fix the bugs

Author: Rich-Harris

src/compile/dom/Block.ts

@@ -142,6 +142,10 @@ export default class Block {
 	}
 
 	addVariable(name: string, init?: string) {
+		if (name[0] === '#') {
+			name = this.alias(name.slice(1));
+		}
+
 		if (this.variables.has(name) && this.variables.get(name) !== init) {
 			throw new Error(
 				`Variable '${name}' already initialised with a different value`
@@ -166,11 +170,16 @@ export default class Block {
 	toString() {
 		const { dev } = this.compiler.options;
 
-		let current;
 		if (this.hasIntroMethod || this.hasOutroMethod) {
-			current = this.getUniqueName('current');
-			this.addVariable(current);
-			this.builders.mount.addLine(`${current} = true;`);
+			this.addVariable('#current');
+
+			if (!this.builders.mount.isEmpty()) {
+				this.builders.mount.addLine(`#current = true;`);
+			}
+
+			if (!this.builders.outro.isEmpty()) {
+				this.builders.outro.addLine(`#current = false;`);
+			}
 		}
 
 		if (this.autofocus) {
@@ -268,24 +277,24 @@ export default class Block {
 		}
 
 		if (this.hasIntroMethod || this.hasOutroMethod) {
-			if (this.builders.mount.isEmpty() && this.builders.outro.isEmpty()) {
+			if (this.builders.mount.isEmpty()) {
 				properties.addBlock(`i: @noop,`);
-				properties.addBlock(`o: @run,`);
 			} else {
 				properties.addBlock(deindent`
 					${dev ? 'i: function intro' : 'i'}(#target, anchor) {
-						console.trace("intro", #component.constructor.name, ${current});
-						if (${current}) return;
+						if (#current) return;
 						${this.builders.intro}
 						this.m(#target, anchor);
 					},
 				`);
+			}
 
+			if (this.builders.outro.isEmpty()) {
+				properties.addBlock(`o: @run,`);
+			} else {
 				properties.addBlock(deindent`
 					${dev ? 'o: function outro' : 'o'}(#outrocallback) {
-						console.trace("outro", #component.constructor.name, ${current});
-						if (!${current}) return;
-						${current} = false;
+						if (!#current) return;
 
 						${this.outros > 1 && `#outrocallback = @callAfter(#outrocallback, ${this.outros});`}
 

src/compile/nodes/Attribute.ts

@@ -232,7 +232,7 @@ export default class Attribute extends Node {
 			if (this.dependencies.size || isSelectValueAttribute) {
 				const dependencies = Array.from(this.dependencies);
 				const changedCheck = (
-					( block.hasOutros ? `#outroing || ` : '' ) +
+					(block.hasOutros ? `!#current || ` : '') +
 					dependencies.map(dependency => `changed.${dependency}`).join(' || ')
 				);
 
@@ -308,7 +308,7 @@ export default class Attribute extends Node {
 				if (propDependencies.size) {
 					const dependencies = Array.from(propDependencies);
 					const condition = (
-						(block.hasOutros ? `#outroing || ` : '') +
+						(block.hasOutros ? `!#current || ` : '') +
 						dependencies.map(dependency => `changed.${dependency}`).join(' || ')
 					);
 

src/compile/nodes/Title.ts

@@ -81,7 +81,7 @@ export default class Title extends Node {
 			if (allDependencies.size) {
 				const dependencies = Array.from(allDependencies);
 				const changedCheck = (
-					( block.hasOutros ? `#outroing || ` : '' ) +
+					( block.hasOutros ? `!#current || ` : '' ) +
 					dependencies.map(dependency => `changed.${dependency}`).join(' || ')
 				);
 

src/compile/nodes/shared/Tag.ts

@@ -35,7 +35,7 @@ export default class Tag extends Node {
 
 		if (dependencies.size) {
 			const changedCheck = (
-				(block.hasOutros ? `#outroing || ` : '') +
+				(block.hasOutros ? `!#current || ` : '') +
 				[...dependencies].map((dependency: string) => `changed.${dependency}`).join(' || ')
 			);