@churnkey/dunning-render

Shared rendering logic for dunning and reactivation emails: merge-field substitution, CTA resolution, design (colors/fonts) resolution, and custom HTML sanitization. Single source of truth consumed by apps/web, churnkey-api, and churnkey-dunning so previews and real sends can never drift.

Plain CommonJS, no build step.

Install

npm install @churnkey/dunning-render

Entry points

• @churnkey/dunning-render — browser-safe: constants and pure transforms. Never pulls in sanitize-html.
• @churnkey/dunning-render/server — everything above plus sanitizeCustomHtml. Server-only.

API

Constants

• CTA_MODE / CTA_MODE_LIST — AUTO (CTA rendered at the [[...]] marker, or auto-appended) | HIDDEN
• FONT_FAMILY / FONT_FAMILY_LIST / FONT_STACKS — curated web-safe font list with email-client-safe CSS stacks (remote/Google fonts were dropped in 0.1.2 — Gmail and Outlook strip them)
• DEFAULT_COLORS, EMAIL_MERGE_FIELDS, RECOVERY_LINK, CTA_MARKER_REGEX, EMPTY_CTA_MARKER_REGEX

Functions

• composeEmail(options) — main orchestrator. Substitutes merge fields, resolves the CTA, and picks the render path: TEMPLATE (content fragment for a Postmark template) or CUSTOM_HTML (full self-contained document). Returns { renderPath, content, fullHtml, subject, previewText, meta }. Pure — callers build valuesMap themselves.
• resolveEffectiveDesign(orgDesign, sequenceDesign) — org default ⊕ sequence override merge.
• resolveDesignTemplateVars(design) — Postmark TemplateModel variables (design_background, design_body_text, design_link, design_cta_text, design_font_family, design_font_import) for the shared template shells.
• substituteMergeFields(content, valuesMap) — {{ KEY }} and {{ KEY | fallback }} substitution.
• resolveCta(content, options) — replaces [[...]] markers with the CTA button (or strips them when hidden).
• sanitizeCustomHtml(html) (server only) — allowlist-based sanitization of customer-supplied HTML. Strips all script surface; keeps email-safe layout markup.

Full signatures in index.d.ts.

Development

npm test   # node --test, no build needed

Releasing

Publishing is manual (this package is not in the monorepo's nx release scope). Follow the release runbook: changelog + version bump → npm test → commit → npm publish → tag → bump the range in churnkey-api/churnkey-dunning (apps/web uses workspace:*, nothing to do).

Lives in the Churnkey monorepo at packages/dunning-render. Keep exports as plain shorthand properties in index.js/server.js — Node's cjs-module-lexer needs that shape to expose named exports to ESM import.