Repository: sveltejs/svelte (JavaScript) — Bug Fix

Issue:
Output ['default'] instead of .default
Things like `slots.default` don't work in Lynx and Mosaic 😀

We need to use `slots['default']` instead. Via https://github.com/sveltejs/svelte/pull/1159


Discussion:
(Forgot to add — we probably only want to do this in `legacy` mode)
Lynx and Mosaic, lol 👌

Resolving patch:
diff --git a/src/generators/nodes/Component.ts b/src/generators/nodes/Component.ts
--- a/src/generators/nodes/Component.ts
+++ b/src/generators/nodes/Component.ts
@@ -5,10 +5,17 @@ import CodeBuilder from '../../utils/CodeBuilder';
 import getTailSnippet from '../../utils/getTailSnippet';
 import getObject from '../../utils/getObject';
 import getExpressionPrecedence from '../../utils/getExpressionPrecedence';
+import isValidIdentifier from '../../utils/isValidIdentifier';
+import reservedNames from '../../utils/reservedNames';
 import Node from './shared/Node';
 import Block from '../dom/Block';
 import Attribute from './Attribute';
 
+function quoteIfNecessary(name, legacy) {
+	if (!isValidIdentifier || (legacy && reservedNames.has(name))) return `"${name}"`;
+	return name;
+}
+
 export default class Component extends Node {
 	type: 'Component';
 	name: string;
@@ -71,11 +78,11 @@ export default class Component extends Node {
 		const componentInitProperties = [`root: #component.root`];
 
 		if (this.children.length > 0) {
-			const slots = Array.from(this._slots).map(name => `${name}: @createFragment()`);
+			const slots = Array.from(this._slots).map(name => `${quoteIfNecessary(name, generator.legacy)}: @createFragment()`);
 			componentInitProperties.push(`slots: { ${slots.join(', ')} }`);
 
 			this.children.forEach((child: Node) => {
-				child.build(block, `${this.var}._slotted.default`, 'nodes');
+				child.build(block, `${this.var}._slotted${generator.legacy ? `["default"]` : `.default`}`, 'nodes');
 			});
 		}
 
@@ -584,7 +591,7 @@ function remount(generator: DomGenerator, node: Node, name: string) {
 	// TODO make this a method of the nodes
 
 	if (node.type === 'Component') {
-		return `${node.var}._mount(${name}._slotted.default, null);`;
+		return `${node.var}._mount(${name}._slotted${generator.legacy ? `["default"]` : `.default`}, null);`;
 	}
 
 	if (node.type === 'Element') {
@@ -593,17 +600,17 @@ function remount(generator: DomGenerator, node: Node, name: string) {
 			return `@appendNode(${node.var}, ${name}._slotted.${node.getStaticAttributeValue('slot')});`;
 		}
 
-		return `@appendNode(${node.var}, ${name}._slotted.default);`;
+		return `@appendNode(${node.var}, ${name}._slotted${generator.legacy ? `["default"]` : `.default`});`;
 	}
 
 	if (node.type === 'Text' || node.type === 'MustacheTag' || node.type === 'RawMustacheTag') {
-		return `@appendNode(${node.var}, ${name}._slotted.default);`;
+		return `@appendNode(${node.var}, ${name}._slotted${generator.legacy ? `["default"]` : `.default`});`;
 	}
 
 	if (node.type === 'EachBlock') {
 		// TODO consider keyed blocks
-		return `for (var #i = 0; #i < ${node.iterations}.length; #i += 1) ${node.iterations}[#i].m(${name}._slotted.default, null);`;
+		return `for (var #i = 0; #i < ${node.iterations}.length; #i += 1) ${node.iterations}[#i].m(${name}._slotted${generator.legacy ? `["default"]` : `.default`}, null);`;
 	}
 
