outroing each blocks

src/compile/dom/Block.ts

@@ -272,7 +272,7 @@ export default class Block {
 						${outroing} = true;
 						${hasIntros && `${introing} = false;`}
 
-						${this.outros > 1 && `var #outros = ${this.outros};`}
+						${this.outros > 1 && `#outrocallback = @callAfter(#outrocallback, ${this.outros});`}
 
 						${this.builders.outro}
 					},

src/compile/nodes/EachBlock.ts

@@ -118,6 +118,10 @@ export default class EachBlock extends Node {
 			);
 			this.else.block.hasUpdateMethod = this.else.block.dependencies.size > 0;
 		}
+
+		if (this.block.hasOutroMethod || (this.else && this.else.block.hasOutroMethod)) {
+			block.addOutro();
+		}
 	}
 
 	build(
@@ -313,9 +317,24 @@ export default class EachBlock extends Node {
 		block.builders.update.addBlock(deindent`
 			var ${this.each_block_value} = ${snippet};
 
+			${this.block.hasOutroMethod && `@transitionManager.groupOutros();`}
 			${blocks} = @updateKeyedEach(${blocks}, #component, changed, ${get_key}, ${dynamic ? '1' : '0'}, ctx, ${this.each_block_value}, ${lookup}, ${updateMountNode}, ${String(this.block.hasOutroMethod)}, ${create_each_block}, "${mountOrIntro}", ${anchor}, ${this.get_each_context});
 		`);
 
+		block.builders.outro.addBlock(deindent`
+			const keys = Object.keys(${lookup}).filter(key => ${lookup}[key]);
+			#outrocallback = @callAfter(#outrocallback, keys.length);
+
+			function outro(key) {
+				${lookup}[key].o(() => {
+					${lookup}[key] = null;
+					#outrocallback();
+				});
+			}
+
+			for (let #i = 0; #i < keys.length; #i += 1) outro(keys[#i]);
+		`)
+
 		block.builders.destroy.addBlock(deindent`
 			for (#i = 0; #i < ${blocks}.length; #i += 1) ${blocks}[#i].d(${parentNode ? '' : 'detach'});
 		`);
@@ -372,6 +391,21 @@ export default class EachBlock extends Node {
 			allDependencies.add(dependency);
 		});
 
+		const outro = this.block.hasOutroMethod && block.getUniqueName('outro')
+		if (outro) {
+			block.builders.init.addBlock(deindent`
+				function ${outro}(i, detach, fn) {
+					if (${iterations}[i]) {
+						${iterations}[i].o(() => {
+							${iterations}[i].d(detach);
+							if (detach) ${iterations}[i] = null;
+							if (fn) fn();
+						});
+					}
+				}
+			`);
+		}
+
 		// TODO do this for keyed blocks as well
 		const condition = Array.from(allDependencies)
 			.map(dependency => `changed.${dependency}`)
@@ -406,27 +440,21 @@ export default class EachBlock extends Node {
 
 			const start = this.block.hasUpdateMethod ? '0' : `${iterations}.length`;
 
-			const outro = block.getUniqueName('outro');
-			const destroy = this.block.hasOutroMethod
-				? deindent`
-					function ${outro}(i) {
-						if (${iterations}[i]) {
-							${iterations}[i].o(function() {
-								${iterations}[i].d(1);
-								${iterations}[i] = null;
-							});
-						}
-					}
+			let destroy;
 
+			if (this.block.hasOutroMethod) {
+				destroy = deindent`
 					@transitionManager.groupOutros();
-					for (; #i < ${iterations}.length; #i += 1) ${outro}(#i);
-				`
-				: deindent`
+					for (; #i < ${iterations}.length; #i += 1) ${outro}(#i, 1);
+				`;
+			} else {
+				destroy = deindent`
 					for (; #i < ${iterations}.length; #i += 1) {
 						${iterations}[#i].d(1);
 					}
 					${iterations}.length = ${this.each_block_value}.${length};
 				`;
+			}
 
 			block.builders.update.addBlock(deindent`
 				if (${condition}) {
@@ -443,6 +471,13 @@ export default class EachBlock extends Node {
 			`);
 		}
 
