0]
 
@@ -102,9 +107,25 @@ def _get_most_relevant_errors(
             # In this case we are still at the top level and can return all errors
             most_relevant_errors = errors
         else:
-            # Return all errors of the lowest level out of which
+            # Use all errors of the lowest level out of which
             # we can construct more informative error messages
             most_relevant_errors = lowest_level.parent.context
+            if lowest_level.validator == "enum":
+                # There might be other possible enums which are allowed, e.g. for
+                # the "timeUnit" property of the "Angle" encoding channel. These do not
+                # necessarily need to be in the same branch of this tree of errors that
+                # we traversed down to the lowest level. We therefore gather
+                # all enums in the leaves of the error tree.
+                enum_errors = _get_all_lowest_errors_with_validator(
+                    top_level_error, validator="enum"
+                )
+                # Remove errors which already exist in enum_errors
+                enum_errors = [
+                    err
+                    for err in enum_errors
+                    if err.message not in [e.message for e in most_relevant_errors]
+                ]
+                most_relevant_errors = most_relevant_errors + enum_errors
 
     # This should never happen but might still be good to test for it as else
     # the original error would just slip through without being raised
@@ -114,6 +135,19 @@ def _get_most_relevant_errors(
     return most_relevant_errors
 
 
+def _get_all_lowest_errors_with_validator(
+    error: jsonschema.ValidationError, validator: str
+) -> List[jsonschema.ValidationError]:
+    matches: List[jsonschema.ValidationError] = []
+    if error.context:
+        for err in error.context:
+            if err.context:
+                matches.extend(_get_all_lowest_errors_with_validator(err, validator))
+            elif err.validator == validator:
+                matches.append(err)
+    return matches
+
+
 def _subclasses(cls):
     """Breadth-first sequence of all classes which inherit from cls."""
     seen = set()

tests/utils/tests/test_schemapi.py

@@ -474,6 +474,10 @@ def chart_example_invalid_y_option_value_with_condition():
     )
 
 
+def chart_example_invalid_timeunit_value():
+    return alt.Chart().encode(alt.Angle().timeUnit("invalid_value"))
+
+
 @pytest.mark.parametrize(
     "chart_func, expected_error_message",
     [
@@ -551,6 +555,17 @@ def chart_example_invalid_y_option_value_with_condition():
                 See the help for `Encoding` to read the full description of these parameters"""  # noqa: W291
             ),
         ),
+        (
+            chart_example_invalid_timeunit_value,
+            inspect.cleandoc(
+                r"""'invalid_value' is an invalid value for `timeUnit`:
+
+                'invalid_value' is not one of \['year', 'quarter', 'month', 'week', 'day', 'dayofyear', 'date', 'hours', 'minutes', 'seconds', 'milliseconds'\]
+                'invalid_value' is not one of \['utcyear', 'utcquarter', 'utcmonth', 'utcweek', 'utcday', 'utcdayofyear', 'utcdate', 'utchours', 'utcminutes', 'utcseconds', 'utcmilliseconds'\]
+                'invalid_value' is not one of \['yearquarter', 'yearquartermonth', 'yearmonth', 'yearmonthdate', 'yearmonthdatehours', 'yearmonthdatehoursminutes', 'yearmonthdatehoursminutesseconds', 'yearweek', 'yearweekday', 'yearweekdayhours', 'yearweekdayhoursminutes', 'yearweekdayhoursminutesseconds', 'yeardayofyear', 'quartermonth', 'monthdate', 'monthdatehours', 'monthdatehoursminutes', 'monthdatehoursminutesseconds', 'weekday', 'weeksdayhours', 'weekdayhoursminutes', 'weekdayhoursminutesseconds', 'dayhours', 'dayhoursminutes', 'dayhoursminutesseconds', 'hoursminutes', 'hoursminutesseconds', 'minutesseconds', 'secondsmilliseconds'\]
+                'invalid_value' is not one of \['utcyearquarter', 'utcyearquartermonth', 'utcyearmonth', 'utcyearmonthdate', 'utcyearmonthdatehours', 'utcyearmonthdatehoursminutes', 'utcyearmonthdatehoursminutesseconds', 'utcyearweek', 'utcyearweekday', 'utcyearweekdayhours', 'utcyearweekdayhoursminutes', 'utcyearweekdayhoursminutesseconds', 'utcyeardayofyear', 'utcquartermonth', 'utcmonthdate', 'utcmonthdatehours', 'utcmonthdatehoursminutes', 'utcmonthdatehoursminutesseconds', 'utcweekday', 'utcweeksdayhours', 'utcweekdayhoursminutes', 'utcweekdayhoursminutesseconds', 'utcdayhours', 'utcdayhoursminutes', 'utcdayhoursminutesseconds', 'utchoursminutes', 'utchoursminutesseconds', 'utcminutesseconds', 'utcsecondsmilliseconds'\]"""
+            ),
+        ),
     ],
 )
 def test_chart_validation_errors(chart_func, expected_error_message):

tools/schemapi/schemapi.py

@@ -82,9 +82,14 @@ def _get_most_relevant_errors(
     if len(errors) == 0:
         return []
 
