Merge branch 'master' into gh-1197

src/css/Selector.ts

@@ -102,7 +102,10 @@ export default class Selector {
 			while (i-- > 1) {
 				const selector = block.selectors[i];
 				if (selector.type === 'PseudoClassSelector' && selector.name === 'global') {
-					validator.error(`:global(...) must be the first element in a compound selector`, selector);
+					validator.error(selector, {
+						code: `css-invalid-global`,
+						message: `:global(...) must be the first element in a compound selector`
+					});
 				}
 			}
 		});
@@ -120,7 +123,10 @@ export default class Selector {
 
 		for (let i = start; i < end; i += 1) {
 			if (this.blocks[i].global) {
-				validator.error(`:global(...) can be at the start or end of a selector sequence, but not in the middle`, this.blocks[i].selectors[0]);
+				validator.error(this.blocks[i].selectors[0], {
+					code: `css-invalid-global`,
+					message: `:global(...) can be at the start or end of a selector sequence, but not in the middle`
+				});
 			}
 		}
 	}

src/css/Stylesheet.ts

@@ -435,6 +435,7 @@ export default class Stylesheet {
 			const message = `Unused CSS selector`;
 
 			onwarn({
+				code: `css-unused-selector`,
 				message,
 				frame,
 				loc: { line: line + 1, column },

src/generators/wrapModule.ts

@@ -276,6 +276,7 @@ function getGlobals(dependencies: Dependency[], options: CompileOptions) {
 				onerror(error);
 			} else {
 				const warning = {
+					code: `options-missing-globals`,
 					message: `No name was supplied for imported module '${d.source}'. Guessing '${d.name}', but you should use options.globals`,
 				};
 

src/interfaces.ts

@@ -31,6 +31,7 @@ export interface Warning {
 	loc?: { line: number; column: number; pos?: number };
 	end?: { line: number; column: number; };
 	pos?: number;
+	code: string;
 	message: string;
 	filename?: string;
 	frame?: string;

src/parse/index.ts

@@ -71,11 +71,19 @@ export class Parser {
 			const current = this.current();
 
 			const type = current.type === 'Element' ? `<${current.name}>` : 'Block';
-			this.error(`${type} was left open`, current.start);
+			const slug = current.type === 'Element' ? 'element' : 'block';
+
+			this.error({
+				code: `unclosed-${slug}`,
+				message: `${type} was left open`
+			}, current.start);
 		}
 
 		if (state !== fragment) {
-			this.error('Unexpected end of input');
+			this.error({
+				code: `unexpected-eof`,
+				message: 'Unexpected end of input'
+			});
 		}
 
 		if (this.html.children.length) {
@@ -97,12 +105,16 @@ export class Parser {
 	}
 
 	acornError(err: any) {
-		this.error(err.message.replace(/ \(\d+:\d+\)$/, ''), err.pos);
+		this.error({
+			code: `parse-error`,
+			message: err.message.replace(/ \(\d+:\d+\)$/, '')
+		}, err.pos);
 	}
 
-	error(message: string, index = this.index) {
+	error({ code, message }: { code: string, message: string }, index = this.index) {
 		error(message, {
 			name: 'ParseError',
+			code,
 			source: this.template,
 			start: index,
 			filename: this.filename
@@ -116,7 +128,10 @@ export class Parser {
 		}
 
 		if (required) {
-			this.error(message || `Expected ${str}`);
+			this.error({
+				code: `unexpected-${this.index === this.template.length ? 'eof' : 'token'}`,
+				message: message || `Expected ${str}`
+			});
 		}
 
 		return false;
@@ -164,7 +179,10 @@ export class Parser {
 		const identifier = this.template.slice(this.index, this.index = i);
 
 		if (reservedNames.has(identifier)) {
-			this.error(`'${identifier}' is a reserved word in JavaScript and cannot be used here`, start);
+			this.error({
+				code: `unexpected-reserved-word`,
+				message: `'${identifier}' is a reserved word in JavaScript and cannot be used here`
+			}, start);
 		}
 
 		return identifier;
@@ -172,7 +190,10 @@ export class Parser {
 
 	readUntil(pattern: RegExp) {
 		if (this.index >= this.template.length)
-			this.error('Unexpected end of input');
+			this.error({
+				code: `unexpected-eof`,
+				message: 'Unexpected end of input'
+			});
 
 		const start = this.index;
 		const match = pattern.exec(this.template.slice(start));
@@ -192,7 +213,10 @@ export class Parser {
 
 	requireWhitespace() {
 		if (!whitespace.test(this.template[this.index])) {
-			this.error(`Expected whitespace`);
+			this.error({
+				code: `missing-whitespace`,
+				message: `Expected whitespace`
+			});
 		}
 
 		this.allowWhitespace();

src/parse/read/directives.ts

@@ -2,7 +2,19 @@ import { parseExpressionAt } from 'acorn';
 import repeat from '../../utils/repeat';
 import { Parser } from '../index';
 
-const DIRECTIVES = {
+const DIRECTIVES: Record<string, {
+	names: string[];
+	attribute: (
+		start: number,
+		end: number,
+		type: string,
+		name: string,
+		expression?: any,
+		directiveName?: string
+	) => { start: number, end: number, type: string, name: string, value?: any, expression?: any };
+	allowedExpressionTypes: string[];
+	error: string;
+}> = {
 	Ref: {
 		names: ['ref'],
 		attribute(start, end, type, name) {
@@ -143,7 +155,10 @@ export function readDirective(
 		try {
 			expression = readExpression(parser, expressionStart, quoteMark);
 			if (directive.allowedExpressionTypes.indexOf(expression.type) === -1) {
-				parser.error(directive.error, expressionStart);
+				parser.error({
+					code: `invalid-directive-value`,
+					message: directive.error
+				}, expressionStart);
 			}
 		} catch (err) {
 			if (parser.template[expressionStart] === '{') {
@@ -155,7 +170,10 @@ export function readDirective(
 					const value = parser.template.slice(expressionStart + (parser.v2 ? 1 : 2), expressionEnd);
 					message += ` — use '${value}', not '${parser.v2 ? `{${value}}` : `{{${value}}}`}'`;
 				}
-				parser.error(message, expressionStart);
+				parser.error({
+					code: `invalid-directive-value`,
+					message
+				}, expressionStart);
 			}
 
 			throw err;

src/parse/read/script.ts

@@ -12,7 +12,10 @@ export default function readScript(parser: Parser, start: number, attributes: No
 	const scriptStart = parser.index;
 	const scriptEnd = parser.template.indexOf(scriptClosingTag, scriptStart);
 
-	if (scriptEnd === -1) parser.error(`<script> must have a closing tag`);
+	if (scriptEnd === -1) parser.error({
+		code: `unclosed-script`,
+		message: `<script> must have a closing tag`
+	});
 
 	const source =
 		repeat(' ', scriptStart) + parser.template.slice(scriptStart, scriptEnd);

src/parse/read/style.ts

@@ -17,7 +17,10 @@ export default function readStyle(parser: Parser, start: number, attributes: Nod
 		});
 	} catch (err) {
 		if (err.name === 'CssSyntaxError') {
-			parser.error(err.message, err.offset);
+			parser.error({
+				code: `css-syntax-error`,
+				message: err.message
+			}, err.offset);
 		} else {
 			throw err;
 		}

src/parse/state/mustache.ts

@@ -56,7 +56,10 @@ export default function mustache(parser: Parser) {
 		} else if (block.type === 'AwaitBlock') {
 			expected = 'await';
 		} else {
-			parser.error(`Unexpected block closing tag`);
+			parser.error({
+				code: `unexpected-block-close`,
+				message: `Unexpected block closing tag`
+			});
 		}
 
 		parser.eat(expected, true);
@@ -86,9 +89,10 @@ export default function mustache(parser: Parser) {
 	} else if (parser.eat(parser.v2 ? ':elseif' : 'elseif')) {
 		const block = parser.current();
 		if (block.type !== 'IfBlock')
-			parser.error(
-				'Cannot have an {{elseif ...}} block outside an {{#if ...}} block'
-			);
+			parser.error({
+				code: `invalid-elseif-placement`,
+				message: 'Cannot have an {{elseif ...}} block outside an {{#if ...}} block'
+			});
 
 		parser.requireWhitespace();
 
@@ -117,9 +121,10 @@ export default function mustache(parser: Parser) {
 	} else if (parser.eat(parser.v2 ? ':else' : 'else')) {
 		const block = parser.current();
 		if (block.type !== 'IfBlock' && block.type !== 'EachBlock') {
-			parser.error(
-				'Cannot have an {{else}} block outside an {{#if ...}} or {{#each ...}} block'
-			);
+			parser.error({
+				code: `invalid-else-placement`,
+				message: 'Cannot have an {{else}} block outside an {{#if ...}} or {{#each ...}} block'
+			});
 		}
 
 		parser.allowWhitespace();
@@ -191,7 +196,10 @@ export default function mustache(parser: Parser) {
 		} else if (parser.eat('await')) {
 			type = 'AwaitBlock';
 		} else {
-			parser.error(`Expected if, each or await`);
+			parser.error({
+				code: `expected-block-type`,
+				message: `Expected if, each or await`
+			});
 		}
 
 		parser.requireWhitespace();
@@ -249,20 +257,30 @@ export default function mustache(parser: Parser) {
 					parser.allowWhitespace();
 
 					const destructuredContext = parser.readIdentifier();
-					if (!destructuredContext) parser.error(`Expected name`);
+					if (!destructuredContext) parser.error({
+						code: `expected-name`,
+						message: `Expected name`
+					});
 
 					block.destructuredContexts.push(destructuredContext);
 					parser.allowWhitespace();
 				} while (parser.eat(','));
 