+		if (outro) {
+			block.builders.outro.addBlock(deindent`
+				#outrocallback = @callAfter(#outrocallback, #i);
+				for (let #i = 0; #i < ${iterations}.length; #i += 1) ${outro}(#i, 0, #outrocallback);`
+			);
+		}
+
 		block.builders.destroy.addBlock(`@destroyEach(${iterations}, detach);`);
 	}
 

src/compile/nodes/Element.ts

@@ -712,7 +712,7 @@ export default class Element extends Node {
 
 			block.builders.outro.addBlock(deindent`
 				${name}.run(0, () => {
-					${block.outros > 1 ? `if (--#outros === 0) #outrocallback();` : `#outrocallback();`}
+					#outrocallback();
 					${name} = null;
 				});
 			`);
@@ -759,9 +759,7 @@ export default class Element extends Node {
 				// group) prior to their removal from the DOM
 				block.builders.outro.addBlock(deindent`
 					${outroName} = @wrapTransition(#component, ${this.var}, ${fn}, ${snippet}, false);
-					${outroName}.run(0, () => {
-						${block.outros > 1 ? `if (--#outros === 0) #outrocallback();` : `#outrocallback();`}
-					});
+					${outroName}.run(0, #outrocallback);
 				`);
 			}
 		}

src/shared/keyed-each.js

@@ -1,5 +1,3 @@
-import { transitionManager } from './transitions.js';
-
 export function destroyBlock(block, lookup) {
 	block.d(1);
 	lookup[block.key] = null;
@@ -45,7 +43,6 @@ export function updateKeyedEach(old_blocks, component, changed, get_key, dynamic
 	var did_move = {};
 
 	var destroy = has_outro ? outroAndDestroyBlock : destroyBlock;
-	if (has_outro) transitionManager.groupOutros();
 
 	function insert(block) {
 		block[intro_method](node, next);

src/shared/utils.js

@@ -12,4 +12,10 @@ export function assignTrue(tar, src) {
 
 export function isPromise(value) {
 	return value && typeof value.then === 'function';
+}
+
+export function callAfter(fn, i) {
+	return () => {
+		if (!--i) fn();
+	};
 }

test/runtime/samples/transition-js-nested-each-keyed/_config.js

@@ -0,0 +1,28 @@
+export default {
+	skipIntroByDefault: true,
+	nestedTransitions: true,
+
+	data: {
+		x: false,
+		things: ['a']
+	},
+
+	test(assert, component, target, window, raf) {
+		component.set({ x: true });
+
+		const div = target.querySelector('div');
+		assert.equal(div.foo, 0);
+
+		raf.tick(100);
+		assert.equal(div.foo, 1);
+
+		component.set({ x: false });
+		assert.htmlEqual(target.innerHTML, '<div></div>');
+
+		raf.tick(150);
+		assert.equal(div.foo, 0.5);
+
+		raf.tick(200);
+		assert.htmlEqual(target.innerHTML, '');
+	},
+};

test/runtime/samples/transition-js-nested-each-keyed/main.html

@@ -0,0 +1,20 @@
+{#if x}
+	{#each things as thing (thing)}
+		<div transition:foo></div>
+	{/each}
+{/if}
+
+<script>
+	export default {
+		transitions: {
+			foo(node, params) {
+				return {
+					duration: 100,
+					tick: t => {
+						node.foo = t;
+					}
+				};
+			}
+		}
+	};
+</script>

test/runtime/samples/transition-js-nested-each/_config.js

@@ -0,0 +1,28 @@
+export default {
+	skipIntroByDefault: true,
+	nestedTransitions: true,
+
+	data: {
+		x: false,
+		things: ['a']
+	},
+
+	test(assert, component, target, window, raf) {
+		component.set({ x: true });
+
+		const div = target.querySelector('div');
+		assert.equal(div.foo, 0);
+
+		raf.tick(100);
+		assert.equal(div.foo, 1);
+
+		component.set({ x: false });
+		assert.htmlEqual(target.innerHTML, '<div></div>');
+
+		raf.tick(150);
+		assert.equal(div.foo, 0.5);
+
+		raf.tick(200);
+		assert.htmlEqual(target.innerHTML, '');
+	},
+};

test/runtime/samples/transition-js-nested-each/main.html

@@ -0,0 +1,20 @@
+{#if x}
+	{#each things as thing}
+		<div transition:foo></div>
+	{/each}
+{/if}
+
+<script>
+	export default {
+		transitions: {
+			foo(node, params) {
+				return {
+					duration: 100,
+					tick: t => {
+						node.foo = t;
+					}
+				};
+			}
+		}
+	};
+</script>