ThroughDBProviderclass

Database provider that passes every operation straight through to a wrapped source provider.

• Base for the layered Through*Provider family (validation, caching, logging, change tracking); subclasses override individual methods to add behaviour and call super to delegate.
• Exposes source and implements Sourceable, so wrapped providers can be discovered with getSource() / requireSource().

The identity pass-through base for wrapping providers. ThroughDBProvider takes a source provider and delegates every method to it. Extend it to intercept only the methods you care about — timing, metrics, access control — without reimplementing the rest.

ValidationDBProvider, DebugDBProvider, and ChangesDBProvider are all ThroughDBProvider subclasses.

Usage

Override only the methods you need and call super to delegate the rest:

import { ThroughDBProvider } from "shelving/db";

class TimingDBProvider extends ThroughDBProvider {
  override async getItem(collection, id) {
    const t = performance.now();
    const result = await super.getItem(collection, id);
    console.log(`getItem took ${performance.now() - t}ms`);
    return result;
  }
}