refactor(runners): only set Priority on overrides for prioritized strategy

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: piotrj

lambdas/functions/control-plane/src/aws/runners.test.ts

@@ -808,22 +808,30 @@ function expectedCreateFleetRequest(expectedValues: ExpectedFleetRequestValues):
           {
             InstanceType: 'm5.large',
             SubnetId: 'subnet-123',
-            Priority: expectedValues.instanceTypePriorities?.['m5.large'] ?? 0,
+            ...(expectedValues.allocationStrategy === 'prioritized' && {
+              Priority: expectedValues.instanceTypePriorities?.['m5.large'] ?? 0,
+            }),
           },
           {
             InstanceType: 'c5.large',
             SubnetId: 'subnet-123',
-            Priority: expectedValues.instanceTypePriorities?.['c5.large'] ?? 1,
+            ...(expectedValues.allocationStrategy === 'prioritized' && {
+              Priority: expectedValues.instanceTypePriorities?.['c5.large'] ?? 1,
+            }),
           },
           {
             InstanceType: 'm5.large',
             SubnetId: 'subnet-456',
-            Priority: expectedValues.instanceTypePriorities?.['m5.large'] ?? 0,
+            ...(expectedValues.allocationStrategy === 'prioritized' && {
+              Priority: expectedValues.instanceTypePriorities?.['m5.large'] ?? 0,
+            }),
           },
           {
             InstanceType: 'c5.large',
             SubnetId: 'subnet-456',
-            Priority: expectedValues.instanceTypePriorities?.['c5.large'] ?? 1,
+            ...(expectedValues.allocationStrategy === 'prioritized' && {
+              Priority: expectedValues.instanceTypePriorities?.['c5.large'] ?? 1,
+            }),
           },
         ],
       },

lambdas/functions/control-plane/src/aws/runners.ts

@@ -136,7 +136,7 @@ function generateFleetOverrides(
         SubnetId: s,
         InstanceType: i as _InstanceType,
         ImageId: amiId,
-        Priority: instanceTypePriorities?.[i] ?? index,
+        ...(instanceTypePriorities !== undefined && { Priority: instanceTypePriorities[i] ?? index }),
       };
       result.push(item);
     });
@@ -279,7 +279,9 @@ async function createInstances(
             runnerParameters.subnets,
             runnerParameters.ec2instanceCriteria.instanceTypes,
             amiIdOverride,
-            runnerParameters.ec2instanceCriteria.instanceTypePriorities,
+            runnerParameters.ec2instanceCriteria.instanceAllocationStrategy === 'prioritized'
+              ? (runnerParameters.ec2instanceCriteria.instanceTypePriorities ?? {})
+              : undefined,
           ),
         },
       ],