Development

This guide covers setting up the development environment, using the component demo, debug mode, the trace-history time-travel debugger, and building from source.

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Building from Source

BareDOM is authored in ClojureScript and compiled with shadow-cljs.

# Install dependencies
npm install

# Start development server with hot reload (http://localhost:8000)
npx shadow-cljs watch app

# Run browser-based tests (http://localhost:8021)
npx shadow-cljs watch test

# Build production ESM library to dist/
npm run build

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Component Demo

BareDOM ships with a built-in demo that lets you browse and interact with every component in isolation. It is intended for developer convenience when working on the library itself.

npm install
npx shadow-cljs watch app

Then open http://localhost:8000. The dev server serves public/index.html and hot-reloads on every source change. Each component is demonstrated in its own section with controls for toggling attributes, properties, and variants.

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Debug Mode

BareDOM includes a visual debug overlay for development. It highlights every component on the page, shows tag names on hover, and lets you inspect and edit live state — no browser extension required.

Activate by adding ?baredom-debug to any dev URL:

http://localhost:8000?baredom-debug

Or toggle from the browser console at any time:

window.BAREDOM_DEBUG = true

When active, debug mode provides:

• Dashed blue outlines around every BareDOM component
• Tag labels that appear on hover (top-right corner)
• Inspection panel — click a label to see current attributes, properties, and computed state
• Inline editing — toggle boolean attributes with a switch, edit string/number values and press Enter to apply
• Console logging — structured console.group output on every attribute change, lifecycle events at console.debug level

Changes made through the debug panel are live but ephemeral — they modify the DOM directly and do not survive a page refresh.

Debug mode is dev-only and is excluded from the production ESM build (npm run build).

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Trace History

BareDOM ships an optional time-travel debugger, x-trace-history, that complements debug mode. Where debug mode answers "what is the state of this element right now?", trace history answers "what happened across the page over time?". Both can be active at the same time.

Activate by adding ?baredom-trace-history to any dev URL:

http://localhost:8000?baredom-trace-history

Or toggle from the browser console:

window.BAREDOM_TRACE_HISTORY = true

For forensic recording — disables the default 16ms sample-rate cap and turns on the state/instance-field-set filter that's off by default — use =raw:

http://localhost:8000?baredom-trace-history=raw

This makes high-frequency animation lanes legible to the recorder, at the cost of larger record buffers.

When active, trace history provides:

• Recording substrate — every CustomEvent, attribute mutation, instance-field write, and lifecycle callback is captured as a plain JS record with a stable schema (schemaVersion: 1).
• Floating dock — cross-instance lanes on a horizontal SVG timeline, with hover tooltips, click-to-filter, and a scrubber for stepping record-by-record (← / → arrow keys).
• Causality view — synchronous cause → effect chains shown as a DAG; jump between a record and the dispatch that produced it.
• Heatmap rendering — animation-heavy lanes automatically switch from individual dots to density bands so the timeline stays legible.
• Full-text search — filter records by any value in the recorded payload.
• Recording sessions — bound a slice of the always-on timeline to a labelled session.
• Export / import — download a .trace.json or drag one onto the dock; share traces via the standalone viewer.html (?trace=<base64> URL param supported).
• Console API — window.BareDOM.traceHistory.records() / pause() / clear() / startSession() / export() / ….

Trace history is opt-in and has zero cost when not activated (one nil-check at each hook site). It ships as a separate ESM module (@vanelsas/baredom/x-trace-history) with full TypeScript declarations.

See docs/x-trace-history.md for the full user guide, docs/x-trace-history-schema.md for the JSON schema reference, and docs/x-trace-history-roadmap.md for the design rationale and what's deferred to future versions.

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Linting

clj-kondo --lint src test

Code must have zero lint warnings and errors before pushing.

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Project Structure

src/baredom/
  components/<name>/     Component source (model.cljs, <name>.cljs)
  exports/<name>.cljs    ESM entry point per component
  utils/                 Shared utilities (dom.cljs, model.cljs)
  dev/                   Dev-only code (hot_reload.cljs, x_debug/, x_trace_history/)
  core.cljs              Dev build entry point
docs/                    Per-component documentation
demo/                    Demo HTML pages
test/                    Browser-based tests
scripts/                 Build and code generation scripts

See CLAUDE.md for the full architecture reference, coding conventions, and contribution guidelines.