-	return `${node.var}.m(${name}._slotted.default, null);`;
+	return `${node.var}.m(${name}._slotted${generator.legacy ? `["default"]` : `.default`}, null);`;
 }
\ No newline at end of file
diff --git a/src/generators/nodes/Slot.ts b/src/generators/nodes/Slot.ts
--- a/src/generators/nodes/Slot.ts
+++ b/src/generators/nodes/Slot.ts
@@ -1,4 +1,6 @@
 import deindent from '../../utils/deindent';
+import isValidIdentifier from '../../utils/isValidIdentifier';
+import reservedNames from '../../utils/reservedNames';
 import Node from './shared/Node';
 import Element from './Element';
 import Attribute from './Attribute';
@@ -35,7 +37,8 @@ export default class Slot extends Element {
 		generator.slots.add(slotName);
 
 		const content_name = block.getUniqueName(`slot_content_${slotName}`);
-		block.addVariable(content_name, `#component._slotted.${slotName}`);
+		const prop = !isValidIdentifier(slotName) || (generator.legacy && reservedNames.has(slotName)) ? `["${slotName}"]` : `.${slotName}`;
+		block.addVariable(content_name, `#component._slotted${prop}`);
 
 		const needsAnchorBefore = this.prev ? this.prev.type !== 'Element' : !parentNode;
 		const needsAnchorAfter = this.next ? this.next.type !== 'Element' : !parentNode;