-				if (!block.destructuredContexts.length) parser.error(`Expected name`);
+				if (!block.destructuredContexts.length) parser.error({
+					code: `expected-name`,
+					message: `Expected name`
+				});
+
 				block.context = block.destructuredContexts.join('_');
 
 				parser.allowWhitespace();
 				parser.eat(']', true);
 			} else {
 				block.context = parser.readIdentifier();
-				if (!block.context) parser.error(`Expected name`);
+				if (!block.context) parser.error({
+					code: `expected-name`,
+					message: `Expected name`
+				});
 			}
 
 			parser.allowWhitespace();
@@ -270,7 +288,11 @@ export default function mustache(parser: Parser) {
 			if (parser.eat(',')) {
 				parser.allowWhitespace();
 				block.index = parser.readIdentifier();
-				if (!block.index) parser.error(`Expected name`);
+				if (!block.index) parser.error({
+					code: `expected-name`,
+					message: `Expected name`
+				});
+
 				parser.allowWhitespace();
 			}
 
@@ -287,7 +309,10 @@ export default function mustache(parser: Parser) {
 					expression.property.computed ||
 					expression.property.type !== 'Identifier'
 				) {
-					parser.error('invalid key', expression.start);
+					parser.error({
+						code: `invalid-key`,
+						message: 'invalid key'
+					}, expression.start);
 				}
 
 				block.key = expression.property.name;
@@ -296,7 +321,10 @@ export default function mustache(parser: Parser) {
 				parser.allowWhitespace();
 			} else if (parser.eat('@')) {
 				block.key = parser.readIdentifier();
-				if (!block.key) parser.error(`Expected name`);
+				if (!block.key) parser.error({
+					code: `expected-name`,
+					message: `Expected name`
+				});
 				parser.allowWhitespace();
 			}
 		}

src/parse/state/tag.ts

@@ -83,21 +83,27 @@ export default function tag(parser: Parser) {
 	const name = readTagName(parser);
 
 	if (metaTags.has(name)) {
+		const slug = metaTags.get(name).toLowerCase();
 		if (isClosingTag) {
 			if ((name === ':Window' || name === 'svelte:window') && parser.current().children.length) {
-				parser.error(
-					`<${name}> cannot have children`,
-					parser.current().children[0].start
-				);
+				parser.error({
+					code: `invalid-window-content`,
+					message: `<${name}> cannot have children`
+				}, parser.current().children[0].start);
 			}
 		} else {
 			if (name in parser.metaTags) {
-				parser.error(`A component can only have one <${name}> tag`, start);
+				parser.error({
+					code: `duplicate-${slug}`,
+					message: `A component can only have one <${name}> tag`
+				}, start);
 			}
 
 			if (parser.stack.length > 1) {
-				console.log(parser.stack);
-				parser.error(`<${name}> tags cannot be inside elements or blocks`, start);
+				parser.error({
+					code: `invalid-${slug}-placement`,
+					message: `<${name}> tags cannot be inside elements or blocks`
+				}, start);
 			}
 
 			parser.metaTags[name] = true;
@@ -121,21 +127,21 @@ export default function tag(parser: Parser) {
 
 	if (isClosingTag) {
 		if (isVoidElementName(name)) {
-			parser.error(
-				`<${name}> is a void element and cannot have children, or a closing tag`,
-				start
-			);
+			parser.error({
+				code: `invalid-void-content`,
+				message: `<${name}> is a void element and cannot have children, or a closing tag`
+			}, start);
 		}
 
-		if (!parser.eat('>')) parser.error(`Expected '>'`);
+		parser.eat('>', true);
 
 		// close any elements that don't have their own closing tags, e.g. <div><p></div>
 		while (parent.name !== name) {
 			if (parent.type !== 'Element')
-				parser.error(
-					`</${name}> attempted to close an element that was not open`,
-					start
-				);
+				parser.error({
+					code: `invalid-closing-tag`,
+					message: `</${name}> attempted to close an element that was not open`
+				}, start);
 
 			parent.end = start;
 			parser.stack.pop();
@@ -161,10 +167,10 @@ export default function tag(parser: Parser) {
 		while (i--) {
 			const item = parser.stack[i];
 			if (item.type === 'EachBlock') {
-				parser.error(
-					`<slot> cannot be a child of an each-block`,
-					start
-				);
+				parser.error({
+					code: `invalid-slot-placement`,
+					message: `<slot> cannot be a child of an each-block`
+				}, start);
 			}
 		}
 	}
@@ -182,7 +188,10 @@ export default function tag(parser: Parser) {
 	let attribute;
 	while ((attribute = readAttribute(parser, uniqueNames))) {
 		if (attribute.type === 'Binding' && !parser.allowBindings) {
-			parser.error(`Two-way binding is disabled`, attribute.start);
+			parser.error({
+				code: `binding-disabled`,
+				message: `Two-way binding is disabled`
+			}, attribute.start);
 		}
 
 		element.attributes.push(attribute);
@@ -193,12 +202,18 @@ export default function tag(parser: Parser) {
 		// TODO post v2, treat this just as any other attribute
 		const index = element.attributes.findIndex(attr => attr.name === 'this');
 		if (!~index) {
-			parser.error(`<svelte:component> must have a 'this' attribute`, start);
+			parser.error({
+				code: `missing-component-definition`,
+				message: `<svelte:component> must have a 'this' attribute`
+			}, start);
 		}
 
 		const definition = element.attributes.splice(index, 1)[0];
 		if (definition.value === true || definition.value.length !== 1 || definition.value[0].type === 'Text') {
-			parser.error(`invalid component definition`, definition.start);
+			parser.error({
+				code: `invalid-component-definition`,
+				message: `invalid component definition`
+			}, definition.start);
 		}
 
 		element.expression = definition.value[0].expression;
@@ -210,9 +225,10 @@ export default function tag(parser: Parser) {
 
 		if (parser[special.property]) {
 			parser.index = start;
-			parser.error(
-				`You can only have one top-level <${name}> tag per component`
-			);
+			parser.error({
+				code: `duplicate-${name}`,
+				message: `You can only have one top-level <${name}> tag per component`
+			});
 		}
 
 		parser.eat('>', true);
@@ -290,10 +306,10 @@ function readTagName(parser: Parser) {
 		}
 
 		if (!legal) {
-			parser.error(
-				`<${SELF}> components can only exist inside if-blocks or each-blocks`,
-				start
-			);
+			parser.error({
+				code: `invalid-self-placement`,
+				message: `<${SELF}> components can only exist inside if-blocks or each-blocks`
+			}, start);
 		}
 
 		return SELF;
@@ -306,7 +322,10 @@ function readTagName(parser: Parser) {
 	if (metaTags.has(name)) return name;
 
 	if (!validTagName.test(name)) {
-		parser.error(`Expected valid tag name`, start);
+		parser.error({
+			code: `invalid-tag-name`,
+			message: `Expected valid tag name`
+		}, start);
 	}
 
 	return name;
@@ -332,7 +351,10 @@ function readAttribute(parser: Parser, uniqueNames: Set<string>) {
 			};
 		} else {
 			if (!parser.v2) {
-				parser.error('Expected spread operator (...)');
+				parser.error({
+					code: `expected-spread`,
+					message: 'Expected spread operator (...)'
+				});
 			}
 
 			const valueStart = parser.index;
@@ -364,7 +386,10 @@ function readAttribute(parser: Parser, uniqueNames: Set<string>) {
 	let name = parser.readUntil(/(\s|=|\/|>)/);
 	if (!name) return null;
 	if (uniqueNames.has(name)) {
-		parser.error('Attributes need to be unique', start);
+		parser.error({
+			code: `duplicate-attribute`,
+			message: 'Attributes need to be unique'
+		}, start);
 	}
 
 	uniqueNames.add(name);
@@ -452,5 +477,8 @@ function readSequence(parser: Parser, done: () => boolean) {
 		}
 	}
 
-	parser.error(`Unexpected end of input`);
+	parser.error({
+		code: `unexpected-eof`,
+		message: `Unexpected end of input`
+	});
 }

src/utils/error.ts

@@ -2,6 +2,7 @@ import { locate } from 'locate-character';
 import getCodeFrame from '../utils/getCodeFrame';
 
 class CompileError extends Error {
+	code: string;
 	loc: { line: number, column: number };
 	end: { line: number, column: number };
 	pos: number;
@@ -15,6 +16,7 @@ class CompileError extends Error {
 
 export default function error(message: string, props: {
 	name: string,
+	code: string,
 	source: string,
 	filename: string,
 	start: number,
@@ -26,6 +28,7 @@ export default function error(message: string, props: {
 	const start = locate(props.source, props.start);
 	const end = locate(props.source, props.end || props.start);
 
+	error.code = props.code;
 	error.loc = { line: start.line + 1, column: start.column };
 	error.end = { line: end.line + 1, column: end.column };
 	error.pos = props.start;

src/validate/html/a11y.ts

@@ -35,7 +35,10 @@ export default function a11y(
 		if (name.startsWith('aria-')) {
 			if (invisibleElements.has(node.name)) {
 				// aria-unsupported-elements
-				validator.warn(`A11y: <${node.name}> should not have aria-* attributes`, attribute);
+				validator.warn(attribute, {
+					code: `a11y-aria-attributes`,
+					message: `A11y: <${node.name}> should not have aria-* attributes`
+				});
 			}
 
 			const type = name.slice(5);
@@ -44,7 +47,10 @@ export default function a11y(
 				let message = `A11y: Unknown aria attribute 'aria-${type}'`;
 				if (match) message += ` (did you mean '${match}'?)`;
 
-				validator.warn(message, attribute);
+				validator.warn(attribute, {
+					code: `a11y-unknown-aria-attribute`,
+					message
+				});
 			}
 		}
 
