@trafficops/template-editor-core

Headless files, archives, host contracts, errors and conformance checks. This package has no React, DOM, Monaco, language-core or runtime dependency. fflate handles ZIP bytes. Browser download links and directory storage belong to hosts.

contract.d.ts is the boundary for project state, analysis, history, actions, previews, AI connection transport and settings. Hosts must return normalized errors with codes conflict, validation, policy, transport or abort. Capabilities remain fixed for a host session; project availability can narrow inline preview, external preview and AI access. Missing optional ports have no key.

validateDialectDescriptor(descriptor, knownIds) validates the host metadata using a caller-owned registry. An empty allowedEntrypoints whitelist means no known entrypoint is currently available, not a selected page. The project state owns its selected entrypoint. Authoritative hosts enforce their own policy on save.

Run runHostConformance(factory, { knownIds, faults }) against a fresh disposable test workspace: the kit saves files, attempts a stale revision, round trips ZIPs, and cancels operations. Optional faults inject transport/permission/validation failures through the real adapter. Do not run it against a user's live project.

The editor tests run it against Studio's directory adapter, HttpHost's protocol mock, and a third host. The third host changes their shared safe dialect, numeric revision and always-available HTML rendering assumptions: it uses the trusted dialect, an opaque revision string, project-gated preview and no HTML export.

The canonical interoperability corpus is under fixtures/. Both the Studio AnalyzerPort tests and PWApps PHP ProjectAnalyzer tests consume these files. Diagnostic parity compares stable code, locale, section, field path, source file and line. Localized human messages must exist but are not compared byte for byte. PWApps installs this package for its tests; there is no second maintained corpus.