Test patch:
diff --git a/test/js/samples/legacy-default/_config.js b/test/js/samples/legacy-default/_config.js
new file mode 100644
--- /dev/null
+++ b/test/js/samples/legacy-default/_config.js
@@ -0,0 +1,5 @@
+export default {
+	options: {
+		legacy: true
+	}
+};
\ No newline at end of file
diff --git a/test/js/samples/legacy-default/expected-bundle.js b/test/js/samples/legacy-default/expected-bundle.js
new file mode 100644
--- /dev/null
+++ b/test/js/samples/legacy-default/expected-bundle.js
@@ -0,0 +1,288 @@
+function noop() {}
+
+function assign(target) {
+	var k,
+		source,
+		i = 1,
+		len = arguments.length;
+	for (; i < len; i++) {
+		source = arguments[i];
+		for (k in source) target[k] = source[k];
+	}
+
+	return target;
+}
+
+function appendNode(node, target) {
+	target.appendChild(node);
+}
+
+function insertNode(node, target, anchor) {
+	target.insertBefore(node, anchor);
+}
+
+function detachNode(node) {
+	node.parentNode.removeChild(node);
+}
+
+function reinsertBetween(before, after, target) {
+	while (before.nextSibling && before.nextSibling !== after) {
+		target.appendChild(before.parentNode.removeChild(before.nextSibling));
+	}
+}
+
+function createFragment() {
+	return document.createDocumentFragment();
+}
+
+function createElement(name) {
+	return document.createElement(name);
+}
+
+function createText(data) {
+	return document.createTextNode(data);
+}
+
+function createComment() {
+	return document.createComment('');
+}
+
+function blankObject() {
+	return Object.create(null);
+}
+
+function destroy(detach) {
+	this.destroy = noop;
+	this.fire('destroy');
+	this.set = this.get = noop;
+
+	if (detach !== false) this._fragment.u();
+	this._fragment.d();
+	this._fragment = this._state = null;
+}
+
+function differs(a, b) {
+	return a !== b || ((a && typeof a === 'object') || typeof a === 'function');
+}
+
+function dispatchObservers(component, group, changed, newState, oldState) {
+	for (var key in group) {
+		if (!changed[key]) continue;
+
+		var newValue = newState[key];
+		var oldValue = oldState[key];
+
+		var callbacks = group[key];
+		if (!callbacks) continue;
+
+		for (var i = 0; i < callbacks.length; i += 1) {
+			var callback = callbacks[i];
+			if (callback.__calling) continue;
+
+			callback.__calling = true;
+			callback.call(component, newValue, oldValue);
+			callback.__calling = false;
+		}
+	}
+}
+
+function fire(eventName, data) {
+	var handlers =
+		eventName in this._handlers && this._handlers[eventName].slice();
+	if (!handlers) return;
+
+	for (var i = 0; i < handlers.length; i += 1) {
+		handlers[i].call(this, data);
+	}
+}
+
+function get(key) {
+	return key ? this._state[key] : this._state;
+}
+
+function init(component, options) {
+	component._observers = { pre: blankObject(), post: blankObject() };
+	component._handlers = blankObject();
+	component._bind = options._bind;
+
+	component.options = options;
+	component.root = options.root || component;
+	component.store = component.root.store || options.store;
+}
+
+function observe(key, callback, options) {
+	var group = options && options.defer
+		? this._observers.post
+		: this._observers.pre;
+
+	(group[key] || (group[key] = [])).push(callback);
+
+	if (!options || options.init !== false) {
+		callback.__calling = true;
+		callback.call(this, this._state[key]);
+		callback.__calling = false;
+	}
+
+	return {
+		cancel: function() {
+			var index = group[key].indexOf(callback);
+			if (~index) group[key].splice(index, 1);
+		}
+	};
+}
+
+function on(eventName, handler) {
+	if (eventName === 'teardown') return this.on('destroy', handler);
+
+	var handlers = this._handlers[eventName] || (this._handlers[eventName] = []);
+	handlers.push(handler);
+
+	return {
+		cancel: function() {
+			var index = handlers.indexOf(handler);
+			if (~index) handlers.splice(index, 1);
+		}
+	};
+}
+
+function set(newState) {
+	this._set(assign({}, newState));
+	if (this.root._lock) return;
+	this.root._lock = true;
+	callAll(this.root._beforecreate);
+	callAll(this.root._oncreate);
+	callAll(this.root._aftercreate);
+	this.root._lock = false;
+}
+
+function _set(newState) {
+	var oldState = this._state,
+		changed = {},
+		dirty = false;
+
+	for (var key in newState) {
+		if (differs(newState[key], oldState[key])) changed[key] = dirty = true;
+	}
+	if (!dirty) return;
+
+	this._state = assign({}, oldState, newState);
+	this._recompute(changed, this._state);
+	if (this._bind) this._bind(changed, this._state);
+
+	if (this._fragment) {
+		dispatchObservers(this, this._observers.pre, changed, this._state, oldState);
+		this._fragment.p(changed, this._state);
+		dispatchObservers(this, this._observers.post, changed, this._state, oldState);
+	}
+}
+
+function callAll(fns) {
+	while (fns && fns.length) fns.shift()();
+}
+
+function _mount(target, anchor) {
+	this._fragment.m(target, anchor);
+}
+
+function _unmount() {
+	if (this._fragment) this._fragment.u();
+}
+
+var proto = {
+	destroy: destroy,
+	get: get,
+	fire: fire,
+	observe: observe,
+	on: on,
+	set: set,
+	teardown: destroy,
+	_recompute: noop,
+	_set: _set,
+	_mount: _mount,
+	_unmount: _unmount
+};
+
+/* generated by Svelte vX.Y.Z */
+function create_main_fragment(state, component) {
