Capturing Runtime Coverage

After Scanning Your Application, make the app report coverage while tests run.

SeaLights supports two runtime coverage modes. Pick the one that matches your application.

Mode	Command	Use for	What it does
Frontend Instrumentation (static)	instrument	Angular, React, Vue, and bundled JavaScript apps	Rewrites the built files before deployment.
Backend Instrumentation (dynamic)	run or preload.js	Node.js services, APIs, and workers	Attaches at startup and instruments code in memory.

The deployment model is different for each mode:

• Static frontend: deploy the instrumented output, usually sl_dist, to a test environment only.
• Dynamic backend: deploy the original code and start it through the agent.

For serverless Node.js backends on AWS Lambda, use AWS Lambda Support.

Choose the right page

• Frontend app — Frontend Instrumentation (static)
• Backend service — Backend Instrumentation (dynamic)
• AWS Lambda — AWS Lambda Support