fix backfill run termination (#24127)

## Summary & Motivation
Could not cancel runs from a backfill - forced users to search on the
runs page and cancel from there.

## How I Tested These Changes
Added a BK test for the `cancelableRuns` field.
Sanity checked with a test run.

## Changelog [Bug]

* Fixed a bug where in-progress runs from a backfill could not be
terminated from the backfill UI.

js_modules/dagster-ui/packages/ui-core/src/instance/backfill/BackfillRow.tsx

@@ -75,9 +75,7 @@ export const BackfillRowLoader = (props: {
   const {data} = statusQueryResult;
   const {hasCancelableRuns} = React.useMemo(() => {
     if (data?.partitionBackfillOrError.__typename === 'PartitionBackfill') {
-      if ('partitionBackfill' in data.partitionBackfillOrError) {
-        return {hasCancelableRuns: data.partitionBackfillOrError.cancelableRuns.length > 0};
-      }
+      return {hasCancelableRuns: data.partitionBackfillOrError.cancelableRuns.length > 0};
     }
     return {hasCancelableRuns: false};
   }, [data]);

python_modules/dagster-graphql/dagster_graphql/schema/backfill.py

@@ -494,7 +494,7 @@ def resolve_cancelableRuns(self, graphene_info: ResolveInfo) -> Sequence["Graphe
         from dagster_graphql.schema.pipelines.pipeline import GrapheneRun
 
         records = self._get_records(graphene_info)
-        return [GrapheneRun(record) for record in records if not record.dagster_run.is_cancelable]
+        return [GrapheneRun(record) for record in records if record.dagster_run.is_cancelable]
 
     def resolve_runs(self, graphene_info: ResolveInfo) -> "Sequence[GrapheneRun]":
         from dagster_graphql.schema.pipelines.pipeline import GrapheneRun

python_modules/dagster-graphql/dagster_graphql_tests/graphql/test_partition_backfill.py

@@ -72,6 +72,10 @@
         user
         title
         description
+        cancelableRuns {
+          id
+          runId
+        }
       }
       ... on PythonError {
         message
@@ -1063,7 +1067,7 @@ def test_backfill_run_incomplete(self, graphql_context):
             [
                 (DagsterRunStatus.SUCCESS, "2"),
                 (DagsterRunStatus.SUCCESS, "3"),
-                (DagsterRunStatus.SUCCESS, "4"),
+                (DagsterRunStatus.STARTED, "4"),
                 (DagsterRunStatus.CANCELED, "5"),
             ],
             backfill_id,
@@ -1080,13 +1084,14 @@ def test_backfill_run_incomplete(self, graphql_context):
         assert result.data["partitionBackfillOrError"]["__typename"] == "PartitionBackfill"
         assert result.data["partitionBackfillOrError"]["status"] == "COMPLETED"
         assert result.data["partitionBackfillOrError"]["numPartitions"] == 4
+        assert len(result.data["partitionBackfillOrError"]["cancelableRuns"]) == 1
         run_stats = _get_run_stats(
             result.data["partitionBackfillOrError"]["partitionStatuses"]["results"]
         )
         assert run_stats.get("total") == 4
         assert run_stats.get("queued") == 0
-        assert run_stats.get("in_progress") == 0
-        assert run_stats.get("success") == 3
+        assert run_stats.get("in_progress") == 1
+        assert run_stats.get("success") == 2
         assert run_stats.get("failure") == 0
         assert run_stats.get("canceled") == 1