@@ -52,7 +58,10 @@ export default function a11y(
 		if (name === 'role') {
 			if (invisibleElements.has(node.name)) {
 				// aria-unsupported-elements
-				validator.warn(`A11y: <${node.name}> should not have role attribute`, attribute);
+				validator.warn(attribute, {
+					code: `a11y-misplaced-role`,
+					message: `A11y: <${node.name}> should not have role attribute`
+				});
 			}
 
 			const value = getStaticAttributeValue(node, 'role');
@@ -61,30 +70,45 @@ export default function a11y(
 				let message = `A11y: Unknown role '${value}'`;
 				if (match) message += ` (did you mean '${match}'?)`;
 
-				validator.warn(message, attribute);
+				validator.warn(attribute, {
+					code: `a11y-unknown-role`,
+					message
+				});
 			}
 		}
 
 		// no-access-key
 		if (name === 'accesskey') {
-			validator.warn(`A11y: Avoid using accesskey`, attribute);
+			validator.warn(attribute, {
+				code: `a11y-accesskey`,
+				message: `A11y: Avoid using accesskey`
+			});
 		}
 
 		// no-autofocus
 		if (name === 'autofocus') {
-			validator.warn(`A11y: Avoid using autofocus`, attribute);
+			validator.warn(attribute, {
+				code: `a11y-autofocus`,
+				message: `A11y: Avoid using autofocus`
+			});
 		}
 
 		// scope
 		if (name === 'scope' && node.name !== 'th') {
-			validator.warn(`A11y: The scope attribute should only be used with <th> elements`, attribute);
+			validator.warn(attribute, {
+				code: `a11y-misplaced-scope`,
+				message: `A11y: The scope attribute should only be used with <th> elements`
+			});
 		}
 
 		// tabindex-no-positive
 		if (name === 'tabindex') {
 			const value = getStaticAttributeValue(node, 'tabindex');
 			if (!isNaN(value) && +value > 0) {
-				validator.warn(`A11y: avoid tabindex values above zero`, attribute);
+				validator.warn(attribute, {
+					code: `a11y-positive-tabindex`,
+					message: `A11y: avoid tabindex values above zero`
+				});
 			}
 		}
 
@@ -98,13 +122,19 @@ export default function a11y(
 				attributes.slice(0, -1).join(', ') + ` or ${attributes[attributes.length - 1]}` :
 				attributes[0];
 
-			validator.warn(`A11y: <${name}> element should have ${article} ${sequence} attribute`, node);
+			validator.warn(node, {
+				code: `a11y-missing-attribute`,
+				message: `A11y: <${name}> element should have ${article} ${sequence} attribute`
+			});
 		}
 	}
 
 	function shouldHaveContent() {
 		if (node.children.length === 0) {
-			validator.warn(`A11y: <${node.name}> element should have child content`, node);
+			validator.warn(node, {
+				code: `a11y-missing-content`,
+				message: `A11y: <${node.name}> element should have child content`
+			});
 		}
 	}
 
@@ -112,7 +142,10 @@ export default function a11y(
 		const href = attributeMap.get(attribute);
 		const value = getStaticAttributeValue(node, attribute);
 		if (value === '' || value === '#') {
-			validator.warn(`A11y: '${value}' is not a valid ${attribute} attribute`, href);
+			validator.warn(href, {
+				code: `a11y-invalid-attribute`,
+				message: `A11y: '${value}' is not a valid ${attribute} attribute`
+			});
 		}
 	}
 
@@ -124,7 +157,10 @@ export default function a11y(
 			// anchor-in-svg-is-valid
 			shouldHaveValidHref('xlink:href')
 		} else {
-			validator.warn(`A11y: <a> element should have an href attribute`, node);
+			validator.warn(node, {
+				code: `a11y-missing-attribute`,
+				message: `A11y: <a> element should have an href attribute`
+			});
 		}
 
 		// anchor-has-content
@@ -143,7 +179,10 @@ export default function a11y(
 		shouldHaveContent();
 
 		if (attributeMap.has('aria-hidden')) {
-			validator.warn(`A11y: <${node.name}> element should not be hidden`, attributeMap.get('aria-hidden'));
+			validator.warn(attributeMap.get('aria-hidden'), {
+				code: `a11y-hidden`,
+				message: `A11y: <${node.name}> element should not be hidden`
+			});
 		}
 	}
 
@@ -159,14 +198,20 @@ export default function a11y(
 
 	// no-distracting-elements
 	if (node.name === 'marquee' || node.name === 'blink') {
-		validator.warn(`A11y: Avoid <${node.name}> elements`, node);
+		validator.warn(node, {
+			code: `a11y-distracting-elements`,
+			message: `A11y: Avoid <${node.name}> elements`
+		});
 	}
 
 	if (node.name === 'figcaption') {
 		const parent = elementStack[elementStack.length - 1];
 		if (parent) {
 			if (parent.name !== 'figure') {
-				validator.warn(`A11y: <figcaption> must be an immediate child of <figure>`, node);
+				validator.warn(node, {
+					code: `a11y-structure`,
+					message: `A11y: <figcaption> must be an immediate child of <figure>`
+				});
 			} else {
 				const children = parent.children.filter(node => {
 					if (node.type === 'Comment') return false;
@@ -177,7 +222,10 @@ export default function a11y(
 				const index = children.indexOf(node);
 
 				if (index !== 0 && index !== children.length - 1) {
-					validator.warn(`A11y: <figcaption> must be first or last child of <figure>`, node);
+					validator.warn(node, {
+						code: `a11y-structure`,
+						message: `A11y: <figcaption> must be first or last child of <figure>`
+					});
 				}
 			}
 		}

src/validate/html/index.ts

@@ -61,15 +61,18 @@ export default function validateHtml(validator: Validator, html: Node) {
 				c += 2;
 				while (/\s/.test(validator.source[c])) c += 1;
 
-				validator.warn(
-					`Context clashes with a helper. Rename one or the other to eliminate any ambiguity`,
-					{ start: c, end: c + node.context.length }
-				);
+				validator.warn({ start: c, end: c + node.context.length }, {
+					code: `each-context-clash`,
+					message: `Context clashes with a helper. Rename one or the other to eliminate any ambiguity`
+				});
 			}
 		}
 
 		if (validator.options.dev && isEmptyBlock(node)) {
-			validator.warn('Empty block', node);
+			validator.warn(node, {
+				code: `empty-block`,
+				message: 'Empty block'
+			});
 		}
 
 		if (node.children) {
@@ -105,7 +108,10 @@ export default function validateHtml(validator: Validator, html: Node) {
 			let message = `'refs.${ref}' does not exist`;
 			if (match) message += ` (did you mean 'refs.${match}'?)`;
 
-			validator.error(message, callee);
+			validator.error(callee, {
+				code: `missing-ref`,
+				message
+			});
 		}
 	});
 }

src/validate/html/validateElement.ts

@@ -20,26 +20,35 @@ export default function validateElement(
 
 	if (!isComponent && /^[A-Z]/.test(node.name[0])) {
 		// TODO upgrade to validator.error in v2
-		validator.warn(`${node.name} component is not defined`, node);
+		validator.warn(node, {
+			code: `missing-component`,
+			message: `${node.name} component is not defined`
+		});
 	}
 
 	if (elementStack.length === 0 && validator.namespace !== namespaces.svg && svg.test(node.name)) {
-		validator.warn(
-			`<${node.name}> is an SVG element – did you forget to add { namespace: 'svg' } ?`,
-			node
-		);
+		validator.warn(node, {
+			code: `missing-namespace`,
+			message: `<${node.name}> is an SVG element – did you forget to add { namespace: 'svg' } ?`
+		});
 	}
 
 	if (node.name === 'slot') {
 		const nameAttribute = node.attributes.find((attribute: Node) => attribute.name === 'name');
 		if (nameAttribute) {
 			if (nameAttribute.value.length !== 1 || nameAttribute.value[0].type !== 'Text') {
-				validator.error(`<slot> name cannot be dynamic`, nameAttribute);
+				validator.error(nameAttribute, {
+					code: `dynamic-slot-name`,
+					message: `<slot> name cannot be dynamic`
+				});
 			}
 
 			const slotName = nameAttribute.value[0].data;
 			if (slotName === 'default') {
-				validator.error(`default is a reserved word — it cannot be used as a slot name`, nameAttribute);
+				validator.error(nameAttribute, {
+					code: `invalid-slot-name`,
+					message: `default is a reserved word — it cannot be used as a slot name`
+				});
 			}
 
