Debug Tag

src/compile/nodes/DebugTag.ts

@@ -0,0 +1,51 @@
+import Node from './shared/Node';
+import Tag from './shared/Tag';
+import Block from '../dom/Block';
+import Expression from './shared/Expression';
+import deindent from '../../utils/deindent';
+
+export default class DebugTag extends Node {
+	expression: Expression;
+
+	constructor(compiler, parent, scope, info) {
+		super(compiler, parent, scope, info);
+		if (info.expression !== null)
+			// Debug when expression nodes change		
+			this.expression = new Expression(compiler, parent, scope, info.expression);
+		else
+			// "Debug all"
+			this.expression = info.expression
+	}
+
+	build(
+		block: Block,
+		parentNode: string,
+		parentNodes: string,
+	) {
+		// Debug all
+		if (this.expression === null) {
+			block.builders.create.addLine('debugger;');
+			block.builders.update.addLine('debugger;');
+		} else {
+			const { dependencies } = this.expression;
+
+			const condition = [...dependencies].map(d => `changed.${d}`).join(' || ');
+
+			const identifiers = this.expression.node.expressions.map(e => e.name).join(', ');
+
+			block.builders.update.addBlock(deindent`
+				if (${condition}) {
+					const { ${identifiers} } = ctx;
+					console.log({ ${identifiers} });
+					debugger;
+				}
+			`);
+
+			block.builders.create.addBlock(deindent`
+				const { ${identifiers} } = ctx;
+				console.log({ ${identifiers} });
+				debugger;
+			`);
+		}
+	}
+}

src/compile/nodes/Element.ts

@@ -21,7 +21,45 @@ import mapChildren from './shared/mapChildren';
 import { dimensions } from '../../utils/patterns';
 
 // source: https://gist.github.com/ArjanSchouten/0b8574a6ad7f5065a5e7
-const booleanAttributes = new Set('async autocomplete autofocus autoplay border challenge checked compact contenteditable controls default defer disabled formnovalidate frameborder hidden indeterminate ismap loop multiple muted nohref noresize noshade novalidate nowrap open readonly required reversed scoped scrolling seamless selected sortable spellcheck translate'.split(' '));
+const booleanAttributes = new Set([
+	'async',
+	'autocomplete',
+	'autofocus',
+	'autoplay',
+	'border',
+	'challenge',
+	'checked',
+	'compact',
+	'contenteditable',
+	'controls',
+	'default',
+	'defer',
+	'disabled',
+	'formnovalidate',
+	'frameborder',
+	'hidden',
+	'indeterminate',
+	'ismap',
+	'loop',
+	'multiple',
+	'muted',
+	'nohref',
+	'noresize',
+	'noshade',
+	'novalidate',
+	'nowrap',
+	'open',
+	'readonly',
+	'required',
+	'reversed',
+	'scoped',
+	'scrolling',
+	'seamless',
+	'selected',
+	'sortable',
+	'spellcheck',
+	'translate'
+]);
 
 export default class Element extends Node {
 	type: 'Element';

src/compile/nodes/shared/mapChildren.ts

@@ -7,6 +7,7 @@ import Head from '../Head';
 import IfBlock from '../IfBlock';
 import MustacheTag from '../MustacheTag';
 import RawMustacheTag from '../RawMustacheTag';
+import DebugTag from '../DebugTag';
 import Slot from '../Slot';
 import Text from '../Text';
 import Title from '../Title';
@@ -24,6 +25,7 @@ function getConstructor(type): typeof Node {
 		case 'IfBlock': return IfBlock;
 		case 'MustacheTag': return MustacheTag;
 		case 'RawMustacheTag': return RawMustacheTag;
+		case 'DebugTag': return DebugTag;
 		case 'Slot': return Slot;
 		case 'Text': return Text;
 		case 'Title': return Title;

src/parse/state/mustache.ts

@@ -313,6 +313,30 @@ export default function mustache(parser: Parser) {
 			type: 'RawMustacheTag',
 			expression,
 		});
+	} else if (parser.eat('@debug')) {
+		let expression;
+
+		// Implies {@debug} which indicates "debug all"
+		if (/\s*}/.test(parser.template[parser.index]))
+			expression = null;
+		else
+			expression = readExpression(parser);				
+
+		if (expression !== null && expression.type !== 'SequenceExpression')
+			parser.error({
+				code: 'invalid-debug-args',
+				message: '{@debug ...} arguments must be identifers, not arbitrary expressions'
+			}, expression.start);
+
+		parser.allowWhitespace();
+		parser.eat('}', true);
+
+		parser.current().children.push({
+			start,
+			end: parser.index,
+			type: 'DebugTag',
+			expression,
+		});
 	} else {
 		const expression = readExpression(parser);
 

