effectcraft/docs/testing.md

Testing

cargo test --workspace     # everything
cargo xtask ci             # fmt, clippy -D warnings, tests, layers, assets, wasm
cargo xtask ci --affected  # the same gates, only for the crates your change can affect

Affected-only CI

The full cargo xtask ci builds and tests every crate in release mode and takes over an hour. For each change, agents and contributors run the affected-only variant; the full CI runs before a release (and on any change it falls back to, below).

cargo xtask ci --affected                  # base: the merge-base of HEAD with main
cargo xtask ci --affected --base HEAD~3    # any git revision
cargo xtask ci --affected --dry-run        # print the plan only

It collects every file that differs from the base (committed, staged, unstaged and untracked) and maps each one to:

• the workspace package whose directory holds it, and
• every package whose sources point at it with a ../ path, such as include_bytes!("../../../assets/fonts/Inter-Regular.ttf") or concat!(env!("CARGO_MANIFEST_DIR"), "/../../docs/effects.md"). So editing docs/preferences.md reruns the engine tests that check it.

The affected set is those packages plus everything that depends on them (transitively through normal and build dependencies) and every package that uses one of them as a dev-dependency. For that set it runs cargo fmt --check (whole workspace, it is fast), cargo clippy --all-targets --release -- -D warnings, the tests (cargo nextest run --release plus cargo test --release --doc when cargo-nextest is installed, otherwise cargo test --release), the layers check, the assets check only when an asset, an .attribution sidecar or ATTRIBUTION.md changed, and the wasm check only for affected L0–L4 crates and the web crates. It prints the plan first and a timing table at the end:

ci --affected: base bc0570888 (HEAD), 1 changed file(s)
  changed: automation
  affected: automation, cli (2 of 35 crates)
  steps: fmt, clippy (2), nextest (2), doctests (1), layers (assets skipped: no asset changes)

Changes to the root Cargo.toml, Cargo.lock, .cargo/, xtask/, rust-toolchain(.toml) or clippy.toml can change every crate's build, so they run the full CI instead and say why. Changes no crate reads (most of docs/, README.md, .github/, packaging/) only get the cheap checks.

Limits: a crate that reads a repo file at run time through a path that is not a ../ literal in its sources is not detected, and building a subset of packages can unify features differently from the whole workspace. Run the full cargo xtask ci before a release.

What the tests cover

• Engine commands (crates/engine/src/tests*.rs): every command family, including undo and redo, and that every menu entry resolves to a registered command.
• Rendering (crates/render): pixel checks on small compositions, for blend modes, masks, mattes, time remapping, 3D projection, lighting and shadows. Fast paths (the layer cache, the affine compositor, blurs, motion blur accumulation) are checked against their reference implementations.
• Effects (crates/effects): each effect has a determinism test and at least one behaviour test (identity at neutral settings, known pixel results, or simulations giving the same frame whether you seek straight to it or play up to it). A registry-wide test checks that effects which read the clock are declared time-dependent. crates/effects/tests/sim_golden.rs pins exact pixel hashes of the simulation effects the GPU shares plans with (CC Rainfall … Card Wipe) at several settings, times, bit depths and resolutions, so any change to their CPU output fails (re-pin with SIM_GOLDEN_PRINT=1 after an intended change; pinned for aarch64 macOS, with the hashes another macOS release's libm gives for unchanged code in LIBM_VARIANTS).
• Export (crates/export/tests): every format is encoded and decoded back, checking frame count, size and pixels. When ffmpeg/ffprobe are installed they are used as an outside check; they are never linked or shipped.
• Automation (crates/automation, apps/effectcraft-cli/tests): MCP protocol round trips and the command-line tool's JSON output.
• Interface (crates/ui-egui): headless egui_kittest tests for panels and dialogs.

Looking at the interface without a window

cargo run -p effectcraft-ui-egui --example snapshot -- --out ui.png \
  --step '{"method":"engine.execute","params":{"command":"layer.select","params":{"layers":["#2"]}}}'

Each --step is a control-channel request; {"method":"snap","params":{"path":"x.png"}} writes an intermediate image.

Benchmarks

cargo run --release -p effectcraft-cli -- bench --n 10 --play 30

prints per-layer and per-effect timings for one frame, and playback timings with and without the layer cache.