 			// TODO should duplicate slots be disallowed? Feels like it's more likely to be a
@@ -61,18 +70,18 @@ export default function validateElement(
 
 	if (node.name === 'title') {
 		if (node.attributes.length > 0) {
-			validator.error(
-				`<title> cannot have attributes`,
-				node.attributes[0]
-			);
+			validator.error(node.attributes[0], {
+				code: `illegal-attribute`,
+				message: `<title> cannot have attributes`
+			});
 		}
 
 		node.children.forEach(child => {
 			if (child.type !== 'Text' && child.type !== 'MustacheTag') {
-				validator.error(
-					`<title> can only contain text and {{tags}}`,
-					child
-				);
+				validator.error(child, {
+					code: 'illegal-structure',
+					message: `<title> can only contain text and {{tags}}`
+				});
 			}
 		});
 	}
@@ -96,10 +105,10 @@ export default function validateElement(
 					node.name !== 'textarea' &&
 					node.name !== 'select'
 				) {
-					validator.error(
-						`'value' is not a valid binding on <${node.name}> elements`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `'value' is not a valid binding on <${node.name}> elements`
+					});
 				}
 
 				if (node.name === 'select') {
@@ -108,43 +117,43 @@ export default function validateElement(
 					);
 
 					if (attribute && isDynamic(attribute)) {
-						validator.error(
-							`'multiple' attribute cannot be dynamic if select uses two-way binding`,
-							attribute
-						);
+						validator.error(attribute, {
+							code: `dynamic-multiple-attribute`,
+							message: `'multiple' attribute cannot be dynamic if select uses two-way binding`
+						});
 					}
 				} else {
 					checkTypeAttribute(validator, node);
 				}
 			} else if (name === 'checked' || name === 'indeterminate') {
 				if (node.name !== 'input') {
-					validator.error(
-						`'${name}' is not a valid binding on <${node.name}> elements`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `'${name}' is not a valid binding on <${node.name}> elements`
+					});
 				}
 
 				if (checkTypeAttribute(validator, node) !== 'checkbox') {
-					validator.error(
-						`'${name}' binding can only be used with <input type="checkbox">`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `'${name}' binding can only be used with <input type="checkbox">`
+					});
 				}
 			} else if (name === 'group') {
 				if (node.name !== 'input') {
-					validator.error(
-						`'group' is not a valid binding on <${node.name}> elements`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `'group' is not a valid binding on <${node.name}> elements`
+					});
 				}
 
 				const type = checkTypeAttribute(validator, node);
 
 				if (type !== 'checkbox' && type !== 'radio') {
-					validator.error(
-						`'checked' binding can only be used with <input type="checkbox"> or <input type="radio">`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `'checked' binding can only be used with <input type="checkbox"> or <input type="radio">`
+					});
 				}
 			} else if (
 				name === 'currentTime' ||
@@ -156,23 +165,26 @@ export default function validateElement(
 				name === 'volume'
 			) {
 				if (node.name !== 'audio' && node.name !== 'video') {
-					validator.error(
-						`'${name}' binding can only be used with <audio> or <video>`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `'${name}' binding can only be used with <audio> or <video>`
+					});
 				}
 			} else {
-				validator.error(
-					`'${attribute.name}' is not a valid binding`,
-					attribute
-				);
+				validator.error(attribute, {
+					code: `invalid-binding`,
+					message: `'${attribute.name}' is not a valid binding`
+				});
 			}
 		} else if (attribute.type === 'EventHandler') {
 			validator.used.events.add(attribute.name);
 			validateEventHandler(validator, attribute, refCallees);
 		} else if (attribute.type === 'Transition') {
 			if (isComponent) {
-				validator.error(`Transitions can only be applied to DOM elements, not components`, attribute);
+				validator.error(attribute, {
+					code: `invalid-transition`,
+					message: `Transitions can only be applied to DOM elements, not components`
+				});
 			}
 
 			validator.used.transitions.add(attribute.name);
@@ -180,31 +192,31 @@ export default function validateElement(
 			const bidi = attribute.intro && attribute.outro;
 
 			if (hasTransition) {
-				if (bidi)
-					validator.error(
-						`An element can only have one 'transition' directive`,
-						attribute
-					);
-				validator.error(
-					`An element cannot have both a 'transition' directive and an '${attribute.intro
-						? 'in'
-						: 'out'}' directive`,
-					attribute
-				);
+				if (bidi) {
+					validator.error(attribute, {
+						code: `duplicate-transition`,
+						message: `An element can only have one 'transition' directive`
+					});
+				}
+
+				validator.error(attribute, {
+					code: `duplicate-transition`,
+					message: `An element cannot have both a 'transition' directive and an '${attribute.intro ? 'in' : 'out'}' directive`
+				});
 			}
 
 			if ((hasIntro && attribute.intro) || (hasOutro && attribute.outro)) {
-				if (bidi)
-					validator.error(
-						`An element cannot have both an '${hasIntro
-							? 'in'
-							: 'out'}' directive and a 'transition' directive`,
-						attribute
-					);
-				validator.error(
-					`An element can only have one '${hasIntro ? 'in' : 'out'}' directive`,
-					attribute
-				);
+				if (bidi) {
+					validator.error(attribute, {
+						code: `duplicate-transition`,
+						message: `An element cannot have both an '${hasIntro ? 'in' : 'out'}' directive and a 'transition' directive`
+					});
+				}
+
+				validator.error(attribute, {
+					code: `duplicate-transition`,
+					message: `An element can only have one '${hasIntro ? 'in' : 'out'}' directive`
+				});
 			}
 
 			if (attribute.intro) hasIntro = true;
@@ -212,18 +224,18 @@ export default function validateElement(
 			if (bidi) hasTransition = true;
 
 			if (!validator.transitions.has(attribute.name)) {
-				validator.error(
-					`Missing transition '${attribute.name}'`,
-					attribute
-				);
+				validator.error(attribute, {
+					code: `missing-transition`,
+					message: `Missing transition '${attribute.name}'`
+				});
 			}
 		} else if (attribute.type === 'Attribute') {
 			if (attribute.name === 'value' && node.name === 'textarea') {
 				if (node.children.length) {
-					validator.error(
-						`A <textarea> can have either a value attribute or (equivalently) child content, but not both`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `textarea-duplicate-value`,
+						message: `A <textarea> can have either a value attribute or (equivalently) child content, but not both`
+					});
 				}
 			}
 
@@ -232,16 +244,19 @@ export default function validateElement(
 			}
 		} else if (attribute.type === 'Action') {
 			if (isComponent) {
-				validator.error(`Actions can only be applied to DOM elements, not components`, attribute);
+				validator.error(attribute, {
+					code: `invalid-action`,
+					message: `Actions can only be applied to DOM elements, not components`
+				});
 			}
 
 			validator.used.actions.add(attribute.name);
 
 			if (!validator.actions.has(attribute.name)) {
-				validator.error(
-					`Missing action '${attribute.name}'`,
-					attribute
-				);
+				validator.error(attribute, {
+					code: `missing-action`,
+					message: `Missing action '${attribute.name}'`
+				});
 			}
 		}
 	});
@@ -254,14 +269,17 @@ function checkTypeAttribute(validator: Validator, node: Node) {
 	if (!attribute) return null;
 
 	if (attribute.value === true) {
-		validator.error(`'type' attribute must be specified`, attribute);
+		validator.error(attribute, {
+			code: `missing-type`,
+			message: `'type' attribute must be specified`
+		});
 	}
 
 	if (isDynamic(attribute)) {
-		validator.error(
-			`'type' attribute cannot be dynamic if input uses two-way binding`,
-			attribute
-		);
+		validator.error(attribute, {
+			code: `invalid-type`,
+			message: `'type' attribute cannot be dynamic if input uses two-way binding`
+		});
 	}
 
 	return attribute.value[0].data;
@@ -269,10 +287,10 @@ function checkTypeAttribute(validator: Validator, node: Node) {
 
 function checkSlotAttribute(validator: Validator, node: Node, attribute: Node, stack: Node[]) {
 	if (isDynamic(attribute)) {
-		validator.error(
-			`slot attribute cannot have a dynamic value`,
-			attribute
-		);
+		validator.error(attribute, {
+			code: `invalid-slot-attribute`,
+			message: `slot attribute cannot have a dynamic value`
+		});
 	}
 
 	let i = stack.length;
@@ -286,11 +304,17 @@ function checkSlotAttribute(validator: Validator, node: Node, attribute: Node, s
 
 		if (parent.type === 'IfBlock' || parent.type === 'EachBlock') {
 			const message = `Cannot place slotted elements inside an ${parent.type === 'IfBlock' ? 'if' : 'each'}-block`;
-			validator.error(message, attribute);
+			validator.error(attribute, {
+				code: `invalid-slotted-content`,
+				message
+			});
 		}
 	}
 
-	validator.error(`Element with a slot='...' attribute must be a descendant of a component or custom element`, attribute);
+	validator.error(attribute, {
+		code: `invalid-slotted-content`,
+		message: `Element with a slot='...' attribute must be a descendant of a component or custom element`
+	});
 }
 
 function isDynamic(attribute: Node) {

src/validate/html/validateEventHandler.ts

@@ -16,7 +16,10 @@ export default function validateEventHandlerCallee(
 	const { callee, type } = attribute.expression;
 
 	if (type !== 'CallExpression') {
-		validator.error(`Expected a call expression`, attribute.expression);
+		validator.error(attribute.expression, {
+			code: `invalid-event-handler`,
+			message: `Expected a call expression`
+		});
 	}
 
 	const { name } = flattenReference(callee);
@@ -30,10 +33,10 @@ export default function validateEventHandlerCallee(
 
 	if (name === 'store' && attribute.expression.callee.type === 'MemberExpression') {
 		if (!validator.options.store) {
-			validator.warn(
-				'compile with `store: true` in order to call store methods',
-				attribute.expression
-			);
+			validator.warn(attribute.expression, {
+				code: `options-missing-store`,
+				message: 'compile with `store: true` in order to call store methods'
+			});
 		}
 		return;
 	}
@@ -59,5 +62,8 @@ export default function validateEventHandlerCallee(
 		message += `. '${callee.name}' exists on 'helpers', did you put it in the wrong place?`;
 	}
 
-	validator.warn(message, attribute.expression);
+	validator.warn(attribute.expression, {
+		code: `invalid-callee`,
+		message
+	});
 }

src/validate/html/validateHead.ts

@@ -4,7 +4,10 @@ import { Node } from '../../interfaces';
 
 export default function validateHead(validator: Validator, node: Node, refs: Map<string, Node[]>, refCallees: Node[]) {
 	if (node.attributes.length) {
-		validator.error(`<:Head> should not have any attributes or directives`, node);
+		validator.error(node.attributes[0], {
+			code: `invalid-attribute`,
+			message: `<:Head> should not have any attributes or directives`
+		});
 	}
 
