diff --git a/src/api/build.ts b/src/api/build.ts
index d589da4be..8999f186e 100644
--- a/src/api/build.ts
+++ b/src/api/build.ts
@@ -20,7 +20,7 @@ type Opts = {
 	legacy?: boolean;
 	bundler?: 'rollup' | 'webpack';
 	ext?: string;
-	oncompile?: ({ type, result }: { type: string, result: CompileResult }) => void;
+	oncompile?: ({ type, result }: { type: string; result: CompileResult }) => void;
 };
 
 export async function build({
diff --git a/src/api/dev.ts b/src/api/dev.ts
index 0ca56a5ee..7429f6a04 100644
--- a/src/api/dev.ts
+++ b/src/api/dev.ts
@@ -16,19 +16,19 @@ import { copy_runtime } from './utils/copy_runtime';
 import { rimraf, mkdirp } from './utils/fs_utils';
 
 type Opts = {
-	cwd?: string,
-	src?: string,
-	dest?: string,
-	routes?: string,
-	output?: string,
-	static?: string,
-	'dev-port'?: number,
-	live?: boolean,
-	hot?: boolean,
-	'devtools-port'?: number,
-	bundler?: 'rollup' | 'webpack',
-	port?: number,
-	ext: string
+	cwd?: string;
+	src?: string;
+	dest?: string;
+	routes?: string;
+	output?: string;
+	static?: string;
+	'dev-port'?: number;
+	live?: boolean;
+	hot?: boolean;
+	'devtools-port'?: number;
+	bundler?: 'rollup' | 'webpack';
+	port?: number;
+	ext: string;
 };
 
 export function dev(opts: Opts) {
@@ -128,9 +128,9 @@ class Watcher extends EventEmitter {
 	async init() {
 		if (this.port) {
 			if (!await ports.check(this.port)) {
-				this.emit('fatal', <FatalEvent>{
+				this.emit('fatal', {
 					message: `Port ${this.port} is unavailable`
-				});
+				} as FatalEvent);
 				return;
 			}
 		} else {
@@ -164,9 +164,9 @@ class Watcher extends EventEmitter {
 				cwd, src, dest, routes, output
 			});
 		} catch (err) {
-			this.emit('fatal', <FatalEvent>{
+			this.emit('fatal', {
 				message: err.message
-			});
+			} as FatalEvent);
 			return;
 		}
 
@@ -192,10 +192,10 @@ class Watcher extends EventEmitter {
 							cwd, src, dest, routes, output
 						});
 					} catch (error) {
-						this.emit('error', <ErrorEvent>{
+						this.emit('error', {
 							type: 'manifest',
 							error
-						});
+						} as ErrorEvent);
 					}
 				}
 			)
@@ -217,9 +217,9 @@ class Watcher extends EventEmitter {
 		const compilers: Compilers = await create_compilers(this.bundler, cwd, src, dest, true);
 
 		const emitFatal = () => {
-			this.emit('fatal', <FatalEvent>{
+			this.emit('fatal', {
 				message: `Server crashed`
-			});
+			} as FatalEvent);
 
 			this.crashed = true;
 			this.proc = null;
@@ -239,10 +239,10 @@ class Watcher extends EventEmitter {
 
 						return ports.wait(this.port)
 							.then((() => {
-								this.emit('ready', <ReadyEvent>{
+								this.emit('ready', {
 									port: this.port,
 									process: this.proc
-								});
+								} as ReadyEvent);
 
 								if (this.hot && this.bundler === 'webpack') {
 									this.dev_server.send({
@@ -257,9 +257,9 @@ class Watcher extends EventEmitter {
 							.catch(err => {
 								if (this.crashed) return;
 
-								this.emit('fatal', <FatalEvent>{
+								this.emit('fatal', {
 									message: `Server is not listening on port ${this.port}`
-								});
+								} as FatalEvent);
 							});
 					};
 
