Animation events sanity (#7629)

src/core/core.animator.js

@@ -40,7 +40,7 @@ export class Animator {
 		callbacks.forEach(fn => fn({
 			chart,
 			numSteps,
-			currentStep: date - anims.start
+			currentStep: Math.min(date - anims.start, numSteps)
 		}));
 	}
 
@@ -98,14 +98,13 @@ export class Animator {
 
 			if (draw) {
 				chart.draw();
+				me._notify(chart, anims, date, 'progress');
 			}
 
 			if (chart.options.animation.debug) {
 				drawFPS(chart, items.length, date, me._lastDate);
 			}
 
-			me._notify(chart, anims, date, 'progress');
-
 			if (!items.length) {
 				anims.running = false;
 				me._notify(chart, anims, date, 'complete');

test/specs/core.animator.tests.js

@@ -0,0 +1,40 @@
+describe('Chart.animator', function() {
+	it('should fire onProgress for each draw', function(done) {
+		let count = 0;
+		let drawCount = 0;
+		const progress = (animation) => {
+			count++;
+			expect(animation.numSteps).toEqual(250);
+			expect(animation.currentStep <= 250).toBeTrue();
+		};
+		acquireChart({
+			type: 'bar',
+			data: {
+				datasets: [
+					{data: [10, 5, 0, 25, 78, -10]}
+				],
+				labels: ['tick1', 'tick2', 'tick3', 'tick4', 'tick5', 'tick6']
+			},
+			options: {
+				animation: {
+					duration: 250,
+					onProgress: progress,
+					onComplete: function() {
+						expect(count).toEqual(drawCount);
+						done();
+					}
+				}
+			},
+			plugins: [{
+				afterDraw() {
+					drawCount++;
+				}
+			}]
+		}, {
+			canvas: {
+				height: 150,
+				width: 250
+			},
+		});
+	});
+});