Performance ModifySimulate Latency• 4 min read
How to Simulate Network Latency and API Delays
Summary: Inject artificial delays (e.g. 1500ms, 3000ms) on individual API endpoints to test asynchronous race conditions and loading UI states.
Why This Rule Matters for Developers & QA
Fast local networks often hide critical UI bugs like missing spinners, flickering skeletons, or unhandled promise race conditions. Adding millisecond delay rules tests real-world mobile scenarios.
Step-by-Step Implementation Guide
1
Choose Endpoint to Throttle
Target the API request where you want to test loading states (e.g. `*/api/search*`).
2
Set Latency in Milliseconds
Specify the exact delay duration (e.g. `2500` for a 2.5 second delay).
3
Observe UI Loading State
Trigger the action in your app and confirm that loading indicators, shimmer effects, and abort controllers behave as intended.
Configuration Snippet
How to Simulate Network Latency and API Delays — proxyceptor-rule.json
JSON
{ "id": "rule_simulate_search_delay", "pattern": "*/api/search*", "action": "delay", "delayMs": 2500, "enabled": true}