ensure var names in binding callbacks are unique — fixes #495

src/generators/dom/visitors/Component/Binding.js

@@ -3,7 +3,7 @@ import flattenReference from '../../../../utils/flattenReference.js';
 import getSetter from '../shared/binding/getSetter.js';
 
 export default function visitBinding ( generator, block, state, node, attribute, local ) {
-	const { name, keypath } = flattenReference( attribute.value );
+	const { name } = flattenReference( attribute.value );
 	const { snippet, contexts, dependencies } = block.contextualise( attribute.value );
 
 	if ( dependencies.length > 1 ) throw new Error( 'An unexpected situation arose. Please raise an issue at https://github.com/sveltejs/svelte/issues — thanks!' );
@@ -35,7 +35,7 @@ export default function visitBinding ( generator, block, state, node, attribute,
 		prop
 	});
 
-	const setter = getSetter({ block, name, keypath, context: '_context', attribute, dependencies, value: 'value' });
+	const setter = getSetter({ block, name, context: '_context', attribute, dependencies, value: 'value' });
 
 	generator.hasComplexBindings = true;
 

src/generators/dom/visitors/Element/Binding.js

@@ -20,7 +20,7 @@ export default function visitBinding ( generator, block, state, node, attribute
 	const bindingGroup = attribute.name === 'group' ? getBindingGroup( generator, keypath ) : null;
 	const value = getBindingValue( generator, block, state, node, attribute, isMultipleSelect, bindingGroup, type );
 
-	let setter = getSetter({ block, name, keypath, context: '_svelte', attribute, dependencies, value });
+	let setter = getSetter({ block, name, context: '_svelte', attribute, dependencies, value });
 	let updateElement = `${state.parentNode}.${attribute.name} = ${snippet};`;
 	const lock = block.getUniqueName( `${state.parentNode}_${attribute.name}_updating` );
 	let updateCondition = `!${lock}`;

src/generators/dom/visitors/shared/binding/getSetter.js

@@ -1,9 +1,10 @@
 import deindent from '../../../../../utils/deindent.js';
 
-export default function getSetter ({ block, name, keypath, context, attribute, dependencies, value }) {
+export default function getSetter ({ block, name, context, attribute, dependencies, value }) {
+	const tail = attribute.value.type === 'MemberExpression' ? getTailSnippet( attribute.value ) : '';
+
 	if ( block.contexts.has( name ) ) {
 		const prop = dependencies[0];
-		const tail = attribute.value.type === 'MemberExpression' ? getTailSnippet( attribute.value ) : '';
 
 		return deindent`
 			var list = this.${context}.${block.listNames.get( name )};
@@ -15,10 +16,12 @@ export default function getSetter ({ block, name, keypath, context, attribute, d
 	}
 
 	if ( attribute.value.type === 'MemberExpression' ) {
+		const alias = block.alias( name );
+
 		return deindent`
-			var ${name} = ${block.component}.get( '${name}' );
-			${keypath} = ${value};
-			${block.component}._set({ ${name}: ${name} });
+			var ${alias} = ${block.component}.get( '${name}' );
+			${alias}${tail} = ${value};
+			${block.component}._set({ ${name}: ${alias} });
 		`;
 	}
 

test/runtime/samples/binding-input-text-deconflicted/_config.js

@@ -1,6 +1,4 @@
 export default {
-	solo: true,
-
 	data: {
 		component: {
 			name: 'world'
@@ -21,14 +19,15 @@ export default {
 		input.value = 'everybody';
 		input.dispatchEvent( event );
 
-		assert.equal( target.innerHTML, `
+		assert.equal( input.value, 'everybody' );
+		assert.htmlEqual( target.innerHTML, `
 			<h1>Hello everybody!</h1>
 			<input>
 		` );
 
-		component.set({ name: 'goodbye' });
+		component.set({ component: { name: 'goodbye' } });
 		assert.equal( input.value, 'goodbye' );
-		assert.equal( target.innerHTML, `
+		assert.htmlEqual( target.innerHTML, `
 			<h1>Hello goodbye!</h1>
 			<input>
 		` );