@@ -393,14 +393,14 @@ class Watcher extends EventEmitter {
 			};
 
 			process.nextTick(() => {
-				this.emit('invalid', <InvalidEvent>{
+				this.emit('invalid', {
 					changed: Array.from(this.current_build.changed),
 					invalid: {
 						server: this.current_build.rebuilding.has('server'),
 						client: this.current_build.rebuilding.has('client'),
 						serviceworker: this.current_build.rebuilding.has('serviceworker'),
 					}
-				});
+				} as InvalidEvent);
 
 				this.restarting = false;
 			});
@@ -408,7 +408,7 @@ class Watcher extends EventEmitter {
 	}
 
 	watch(compiler: Compiler, { name, invalid = noop, handle_result = noop }: {
-		name: string,
+		name: string;
 		invalid?: (filename: string) => void;
 		handle_result?: (result: CompileResult) => void;
 	}) {
@@ -416,10 +416,10 @@ class Watcher extends EventEmitter {
 
 		compiler.watch((error?: Error, result?: CompileResult) => {
 			if (error) {
-				this.emit('error', <ErrorEvent>{
+				this.emit('error', {
 					type: name,
 					error
-				});
+				} as ErrorEvent);
 			} else {
 				this.emit('build', {
 					type: name,
@@ -489,7 +489,7 @@ class DevServer {
 
 function watch_dir(
 	dir: string,
-	filter: ({ path, stats }: { path: string, stats: fs.Stats }) => boolean,
+	filter: ({ path, stats }: { path: string; stats: fs.Stats }) => boolean,
 	callback: () => void
 ) {
 	let watch: any;
diff --git a/src/api/export.ts b/src/api/export.ts
index 441a5dbc1..2d88f2d24 100644
--- a/src/api/export.ts
+++ b/src/api/export.ts
@@ -13,26 +13,26 @@ import { noop } from './utils/noop';
 import { parse as parseLinkHeader } from 'http-link-header';
 import { rimraf, copy, mkdirp } from './utils/fs_utils';
 
-const writeFile = promisify(fs.writeFile)
+const writeFile = promisify(fs.writeFile);
 
 type Opts = {
-	build_dir?: string,
-	export_dir?: string,
-	cwd?: string,
-	static?: string,
-	basepath?: string,
-	host_header?: string,
-	timeout?: number | false,
-	concurrent?: number,
+	build_dir?: string;
+	export_dir?: string;
+	cwd?: string;
+	static?: string;
+	basepath?: string;
+	host_header?: string;
+	timeout?: number | false;
+	concurrent?: number;
 	oninfo?: ({ message }: { message: string }) => void;
 	onfile?: ({ file, size, status }: { file: string, size: number, status: number }) => void;
 	entry?: string;
 };
 
 type Ref = {
-	uri: string,
-	rel: string,
-	as: string
+	uri: string;
+	rel: string;
+	as: string;
 };
 
 type URL = url.UrlWithStringQuery;
@@ -42,7 +42,7 @@ function resolve(from: string, to: string) {
 }
 
 function cleanPath(path: string) {
-	return path.replace(/^\/|\/$|\/*index(.html)*$|.html$/g, '')
+	return path.replace(/^\/|\/$|\/*index(.html)*$|.html$/g, '');
 }
 
 function get_href(attrs: string) {
@@ -110,7 +110,7 @@ async function _export({
 	const saved = new Set();
 
 	function save(url: string, status: number, type: string, body: string) {
-		let { pathname } = resolve(origin, url);
+		const { pathname } = resolve(origin, url);
 		let file = decodeURIComponent(pathname.slice(1));
 
 		if (saved.has(file)) return;
@@ -141,7 +141,7 @@ async function _export({
 	function handle(url: URL, fetchOpts: FetchOpts, addCallback: Function) {
 		let pathname = url.pathname;
 		if (pathname !== '/service-worker-index.html') {
-			pathname = pathname.replace(fetchOpts.root.pathname, '') || '/'
+			pathname = pathname.replace(fetchOpts.root.pathname, '') || '/';
 		}
 
 		if (seen.has(pathname)) return;
@@ -190,11 +190,11 @@ async function _export({
 
 		if (range === 2 && type === 'text/html') {
 			// parse link rel=preload headers and embed them in the HTML
-			let link = parseLinkHeader(response.headers.get('Link') || '');
+			const link = parseLinkHeader(response.headers.get('Link') || '');
 			link.refs.forEach((ref: Ref) => {
 				if (ref.rel === 'preload') {
 					body = body.replace('</head>',
-						`<link rel="preload" as=${JSON.stringify(ref.as)} href=${JSON.stringify(ref.uri)}></head>`)
+						`<link rel="preload" as=${JSON.stringify(ref.as)} href=${JSON.stringify(ref.uri)}></head>`);
 				}
 			});
 