src/utils/error.ts

@@ -22,6 +22,7 @@ export default function error(message: string, props: {
 	start: number,
 	end?: number
 }) {
+	console.error(props);
 	const error = new CompileError(message);
 	error.name = props.name;
 

test/js/samples/debug-empty/expected-bundle.js

@@ -0,0 +1,200 @@
+function noop() {}
+
+function assign(tar, src) {
+	for (var k in src) tar[k] = src[k];
+	return tar;
+}
+
+function append(target, node) {
+	target.appendChild(node);
+}
+
+function insert(target, node, anchor) {
+	target.insertBefore(node, anchor);
+}
+
+function detachNode(node) {
+	node.parentNode.removeChild(node);
+}
+
+function createElement(name) {
+	return document.createElement(name);
+}
+
+function createText(data) {
+	return document.createTextNode(data);
+}
+
+function setData(text, data) {
+	text.data = '' + data;
+}
+
+function blankObject() {
+	return Object.create(null);
+}
+
+function destroy(detach) {
+	this.destroy = noop;
+	this.fire('destroy');
+	this.set = noop;
+
+	this._fragment.d(detach !== false);
+	this._fragment = null;
+	this._state = {};
+}
+
+function _differs(a, b) {
+	return a != a ? b == b : a !== b || ((a && typeof a === 'object') || typeof a === 'function');
+}
+
+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) {
+		var handler = handlers[i];
+
+		if (!handler.__calling) {
+			try {
+				handler.__calling = true;
+				handler.call(this, data);
+			} finally {
+				handler.__calling = false;
+			}
+		}
+	}
+}
+
+function get() {
+	return this._state;
+}
+
+function init(component, options) {
+	component._handlers = blankObject();
+	component._bind = options._bind;
+
+	component.options = options;
+	component.root = options.root || component;
+	component.store = options.store || component.root.store;
+}
+
+function on(eventName, 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 (this._differs(newState[key], oldState[key])) changed[key] = dirty = true;
+	}
+	if (!dirty) return;
+
+	this._state = assign(assign({}, oldState), newState);
+	this._recompute(changed, this._state);
+	if (this._bind) this._bind(changed, this._state);
+
+	if (this._fragment) {
+		this.fire("state", { changed: changed, current: this._state, previous: oldState });
+		this._fragment.p(changed, this._state);
+		this.fire("update", { changed: changed, current: this._state, previous: oldState });
+	}
+}
+
+function callAll(fns) {
+	while (fns && fns.length) fns.shift()();
+}
+
+function _mount(target, anchor) {
+	this._fragment[this._fragment.i ? 'i' : 'm'](target, anchor || null);
+}
+
+var proto = {
+	destroy,
+	get,
+	fire,
+	on,
+	set,
+	_recompute: noop,
+	_set,
+	_mount,
+	_differs
+};
+
+/* generated by Svelte vX.Y.Z */
+
+function create_main_fragment(component, ctx) {
+	var h1, text, text_1, text_2, text_3;
+
+	return {
+		c() {
+			h1 = createElement("h1");
+			text = createText("Hello ");
+			text_1 = createText(ctx.name);
+			text_2 = createText("!");
+			text_3 = createText("\n");
+			debugger;
+		},
+
+		m(target, anchor) {
+			insert(target, h1, anchor);
+			append(h1, text);
+			append(h1, text_1);
+			append(h1, text_2);
+			insert(target, text_3, anchor);
+		},
+
+		p(changed, ctx) {
+			if (changed.name) {
+				setData(text_1, ctx.name);
+			}
+
+			debugger;
+		},
+
+		d(detach) {
+			if (detach) {
+				detachNode(h1);
+				detachNode(text_3);
+			}
+		}
+	};
+}
+
+function SvelteComponent(options) {
+	init(this, options);
+	this._state = assign({}, options.data);
+	this._intro = true;
+
+	this._fragment = create_main_fragment(this, this._state);
+
+	if (options.target) {
+		this._fragment.c();
+		this._mount(options.target, options.anchor);
+	}
+}
+
+assign(SvelteComponent.prototype, proto);
+
+export default SvelteComponent;