 	// TODO ensure only valid elements are included here

src/validate/html/validateWindow.ts

@@ -21,12 +21,10 @@ export default function validateWindow(validator: Validator, node: Node, refs: M
 			if (attribute.value.type !== 'Identifier') {
 				const { parts } = flattenReference(attribute.value);
 
-				validator.error(
-					`Bindings on <:Window/> must be to top-level properties, e.g. '${parts[
-						parts.length - 1
-					]}' rather than '${parts.join('.')}'`,
-					attribute.value
-				);
+				validator.error(attribute.value, {
+					code: `invalid-binding`,
+					message: `Bindings on <:Window/> must be to top-level properties, e.g. '${parts[parts.length - 1]}' rather than '${parts.join('.')}'`
+				});
 			}
 
 			if (!~validBindings.indexOf(attribute.name)) {
@@ -39,15 +37,15 @@ export default function validateWindow(validator: Validator, node: Node, refs: M
 				const message = `'${attribute.name}' is not a valid binding on <:Window>`;
 
 				if (match) {
-					validator.error(
-						`${message} (did you mean '${match}'?)`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `${message} (did you mean '${match}'?)`
+					});
 				} else {
-					validator.error(
-						`${message} — valid bindings are ${list(validBindings)}`,
-						attribute
-					);
+					validator.error(attribute, {
+						code: `invalid-binding`,
+						message: `${message} — valid bindings are ${list(validBindings)}`
+					});
 				}
 			}
 		} else if (attribute.type === 'EventHandler') {

src/validate/index.ts

@@ -59,9 +59,10 @@ export class Validator {
 		};
 	}
 
-	error(message: string, pos: { start: number, end: number }) {
+	error(pos: { start: number, end: number }, { code, message } : { code: string, message: string }) {
 		error(message, {
 			name: 'ValidationError',
+			code,
 			source: this.source,
 			start: pos.start,
 			end: pos.end,
@@ -69,7 +70,7 @@ export class Validator {
 		});
 	}
 
-	warn(message: string, pos: { start: number, end: number }) {
+	warn(pos: { start: number, end: number }, { code, message }: { code: string, message: string }) {
 		if (!this.locator) this.locator = getLocator(this.source);
 		const start = this.locator(pos.start);
 		const end = this.locator(pos.end);
@@ -77,6 +78,7 @@ export class Validator {
 		const frame = getCodeFrame(this.source, start.line, start.column);
 
 		this.onwarn({
+			code,
 			message,
 			frame,
 			loc: { line: start.line + 1, column: start.column },
@@ -105,6 +107,7 @@ export default function validate(
 		if (name && /^[a-z]/.test(name)) {
 			const message = `options.name should be capitalised`;
 			onwarn({
+				code: `options-lowercase-name`,
 				message,
 				filename,
 				toString: () => message,
@@ -148,10 +151,10 @@ export default function validate(
 					definitions.value.properties.forEach(prop => {
 						const { name } = prop.key;
 						if (!validator.used[category].has(name)) {
-							validator.warn(
-								`The '${name}' ${categories[category]} is unused`,
-								prop
-							);
+							validator.warn(prop, {
+								code: `unused-${category.slice(0, -1)}`,
+								message: `The '${name}' ${categories[category]} is unused`
+							});
 						}
 					});
 				}

src/validate/js/index.ts

@@ -14,15 +14,18 @@ export default function validateJs(validator: Validator, js: Node) {
 	js.content.body.forEach((node: Node) => {
 		// check there are no named exports
 		if (node.type === 'ExportNamedDeclaration') {
-			validator.error(`A component can only have a default export`, node);
+			validator.error(node, {
+				code: `named-export`,
+				message: `A component can only have a default export`
+			});
 		}
 
 		if (node.type === 'ExportDefaultDeclaration') {
 			if (node.declaration.type !== 'ObjectExpression') {
-				return validator.error(
-					`Default export must be an object literal`,
-					node.declaration
-				);
+				validator.error(node.declaration, {
+					code: `invalid-default-export`,
+					message: `Default export must be an object literal`
+				});
 			}
 
 			checkForComputedKeys(validator, node.declaration.properties);
@@ -36,17 +39,17 @@ export default function validateJs(validator: Validator, js: Node) {
 
 			// Remove these checks in version 2
 			if (props.has('oncreate') && props.has('onrender')) {
-				validator.error(
-					'Cannot have both oncreate and onrender',
-					props.get('onrender')
-				);
+				validator.error(props.get('onrender'), {
+					code: `duplicate-oncreate`,
+					message: 'Cannot have both oncreate and onrender'
+				});
 			}
 
 			if (props.has('ondestroy') && props.has('onteardown')) {
-				validator.error(
-					'Cannot have both ondestroy and onteardown',
-					props.get('onteardown')
-				);
+				validator.error(props.get('onteardown'), {
+					code: `duplicate-ondestroy`,
+					message: 'Cannot have both ondestroy and onteardown'
+				});
 			}
 
 			// ensure all exported props are valid
@@ -59,20 +62,20 @@ export default function validateJs(validator: Validator, js: Node) {
 				} else {
 					const match = fuzzymatch(name, validPropList);
 					if (match) {
-						validator.error(
-							`Unexpected property '${name}' (did you mean '${match}'?)`,
-							prop
-						);
+						validator.error(prop, {
+							code: `unexpected-property`,
+							message: `Unexpected property '${name}' (did you mean '${match}'?)`
+						});
 					} else if (/FunctionExpression/.test(prop.value.type)) {
-						validator.error(
-							`Unexpected property '${name}' (did you mean to include it in 'methods'?)`,
-							prop
-						);
+						validator.error(prop, {
+							code: `unexpected-property`,
+							message: `Unexpected property '${name}' (did you mean to include it in 'methods'?)`
+						});
 					} else {
-						validator.error(
-							`Unexpected property '${name}'`,
-							prop
-						);
+						validator.error(prop, {
+							code: `unexpected-property`,
+							message: `Unexpected property '${name}'`
+						});
 					}
 				}
 			});

src/validate/js/propValidators/actions.ts

@@ -1,14 +1,14 @@
 import checkForDupes from '../utils/checkForDupes';
 import checkForComputedKeys from '../utils/checkForComputedKeys';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function actions(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ObjectExpression') {
-		validator.error(
-			`The 'actions' property must be an object literal`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-actions`,
+			message: `The 'actions' property must be an object literal`
+		});
 	}
 
 	checkForDupes(validator, prop.value.properties);

src/validate/js/propValidators/components.ts

@@ -1,15 +1,15 @@
 import checkForDupes from '../utils/checkForDupes';
 import checkForComputedKeys from '../utils/checkForComputedKeys';
 import getName from '../../../utils/getName';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function components(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ObjectExpression') {
-		validator.error(
-			`The 'components' property must be an object literal`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-components-property`,
+			message: `The 'components' property must be an object literal`
+		});
 	}
 
 	checkForDupes(validator, prop.value.properties);
@@ -19,14 +19,18 @@ export default function components(validator: Validator, prop: Node) {
 		const name = getName(component.key);
 
 		if (name === 'state') {
-			validator.error(
-				`Component constructors cannot be called 'state' due to technical limitations`,
-				component
-			);
+			// TODO is this still true?
+			validator.error(component, {
+				code: `invalid-name`,
+				message: `Component constructors cannot be called 'state' due to technical limitations`
+			});
 		}
 
 		if (!/^[A-Z]/.test(name)) {
-			validator.warn(`Component names should be capitalised`, component);
+			validator.warn(component, {
+				code: `component-lowercase`,
+				message: `Component names should be capitalised`
+			});
 		}
 	});
 }

src/validate/js/propValidators/computed.ts

@@ -3,7 +3,7 @@ import checkForComputedKeys from '../utils/checkForComputedKeys';
 import getName from '../../../utils/getName';
 import isValidIdentifier from '../../../utils/isValidIdentifier';
 import reservedNames from '../../../utils/reservedNames';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 import walkThroughTopFunctionScope from '../../../utils/walkThroughTopFunctionScope';
 import isThisGetCallExpression from '../../../utils/isThisGetCallExpression';
@@ -15,10 +15,10 @@ const isFunctionExpression = new Set([
 
 export default function computed(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ObjectExpression') {
-		validator.error(
-			`The 'computed' property must be an object literal`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-computed-property`,
+			message: `The 'computed' property must be an object literal`
+		});
 	}
 
 	checkForDupes(validator, prop.value.properties);
@@ -29,49 +29,49 @@ export default function computed(validator: Validator, prop: Node) {
 
 		if (!isValidIdentifier(name)) {
 			const suggestion = name.replace(/[^_$a-z0-9]/ig, '_').replace(/^\d/, '_$&');
-			validator.error(
-				`Computed property name '${name}' is invalid — must be a valid identifier such as ${suggestion}`,
-				computation
-			);
+			validator.error(computation, {
+				code: `invalid-computed-name`,
+				message: `Computed property name '${name}' is invalid — must be a valid identifier such as ${suggestion}`
+			});
 		}
 
 		if (reservedNames.has(name)) {
-			validator.error(
-				`Computed property name '${name}' is invalid — cannot be a JavaScript reserved word`,
-				computation
-			);
+			validator.error(computation, {
+				code: `invalid-computed-name`,
+				message: `Computed property name '${name}' is invalid — cannot be a JavaScript reserved word`
+			});
 		}
 
 		if (!isFunctionExpression.has(computation.value.type)) {
-			validator.error(
-				`Computed properties can be function expressions or arrow function expressions`,
-				computation.value
-			);
+			validator.error(computation.value, {
+				code: `invalid-computed-value`,
+				message: `Computed properties can be function expressions or arrow function expressions`
+			});
 		}
 
 		const { body, params } = computation.value;
 
