waste_lens_dio

Dio add-on for waste_lens: detect redundant API calls, coalesce in-flight duplicates, and report wasted bytes.

The interceptor sits at the network edge — the wrong place to decide a call is unnecessary — so it is a safety net + diagnostic: it eliminates exact in-flight duplicates, flags everything else, and points you at the call site to fix properly.

Install

dependencies:
  waste_lens: ^0.1.0
  waste_lens_dio: ^0.1.0
  dio: ^5.9.2

Usage

import 'package:waste_lens/waste_lens.dart';
import 'package:waste_lens_dio/waste_lens_dio.dart';

final dio = Dio()
  ..interceptors.add(
    RedundantCallInterceptor(
      bus: WasteLens.current?.bus, // mirror findings to the overlay
      coalesce: true,              // collapse in-flight idempotent duplicates
      redundancyWindow: const Duration(seconds: 2),
    ),
  );

What it does

Case	Behaviour
Concurrent duplicate (idempotent, in-flight)	Coalesced into one network call (opt-in).
Recent duplicate (within the window)	Flagged; optionally served from a short-lived cache (`serveCache`).
Everything else	Identified and counted; never silently suppressed.

Non-idempotent methods (POST/PATCH/DELETE) are never coalesced. Streamed responses are left untouched.

Reports

final report = interceptor.report; // CallReport
print('${report.wastedPercent}% wasted, ${report.redundantCalls} redundant');
for (final e in report.topOffenders()) {
  print('${e.endpoint}: ${e.wastedBytes} bytes');
}

The real fix

The most common redundant call is a FutureProvider/AsyncNotifier re-firing on an unrelated rebuild. The interceptor catches the symptom; the cure is to cache at the provider and narrow with ref.watch(p.select(...)).

License

MIT.