+	var text, p, text_1, text_2, text_3, slot_content_default = component._slotted["default"], slot_content_default_before, slot_content_default_after;
+
+	var foo = new Foo({
+		root: component.root,
+		slots: { "default": createFragment() }
+	});
+
+	return {
+		c: function create() {
+			text = createText("\n\t");
+			p = createElement("p");
+			text_1 = createText("some default slotted content");
+			text_2 = createText("\n");
+			foo._fragment.c();
+			text_3 = createText("\n\n");
+		},
+
+		m: function mount(target, anchor) {
+			appendNode(text, foo._slotted["default"]);
+			appendNode(p, foo._slotted["default"]);
+			appendNode(text_1, p);
+			appendNode(text_2, foo._slotted["default"]);
+			foo._mount(target, anchor);
+			insertNode(text_3, target, anchor);
+
+			if (slot_content_default) {
+				insertNode(slot_content_default_before || (slot_content_default_before = createComment()), target, anchor);
+				insertNode(slot_content_default, target, anchor);
+				insertNode(slot_content_default_after || (slot_content_default_after = createComment()), target, anchor);
+			}
+		},
+
+		p: noop,
+
+		u: function unmount() {
+			foo._unmount();
+			detachNode(text_3);
+
+			if (slot_content_default) {
+				reinsertBetween(slot_content_default_before, slot_content_default_after, slot_content_default);
+				detachNode(slot_content_default_before);
+				detachNode(slot_content_default_after);
+			}
+		},
+
+		d: function destroy$$1() {
+			foo.destroy(false);
+		}
+	};
+}
+
+function SvelteComponent(options) {
+	init(this, options);
+	this._state = assign({}, options.data);
+
+	this._slotted = options.slots || {};
+
+	if (!options.root) {
+		this._oncreate = [];
+		this._beforecreate = [];
+		this._aftercreate = [];
+	}
+
+	this.slots = {};
+
+	this._fragment = create_main_fragment(this._state, this);
+
+	if (options.target) {
+		this._fragment.c();
+		this._fragment.m(options.target, options.anchor || null);
+
+		this._lock = true;
+		callAll(this._beforecreate);
+		callAll(this._oncreate);
+		callAll(this._aftercreate);
+		this._lock = false;
+	}
+}
+
+assign(SvelteComponent.prototype, proto);
+
+export default SvelteComponent;
diff --git a/test/js/samples/legacy-default/expected.js b/test/js/samples/legacy-default/expected.js
new file mode 100644
--- /dev/null
+++ b/test/js/samples/legacy-default/expected.js
@@ -0,0 +1,85 @@
+/* generated by Svelte vX.Y.Z */
+import { appendNode, assign, callAll, createComment, createElement, createFragment, createText, detachNode, init, insertNode, noop, proto, reinsertBetween } from "svelte/shared.js";
+
+function create_main_fragment(state, component) {
+	var text, p, text_1, text_2, text_3, slot_content_default = component._slotted["default"], slot_content_default_before, slot_content_default_after;
+
+	var foo = new Foo({
+		root: component.root,
+		slots: { "default": createFragment() }
+	});
+
+	return {
+		c: function create() {
+			text = createText("\n\t");
+			p = createElement("p");
+			text_1 = createText("some default slotted content");
+			text_2 = createText("\n");
+			foo._fragment.c();
+			text_3 = createText("\n\n");
+		},
+
+		m: function mount(target, anchor) {
+			appendNode(text, foo._slotted["default"]);
+			appendNode(p, foo._slotted["default"]);
+			appendNode(text_1, p);
+			appendNode(text_2, foo._slotted["default"]);
+			foo._mount(target, anchor);
+			insertNode(text_3, target, anchor);
+
+			if (slot_content_default) {
+				insertNode(slot_content_default_before || (slot_content_default_before = createComment()), target, anchor);
+				insertNode(slot_content_default, target, anchor);
+				insertNode(slot_content_default_after || (slot_content_default_after = createComment()), target, anchor);
+			}
+		},
+
+		p: noop,
+
+		u: function unmount() {
+			foo._unmount();
+			detachNode(text_3);
+
+			if (slot_content_default) {
+				reinsertBetween(slot_content_default_before, slot_content_default_after, slot_content_default);
+				detachNode(slot_content_default_before);
+				detachNode(slot_content_default_after);
+			}
+		},
+
+		d: function destroy() {
+			foo.destroy(false);
+		}
+	};
+}
+
+function SvelteComponent(options) {
+	init(this, options);
+	this._state = assign({}, options.data);
+
+	this._slotted = options.slots || {};
+
+	if (!options.root) {
+		this._oncreate = [];
+		this._beforecreate = [];
+		this._aftercreate = [];
+	}
+
+	this.slots = {};
+
+	this._fragment = create_main_fragment(this._state, this);
+
+	if (options.target) {
+		this._fragment.c();
+		this._fragment.m(options.target, options.anchor || null);
+
+		this._lock = true;
+		callAll(this._beforecreate);
+		callAll(this._oncreate);
+		callAll(this._aftercreate);
+		this._lock = false;
+	}
+}
+
+assign(SvelteComponent.prototype, proto);
+export default SvelteComponent;
\ No newline at end of file
diff --git a/test/js/samples/legacy-default/input.html b/test/js/samples/legacy-default/input.html
new file mode 100644
--- /dev/null
+++ b/test/js/samples/legacy-default/input.html
@@ -0,0 +1,11 @@
+<Foo>
+	<p>some default slotted content</p>
+</Foo>
+
+<slot></slot>
+
+<script>
+	export default {
+		components: { Foo }
+	};
+</script>
\ No newline at end of file