all tests passing once more. now the real work begins

src/generators/Generator.js

@@ -62,14 +62,14 @@ export default class Generator {
 		return alias;
 	}
 
-	contextualise ( expression, isEventHandler ) {
+	contextualise ( fragment, expression, isEventHandler ) {
 		this.addSourcemapLocations( expression );
 
 		const usedContexts = [];
 		const dependencies = [];
 
 		const { code, helpers } = this;
-		const { contextDependencies, contexts, indexes } = this.current;
+		const { contextDependencies, contexts, indexes } = fragment;
 
 		let scope = annotateWithScopes( expression );
 

src/generators/dom/visitors/EachBlock.js

@@ -17,7 +17,7 @@ export default function visitEachBlock ( generator, fragment, node ) {
 
 	generator.addSourcemapLocations( node.expression );
 
-	const { dependencies, snippet } = generator.contextualise( node.expression );
+	const { dependencies, snippet } = generator.contextualise( fragment, node.expression );
 
 	const anchor = fragment.getUniqueName( `${name}_anchor` );
 	fragment.createAnchor( anchor );
@@ -221,17 +221,19 @@ export default function visitEachBlock ( generator, fragment, node ) {
 	generator.pop();
 
 	if ( node.else ) {
-		const childFragment = this.current.child({
+		const childFragment = fragment.child({
 			type: 'block',
 			name: renderElse,
 			target: 'target',
 			localElementDepth: 0,
 			builders: getBuilders(),
-			getUniqueName: this.getUniqueNameMaker( this.current.params )
+			getUniqueName: generator.getUniqueNameMaker( fragment.params )
 		});
 
 		node.else.children.forEach( child => {
 			visit( generator, childFragment, child );
 		});
+
+		generator.addRenderer( childFragment );
 	}
 }

src/generators/dom/visitors/IfBlock.js

@@ -7,7 +7,7 @@ function getConditionsAndBlocks ( generator, fragment, node, _name, i = 0 ) {
 	const name = generator.getUniqueName( `${_name}_${i}` );
 
 	const conditionsAndBlocks = [{
-		condition: generator.contextualise( node.expression ).snippet,
+		condition: generator.contextualise( fragment, node.expression ).snippet,
 		block: name
 	}];
 
@@ -35,7 +35,7 @@ function getConditionsAndBlocks ( generator, fragment, node, _name, i = 0 ) {
 function generateBlock ( generator, fragment, node, name, type ) {
 	const childFragment = fragment.child({
 		type,
-		isIfBlock: true, 
+		isIfBlock: true,
 		name,
 		target: 'target',
 		builders: getBuilders(),

src/generators/dom/visitors/MustacheTag.js

@@ -4,7 +4,7 @@ import findBlock from '../utils/findBlock.js';
 export default function visitMustacheTag ( generator, fragment, node ) {
 	const name = fragment.getUniqueName( 'text' );
 
-	const { snippet } = generator.contextualise( node.expression );
+	const { snippet } = generator.contextualise( fragment, node.expression );
 
 	fragment.builders.create.addLine( `var last_${name} = ${snippet};` );
 	fragment.addElement( name, `${generator.helper( 'createText' )}( last_${name} )`, true );

src/generators/dom/visitors/RawMustacheTag.js

@@ -4,7 +4,7 @@ import findBlock from '../utils/findBlock.js';
 export default function visitRawMustacheTag ( generator, fragment, node ) {
 	const name = fragment.getUniqueName( 'raw' );
 
-	const { snippet } = generator.contextualise( node.expression );
+	const { snippet } = generator.contextualise( fragment, node.expression );
 
 	// we would have used comments here, but the `insertAdjacentHTML` api only
 	// exists for `Element`s.

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

@@ -37,7 +37,7 @@ export default function addComponentAttributes ( generator, fragment, node, loca
 
 				else {
 					// simple dynamic attributes
-					const { dependencies, string } = generator.contextualise( value.expression );
+					const { dependencies, string } = generator.contextualise( fragment, value.expression );
 