 		walkThroughTopFunctionScope(body, (node: Node) => {
 			if (isThisGetCallExpression(node) && !node.callee.property.computed) {
-				validator.error(
-					`Cannot use this.get(...) — values must be passed into the function as arguments`,
-					node
-				);
+				validator.error(node, {
+					code: `impure-computed`,
+					message: `Cannot use this.get(...) — values must be passed into the function as arguments`
+				});
 			}
 
 			if (node.type === 'ThisExpression') {
-				validator.error(
-					`Computed properties should be pure functions — they do not have access to the component instance and cannot use 'this'. Did you mean to put this in 'methods'?`,
-					node
-				);
+				validator.error(node, {
+					code: `impure-computed`,
+					message: `Computed properties should be pure functions — they do not have access to the component instance and cannot use 'this'. Did you mean to put this in 'methods'?`
+				});
 			}
 		});
 
 		if (params.length === 0) {
-			validator.error(
-				`A computed value must depend on at least one property`,
-				computation.value
-			);
+			validator.error(computation.value, {
+				code: `impure-computed`,
+				message: `A computed value must depend on at least one property`
+			});
 		}
 
 		params.forEach((param: Node) => {
@@ -81,10 +81,11 @@ export default function computed(validator: Validator, prop: Node) {
 					param.left.type === 'Identifier');
 
 			if (!valid) {
-				validator.error(
-					`Computed properties cannot use destructuring in function parameters`,
-					param
-				);
+				// TODO change this for v2
+				validator.error(param, {
+					code: `invalid-computed-arguments`,
+					message: `Computed properties cannot use destructuring in function parameters`
+				});
 			}
 		});
 	});

src/validate/js/propValidators/data.ts

@@ -1,4 +1,4 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 const disallowed = new Set(['Literal', 'ObjectExpression', 'ArrayExpression']);
@@ -7,6 +7,9 @@ export default function data(validator: Validator, prop: Node) {
 	while (prop.type === 'ParenthesizedExpression') prop = prop.expression;
 
 	if (disallowed.has(prop.value.type)) {
-		validator.error(`'data' must be a function`, prop.value);
+		validator.error(prop.value, {
+			code: `invalid-data-property`,
+			message: `'data' must be a function`
+		});
 	}
 }

src/validate/js/propValidators/events.ts

@@ -1,14 +1,14 @@
 import checkForDupes from '../utils/checkForDupes';
 import checkForComputedKeys from '../utils/checkForComputedKeys';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function events(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ObjectExpression') {
-		validator.error(
-			`The 'events' property must be an object literal`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-events-property`,
+			message: `The 'events' property must be an object literal`
+		});
 	}
 
 	checkForDupes(validator, prop.value.properties);

src/validate/js/propValidators/helpers.ts

@@ -1,17 +1,17 @@
 import checkForDupes from '../utils/checkForDupes';
 import checkForComputedKeys from '../utils/checkForComputedKeys';
 import { walk } from 'estree-walker';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 import walkThroughTopFunctionScope from '../../../utils/walkThroughTopFunctionScope';
 import isThisGetCallExpression from '../../../utils/isThisGetCallExpression';
 
 export default function helpers(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ObjectExpression') {
-		validator.error(
-			`The 'helpers' property must be an object literal`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-helpers-property`,
+			message: `The 'helpers' property must be an object literal`
+		});
 	}
 
 	checkForDupes(validator, prop.value.properties);
@@ -24,27 +24,27 @@ export default function helpers(validator: Validator, prop: Node) {
 
 		walkThroughTopFunctionScope(prop.value.body, (node: Node) => {
 			if (isThisGetCallExpression(node) && !node.callee.property.computed) {
-				validator.error(
-					`Cannot use this.get(...) — values must be passed into the helper function as arguments`,
-					node
-				);
+				validator.error(node, {
+					code: `impure-helper`,
+					message: `Cannot use this.get(...) — values must be passed into the helper function as arguments`
+				});
 			}
 
 			if (node.type === 'ThisExpression') {
-				validator.error(
-					`Helpers should be pure functions — they do not have access to the component instance and cannot use 'this'. Did you mean to put this in 'methods'?`,
-					node
-				);
+				validator.error(node, {
+					code: `impure-helper`,
+					message: `Helpers should be pure functions — they do not have access to the component instance and cannot use 'this'. Did you mean to put this in 'methods'?`
+				});
 			} else if (node.type === 'Identifier' && node.name === 'arguments') {
 				usesArguments = true;
 			}
 		});
 
 		if (prop.value.params.length === 0 && !usesArguments) {
-			validator.warn(
-				`Helpers should be pure functions, with at least one argument`,
-				prop
-			);
+			validator.warn(prop, {
+				code: `impure-helper`,
+				message: `Helpers should be pure functions, with at least one argument`
+			});
 		}
 	});
 }

src/validate/js/propValidators/immutable.ts

@@ -1,11 +1,11 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function immutable(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'Literal' || typeof prop.value.value !== 'boolean') {
-		validator.error(
-			`'immutable' must be a boolean literal`,
-			prop.value
-		);
+		validator.error(prop.value, {
+			code: `invalid-immutable-property`,
+			message: `'immutable' must be a boolean literal`
+		});
 	}
 }

src/validate/js/propValidators/methods.ts

@@ -3,17 +3,17 @@ import checkForDupes from '../utils/checkForDupes';
 import checkForComputedKeys from '../utils/checkForComputedKeys';
 import usesThisOrArguments from '../utils/usesThisOrArguments';
 import getName from '../../../utils/getName';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 const builtin = new Set(['set', 'get', 'on', 'fire', 'observe', 'destroy']);
 
 export default function methods(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ObjectExpression') {
-		validator.error(
-			`The 'methods' property must be an object literal`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-methods-property`,
+			message: `The 'methods' property must be an object literal`
+		});
 	}
 
 	checkForAccessors(validator, prop.value.properties, 'Methods');
@@ -24,19 +24,18 @@ export default function methods(validator: Validator, prop: Node) {
 		const name = getName(prop.key);
 
 		if (builtin.has(name)) {
-			validator.error(
-				`Cannot overwrite built-in method '${name}'`,
-				prop
-			);
+			validator.error(prop, {
+				code: `invalid-method-name`,
+				message: `Cannot overwrite built-in method '${name}'`
+			});
 		}
 
 		if (prop.value.type === 'ArrowFunctionExpression') {
 			if (usesThisOrArguments(prop.value.body)) {
-				validator.error(
-					`Method '${prop.key
-						.name}' should be a function expression, not an arrow function expression`,
-					prop
-				);
+				validator.error(prop, {
+					code: `invalid-method-value`,
+					message: `Method '${prop.key.name}' should be a function expression, not an arrow function expression`
+				});
 			}
 		}
 	});

src/validate/js/propValidators/namespace.ts

@@ -1,7 +1,7 @@
 import * as namespaces from '../../../utils/namespaces';
 import nodeToString from '../../../utils/nodeToString'
 import fuzzymatch from '../../utils/fuzzymatch';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 const valid = new Set(namespaces.validNamespaces);
@@ -10,21 +10,24 @@ export default function namespace(validator: Validator, prop: Node) {
 	const ns = nodeToString(prop.value);
 
 	if (typeof ns !== 'string') {
-		validator.error(
-			`The 'namespace' property must be a string literal representing a valid namespace`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-namespace-property`,
+			message: `The 'namespace' property must be a string literal representing a valid namespace`
+		});
 	}
 
 	if (!valid.has(ns)) {
 		const match = fuzzymatch(ns, namespaces.validNamespaces);
 		if (match) {
-			validator.error(
-				`Invalid namespace '${ns}' (did you mean '${match}'?)`,
-				prop
-			);
+			validator.error(prop, {
+				code: `invalid-namespace-property`,
+				message: `Invalid namespace '${ns}' (did you mean '${match}'?)`
+			});
 		} else {
-			validator.error(`Invalid namespace '${ns}'`, prop);
+			validator.error(prop, {
+				code: `invalid-namespace-property`,
+				message: `Invalid namespace '${ns}'`
+			});
 		}
 	}
 }

src/validate/js/propValidators/oncreate.ts

@@ -1,14 +1,14 @@
 import usesThisOrArguments from '../utils/usesThisOrArguments';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function oncreate(validator: Validator, prop: Node) {
 	if (prop.value.type === 'ArrowFunctionExpression') {
 		if (usesThisOrArguments(prop.value.body)) {
-			validator.error(
-				`'oncreate' should be a function expression, not an arrow function expression`,
-				prop
-			);
+			validator.error(prop, {
+				code: `invalid-oncreate-property`,
+				message: `'oncreate' should be a function expression, not an arrow function expression`
+			});
 		}
 	}
 }

src/validate/js/propValidators/ondestroy.ts

@@ -1,14 +1,14 @@
 import usesThisOrArguments from '../utils/usesThisOrArguments';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function ondestroy(validator: Validator, prop: Node) {
 	if (prop.value.type === 'ArrowFunctionExpression') {
 		if (usesThisOrArguments(prop.value.body)) {
-			validator.error(
-				`'ondestroy' should be a function expression, not an arrow function expression`,
-				prop
-			);
+			validator.error(prop, {
+				code: `invalid-ondestroy-property`,
+				message: `'ondestroy' should be a function expression, not an arrow function expression`
+			});
 		}
 	}
 }

src/validate/js/propValidators/onrender.ts

@@ -1,11 +1,12 @@
 import oncreate from './oncreate';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function onrender(validator: Validator, prop: Node) {
-	validator.warn(
-		`'onrender' has been deprecated in favour of 'oncreate', and will cause an error in Svelte 2.x`,
-		prop
-	);
+	validator.warn(prop, {
+		code: `deprecated-onrender`,
+		message: `'onrender' has been deprecated in favour of 'oncreate', and will cause an error in Svelte 2.x`
+	});
+
 	oncreate(validator, prop);
 }

