abort transition on detach - alternative fix for #1561

src/compile/nodes/Element.ts

@@ -712,6 +712,8 @@ export default class Element extends Node {
 					${name} = null;
 				});
 			`);
+
+			block.builders.destroy.addConditional('detach', `if (${name}) ${name}.abort();`);
 		} else {
 			const introName = intro && block.getUniqueName(`${this.var}_intro`);
 			const outroName = outro && block.getUniqueName(`${this.var}_outro`);
@@ -726,8 +728,8 @@ export default class Element extends Node {
 
 				if (outro) {
 					block.builders.intro.addBlock(deindent`
-						if (${introName}) ${introName}.abort();
-						if (${outroName}) ${outroName}.abort();
+						if (${introName}) ${introName}.abort(1);
+						if (${outroName}) ${outroName}.abort(1);
 					`);
 				}
 
@@ -748,7 +750,7 @@ export default class Element extends Node {
 				const fn = `%transitions-${outro.name}`;
 
 				block.builders.intro.addBlock(deindent`
-					if (${outroName}) ${outroName}.abort();
+					if (${outroName}) ${outroName}.abort(1);
 				`);
 
 				// TODO hide elements that have outro'd (unless they belong to a still-outroing
@@ -757,6 +759,8 @@ export default class Element extends Node {
 					${outroName} = @wrapTransition(#component, ${this.var}, ${fn}, ${snippet}, false);
 					${outroName}.run(0, #outrocallback);
 				`);
+
+				block.builders.destroy.addConditional('detach', `if (${outroName}) ${outroName}.abort();`);
 			}
 		}
 	}

src/shared/transitions.js

@@ -148,9 +148,9 @@ export function wrapTransition(component, node, fn, params, intro) {
 			this.running = !!this.pending;
 		},
 
-		abort() {
+		abort(reset) {
 			if (this.program) {
-				if (obj.tick) obj.tick(1, 0);
+				if (reset && obj.tick) obj.tick(1, 0);
 				if (obj.css) transitionManager.deleteRule(node, this.program.name);
 				this.program = this.pending = null;
 				this.running = false;

test/runtime/samples/transition-js-destroyed-before-end/_config.js

@@ -0,0 +1,19 @@
+export default {
+	skipIntroByDefault: true,
+
+	data: {
+		visible: true
+	},
+
+	test(assert, component, target, window, raf) {
+		component.set({ visible: false });
+		const div = target.querySelector('div');
+
+		raf.tick(50);
+		assert.equal(div.foo, 0.5);
+
+		component.destroy();
+
+		raf.tick(100);
+	},
+};

test/runtime/samples/transition-js-destroyed-before-end/main.html

@@ -0,0 +1,18 @@
+{#if visible}
+	<div transition:foo>destroy me</div>
+{/if}
+
+<script>
+	export default {
+		transitions: {
+			foo(node, params) {
+				return {
+					duration: 100,
+					tick: t => {
+						node.foo = t;
+					}
+				};
+			}
+		}
+	};
+</script>