[Copilot]

LatencyPlugin picked its delay with Random.Next(MinMs, MaxMs). That method excludes the upper bound, so the configured maxMs was never applied. The schema describes maxMs as the maximum delay, so it should be a possible value.

Changes

• LatencyPlugin: both ApplyDelayAsync overloads (HTTP and stdio) now call a new internal helper, GetDelay, which picks from minMs to maxMs inclusive. The upper bound is computed as a long, so MaxMs + 1 can't overflow when maxMs is int.MaxValue.

  internal static int GetDelay(Random random, int minMs, int maxMs) =>
      (int)random.NextInt64(minMs, (long)maxMs + 1);

• Tests (BehaviorPluginsIntegrationTests): the new test checks three cases:

  • With 0..1, the delay is sometimes 1. The old code always returned 0.
  • With min == max, the delay equals that value.
  • maxMs = int.MaxValue doesn't overflow.

  GetDelay is reachable from the tests through the existing InternalsVisibleTo entry.

minMs > maxMs still throws, as it did before.

• Fixes LatencyPlugin never applies maxMs because the upper bound is exclusive #1927

[Copilot]

🟢 Approval recommended

The focused fix handles inclusive bounds safely with regression coverage; tests were not executed.

No open issues 🎉

What changed in this PR

Fixes #1927 by allowing LatencyPlugin to select the configured maxMs delay.

Changes:

• Uses a shared, overflow-safe inclusive delay calculation for HTTP and stdio.
• Adds regression coverage for inclusive, equal, and int.MaxValue bounds.

File	Description
DevProxy.Plugins/​Behavior/​LatencyPlugin.cs	Applies inclusive bounds to both delay paths.
DevProxy.Integration.Tests/​BehaviorPluginsIntegrationTests.cs	Tests upper-bound inclusion and boundary cases.

_{Review effort: Balanced}