test: refactor eventloopdelay test for clarity

Extract assertions into separate function and simplify control flow.
Use setImmediate for final assertions to ensure histogram has
recorded all samples.

Author: mcollina

test/sequential/test-performance-eventloopdelay.js

@@ -59,6 +59,49 @@ const { sleep } = require('internal/util');
     return histogram.count > 0 && histogram.min > 0 && histogram.max > 0;
   }
 
+  // Final assertions - call this when ready to verify histogram values
+  function runAssertions() {
+    setImmediate(common.mustCall(() => {
+      histogram.disable();
+      // The values are non-deterministic, so we just check that a value is
+      // present, as opposed to a specific value.
+      assert(histogram.count > 0, `Expected samples to be recorded, got count=${histogram.count}`);
+      assert(histogram.min > 0, `Expected min > 0, got ${histogram.min}`);
+      assert(histogram.max > 0);
+      assert(histogram.stddev > 0);
+      assert(histogram.mean > 0);
+      assert(histogram.percentiles.size > 0);
+      for (let n = 1; n < 100; n = n + 0.1) {
+        assert(histogram.percentile(n) >= 0);
+      }
+      histogram.reset();
+      assert.strictEqual(histogram.min, 9223372036854776000);
+      assert.strictEqual(histogram.max, 0);
+      assert(Number.isNaN(histogram.stddev));
+      assert(Number.isNaN(histogram.mean));
+      assert.strictEqual(histogram.percentiles.size, 1);
+
+      ['a', false, {}, []].forEach((i) => {
+        assert.throws(
+          () => histogram.percentile(i),
+          {
+            name: 'TypeError',
+            code: 'ERR_INVALID_ARG_TYPE',
+          }
+        );
+      });
+      [-1, 0, 101, NaN].forEach((i) => {
+        assert.throws(
+          () => histogram.percentile(i),
+          {
+            name: 'RangeError',
+            code: 'ERR_OUT_OF_RANGE',
+          }
+        );
+      });
+    }));
+  }
+
   // Spin the event loop with blocking work to generate measurable delays.
   // Some configurations (s390x, sharedlibs) need more iterations.
   let spinsRemaining = 5;
@@ -72,55 +115,15 @@ const { sleep } = require('internal/util');
     } else {
       // Give the histogram a chance to record final samples before checking.
       setImmediate(() => {
-        // If we don't have valid samples yet, retry with more spinning.
-        // This handles slower configurations like sharedlibs builds.
-        if (!hasValidSamples() && retries < maxRetries) {
+        // If we have valid samples or exhausted retries, run assertions.
+        // Otherwise retry with more spinning for slower configurations.
+        if (hasValidSamples() || retries >= maxRetries) {
+          runAssertions();
+        } else {
           retries++;
           spinsRemaining = 5;
           setTimeout(spinAWhile, common.platformTimeout(500));
-          return;
         }
-
-        // Wrap final assertions in mustCall to ensure they run
-        common.mustCall(() => {
-          histogram.disable();
-          // The values are non-deterministic, so we just check that a value is
-          // present, as opposed to a specific value.
-          assert(histogram.count > 0, `Expected samples to be recorded, got count=${histogram.count}`);
-          assert(histogram.min > 0, `Expected min > 0, got ${histogram.min}`);
-          assert(histogram.max > 0);
-          assert(histogram.stddev > 0);
-          assert(histogram.mean > 0);
-          assert(histogram.percentiles.size > 0);
-          for (let n = 1; n < 100; n = n + 0.1) {
-            assert(histogram.percentile(n) >= 0);
-          }
-          histogram.reset();
-          assert.strictEqual(histogram.min, 9223372036854776000);
-          assert.strictEqual(histogram.max, 0);
-          assert(Number.isNaN(histogram.stddev));
-          assert(Number.isNaN(histogram.mean));
-          assert.strictEqual(histogram.percentiles.size, 1);
-
-          ['a', false, {}, []].forEach((i) => {
-            assert.throws(
-              () => histogram.percentile(i),
-              {
-                name: 'TypeError',
-                code: 'ERR_INVALID_ARG_TYPE',
-              }
-            );
-          });
-          [-1, 0, 101, NaN].forEach((i) => {
-            assert.throws(
-              () => histogram.percentile(i),
-              {
-                name: 'RangeError',
-                code: 'ERR_OUT_OF_RANGE',
-              }
-            );
-          });
-        })();
       });
     }
   }