fix(on-demand): Fix p100 and percentiles (#58511)

Author: iambriccardo

Diff for: src/sentry/search/events/builder/metrics.py

@@ -126,9 +126,6 @@ def _on_demand_metric_spec(self) -> Optional[OnDemandMetricSpec]:
         if not field:
             return None
 
-        if self.query is None:
-            return None
-
         if not should_use_on_demand_metrics(self.dataset, field, self.query):
             return None
 

Diff for: src/sentry/snuba/metrics/extraction.py

@@ -118,7 +118,8 @@
     "p75": "p75",
     "p95": "p95",
     "p99": "p99",
-    "p100": "p100"
+    # p100 is not supported in the metrics layer, so we convert to max which is equivalent.
+    "p100": "max"
     # generic percentile is not supported by metrics layer.
 }
 
@@ -311,7 +312,6 @@ def _get_aggregate_supported_by(aggregate: str) -> SupportedBy:
             return SupportedBy.neither()
 
         match = fields.is_function(aggregate)
-
         if not match:
             raise InvalidSearchQuery(f"Invalid characters in field {aggregate}")
 
@@ -320,7 +320,6 @@ def _get_aggregate_supported_by(aggregate: str) -> SupportedBy:
         args_support = _get_args_support(function, args)
 
         return SupportedBy.combine(function_support, args_support)
-
     except InvalidSearchQuery:
         logger.error(f"Failed to parse aggregate: {aggregate}", exc_info=True)
 
@@ -348,7 +347,7 @@ def _get_percentile_support(args: Sequence[str]) -> SupportedBy:
     if not _get_percentile_op(args):
         return SupportedBy.neither()
 
-    return SupportedBy(standard_metrics=False, on_demand_metrics=True)
+    return SupportedBy.both()
 
 
 def _get_percentile_op(args: Sequence[str]) -> Optional[MetricOperationType]:
@@ -924,6 +923,7 @@ def _process_query(self) -> Optional[RuleCondition]:
                 # derived metrics have their conditions injected in the tags
                 if self._get_op(parsed_field.function, parsed_field.arguments) in _DERIVED_METRICS:
                     return None
+
                 raise Exception("This query should not use on demand metrics")
 
             return aggregate_conditions
@@ -963,10 +963,7 @@ def _parse_arguments(
             raise Exception(f"The operation {op} supports one or more parameters")
 
         arguments = parsed_field.arguments
-        map_argument = op not in _MULTIPLE_ARGS_METRICS
-
-        first_argument = arguments[0]
-        return [_map_field_name(first_argument)] if map_argument else arguments
+        return [_map_field_name(arguments[0])] if op not in _MULTIPLE_ARGS_METRICS else arguments
 
     @staticmethod
     def _get_op(function: str, args: Sequence[str]) -> MetricOperationType:
@@ -995,7 +992,6 @@ def _get_metric_type(function: str) -> str:
     def _parse_field(value: str) -> Optional[FieldParsingResult]:
         try:
             match = fields.is_function(value)
-
             if not match:
                 raise InvalidSearchQuery(f"Invalid characters in field {value}")