Pricing and Widgets

Rule Step Shape

src/lib/widgets.ts defines:

• RuleStep: { id, widgetId, config }
• WidgetManifest: widget metadata, configurable fields, and engine definition.
• WidgetField: number or select field metadata used by UI and validation.

Default Widget Catalog

DEFAULT_WIDGETS includes:

• price.addPercent
• price.margin
• price.round9
• price.round5

Current default engines:

• price.addPercent -> percentAdjust
• price.margin -> marginFromCost
• price.round9 -> roundNearest9
• price.round5 -> roundNearest5

Engine Execution

src/lib/rules.ts:

• applyStep(input, step, widgetsById) resolves widget engine and applies one transformation.
• applyPipeline(start, steps, widgetsById) applies all steps in order and returns intermediate outputs plus final value.
• money(n) formats USD display strings.

Engine Rules

• Unknown widget ID: step is ignored (input passes through).
• Numeric config values are read using the engine's configured key names.
• marginFromCost computes input / (1 - percent/100) and safely passes through when denominator is <= 0.
• roundNearest9 rounds to the nearest whole-dollar value ending in 9.
• roundNearest5 rounds to the nearest multiple of 5.

Widget Helpers

src/lib/widgets.ts also provides:

• createStepFromWidget(widget, id) for generating step defaults from widget field defaults.
• mapWidgetsById(widgets) for building a lookup map used by execution and UI.

Tier Pricing Integration

• Tier policy parsing and calculation live in src/lib/tier-pricing-policy.ts.
• Products and builder previews combine:
  • pipeline final output from applyPipeline
  • tier derivation from computeTierPrices
• See _docs/tier-pricing-policy.md for full tier model details.

Key Separation of Concerns

• Widget schemas/defaults/helpers: src/lib/widgets.ts
• Runtime step math: src/lib/rules.ts
• Tier math and policy parsing: src/lib/tier-pricing-policy.ts
• Step and tier validation when persisting rulesets: src/lib/s3-rulesets.ts