Test assets

A fixture earns its place by being a pinned input with a known consumer, not by being realistic or popular.

Choose what the test needs

• Start from the behavior under test, then select the smallest representative world, model, recording, dataset slice, checkpoint, or golden.
• Prefer a recognizable public asset when it matches the behavior. It gives reviewers context and avoids maintaining an equivalent private fixture.
• Add an asset only when an active test consumes it. Record the upstream revision, license, verification method, entrypoint, and derivation.
• Reuse outputs from verified scenarios when useful: a generated map or bag can become the pinned input to the next layer.

Choose how it is owned

• Use a pinned pointer for large or independently maintained assets. Verify an immutable revision and checksum, and cache the fetched bytes.
• Vendor only when the test must survive upstream availability or inspect the exact bytes, redistribution is allowed, and the project has a stated size budget.
• Generate project-specific bags and goldens from a committed, seeded producer when no canonical source exists.
• Compare re-simulated behavior with tolerance bands. Reserve byte equality for pure replay or deterministic transforms.

Go deeper only when needed

• To select a known world, robot model, dataset, or recording, read references/canonical-assets.md and verify its dated evidence against the current source before adoption.
• To define a project catalog, manifest, slice, or golden, read references/test-assets-layout.md.
• Use examples/catalog.yaml only as a proven catalog shape, not as a universal asset set.
• Use scripts/fetch_assets.py only for checksum-pinned pointer archives that match its supported manifest shape.
• Testing owns the test layers and pass bars. Data owns training-data sourcing; the simulator and Hub skills own loading and transfer mechanics.

Done

• Every fixture has an active consumer, reproducible source or generator, license evidence, and an assertion whose tolerance matches how the fixture is produced.