fix: #1966 unit test for Particles (#2097)

fix: 🐛 Unit tests for particles #1966: Unit test for Particles

packages/flame/test/particles/circle_particle_test.dart

@@ -0,0 +1,41 @@
+import 'package:canvas_test/canvas_test.dart';
+import 'package:flame/components.dart';
+import 'package:flame/particles.dart';
+import 'package:flame_test/flame_test.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mocktail/mocktail.dart';
+
+class MockParticle extends Mock implements CircleParticle {}
+
+void main() {
+ group('CircleParticle', () {
+ test('Should render this Particle to given Canvas', () {
+ final particle = MockParticle();
+
+ final canvas = MockCanvas();
+ ParticleSystemComponent(particle: particle).render(canvas);
+
+ verify(() => particle.render(canvas)).called(1);
+ });
+
+ testWithFlameGame(
+ 'Consider composing this with other Particle to achieve needed effects',
+ (game) async {
+ final childParticle = CircleParticle(
+ paint: Paint()..color = Colors.red,
+ lifespan: 2,
+ );
+
+ final component = ParticleSystemComponent(
+ particle: childParticle,
+ );
+
+ game.add(component);
+ await game.ready();
+ game.update(1);
+
+ expect(childParticle.progress, 0.5);
+ });
+ });
+}

packages/flame/test/particles/computed_particle_test.dart

@@ -0,0 +1,82 @@
+import 'package:flame/particles.dart';
+import 'package:flame/src/components/particle_system_component.dart';
+import 'package:flame_test/flame_test.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+ group('ComputedParticle', () {
+ testWithFlameGame(
+ 'Particle container which delegates rendering particle on each frame',
+ (game) async {
+ final cellSize = game.size / 5.0;
+ final halfCellSize = cellSize / 2;
+
+ final particle = ComputedParticle(
+ renderer: (canvas, particle) {
+ canvas.drawCircle(
+ Offset.zero,
+ particle.progress * halfCellSize.x,
+ Paint()
+ ..color = Color.lerp(
+ Colors.red,
+ Colors.blue,
+ particle.progress,
+ )!,
+ );
+ },
+ lifespan: 2,
+ );
+
+ final component = ParticleSystemComponent(
+ particle: particle,
+ );
+
+ game.add(component);
+ await game.ready();
+ game.update(1);
+ expect(particle.progress, 0.5);
+
+ game.update(1);
+ expect(particle.progress, 1);
+ });
+
+ testWithFlameGame('Particle to use custom tweening', (game) async {
+ final cellSize = game.size / 5.0;
+ final halfCellSize = cellSize / 2;
+ final steppedTween = StepTween(begin: 0, end: 5);
+
+ final particle = ComputedParticle(
+ lifespan: 2,
+ renderer: (canvas, particle) {
+ const steps = 5;
+ final steppedProgress =
+ steppedTween.transform(particle.progress) / steps;
+
+ canvas.drawCircle(
+ Offset.zero,
+ (1 - steppedProgress) * halfCellSize.x,
+ Paint()
+ ..color = Color.lerp(
+ Colors.red,
+ Colors.blue,
+ steppedProgress,
+ )!,
+ );
+ },
+ );
+
+ final component = ParticleSystemComponent(
+ particle: particle,
+ );
+
+ game.add(component);
+ await game.ready();
+ game.update(1);
+ expect(particle.progress, 0.5);
+
+ game.update(1);
+ expect(particle.progress, 1);
+ });
+ });
+}

packages/flame/test/particles/curved_particle_test.dart

@@ -0,0 +1,37 @@
+import 'package:flame/src/components/particle_system_component.dart';
+import 'package:flame/src/particles/curved_particle.dart';
+import 'package:flame_test/flame_test.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+ group('CurvedParticle', () {
+ test('A Particle which applies certain Curve', () async {
+ final particle = CurvedParticle();
+
+ expect(particle.curve, Curves.linear);
+ });
+
+ test('A Particle which applies certain Curve', () async {
+ final particle = CurvedParticle(curve: Curves.decelerate);
+
+ expect(particle.curve, Curves.decelerate);
+ });
+
+ testWithFlameGame(
+ 'A Particle which applies certain Curve for easing or other purposes'
+ ' to its progress getter.', (game) async {
+ final particle = CurvedParticle(lifespan: 2);
+ final component = ParticleSystemComponent(
+ particle: particle,
+ );
+
+ game.add(component);
+ await game.ready();
+ game.update(1);
+
+ expect(particle.curve, Curves.linear);
+ expect(particle.progress, 0.5);
+ });
+ });
+}