 					// TODO only update attributes that have changed
 					local.dynamicAttributes.push({
@@ -57,7 +57,7 @@ export default function addComponentAttributes ( generator, fragment, node, loca
 						if ( chunk.type === 'Text' ) {
 							return JSON.stringify( chunk.data );
 						} else {
-							const { dependencies, string } = generator.contextualise( chunk.expression );
+							const { dependencies, string } = generator.contextualise( fragment, chunk.expression );
 							dependencies.forEach( dependency => {
 								if ( !~allDependencies.indexOf( dependency ) ) allDependencies.push( dependency );
 							});
@@ -82,7 +82,7 @@ export default function addComponentAttributes ( generator, fragment, node, loca
 
 			const usedContexts = [];
 			attribute.expression.arguments.forEach( arg => {
-				const { contexts } = generator.contextualise( arg, true );
+				const { contexts } = generator.contextualise( fragment, arg, true );
 
 				contexts.forEach( context => {
 					if ( !~usedContexts.indexOf( context ) ) usedContexts.push( context );

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

@@ -4,7 +4,7 @@ import getSetter from './binding/getSetter.js';
 
 export default function addComponentBinding ( generator, node, attribute, fragment, local ) {
 	const { name, keypath } = flattenReference( attribute.value );
-	const { snippet, contexts, dependencies } = generator.contextualise( attribute.value );
+	const { snippet, contexts, dependencies } = generator.contextualise( fragment, 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!' );
 

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

@@ -93,7 +93,7 @@ export default function addElementAttributes ( generator, fragment, node, local
 					dynamic = true;
 
 					// dynamic – but potentially non-string – attributes
-					const { snippet } = generator.contextualise( value.expression );
+					const { snippet } = generator.contextualise( fragment, value.expression );
 
 					const last = `last_${local.name}_${name.replace( /-/g, '_')}`;
 					local.create.addLine( `var ${last} = ${snippet};` );
@@ -128,7 +128,7 @@ export default function addElementAttributes ( generator, fragment, node, local
 						if ( chunk.type === 'Text' ) {
 							return JSON.stringify( chunk.data );
 						} else {
-							const { snippet } = generator.contextualise( chunk.expression );
+							const { snippet } = generator.contextualise( fragment, chunk.expression );
 							return `( ${snippet} )`;
 						}
 					}).join( ' + ' )
@@ -165,7 +165,7 @@ export default function addElementAttributes ( generator, fragment, node, local
 
 			const usedContexts = [];
 			attribute.expression.arguments.forEach( arg => {
-				const { contexts } = generator.contextualise( arg, true );
+				const { contexts } = generator.contextualise( fragment, arg, true );
 
 				contexts.forEach( context => {
 					if ( !~usedContexts.indexOf( context ) ) usedContexts.push( context );

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

@@ -5,7 +5,7 @@ import getStaticAttributeValue from './binding/getStaticAttributeValue.js';
 
 export default function addElementBinding ( generator, node, attribute, fragment, local ) {
 	const { name, keypath } = flattenReference( attribute.value );
-	const { snippet, contexts, dependencies } = generator.contextualise( attribute.value );
+	const { snippet, contexts, dependencies } = generator.contextualise( fragment, 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!' );
 

src/generators/server-side-rendering/Fragment.js

@@ -0,0 +1,30 @@
+import deindent from '../../utils/deindent.js';
+import flattenReference from '../../utils/flattenReference.js';
+
+export default class Fragment {
+	constructor ( options ) {
+		Object.assign( this, options );
+	}
+
+	addBinding ( binding, name ) {
+		const conditions = [ `!( '${binding.name}' in root )`].concat( // TODO handle contextual bindings...
+			this.conditions.map( c => `(${c})` )
+		);
+
+		const { keypath } = flattenReference( binding.value );
+
+		this.generator.bindings.push( deindent`
+			if ( ${conditions.join( '&&' )} ) {
+				tmp = ${name}.data();
+				if ( '${keypath}' in tmp ) {
+					root.${binding.name} = tmp.${keypath};
+					settled = false;
+				}
+			}
+		` );
+	}
+
+	child ( options ) {
+		return new Fragment( Object.assign( {}, this, options, { parent: this } ) );
+	}
+}

src/generators/server-side-rendering/index.js

@@ -2,6 +2,7 @@ import deindent from '../../utils/deindent.js';
 import CodeBuilder from '../../utils/CodeBuilder.js';
 import flattenReference from '../../utils/flattenReference.js';
 import Generator from '../Generator.js';
+import Fragment from './Fragment.js';
 import visit from './visit.js';
 
 class SsrGenerator extends Generator {
@@ -50,14 +51,15 @@ export default function ssr ( parsed, source, options ) {
 	};
 
 	// create main render() function
-	generator.push({
+	const mainFragment = new Fragment({
+		generator,
 		contexts: new Map(),
 		indexes: new Map(),
 		conditions: []
 	});
 
 	parsed.html.children.forEach( node => {
-		visit( node, generator );
+		visit( generator, mainFragment, node );
 	});
 
 	builders.render.addLine(

src/generators/server-side-rendering/visit.js

@@ -1,6 +1,6 @@
 import visitors from './visitors/index.js';
 
