Function buildBindingKey

packages/context/src/binding-inspector.ts:334–372

* Build the binding key for a class with optional binding metadata. * The binding key is resolved in the following steps: * * 1. Check `options.key`, if it exists, return it * 2. Check if the binding metadata has `key` tag, if yes, return its tag value * 3. Identify `namespace` and `name` to fo

(
  cls: Constructor<T | Provider<T>>,
  options: BindingFromClassOptions = {},
)

 * @typeParam T - Value type
 */
function buildBindingKey<T>(
  cls: Constructor<T | Provider<T>>,
  options: BindingFromClassOptions = {},
) {
  if (options.key) return options.key;

  const templateFn = bindingTemplateFor(cls);
  // Create a temporary binding
  const bindingTemplate = new Binding('template').apply(templateFn);
  // Is there a `key` tag?
  let key: string = bindingTemplate.tagMap[ContextTags.KEY];
  if (key) return key;

  let namespace =
    options.namespace ??
    bindingTemplate.tagMap[ContextTags.NAMESPACE] ??
    options.defaultNamespace;
  if (!namespace) {
    const namespaces = Object.assign(
      {},
      DEFAULT_TYPE_NAMESPACES,
      options.typeNamespaceMapping,
    );
    // Derive the key from type + name
    let type = options.type ?? bindingTemplate.tagMap[ContextTags.TYPE];
    if (!type) {
      type =
        bindingTemplate.tagNames.find(t => namespaces[t] != null) ??
        ContextTags.CLASS;
    }
    namespace = getNamespace(type, namespaces);
  }

  const name =
    options.name ?? (bindingTemplate.tagMap[ContextTags.NAME] || cls.name);
  key = `${namespace}.${name}`;

  return key;
}