// Guards for the streamed `chain update apply` path.
//
// Applying an update downloads and swaps a binary and takes minutes.
// The bug class: a caller that passes a line callback and silently
// gets nothing back, or a streaming path that stops honouring the
// test override and starts spawning real processes in the suite.

import 'package:chain_studio/data/system_actions.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  tearDown(() => SystemActions.debugRunFaiOverride = null);

  test('the test override still wins over the streaming path', () async {
    // Hermetic by construction: with an override installed, no process
    // may be started even when a line callback is supplied.
    var seenArgs = <String>[];
    SystemActions.debugRunFaiOverride = (args) async {
      seenArgs = args;
      return (ok: true, stdout: 'done', stderr: '');
    };

    var lines = <String>[];
    final r = await SystemActions.chainUpdateApply(
      'stable',
      onLine: lines.add,
    );

    expect(r.ok, isTrue);
    expect(r.stdout, 'done');
    expect(seenArgs, ['update', 'apply', '--channel', 'stable']);
    expect(lines, isEmpty, reason: 'the override produces no live lines');
  });

  test('the channel reaches the CLI unchanged', () async {
    var seenArgs = <String>[];
    SystemActions.debugRunFaiOverride = (args) async {
      seenArgs = args;
      return (ok: true, stdout: '', stderr: '');
    };

    await SystemActions.chainUpdateApply('beta', onLine: (_) {});
    expect(seenArgs, contains('beta'));
  });

  test('callers without a line callback keep the buffered behaviour',
      () async {
    SystemActions.debugRunFaiOverride =
        (args) async => (ok: false, stdout: '', stderr: 'boom');

    final r = await SystemActions.chainUpdateApply('stable');
    expect(r.ok, isFalse);
    expect(r.stderr, 'boom');
  });
}