transpile/remove stuff that wont work in Node 4

rollup/rollup.config.main.js

@@ -1,6 +1,7 @@
 import nodeResolve from 'rollup-plugin-node-resolve';
 import commonjs from 'rollup-plugin-commonjs';
 import json from 'rollup-plugin-json';
+import buble from 'rollup-plugin-buble';
 
 export default {
 	entry: 'src/index.js',
@@ -11,7 +12,14 @@ export default {
 	plugins: [
 		nodeResolve({ jsnext: true, module: true }),
 		commonjs(),
-		json()
+		json(),
+		buble({
+			include: 'src/**',
+			exclude: 'src/shared/**',
+			transforms: {
+				dangerousTaggedTemplateString: true
+			}
+		})
 	],
 	external: [ 'magic-string' ],
 	globals: {

rollup/rollup.config.ssr.js

@@ -1,6 +1,7 @@
 import * as path from 'path';
 import nodeResolve from 'rollup-plugin-node-resolve';
 import commonjs from 'rollup-plugin-commonjs';
+import buble from 'rollup-plugin-buble';
 
 export default {
 	entry: 'src/server-side-rendering/register.js',
@@ -10,7 +11,14 @@ export default {
 	],
 	plugins: [
 		nodeResolve({ jsnext: true, module: true }),
-		commonjs()
+		commonjs(),
+		buble({
+			include: 'src/**',
+			exclude: 'src/shared/**',
+			transforms: {
+				dangerousTaggedTemplateString: true
+			}
+		})
 	],
 	external: [ path.resolve( 'src/index.js' ), 'fs', 'path', 'magic-string' ],
 	paths: {

src/generators/dom/visitors/Component.js

@@ -16,7 +16,7 @@ export default {
 			namespace: generator.current.namespace,
 			isComponent: true,
 
-			allUsedContexts: new Set(),
+			allUsedContexts: [],
 
 			init: new CodeBuilder(),
 			update: new CodeBuilder()
@@ -28,10 +28,8 @@ export default {
 
 		addComponentAttributes( generator, node, local );
 
-		if ( local.allUsedContexts.size ) {
-			const contextNames = [...local.allUsedContexts];
-
-			const initialProps = contextNames.map( contextName => {
+		if ( local.allUsedContexts.length ) {
+			const initialProps = local.allUsedContexts.map( contextName => {
 				if ( contextName === 'root' ) return `root: root`;
 
 				const listName = generator.current.listNames[ contextName ];
@@ -40,7 +38,7 @@ export default {
 				return `${listName}: ${listName},\n${indexName}: ${indexName}`;
 			}).join( ',\n' );
 
-			const updates = contextNames.map( contextName => {
+			const updates = local.allUsedContexts.map( contextName => {
 				if ( contextName === 'root' ) return `${name}._context.root = root;`;
 
 				const listName = generator.current.listNames[ contextName ];

src/generators/dom/visitors/Element.js

@@ -17,7 +17,7 @@ export default {
 			namespace: node.name === 'svg' ? 'http://www.w3.org/2000/svg' : generator.current.namespace,
 			isComponent: false,
 
-			allUsedContexts: new Set(),
+			allUsedContexts: [],
 
 			init: new CodeBuilder(),
 			update: new CodeBuilder()
@@ -27,10 +27,8 @@ export default {
 
 		addElementAttributes( generator, node, local );
 
-		if ( local.allUsedContexts.size ) {
-			const contextNames = [...local.allUsedContexts];
-
-			const initialProps = contextNames.map( contextName => {
+		if ( local.allUsedContexts.length ) {
+			const initialProps = local.allUsedContexts.map( contextName => {
 				if ( contextName === 'root' ) return `root: root`;
 
 				const listName = generator.current.listNames[ contextName ];
@@ -39,7 +37,7 @@ export default {
 				return `${listName}: ${listName},\n${indexName}: ${indexName}`;
 			}).join( ',\n' );
 
-			const updates = contextNames.map( contextName => {
+			const updates = local.allUsedContexts.map( contextName => {
 				if ( contextName === 'root' ) return `${name}.__svelte.root = root;`;
 
 				const listName = generator.current.listNames[ contextName ];

src/generators/dom/visitors/attributes/addComponentAttributes.js

@@ -82,18 +82,18 @@ export default function addComponentAttributes ( generator, node, local ) {
 			generator.addSourcemapLocations( attribute.expression );
 			generator.code.prependRight( attribute.expression.start, 'component.' );
 
-			const usedContexts = new Set();
+			const usedContexts = [];
 			attribute.expression.arguments.forEach( arg => {
 				const { contexts } = generator.contextualise( arg, true, true );
 
 				contexts.forEach( context => {
-					usedContexts.add( context );
-					local.allUsedContexts.add( context );
+					if ( !~usedContexts.indexOf( context ) ) usedContexts.push( context );
+					if ( !~local.allUsedContexts.indexOf( context ) ) local.allUsedContexts.push( context );
 				});
 			});
 
 			// TODO hoist event handlers? can do `this.__component.method(...)`
-			const declarations = [...usedContexts].map( name => {
+			const declarations = usedContexts.map( name => {
 				if ( name === 'root' ) return 'var root = this._context.root;';
 
 				const listName = generator.current.listNames[ name ];

src/generators/dom/visitors/attributes/addElementAttributes.js

@@ -155,18 +155,18 @@ export default function addElementAttributes ( generator, node, local ) {
 				generator.code.prependRight( attribute.expression.start, 'component.' );
 			}
 
-			const usedContexts = new Set();
+			const usedContexts = [];
 			attribute.expression.arguments.forEach( arg => {
 				const { contexts } = generator.contextualise( arg, true );
 
 				contexts.forEach( context => {
-					usedContexts.add( context );
-					local.allUsedContexts.add( context );
+					if ( !~usedContexts.indexOf( context ) ) usedContexts.push( context );
+					if ( !~local.allUsedContexts.indexOf( context ) ) local.allUsedContexts.push( context );
 				});
 			});
 
 			// TODO hoist event handlers? can do `this.__component.method(...)`
-			const declarations = [...usedContexts].map( name => {
+			const declarations = usedContexts.map( name => {
 				if ( name === 'root' ) return 'var root = this.__svelte.root;';
 
 				const listName = generator.current.listNames[ name ];

src/generators/dom/visitors/attributes/binding/index.js

@@ -8,7 +8,9 @@ export default function createBinding ( generator, node, attribute, current, loc
 	const deep = parts.length > 1;
 	const contextual = parts[0] in current.contexts;
 
-	if ( contextual ) local.allUsedContexts.add( parts[0] );
+	if ( contextual && !~local.allUsedContexts.indexOf( parts[0] ) ) {
+		local.allUsedContexts.push( parts[0] );
+	}
 
 	if ( local.isComponent ) {
 		let obj;