-export default function visit ( node, generator ) {
+export default function visit ( generator, fragment, node ) {
 	const visitor = visitors[ node.type ];
-	visitor( generator, node );
+	visitor( generator, fragment, node );
 }

src/generators/server-side-rendering/visitors/Component.js

@@ -1,11 +1,11 @@
 import flattenReference from '../../../utils/flattenReference.js';
 import visit from '../visit.js';
 
-export default function visitComponent ( generator, node ) {
+export default function visitComponent ( generator, fragment, node ) {
 	function stringify ( chunk ) {
 		if ( chunk.type === 'Text' ) return chunk.data;
 		if ( chunk.type === 'MustacheTag' ) {
-			const { snippet } = generator.contextualise( chunk.expression );
+			const { snippet } = generator.contextualise( fragment, chunk.expression );
 			return '${__escape( ' + snippet + ')}';
 		}
 	}
@@ -34,7 +34,7 @@ export default function visitComponent ( generator, node ) {
 				if ( chunk.type === 'Text' ) {
 					value = isNaN( chunk.data ) ? JSON.stringify( chunk.data ) : chunk.data;
 				} else {
-					const { snippet } = generator.contextualise( chunk.expression );
+					const { snippet } = generator.contextualise( fragment, chunk.expression );
 					value = snippet;
 				}
 			} else {
@@ -45,7 +45,7 @@ export default function visitComponent ( generator, node ) {
 		})
 		.concat( bindings.map( binding => {
 			const { name, keypath } = flattenReference( binding.value );
-			const value = generator.current.contexts.has( name ) ? keypath : `root.${keypath}`;
+			const value = fragment.contexts.has( name ) ? keypath : `root.${keypath}`;
 			return `${binding.name}: ${value}`;
 		}))
 		.join( ', ' );
@@ -53,7 +53,7 @@ export default function visitComponent ( generator, node ) {
 	const expression = node.name === ':Self' ? generator.name : generator.importedComponents.get( node.name ) || `${generator.alias( 'template' )}.components.${node.name}`;
 
 	bindings.forEach( binding => {
-		generator.addBinding( binding, expression );
+		fragment.addBinding( binding, expression );
 	});
 
 	let open = `\${${expression}.render({${props}}`;
@@ -67,7 +67,7 @@ export default function visitComponent ( generator, node ) {
 	generator.elementDepth += 1;
 
 	node.children.forEach( child => {
-		visit( child, generator );
+		visit( generator, fragment, child );
 	});
 
 	generator.elementDepth -= 1;

src/generators/server-side-rendering/visitors/EachBlock.js

@@ -1,34 +1,32 @@
 import visit from '../visit.js';
 
-export default function visitEachBlock ( generator, node ) {
-	const { dependencies, snippet } = generator.contextualise( node.expression );
+export default function visitEachBlock ( generator, fragment, node ) {
+	const { dependencies, snippet } = generator.contextualise( fragment, node.expression );
 
 	const open = `\${ ${snippet}.map( ${ node.index ? `( ${node.context}, ${node.index} )` : node.context} => \``;
 	generator.append( open );
 
 	// TODO should this be the generator's job? It's duplicated between
 	// here and the equivalent DOM compiler visitor
-	const contexts = new Map( generator.current.contexts );
+	const contexts = new Map( fragment.contexts );
 	contexts.set( node.context, node.context );
 
-	const indexes = new Map( generator.current.indexes );
+	const indexes = new Map( fragment.indexes );
 	if ( node.index ) indexes.set( node.index, node.context );
 
-	const contextDependencies = new Map( generator.current.contextDependencies );
+	const contextDependencies = new Map( fragment.contextDependencies );
 	contextDependencies.set( node.context, dependencies );
 
-	generator.push({
+	const childFragment = fragment.child({
 		contexts,
 		indexes,
 		contextDependencies
 	});
 
 	node.children.forEach( child => {
-		visit( child, generator );
+		visit( generator, childFragment, child );
 	});
 
 	const close = `\` ).join( '' )}`;
 	generator.append( close );
-
-	generator.pop();
 }

src/generators/server-side-rendering/visitors/Element.js

@@ -7,13 +7,13 @@ const meta = {
 	':Window': visitWindow
 };
 