src/validate/js/propValidators/onteardown.ts

@@ -1,11 +1,12 @@
 import ondestroy from './ondestroy';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function onteardown(validator: Validator, prop: Node) {
-	validator.warn(
-		`'onteardown' has been deprecated in favour of 'ondestroy', and will cause an error in Svelte 2.x`,
-		prop
-	);
+	validator.warn(prop, {
+		code: `deprecated-onteardown`,
+		message: `'onteardown' has been deprecated in favour of 'ondestroy', and will cause an error in Svelte 2.x`
+	});
+
 	ondestroy(validator, prop);
 }

src/validate/js/propValidators/preload.ts

@@ -1,4 +1,4 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function preload(validator: Validator, prop: Node) {

src/validate/js/propValidators/props.ts

@@ -1,21 +1,21 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 import nodeToString from '../../../utils/nodeToString';
 
 export default function props(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ArrayExpression') {
-		validator.error(
-			`'props' must be an array expression, if specified`,
-			prop.value
-		);
+		validator.error(prop.value, {
+			code: `invalid-props-property`,
+			message: `'props' must be an array expression, if specified`
+		});
 	}
 
 	prop.value.elements.forEach((element: Node) => {
 		if (typeof nodeToString(element) !== 'string') {
-			validator.error(
-				`'props' must be an array of string literals`,
-				element
-			);
+			validator.error(element, {
+				code: `invalid-props-property`,
+				message: `'props' must be an array of string literals`
+			});
 		}
 	});
 }

src/validate/js/propValidators/setup.ts

@@ -1,4 +1,4 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 const disallowed = new Set(['Literal', 'ObjectExpression', 'ArrayExpression']);
@@ -7,6 +7,9 @@ export default function setup(validator: Validator, prop: Node) {
 	while (prop.type === 'ParenthesizedExpression') prop = prop.expression;
 
 	if (disallowed.has(prop.value.type)) {
-		validator.error(`'setup' must be a function`, prop.value);
+		validator.error(prop.value, {
+			code: `invalid-setup-property`,
+			message: `'setup' must be a function`
+		});
 	}
 }

src/validate/js/propValidators/store.ts

@@ -1,4 +1,4 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function store(validator: Validator, prop: Node) {

src/validate/js/propValidators/tag.ts

@@ -1,20 +1,20 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 import nodeToString from '../../../utils/nodeToString';
 
 export default function tag(validator: Validator, prop: Node) {
 	const tag = nodeToString(prop.value);
 	if (typeof tag !== 'string') {
-		validator.error(
-			`'tag' must be a string literal`,
-			prop.value
-		);
+		validator.error(prop.value, {
+			code: `invalid-tag-property`,
+			message: `'tag' must be a string literal`
+		});
 	}
 
 	if (!/^[a-zA-Z][a-zA-Z0-9]*-[a-zA-Z0-9-]+$/.test(tag)) {
-		validator.error(
-			`tag name must be two or more words joined by the '-' character`,
-			prop.value
-		);
+		validator.error(prop.value, {
+			code: `invalid-tag-property`,
+			message: `tag name must be two or more words joined by the '-' character`
+		});
 	}
 }

src/validate/js/propValidators/transitions.ts

@@ -1,14 +1,14 @@
 import checkForDupes from '../utils/checkForDupes';
 import checkForComputedKeys from '../utils/checkForComputedKeys';
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function transitions(validator: Validator, prop: Node) {
 	if (prop.value.type !== 'ObjectExpression') {
-		validator.error(
-			`The 'transitions' property must be an object literal`,
-			prop
-		);
+		validator.error(prop, {
+			code: `invalid-transitions-property`,
+			message: `The 'transitions' property must be an object literal`
+		});
 	}
 
 	checkForDupes(validator, prop.value.properties);

src/validate/js/utils/checkForAccessors.ts

@@ -1,4 +1,4 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function checkForAccessors(
@@ -8,7 +8,10 @@ export default function checkForAccessors(
 ) {
 	properties.forEach(prop => {
 		if (prop.kind !== 'init') {
-			validator.error(`${label} cannot use getters and setters`, prop);
+			validator.error(prop, {
+				code: `illegal-accessor`,
+				message: `${label} cannot use getters and setters`
+			});
 		}
 	});
 }

src/validate/js/utils/checkForComputedKeys.ts

@@ -1,4 +1,4 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 
 export default function checkForComputedKeys(
@@ -7,7 +7,10 @@ export default function checkForComputedKeys(
 ) {
 	properties.forEach(prop => {
 		if (prop.key.computed) {
-			validator.error(`Cannot use computed keys`, prop);
+			validator.error(prop, {
+				code: `computed-key`,
+				message: `Cannot use computed keys`
+			});
 		}
 	});
 }

src/validate/js/utils/checkForDupes.ts

@@ -1,4 +1,4 @@
-import { Validator } from '../../';
+import { Validator } from '../../index';
 import { Node } from '../../../interfaces';
 import getName from '../../../utils/getName';
 
@@ -12,7 +12,10 @@ export default function checkForDupes(
 		const name = getName(prop.key);
 
 		if (seen.has(name)) {
-			validator.error(`Duplicate property '${name}'`, prop);
+			validator.error(prop, {
+				code: `duplicate-property`,
+				message: `Duplicate property '${name}'`
+			});
 		}
 
 		seen.add(name);

test/css/samples/empty-class/_config.js

@@ -3,6 +3,7 @@ export default {
 
 	warnings: [{
 		filename: "SvelteComponent.html",
+		code: `css-unused-selector`,
 		message: "Unused CSS selector",
 		loc: {
 			line: 4,

test/css/samples/omit-scoping-attribute-descendant/_config.js

@@ -2,6 +2,7 @@ export default {
 	cascade: false,
 
 	warnings: [{
+		code: `css-unused-selector`,
 		message: 'Unused CSS selector',
 		loc: {
 			line: 8,
@@ -9,7 +10,7 @@ export default {
 		},
 		pos: 74,
 		frame: `
-			 6: 
+			 6:
 			 7: <style>
 			 8:   div > p {
 			      ^

test/css/samples/omit-scoping-element-uppercase/_config.js

@@ -2,6 +2,7 @@ export default {
 	cascade: false,
 
 	warnings: [{
+		code: 'missing-component',
 		message: 'P component is not defined',
 		loc: {
 			line: 2,

test/css/samples/refs-qualified/_config.js

@@ -6,6 +6,7 @@ export default {
 	},
 
 	warnings: [{
+		code: `css-unused-selector`,
 		message: 'Unused CSS selector',
 		loc: {
 			column: 1,

test/css/samples/refs/_config.js

@@ -2,6 +2,7 @@ export default {
 	cascade: false,
 
 	warnings: [{
+		code: `css-unused-selector`,
 		message: 'Unused CSS selector',
 		loc: {
 			column: 1,

test/css/samples/unused-selector-leading/_config.js

@@ -4,6 +4,7 @@ export default {
 	warnings: [
 		{
 			filename: "SvelteComponent.html",
+			code: `css-unused-selector`,
 			message: "Unused CSS selector",
 			loc: {
 				line: 4,
@@ -21,6 +22,7 @@ export default {
 
 		{
 			filename: "SvelteComponent.html",
+			code: `css-unused-selector`,
 			message: "Unused CSS selector",
 			loc: {
 				line: 4,

test/css/samples/unused-selector-ternary/_config.js

@@ -7,6 +7,7 @@ export default {
 
 	warnings: [{
 		filename: "SvelteComponent.html",
+		code: `css-unused-selector`,
 		message: "Unused CSS selector",
 		loc: {
 			line: 12,

test/css/samples/unused-selector/_config.js

@@ -3,6 +3,7 @@ export default {
 
 	warnings: [{
 		filename: "SvelteComponent.html",
+		code: `css-unused-selector`,
 		message: "Unused CSS selector",
 		loc: {
 			line: 8,
@@ -11,7 +12,7 @@ export default {
 		pos: 60,
 		frame: `
 			 6:   }
-			 7: 
+			 7:
 			 8:   .bar {
 			      ^
 			 9:     color: blue;

test/formats/index.js

@@ -184,6 +184,7 @@ describe("formats", () => {
 			);
 
 			assert.deepEqual(warnings, [{
+				code: `options-missing-globals`,
 				message: `No name was supplied for imported module 'lodash'. Guessing '_', but you should use options.globals`
 			}]);
 		});

test/parser/index.js

@@ -32,6 +32,7 @@ describe('parse', () => {
 					if (!expectedError) throw err;
 
 					try {
+						assert.equal(err.code, expectedError.code);
 						assert.equal(err.message, expectedError.message);
 						assert.deepEqual(err.loc, expectedError.loc);
 						assert.equal(err.pos, expectedError.pos);

test/parser/samples/attribute-unique-error/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "duplicate-attribute",
 	"message": "Attributes need to be unique",
 	"loc": {
 		"line": 1,

test/parser/samples/attribute-unique-error/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "duplicate-attribute",
 	"message": "Attributes need to be unique",
 	"loc": {
 		"line": 1,

test/parser/samples/error-binding-disabled/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "binding-disabled",
 	"message": "Two-way binding is disabled",
 	"loc": {
 		"line": 1,

test/parser/samples/error-binding-disabled/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "binding-disabled",
 	"message": "Two-way binding is disabled",
 	"loc": {
 		"line": 1,

test/parser/samples/error-binding-mustaches/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "directive values should not be wrapped — use 'foo', not '{foo}'",
 	"loc": {
 		"line": 1,

test/parser/samples/error-binding-mustaches/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "directive values should not be wrapped — use 'foo', not '{{foo}}'",
 	"loc": {
 		"line": 1,

test/parser/samples/error-binding-rvalue/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "Can only bind to an identifier (e.g. `foo`) or a member expression (e.g. `foo.bar` or `foo[baz]`)",
 	"pos": 19,
 	"loc": {

