Frontend tests and what to run

npm test                  # node --test tests/*.test.ts
npx tsc --noEmit -p .     # type check (strict, no unused locals or parameters)

The tests use the built-in node:test runner. Node 23.6 or newer runs TypeScript directly; on Node 22 add --experimental-strip-types. Most test a pure frontend module (one with no Tauri or React imports, so Node can load it); the guard tests at the end read the sources instead and enforce rules that would otherwise only fail in the running app.

Test	What it covers
midiEdit.test.ts	The Piano Roll functions in src/midiEdit.ts: grid lengths, snapping, quantize with strength, swing and ends, and the rest.
ccCurves.test.ts	Controller lane curves (src/ccCurves.ts): curve shapes, ramps, Create Ramp, Thin Out.
eventList.test.ts	The Event List’s positions across tempo and signature changes, typed values and edits.
noteSelect.test.ts	Edit › Select on notes and events in the Piano Roll and the Event List.
stepInput.test.ts	Step Input: step lengths through the tempo map, the chord and advance state machine, the region edits.
stepSeq.test.ts	The Step Sequencer: step edits, rows, paint values for each edit mode, names, the playing step of each row.
tempo.test.ts	src/tempo.ts, the mirror of the engine’s tempo map.
musicalMove.test.ts	Region moves and nudges in bars and beats through the tempo map.
audioEdit.test.ts	The Audio Track Editor’s range arithmetic (src/audioRange.ts).
regionSelect.test.ts	Edit › Select’s region criteria (src/regionSelect.ts).
regionParams.test.ts	The Region inspector’s playback parameter values.
regionGain.test.ts	The region gain handle’s geometry and arithmetic.
fades.test.ts	Fade curves and crossfades for drawing, mirroring fades.rs.
dragModes.test.ts	The drag preview’s copy of drag_modes.rs, with the Rust module’s cases.
newTrackDrag.test.ts	Which source lanes a drag past the last track makes new tracks for (src/newTrackDrag.ts).
comps.test.ts	Take folder comp names and the folder’s name bar label.
arrangement.test.ts	The Arrangement track’s drawing and drag helpers.
tools.test.ts	The Tracks area’s tools (src/tools.ts) and the marquee (src/marquee.ts).
overview.test.ts	The overview strip’s mapping: time, track rows, the visible-area box, scroll and zoom drags.
scrolling.test.ts	Mouse Wheel Scrolls (src/wheel.ts) and bringing the playhead into view (revealLeft in src/view.ts).
trackHeader.test.ts	Track header layouts by height, the volume slider’s meter scale, and region name bars (src/regionBar.ts).
autoLanes.test.ts	Automation curves, Show Used Automation, the extra lanes and their boxes.
laneFollow.test.ts	The shown lane following a plug-in moved to another track.
alternatives.test.ts	Backup labels, alternative names and track alternatives (src/alternativesModel.ts).
bounceFormat.test.ts	The Bounce dialog’s formats, resolutions and file names.
fxFormat.test.ts	Built-in effect readouts and control mapping.
fxShapes.test.ts	The curves the modulation, distortion and Gain panels draw, against the engine’s values.
fxDock.test.ts	Plug-in panels docked or floating: the slot toggle, closing back, one Channel EQ at a time, Esc, pruning, resize maths and saved sizes.
linearPhaseEq.test.ts	The Linear Phase EQ’s parameters as Channel EQ settings.
cpuMeter.test.ts	The CPU meter’s tooltip and where its peak tick goes.
stripMeters.test.ts	The clip indicator readout and the gain-reduction meter.
vca.test.ts	VCA offsets and loop checks in the Mixer.
trackOff.test.ts	Whether a track is off through its stacks (src/trackOff.ts), and the power button’s tooltip.
controllers.test.ts	Controller assignment types and labels (MIDI Learn).
keyFormat.test.ts	Shortcuts written as each platform writes them.
pluginKeys.test.ts	Keys forwarded from a plug-in’s editor window become the KeyboardEvent the main window would see.
detach.test.ts	Detached windows (src/detachModel.ts): panel keys and labels, the shared UI state, fitting windows onto the monitors.
sheetKeys.test.ts	Which keys reach the app while sheets are open (src/sheetKeysModel.ts), and that every sheet registers with sheetKeys.ts.
storeSelectors.test.ts	Guard: no useStore, useEd or useSettings selector builds a new array or object on each call (which re-renders forever and blanks the window).
commands.test.ts	Guard: every key command and native menu item is handled, and no two key commands share a default key.
tauriCommands.test.ts	Guard: every Tauri command the frontend calls is registered, and each call passes its required arguments in camelCase and nothing else.
pianoRollModel.test.ts	The Piano Roll’s lanes, what a point hits, and its grid sums in musical time.
regionGrab.test.ts	What a press on a region in the Tracks area grabs: the loop tool, trims and fades.
audioEditorModel.test.ts	The Audio Track Editor’s layout, zoom range and what a press grabs.
automationParams.test.ts	Automation parameters: labels, each strip’s list, Stereo Out as a track, the lane’s scale.
settingsText.test.ts	The MIDI monitor’s wording, plug-in types and the Recovery sheet’s texts.
compressorModel.test.ts	The transfer curve’s copy of static_reduction for each circuit.
dynScale.test.ts	The dynamics panels’ value formatting and knob maths.
styles.test.ts	Guard: src/styles/index.css imports every stylesheet exactly once with the tokens first, no other file imports CSS, and each file’s braces balance.
browserDialogs.test.ts	Guard: no window.prompt, confirm or alert in src/ (macOS’s web view doesn’t implement them; use askName or the dialog plug-in).

What to run before sending a change

• cargo test -p daw-engine --lib and cargo test -p daw
• every headless example that touches your area (for engine changes, scripts/headless-checks.sh and the plug-in checks pdc_check and freeze_check); for a built-in effect, fx_check and fx_bench
• npm test, npx tsc --noEmit -p . and npm run build (the Vite bundle and CSS)
• cargo clippy --workspace --all-targets -- -D warnings and cargo fmt --all --check
• a visual check in the running app for UI changes