chore(cli): measure performance against wall-clock (#18357)

Fixes test flake by requiring perf to be <150% of wall-clock time rather
than <500ms.

1 files changed, 7 insertions, 2 deletions

diff --git a/cli/tests/unit/performance_test.ts b/cli/tests/unit/performance_test.ts
index 3211bb415..accedd2e4 100644
--- a/cli/tests/unit/performance_test.ts
+++ b/cli/tests/unit/performance_test.ts
@@ -81,9 +81,12 @@ Deno.test(function performanceMeasure() {
   const measureName1 = "measure1";
   const measureName2 = "measure2";
   const mark1 = performance.mark(markName1);
+  // Measure against the inaccurate-but-known-good wall clock
+  const now = new Date().valueOf();
   return new Promise((resolve, reject) => {
     setTimeout(() => {
       try {
+        const later = new Date().valueOf();
         const measure1 = performance.measure(measureName1, markName1);
         const measure2 = performance.measure(
           measureName2,
@@ -103,8 +106,10 @@ Deno.test(function performanceMeasure() {
           `duration below 100ms: ${measure1.duration}`,
         );
         assert(
-          measure1.duration < 500,
-          `duration exceeds 500ms: ${measure1.duration}`,
+          measure1.duration < (later - now) * 1.50,
+          `duration exceeds 150% of wallclock time: ${measure1.duration}ms vs ${
+            later - now
+          }ms`,
         );
         const entries = performance.getEntries();
         assert(entries[entries.length - 1] === measure2);