-export default function visitElement ( generator, node ) {
+export default function visitElement ( generator, fragment, node ) {
 	if ( node.name in meta ) {
-		return meta[ node.name ]( generator, node );
+		return meta[ node.name ]( generator, fragment, node );
 	}
 
 	if ( generator.components.has( node.name ) || node.name === ':Self' ) {
-		visitComponent( generator, node );
+		visitComponent( generator, fragment, node );
 		return;
 	}
 
@@ -30,7 +30,7 @@ export default function visitElement ( generator, node ) {
 					return chunk.data;
 				}
 
-				const { snippet } = generator.contextualise( chunk.expression );
+				const { snippet } = generator.contextualise( fragment, chunk.expression );
 				return '${' + snippet + '}';
 			}).join( '' ) + `"`;
 		}
@@ -49,7 +49,7 @@ export default function visitElement ( generator, node ) {
 	generator.elementDepth += 1;
 
 	node.children.forEach( child => {
-		visit( child, generator );
+		visit( generator, fragment, child );
 	});
 
 	generator.elementDepth -= 1;

src/generators/server-side-rendering/visitors/IfBlock.js

@@ -1,27 +1,25 @@
 import visit from '../visit.js';
 
-export default function visitIfBlock ( generator, node ) {
-	const { snippet } = generator.contextualise( node.expression );
+export default function visitIfBlock ( generator, fragment, node ) {
+	const { snippet } = generator.contextualise( fragment, node.expression );
 
 	generator.append( '${ ' + snippet + ' ? `' );
 
-	generator.push({
-		conditions: generator.current.conditions.concat( snippet )
+	const childFragment = fragment.child({
+		conditions: fragment.conditions.concat( snippet )
 	});
 
 	node.children.forEach( child => {
-		visit( child, generator );
+		visit( generator, childFragment, child );
 	});
 
 	generator.append( '` : `' );
 
 	if ( node.else ) {
 		node.else.children.forEach( child => {
-			visit( child, generator );
+			visit( generator, childFragment, child );
 		});
 	}
 
 	generator.append( '` }' );
-
-	generator.pop();
 }

src/generators/server-side-rendering/visitors/MustacheTag.js

@@ -1,4 +1,4 @@
-export default function visitMustacheTag ( generator, node ) {
-	const { snippet } = generator.contextualise( node.expression );
+export default function visitMustacheTag ( generator, fragment, node ) {
+	const { snippet } = generator.contextualise( fragment, node.expression );
 	generator.append( '${__escape( ' + snippet + ' )}' );
 }

src/generators/server-side-rendering/visitors/RawMustacheTag.js

@@ -1,4 +1,4 @@
-export default function visitRawMustacheTag ( generator, node ) {
-	const { snippet } = generator.contextualise( node.expression );
+export default function visitRawMustacheTag ( generator, fragment, node ) {
+	const { snippet } = generator.contextualise( fragment, node.expression );
 	generator.append( '${' + snippet + '}' );
 }

src/generators/server-side-rendering/visitors/Text.js

@@ -1,3 +1,3 @@
-export default function visitText ( generator, node ) {
+export default function visitText ( generator, fragment, node ) {
 	generator.append( node.data.replace( /\${/g, '\\${' ) );
 }

test/runtime/samples/each-block-else/_config.js

@@ -3,15 +3,35 @@ export default {
 		animals: [ 'alpaca', 'baboon', 'capybara' ],
 		foo: 'something else'
 	},
-	html: 'before\n<p>alpaca</p><p>baboon</p><p>capybara</p>\nafter',
+
+	html: `
+		before
+		<p>alpaca</p>
+		<p>baboon</p>
+		<p>capybara</p>
+		after
+	`,
+
 	test ( assert, component, target ) {
 		component.set({ animals: [] });
-		assert.htmlEqual( target.innerHTML, 'before\n<p>no animals, but rather something else</p>\nafter' );
+		assert.htmlEqual( target.innerHTML, `
+			before
+			<p>no animals, but rather something else</p>
+			after
+		` );
 
 		component.set({ foo: 'something other' });
-		assert.htmlEqual( target.innerHTML, 'before\n<p>no animals, but rather something other</p>\nafter' );
-		
+		assert.htmlEqual( target.innerHTML, `
+			before
+			<p>no animals, but rather something other</p>
+			after
+		` );
+
 		component.set({ animals: ['wombat'] });
-		assert.htmlEqual( target.innerHTML, 'before\n<p>wombat</p>\nafter' );
+		assert.htmlEqual( target.innerHTML, `
+			before
+			<p>wombat</p>
+			after
+		` );
 	}
 };