feat(webhook): use priority field as tiebreaker in matcher dispatch

lambdas/functions/webhook/src/runners/dispatch.test.ts

@@ -153,6 +153,54 @@ describe('Dispatcher', () => {
       });
     });
 
+    it('should dispatch to lowest priority pool when multiple pools match the same labels', async () => {
+      config = await createConfig(undefined, [
+        {
+          ...runnerConfig[0],
+          id: 'large-ondemand',
+          matcherConfig: {
+            labelMatchers: [['self-hosted', 'linux', 'x64', 'large', 'ondemand']],
+            exactMatch: true,
+            priority: 100,
+          },
+        },
+        {
+          ...runnerConfig[0],
+          id: 'medium-spot',
+          matcherConfig: {
+            labelMatchers: [['self-hosted', 'linux', 'x64', 'medium', 'spot']],
+            exactMatch: true,
+            priority: 5,
+          },
+        },
+        {
+          ...runnerConfig[0],
+          id: 'small-spot',
+          matcherConfig: {
+            labelMatchers: [['self-hosted', 'linux', 'x64', 'small', 'spot']],
+            exactMatch: true,
+            priority: 1,
+          },
+        },
+      ]);
+
+      // Job requests only the common subset — all pools match
+      const event = {
+        ...workFlowJobEvent,
+        workflow_job: {
+          ...workFlowJobEvent.workflow_job,
+          labels: ['self-hosted', 'linux', 'x64'],
+        },
+      } as unknown as WorkflowJobEvent;
+      const resp = await dispatch(event, 'workflow_job', config);
+      expect(resp.statusCode).toBe(201);
+      expect(sendActionRequest).toHaveBeenCalledWith(
+        expect.objectContaining({
+          queueId: 'small-spot',
+        }),
+      );
+    });
+
     it('should not accept jobs where not all labels are supported (single matcher).', async () => {
       config = await createConfig(undefined, [
         {

lambdas/functions/webhook/src/runners/dispatch.ts

@@ -42,9 +42,12 @@ async function handleWorkflowJob(
       `Job ID: ${body.workflow_job.id}, Job Name: ${body.workflow_job.name}, ` +
       `Run ID: ${body.workflow_job.run_id}, Labels: ${JSON.stringify(body.workflow_job.labels)}`,
   );
-  // sort the queuesConfig by order of matcher config exact match, with all true matches lined up ahead.
+  // Sort: exact-match first, then by ascending priority (lower = preferred/cheaper).
   matcherConfig.sort((a, b) => {
-    return a.matcherConfig.exactMatch === b.matcherConfig.exactMatch ? 0 : a.matcherConfig.exactMatch ? -1 : 1;
+    if (a.matcherConfig.exactMatch !== b.matcherConfig.exactMatch) {
+      return a.matcherConfig.exactMatch ? -1 : 1;
+    }
+    return (a.matcherConfig.priority ?? 999) - (b.matcherConfig.priority ?? 999);
   });
   for (const queue of matcherConfig) {
     if (canRunJob(body.workflow_job.labels, queue.matcherConfig.labelMatchers, queue.matcherConfig.exactMatch)) {

lambdas/functions/webhook/src/sqs/index.ts

@@ -17,6 +17,7 @@ export interface ActionRequestMessage {
 export interface MatcherConfig {
   labelMatchers: string[][];
   exactMatch: boolean;
+  priority?: number;
 }
 
 export type RunnerConfig = RunnerMatcherConfig[];