Add listEC2Runners verification to maximum runners test (#4980)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: stuartp44 <[email protected]>

Author: Copilot

.gitignore

@@ -29,3 +29,4 @@ secrets.auto.tfvars
 
 node_modules/
 site/
+lambdas/package-lock.json

lambdas/functions/control-plane/src/scale-runners/scale-up.test.ts

@@ -1756,6 +1756,13 @@ describe('Retry mechanism tests', () => {
 
     await scaleUpModule.scaleUp(messages);
 
+    // Verify listEC2Runners is called to check current runner count
+    expect(listEC2Runners).toHaveBeenCalledWith({
+      environment: 'unit-test-environment',
+      runnerType: 'Org',
+      runnerOwner: TEST_DATA_SINGLE.repositoryOwner,
+    });
+
     // publishRetryMessage should still be called even though no runners will be created
     expect(mockPublishRetryMessage).toHaveBeenCalledTimes(2);
     expect(createRunner).not.toHaveBeenCalled();