test/parser/samples/error-binding-rvalue/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "Can only bind to an identifier (e.g. `foo`) or a member expression (e.g. `foo.bar` or `foo[baz]`)",
 	"pos": 19,
 	"loc": {

test/parser/samples/error-comment-unclosed/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "unexpected-eof",
 	"message": "comment was left open, expected -->",
 	"loc": {
 		"line": 1,

test/parser/samples/error-comment-unclosed/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "unexpected-eof",
 	"message": "comment was left open, expected -->",
 	"loc": {
 		"line": 1,

test/parser/samples/error-css/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "css-syntax-error",
 	"message": "LeftCurlyBracket is expected",
 	"loc": {
 		"line": 2,

test/parser/samples/error-css/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "css-syntax-error",
 	"message": "LeftCurlyBracket is expected",
 	"loc": {
 		"line": 2,

test/parser/samples/error-event-handler/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "Expected a method call",
 	"loc": {
 		"line": 1,

test/parser/samples/error-event-handler/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "Expected a method call",
 	"loc": {
 		"line": 1,

test/parser/samples/error-illegal-expression/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "parse-error",
 	"message": "Assigning to rvalue",
 	"loc": {
 		"line": 1,

test/parser/samples/error-illegal-expression/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "parse-error",
 	"message": "Assigning to rvalue",
 	"loc": {
 		"line": 1,

test/parser/samples/error-multiple-styles/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "duplicate-style",
 	"message": "You can only have one top-level <style> tag per component",
 	"loc": {
 		"line": 9,

test/parser/samples/error-multiple-styles/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "duplicate-style",
 	"message": "You can only have one top-level <style> tag per component",
 	"loc": {
 		"line": 9,

test/parser/samples/error-ref-value/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "ref directives cannot have a value",
 	"loc": {
 		"line": 1,

test/parser/samples/error-ref-value/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-directive-value",
 	"message": "ref directives cannot have a value",
 	"loc": {
 		"line": 1,

test/parser/samples/error-script-unclosed/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "unclosed-script",
 	"message": "<script> must have a closing tag",
 	"loc": {
 		"line": 3,

test/parser/samples/error-script-unclosed/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "unclosed-script",
 	"message": "<script> must have a closing tag",
 	"loc": {
 		"line": 3,

test/parser/samples/error-self-reference/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-self-placement",
 	"message": "<svelte:self> components can only exist inside if-blocks or each-blocks",
 	"loc": {
 		"line": 1,

test/parser/samples/error-self-reference/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-self-placement",
 	"message": "<:Self> components can only exist inside if-blocks or each-blocks",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input-b/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "unexpected-eof",
 	"message": "Unexpected end of input",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input-b/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "unexpected-eof",
 	"message": "Unexpected end of input",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input-c/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "unexpected-eof",
 	"message": "Unexpected end of input",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input-c/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "unexpected-eof",
 	"message": "Unexpected end of input",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input-d/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "unclosed-block",
 	"message": "Block was left open",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input-d/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "unclosed-block",
 	"message": "Block was left open",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "unclosed-element",
 	"message": "<div> was left open",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unexpected-end-of-input/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "unclosed-element",
 	"message": "<div> was left open",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unmatched-closing-tag/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-closing-tag",
 	"message": "</div> attempted to close an element that was not open",
 	"loc": {
 		"line": 1,

test/parser/samples/error-unmatched-closing-tag/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-closing-tag",
 	"message": "</div> attempted to close an element that was not open",
 	"loc": {
 		"line": 1,

test/parser/samples/error-void-closing/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-void-content",
 	"message": "<input> is a void element and cannot have children, or a closing tag",
 	"loc": {
 		"line": 1,

test/parser/samples/error-void-closing/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-void-content",
 	"message": "<input> is a void element and cannot have children, or a closing tag",
 	"loc": {
 		"line": 1,

test/parser/samples/error-window-children/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-window-content",
 	"message": "<svelte:window> cannot have children",
 	"loc": {
 		"line": 1,

test/parser/samples/error-window-children/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-window-content",
 	"message": "<:Window> cannot have children",
 	"loc": {
 		"line": 1,

test/parser/samples/error-window-duplicate/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "duplicate-window",
 	"message": "A component can only have one <svelte:window> tag",
 	"loc": {
 		"line": 2,

test/parser/samples/error-window-duplicate/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "duplicate-window",
 	"message": "A component can only have one <:Window> tag",
 	"loc": {
 		"line": 2,

test/parser/samples/error-window-inside-block/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-window-placement",
 	"message": "<svelte:window> tags cannot be inside elements or blocks",
 	"loc": {
 		"line": 2,

test/parser/samples/error-window-inside-block/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-window-placement",
 	"message": "<:Window> tags cannot be inside elements or blocks",
 	"loc": {
 		"line": 2,

test/parser/samples/error-window-inside-element/error-v2.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-window-placement",
 	"message": "<svelte:window> tags cannot be inside elements or blocks",
 	"loc": {
 		"line": 2,

test/parser/samples/error-window-inside-element/error.json

@@ -1,4 +1,5 @@
 {
+	"code": "invalid-window-placement",
 	"message": "<:Window> tags cannot be inside elements or blocks",
 	"loc": {
 		"line": 2,

test/validator/index.js

@@ -25,12 +25,8 @@ describe("validate", () => {
 
 					const { stats } = svelte.compile(input, {
 						onwarn(warning) {
-							warnings.push({
-								message: warning.message,
-								pos: warning.pos,
-								loc: warning.loc,
-								end: warning.end,
-							});
+							const { code, message, pos, loc, end } = warning;
+							warnings.push({ code, message, pos, loc, end });
 						},
 						dev: config.dev
 					});
@@ -39,6 +35,7 @@ describe("validate", () => {
 					stats.warnings.forEach((full, i) => {
 						const lite = warnings[i];
 						assert.deepEqual({
+							code: full.code,
 							message: full.message,
 							pos: full.pos,
 							loc: full.loc,
@@ -62,6 +59,7 @@ describe("validate", () => {
 						throw new Error(`Expected an error: ${expected.message}`);
 					}
 
+					assert.equal(error.code, expected.code);
 					assert.equal(error.message, expected.message);
 					assert.deepEqual(error.loc, expected.loc);
 					assert.deepEqual(error.end, expected.end);
@@ -100,6 +98,7 @@ describe("validate", () => {
 			name: "lowercase",
 			onwarn(warning) {
 				warnings.push({
+					code: warning.code,
 					message: warning.message,
 					pos: warning.pos,
 					loc: warning.loc
@@ -108,6 +107,7 @@ describe("validate", () => {
 		});
 		assert.deepEqual(warnings, [
 			{
+				code: `options-lowercase-name`,
 				message: "options.name should be capitalised",
 				pos: undefined,
 				loc: undefined
@@ -121,6 +121,7 @@ describe("validate", () => {
 			name: "_",
 			onwarn(warning) {
 				warnings.push({
+					code: warning.code,
 					message: warning.message,
 					pos: warning.pos,
 					loc: warning.loc

test/validator/samples/a11y-alt-text/warnings.json

@@ -1,5 +1,6 @@
 [
 	{
+		"code": "a11y-missing-attribute",
 		"message": "A11y: <img> element should have an alt attribute",
 		"loc": {
 			"line": 1,
@@ -13,6 +14,7 @@
 	},
 
 	{
+		"code": "a11y-missing-attribute",
 		"message": "A11y: <area> element should have an alt, aria-label or aria-labelledby attribute",
 		"loc": {
 			"line": 4,
@@ -26,6 +28,7 @@
 	},
 
 	{
+		"code": "a11y-missing-attribute",
 		"message": "A11y: <object> element should have a title, aria-label or aria-labelledby attribute",
 		"loc": {
 			"line": 7,
@@ -39,6 +42,7 @@
 	},
 
 	{
+		"code": "a11y-missing-attribute",
 		"message": "A11y: <input type=\"image\"> element should have an alt, aria-label or aria-labelledby attribute",
 		"loc": {
 			"line": 9,

test/validator/samples/a11y-anchor-has-content/warnings.json

@@ -1,4 +1,5 @@
 [{
+	"code": "a11y-missing-content",
 	"message": "A11y: <a> element should have child content",
 	"loc": {
 		"line": 1,

test/validator/samples/a11y-anchor-in-svg-is-valid/warnings.json

@@ -1,5 +1,6 @@
 [
   {
+    "code": "a11y-missing-attribute",
     "message": "A11y: <a> element should have an href attribute",
     "loc": {
       "line": 1,
@@ -12,6 +13,7 @@
     "pos": 11
   },
   {
+    "code": "a11y-invalid-attribute",
     "message": "A11y: '' is not a valid xlink:href attribute",
     "loc": {
       "line": 2,
@@ -24,6 +26,7 @@
     "pos": 65
   },
   {
+    "code": "a11y-invalid-attribute",
     "message": "A11y: '#' is not a valid xlink:href attribute",
     "loc": {
       "line": 3,

test/validator/samples/a11y-anchor-is-valid/warnings.json

@@ -1,5 +1,6 @@
 [
 	{
+		"code": "a11y-missing-attribute",
 		"message": "A11y: <a> element should have an href attribute",
 		"loc": {
 			"line": 1,
@@ -12,6 +13,7 @@
 		"pos": 0
 	},
 	{
+		"code": "a11y-invalid-attribute",
 		"message": "A11y: '' is not a valid href attribute",
 		"loc": {
 			"line": 2,
@@ -24,6 +26,7 @@
 		"pos": 30
 	},
 	{
+		"code": "a11y-invalid-attribute",
 		"message": "A11y: '#' is not a valid href attribute",
 		"loc": {
 			"line": 3,