Getting 'unexpected_rows" in ColumnPairMapExpectation

[mykola-yesypchuk-inflection]

Problem:
Almost all column expectations can return "unexpected_rows" when we validate data with parameters result_format=SUMMARY and include_unexpected_rows=True. It helps to get invalid rows consider "partial_unexpected_count" parameter.

But expectations that inherit ColumnPairMapExpectation can't return "unexpected_rows".
Why:

1. unexpected_rows enable when result_format is "COMPLETE".

   great_expectations/great_expectations/expectations/expectation.py

   Lines 2352 to 2367 in 5449e96

   	if result_format_str in ["BASIC", "SUMMARY"]:
   	return dependencies
   	if include_unexpected_rows:
   	metric_kwargs = get_metric_kwargs(
   	f"{self.map_metric}.unexpected_rows",
   	configuration=configuration,
   	runtime_configuration=runtime_configuration,
   	)
   	metric_dependencies[
   	f"{self.map_metric}.unexpected_rows"
   	] = MetricConfiguration(
   	metric_name=f"{self.map_metric}.unexpected_rows",
   	metric_domain_kwargs=metric_kwargs["metric_domain_kwargs"],
   	metric_value_kwargs=metric_kwargs["metric_value_kwargs"],
   	)

2. But due missing definition of "unexpected_rows" metric variable in ColumnPairMapExpectation._validate() method it can't be returned.

   great_expectations/great_expectations/expectations/expectation.py

   Line 2385 in 5449e96

   def _validate(

Example, when unexpected_rows is returned correctly:

great_expectations/great_expectations/expectations/expectation.py

Lines 2139 to 2154 in 5449e96

	if include_unexpected_rows:
	metric_kwargs = get_metric_kwargs(
	f"{self.map_metric}.unexpected_rows",
	configuration=configuration,
	runtime_configuration=runtime_configuration,
	)
	metric_dependencies[
	f"{self.map_metric}.unexpected_rows"
	] = MetricConfiguration(
	metric_name=f"{self.map_metric}.unexpected_rows",
	metric_domain_kwargs=metric_kwargs["metric_domain_kwargs"],
	metric_value_kwargs=metric_kwargs["metric_value_kwargs"],
	)
	if result_format_str in ["BASIC", "SUMMARY"]:
	return dependencies

Solution:

1. Add code with "unexpected_rows" metric in ColumnPairMapExpectation.get_validation_dependencies(), like example above:

         if include_unexpected_rows:
            metric_kwargs = get_metric_kwargs(
                f"{self.map_metric}.unexpected_rows",
                configuration=configuration,
                runtime_configuration=runtime_configuration,
            )
            metric_dependencies[
                f"{self.map_metric}.unexpected_rows"
            ] = MetricConfiguration(
                metric_name=f"{self.map_metric}.unexpected_rows",
                metric_domain_kwargs=metric_kwargs["metric_domain_kwargs"],
                metric_value_kwargs=metric_kwargs["metric_value_kwargs"],
            )

        if result_format_str in ["BASIC", "SUMMARY"]:
            return dependencies

2. And add definition of "unexpected_rows" metric in ColumnPairMapExpectation._validate():

unexpected_rows= metrics.get(f"{self.map_metric}.unexpected_rows")
--------
return _format_map_output(
            result_format=parse_result_format(result_format),
            success=success,
            element_count=total_count,
            nonnull_count=filtered_row_count,
            unexpected_count=unexpected_count,
            unexpected_list=unexpected_values,
            unexpected_index_list=unexpected_index_list,
            unexpected_rows=unexpected_rows
        )