packages/flame/test/particles/moving_particle_test.dart

@@ -0,0 +1,35 @@
+import 'package:flame/extensions.dart';
+import 'package:flame/src/components/particle_system_component.dart';
+import 'package:flame/src/particles/circle_particle.dart';
+import 'package:flame/src/particles/moving_particle.dart';
+import 'package:flame_test/flame_test.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+ group('MovingParticle', () {
+ testWithFlameGame(
+ 'Particle which is moving from one predefined position to another one',
+ (game) async {
+ final childParticle = CircleParticle(
+ paint: Paint()..color = Colors.red,
+ lifespan: 2,
+ );
+
+ final particle = MovingParticle(
+ from: Vector2(-20, -20),
+ to: Vector2(20, 20),
+ child: childParticle,
+ );
+
+ final component = ParticleSystemComponent(
+ particle: particle,
+ );
+
+ game.add(component);
+ await game.ready();
+ game.update(1);
+ expect(particle.progress, 1.0);
+ });
+ });
+}

packages/flame/test/particles/scaled_particle_test.dart

@@ -0,0 +1,42 @@
+import 'dart:math';
+
+import 'package:flame/src/components/particle_system_component.dart';
+import 'package:flame/src/particles/computed_particle.dart';
+import 'package:flame/src/particles/rotating_particle.dart';
+import 'package:flame/src/particles/scaled_particle.dart';
+import 'package:flame_test/flame_test.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+ group('ScaledParticle', () {
+ testWithFlameGame(
+ 'A particle which rotates its child over the lifespan between two '
+ 'given bounds in radians', (game) async {
+ final paint = Paint()..color = Colors.red;
+ final rect = ComputedParticle(
+ renderer: (canvas, _) => canvas.drawRect(
+ Rect.fromCenter(center: Offset.zero, width: 10, height: 10),
+ paint,
+ ),
+ );
+
+ final particle = ScaledParticle(
+ lifespan: 2,
+ child: rect.rotating(to: pi / 2),
+ );
+
+ final component = ParticleSystemComponent(
+ particle: particle,
+ );
+
+ game.add(component);
+ await game.ready();
+ game.update(1);
+
+ expect(particle.scale, 1.0);
+ expect(particle.child, isInstanceOf<RotatingParticle>());
+ expect(particle.child.progress, 0.5);
+ });
+ });
+}

packages/flame/test/particles/sprite_particle_test.dart

@@ -0,0 +1,45 @@
+import 'package:canvas_test/canvas_test.dart';
+import 'package:flame/extensions.dart';
+import 'package:flame/src/components/particle_system_component.dart';
+import 'package:flame/src/particles/sprite_particle.dart';
+import 'package:flame_test/flame_test.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mocktail/mocktail.dart';
+
+class MockParticle extends Mock implements SpriteParticle {}
+
+Future<void> main() async {
+ // Generate an image
+ final image = await generateImage();
+
+ group('SpriteParticle', () {
+ test('Should render this Particle to given Canvas', () {
+ final particle = MockParticle();
+
+ final canvas = MockCanvas();
+ ParticleSystemComponent(particle: particle).render(canvas);
+
+ verify(() => particle.render(canvas)).called(1);
+ });
+
+ final sprite = Sprite(image);
+ testWithFlameGame(
+ 'SpriteParticle allows easily embed Flames Sprite into the effect',
+ (game) async {
+ final particle = SpriteParticle(
+ sprite: sprite,
+ size: Vector2(50, 50),
+ lifespan: 2,
+ );
+
+ final component = ParticleSystemComponent(
+ particle: particle,
+ );
+
+ game.add(component);
+ await game.ready();
+ game.update(1);
+ expect(particle.progress, 0.5);
+ });
+ });
+}