Author an Asset-Generation Test Case

Scope

Scaffold an asset-generation test case of asset_kind sprite or sprite-sheet: a 2D image a model draws with the draw or draw-sheet binary, one recorded operation at a time, to match a written brief. Read Authoring an Asset-Generation Test Case for the full procedure; Sprite cases is the authoritative schema.

The sibling asset kinds each have their own quickstart: 3D models and rigs, UI art, PBR materials, particle effects, and audio.

Layout

A version lives at test-cases/asset-generation/<difficulty>/<slug>/<version>/. A version with runs recorded against it is frozen; revise a case by adding a new version.

test-cases/asset-generation/<difficulty>/<slug>/<version>/
  test-case.toml         # manifest: type, asset_kind, canvas, tool, output
  variants/              # one standalone TOML file per variant
  prompt.hbs             # rendered into the harness instruction; not seeded
  changelog.md           # required per-version entry; not seeded
  description.md         # site blurb; not seeded
  specs/brief.md         # what to draw and how the tool behaves; seeded

The case is reviewed by a human against its brief, so it declares no [[reference]] and carries no target image.

Steps

1. Pick a catalog slug and the subject to draw. It should read clearly at the canvas size and need no in-game context.
2. Write specs/brief.md: the subject, its silhouette, the exact palette, framing, and how the tool behaves, including that --help lists the operations. Keep it self-contained; the model sees only the seeded files.
3. Write prompt.hbs. It renders in strict mode against {{variant.*}}, {{#each specs}}, {{workspace}}, and {{time_limit_hours}}. Point the model at the binary’s --help.
4. Write test-case.toml: metadata (name, difficulty, tags), the required changelog, type = "asset-generation", asset_kind ("sprite", the default, or "sprite-sheet"), the variants list, and the [canvas], [tool], and [output] tables.
5. A sprite-sheet case adds the [sheet] table: [[sheet.frame]] entries, each carrying just an index, and named [[sheet.sequence]] animations, each carrying a slug, an ordered frames list, and an fps rate.
6. Declare the single overall [[domain]] a human rates the drawing under. The drawing is judged as a whole against its brief on that one rating, so the case declares no [[review_item]] checklist, no [build], and no [[check]].

Worked examples: spectra-fighter, spectra-flux, spectra-prism, and spectra-shard for single sprites; lanternjaw, drifter, gloamfin, flarefish, trench-walls, and flare-bloom for sprite sheets. Read the one matching the kind you are authoring.

Validate

Run these for every variant.

npm run lint:specs
tcab prompt --test-case <slug> --version <version> --variant <variant>
tcab seed   --test-case <slug> --version <version> --variant <variant>

prompt catches strict-mode template and manifest errors. seed writes the seeded repository under tmp/, holding the brief, draw.config.json, an empty layers.json, and a blank starting frame per declared frame.

Next steps

• Create a Single-Sprite Variant or Create a Sprite-Sheet Variant, picked by the case’s asset_kind.
• Run a Test Case to exercise it end to end.