Check a scenario before a real run

vegaload validate examples/scenarios/crud-flow.vl.js

validate runs the scenario once, with one user and one iteration, and says whether it works. It catches a script that will not load (a syntax error, a missing file, no iteration() in Python) and an iteration that fails (a wrong URL, a thrown error, a host that is not allowed). It makes real network calls, under the same host rules as run, so a host that is not localhost needs -allow-target or -yes. Any check() results are listed, and a failed check does not make the scenario invalid. Add -output json for a machine-readable result.

Exit code	Meaning
0	The scenario loaded and its iteration ran
1	The scenario is not valid
2	Bad usage

From an agent, the validate_scenario tool does the same and returns valid, and for an invalid scenario the stage (load or iteration) and error.