Ocideck/test/annotation_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:ocideck/models/annotation.dart';
import 'package:ocideck/models/slide.dart';
import 'package:ocideck/services/annotation_codec.dart';

void main() {
  group('InkStroke JSON', () {
    test('round-trips tool, color, width and points', () {
      const stroke = InkStroke(
        tool: InkTool.highlighter,
        color: 0xFF22C55E,
        width: 0.022,
        points: [Offset(0.1, 0.2), Offset(0.3, 0.45)],
      );
      final back = InkStroke.fromJson(stroke.toJson());
      expect(back.tool, InkTool.highlighter);
      expect(back.color, 0xFF22C55E);
      expect(back.width, closeTo(0.022, 1e-9));
      expect(back.points.length, 2);
      expect(back.points[1].dx, closeTo(0.3, 1e-4));
      expect(back.points[1].dy, closeTo(0.45, 1e-4));
    });
  });

  group('AnnotationCodec', () {
    InkStroke stroke() => const InkStroke(
      tool: InkTool.pen,
      color: 0xFFEF4444,
      width: 0.004,
      points: [Offset(0.1, 0.1), Offset(0.2, 0.2)],
    );

    test('encodes nothing when there are no strokes', () {
      final slides = [Slide.create(SlideType.bullets)];
      expect(AnnotationCodec.encode(slides, {}), isNull);
    });

    test('round-trips strokes for the same deck', () {
      final slides = [
        Slide.create(SlideType.bullets).copyWith(title: 'A'),
        Slide.create(SlideType.bullets).copyWith(title: 'B'),
      ];
      final ann = {
        slides[1].id: [stroke()],
      };
      final json = AnnotationCodec.encode(slides, ann)!;
      final back = AnnotationCodec.decode(json, slides);
      expect(back.keys, [slides[1].id]);
      expect(back[slides[1].id]!.single.points.length, 2);
    });

    test('re-anchors strokes to the matching slide after reordering', () {
      final a = Slide.create(SlideType.bullets).copyWith(title: 'A');
      final b = Slide.create(SlideType.bullets).copyWith(title: 'B');
      final json = AnnotationCodec.encode([a, b], {
        a.id: [stroke()],
      })!;

      // Reload parses fresh slides with NEW ids but identical content, in a
      // different order.
      final a2 = Slide.create(SlideType.bullets).copyWith(title: 'A');
      final b2 = Slide.create(SlideType.bullets).copyWith(title: 'B');
      final back = AnnotationCodec.decode(json, [b2, a2]);
      expect(back.containsKey(a2.id), isTrue);
      expect(back.containsKey(b2.id), isFalse);
    });

    test('drops strokes when the slide content changed', () {
      final a = Slide.create(SlideType.bullets).copyWith(title: 'A');
      final json = AnnotationCodec.encode([a], {
        a.id: [stroke()],
      })!;
      final edited = Slide.create(
        SlideType.bullets,
      ).copyWith(title: 'A (changed)');
      final back = AnnotationCodec.decode(json, [edited]);
      expect(back, isEmpty);
    });
  });
}