twonly-app-dependencies/lottie/test/gradient_test.dart

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:lottie/lottie.dart';

void main() {
  void testGradient(String name, ValueDelegate valueDelegate) {
    testWidgets(name, (tester) async {
      var composition = await LottieComposition.fromBytes(
        File('example/assets/Tests/DynamicGradient.json').readAsBytesSync(),
      );

      var animation = AnimationController(
        vsync: tester,
        duration: composition.duration,
      );

      await tester.pumpWidget(
        Lottie(
          composition: composition,
          controller: animation,
          delegates: LottieDelegates(values: [valueDelegate]),
        ),
      );

      var screenshotName = name
          .toLowerCase()
          .replaceAll(RegExp('[^a-z0-9 ]'), '')
          .replaceAll(' ', '_');

      await expectLater(
        find.byType(Lottie),
        matchesGoldenFile('goldens/gradients/$screenshotName.png'),
      );
    });
  }

  testGradient(
    'Linear Gradient Fill',
    ValueDelegate.gradientColor(
      ['Linear', 'Rectangle', 'Gradient Fill'],
      value: const [Color(0xFFFFFF00), Color(0xFF00FF00)],
    ),
  );

  testGradient(
    'Radial Gradient Fill',
    ValueDelegate.gradientColor(
      ['Radial', 'Rectangle', 'Gradient Fill'],
      value: const [Color(0xFFFFFF00), Color(0xFF00FF00)],
    ),
  );

  testGradient(
    'Linear Gradient Stroke',
    ValueDelegate.gradientColor(
      ['Linear', 'Rectangle', 'Gradient Stroke'],
      value: const [Color(0xFFFFFF00), Color(0xFF00FF00)],
    ),
  );

  testGradient(
    'Radial Gradient Stroke',
    ValueDelegate.gradientColor(
      ['Radial', 'Rectangle', 'Gradient Stroke'],
      value: const [Color(0xFFFFFF00), Color(0xFF00FF00)],
    ),
  );

  testGradient(
    'Opacity Linear Gradient Fill',
    ValueDelegate.opacity(['Linear', 'Rectangle', 'Gradient Fill'], value: 50),
  );

  testWidgets('Can change gradient dynamically with value', (tester) async {
    var composition = await LottieComposition.fromBytes(
      File('example/assets/blub.json').readAsBytesSync(),
    );

    var animation = AnimationController(
      vsync: tester,
      duration: composition.duration,
    );

    await tester.pumpWidget(
      Lottie(
        composition: composition,
        controller: animation,
        delegates: LottieDelegates(
          values: [
            ValueDelegate.gradientColor(
              const ['灯光', '灯光', 'Gradient Fill 2'],
              value: [Colors.yellow, Colors.white],
            ),
          ],
        ),
      ),
    );
    await tester.pumpWidget(
      Lottie(
        composition: composition,
        controller: animation,
        delegates: LottieDelegates(
          values: [
            ValueDelegate.gradientColor(
              const ['灯光', '灯光', 'Gradient Fill 2'],
              value: [Colors.red, Colors.white],
            ),
          ],
        ),
      ),
    );

    await expectLater(
      find.byType(Lottie),
      matchesGoldenFile('goldens/gradients/blub_red_value.png'),
    );
  });

  testWidgets('Can change gradient dynamically with callback', (tester) async {
    var composition = await LottieComposition.fromBytes(
      File('example/assets/blub.json').readAsBytesSync(),
    );

    var animation = AnimationController(
      vsync: tester,
      duration: composition.duration,
    );

    await tester.pumpWidget(
      Lottie(
        composition: composition,
        controller: animation,
        delegates: LottieDelegates(
          values: [
            ValueDelegate.gradientColor(const [
              '灯光',
              '灯光',
              'Gradient Fill 2',
            ], callback: (_) => [Colors.yellow, Colors.white]),
          ],
        ),
      ),
    );
    await tester.pumpWidget(
      Lottie(
        composition: composition,
        controller: animation,
        delegates: LottieDelegates(
          values: [
            ValueDelegate.gradientColor(const [
              '灯光',
              '灯光',
              'Gradient Fill 2',
            ], callback: (_) => [Colors.red, Colors.white]),
          ],
        ),
      ),
    );

    await expectLater(
      find.byType(Lottie),
      matchesGoldenFile('goldens/gradients/blub_red_callback.png'),
    );
  });
}