+    # Start from the first error on the top-level as we want to show
+    # an error message for one specific error only even if the chart
+    # specification might have multiple issues
+    top_level_error = errors[0]
+
     # Go to lowest level in schema where an error happened as these give
-    # the most relevant error messages
-    lowest_level = errors[0]
+    # the most relevant error messages.
+    lowest_level = top_level_error
     while lowest_level.context:
         lowest_level = lowest_level.context[0]
 
@@ -100,9 +105,25 @@ def _get_most_relevant_errors(
             # In this case we are still at the top level and can return all errors
             most_relevant_errors = errors
         else:
-            # Return all errors of the lowest level out of which
+            # Use all errors of the lowest level out of which
             # we can construct more informative error messages
             most_relevant_errors = lowest_level.parent.context
+            if lowest_level.validator == "enum":
+                # There might be other possible enums which are allowed, e.g. for
+                # the "timeUnit" property of the "Angle" encoding channel. These do not
+                # necessarily need to be in the same branch of this tree of errors that
+                # we traversed down to the lowest level. We therefore gather
+                # all enums in the leaves of the error tree.
+                enum_errors = _get_all_lowest_errors_with_validator(
+                    top_level_error, validator="enum"
+                )
+                # Remove errors which already exist in enum_errors
+                enum_errors = [
+                    err
+                    for err in enum_errors
+                    if err.message not in [e.message for e in most_relevant_errors]
+                ]
+                most_relevant_errors = most_relevant_errors + enum_errors
 
     # This should never happen but might still be good to test for it as else
     # the original error would just slip through without being raised
@@ -112,6 +133,19 @@ def _get_most_relevant_errors(
     return most_relevant_errors
 
 
+def _get_all_lowest_errors_with_validator(
+    error: jsonschema.ValidationError, validator: str
+) -> List[jsonschema.ValidationError]:
+    matches: List[jsonschema.ValidationError] = []
+    if error.context:
+        for err in error.context:
+            if err.context:
+                matches.extend(_get_all_lowest_errors_with_validator(err, validator))
+            elif err.validator == validator:
+                matches.append(err)
+    return matches
+
+
 def _subclasses(cls):
     """Breadth-first sequence of all classes which inherit from cls."""
     seen = set()

tools/schemapi/tests/test_schemapi.py

@@ -472,6 +472,10 @@ def chart_example_invalid_y_option_value_with_condition():
     )
 
 
+def chart_example_invalid_timeunit_value():
+    return alt.Chart().encode(alt.Angle().timeUnit("invalid_value"))
+
+
 @pytest.mark.parametrize(
     "chart_func, expected_error_message",
     [
@@ -549,6 +553,17 @@ def chart_example_invalid_y_option_value_with_condition():
                 See the help for `Encoding` to read the full description of these parameters"""  # noqa: W291
             ),
         ),
+        (
+            chart_example_invalid_timeunit_value,
+            inspect.cleandoc(
+                r"""'invalid_value' is an invalid value for `timeUnit`:
+
+                'invalid_value' is not one of \['year', 'quarter', 'month', 'week', 'day', 'dayofyear', 'date', 'hours', 'minutes', 'seconds', 'milliseconds'\]
+                'invalid_value' is not one of \['utcyear', 'utcquarter', 'utcmonth', 'utcweek', 'utcday', 'utcdayofyear', 'utcdate', 'utchours', 'utcminutes', 'utcseconds', 'utcmilliseconds'\]
+                'invalid_value' is not one of \['yearquarter', 'yearquartermonth', 'yearmonth', 'yearmonthdate', 'yearmonthdatehours', 'yearmonthdatehoursminutes', 'yearmonthdatehoursminutesseconds', 'yearweek', 'yearweekday', 'yearweekdayhours', 'yearweekdayhoursminutes', 'yearweekdayhoursminutesseconds', 'yeardayofyear', 'quartermonth', 'monthdate', 'monthdatehours', 'monthdatehoursminutes', 'monthdatehoursminutesseconds', 'weekday', 'weeksdayhours', 'weekdayhoursminutes', 'weekdayhoursminutesseconds', 'dayhours', 'dayhoursminutes', 'dayhoursminutesseconds', 'hoursminutes', 'hoursminutesseconds', 'minutesseconds', 'secondsmilliseconds'\]
+                'invalid_value' is not one of \['utcyearquarter', 'utcyearquartermonth', 'utcyearmonth', 'utcyearmonthdate', 'utcyearmonthdatehours', 'utcyearmonthdatehoursminutes', 'utcyearmonthdatehoursminutesseconds', 'utcyearweek', 'utcyearweekday', 'utcyearweekdayhours', 'utcyearweekdayhoursminutes', 'utcyearweekdayhoursminutesseconds', 'utcyeardayofyear', 'utcquartermonth', 'utcmonthdate', 'utcmonthdatehours', 'utcmonthdatehoursminutes', 'utcmonthdatehoursminutesseconds', 'utcweekday', 'utcweeksdayhours', 'utcweekdayhoursminutes', 'utcweekdayhoursminutesseconds', 'utcdayhours', 'utcdayhoursminutes', 'utcdayhoursminutesseconds', 'utchoursminutes', 'utchoursminutesseconds', 'utcminutesseconds', 'utcsecondsmilliseconds'\]"""
+            ),
+        ),
     ],
 )
 def test_chart_validation_errors(chart_func, expected_error_message):