microsoft-webui-discovery

External component discovery for the WebUI framework. Resolves web component definitions from npm packages and local paths for use during the build step.

discover_source uses WebUI's native package layout. Framework integrations can implement DiscoveryPlugin and call discover_source_with_plugin to map a different validated package layout into the same DiscoveredComponent runtime contract. Built-in WebUI and FAST discovery plugins are provided.

Default WebUI discovery uses <component-name>.html: the filename is the custom element name. npm packages are scanned beneath components/ by default, without falling back to the package root. To use another layout, declare the ordinary HTML catalog roots in package.json:

{ "webui": { "components": ["./src/components"] } }

Only these directories are scanned when the field is present; [] disables ordinary HTML discovery. Paths must be readable directories within the resolved package, including symlink targets. Invalid metadata or paths fail discovery. Overlapping roots do not suppress duplicate component errors. Nested directories are supported; their names do not determine component names. Matching .css files provide styles and matching .ts/.js siblings mark authored components. Explicit local sources are scanned as given and do not read this package metadata.

Template/style exports and Custom Elements Manifest names are not interpreted by default discovery. Browser registrations are imported through package module exports separately. .spec.ts files do not make a component scripted or require a projection entry.

Named packages are resolved from each ancestor's node_modules, so a nearer directory containing unrelated dependencies does not hide an installed catalog. Bare scopes use the same lookup, selecting the nearest matching scope directory. Scope searches skip unrelated packages but report failures in packages that declare components. The collection spellings @scope/* and @scope/package/* are equivalent to @scope and @scope/package, respectively.

Documentation

See the WebUI repository for full usage guides and examples. Plugin-specific behavior is documented in the FAST discovery guide.

License

MIT — Copyright (c) Microsoft Corporation.