@@ -206,7 +206,7 @@ async function _export({
 				const base = resolve(url.href, base_href);
 
 				let match;
-				let pattern = /<a ([\s\S]+?)>/gm;
+				const pattern = /<a ([\s\S]+?)>/gm;
 
 				while (match = pattern.exec(cleaned)) {
 					const attrs = match[1];
@@ -216,7 +216,7 @@ async function _export({
 						const url = resolve(base.href, href);
 
 						if (url.protocol === protocol && url.host === host) {
-							handle(url, fetchOpts, queue.add)
+							handle(url, fetchOpts, queue.add);
 						}
 					}
 				}
diff --git a/src/api/utils/export_queue.ts b/src/api/utils/export_queue.ts
index fbc3b84eb..100c789ec 100644
--- a/src/api/utils/export_queue.ts
+++ b/src/api/utils/export_queue.ts
@@ -25,23 +25,23 @@ type QueueOpts = {
 	callbacks?: {
 		onDone?: () => void;
 		[key: string]: Function;
-	}
+	};
 };
 
 // determines current state of a promise
 function promiseState(p: Promise<any>) {
-	const t = {}
+	const t = {};
 	return Promise.race([p, t]).then(v => (v === t) ? "pending" : "fulfilled", () => "rejected");
 }
 
 // finds first non-pending promise in a list of promises
-async function findNotPendingIndex(list: Promise<any>[]) {
+async function findNotPendingIndex(list: Array<Promise<any>>) {
 	const states = await Promise.all(list.map(p => promiseState(p)));
 	return states.findIndex(state => state !== 'pending');
 }
 
 // filters any non-pending promises out of a list of promises
-async function filterNotPending(list: Promise<any>[]) {
+async function filterNotPending(list: Array<Promise<any>>) {
 	const states = await Promise.all(list.map(p => promiseState(p)));
 	return states.reduce((acc, curr, index) => {
 		if (curr === 'pending') {
@@ -56,12 +56,12 @@ async function filterNotPending(list: Promise<any>[]) {
 // url array can contain any number of urls found during export process
 // fetching array can contain a number of fetch api returns equal to the concurrent option
 // saving array can contain a number of promisified writeFile returns equal to the concurrent option
-function exportQueue({ concurrent, handleFetch, handleResponse, fetchOpts, callbacks } : QueueOpts) {
+function exportQueue({ concurrent, handleFetch, handleResponse, fetchOpts, callbacks }: QueueOpts) {
 	const urls: URL[] = [];
-	let fetching : Promise<any>[] = [];
-	let saving : Promise<any>[] = [];
+	const fetching: Array<Promise<any>> = [];
+	let saving: Array<Promise<any>> = [];
 
-	function addToQueue(p: Promise<any>, queue: Promise<any>[]) {
+	function addToQueue(p: Promise<any>, queue: Array<Promise<any>>) {
 		const queuePromise = new Promise((res, rej) => {
 			p.then((ret?: any) => {
 				res(ret);
@@ -113,6 +113,6 @@ function exportQueue({ concurrent, handleFetch, handleResponse, fetchOpts, callb
 			callbacks[event] = fn;
 		}
 	};
-};
+}
 
 export { exportQueue, FetchOpts, FetchRet };
diff --git a/src/cli.ts b/src/cli.ts
index 8af53a858..d8593b9bb 100755
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -33,19 +33,19 @@ prog.command('dev')
 	.option('--build-dir', 'Development build directory', '__sapper__/dev')
 	.option('--ext', 'Custom Route Extension', '.svelte .html')
 	.action(async (opts: {
-		port: number,
-		open: boolean,
-		'dev-port': number,
-		live: boolean,
-		hot: boolean,
-		bundler?: 'rollup' | 'webpack',
-		cwd: string,
-		src: string,
-		routes: string,
-		static: string,
-		output: string,
-		'build-dir': string,
-		ext: string
+		port: number;
+		open: boolean;
+		'dev-port': number;
+		live: boolean;
+		hot: boolean;
+		bundler?: 'rollup' | 'webpack';
+		cwd: string;
+		src: string;
+		routes: string;
+		static: string;
+		output: string;
+		'build-dir': string;
+		ext: string;
 	}) => {
 		const { dev } = await import('./api/dev');
 
@@ -157,14 +157,14 @@ prog.command('build [dest]')
 	.option('--ext', 'Custom page route extensions (space separated)', '.svelte .html')
 	.example(`build custom-dir -p 4567`)
 	.action(async (dest = '__sapper__/build', opts: {
-		port: string,
-		legacy: boolean,
-		bundler?: 'rollup' | 'webpack',
-		cwd: string,
-		src: string,
-		routes: string,
-		output: string,
-		ext: string
+		port: string;
+		legacy: boolean;
+		bundler?: 'rollup' | 'webpack';
+		cwd: string;
+		src: string;
+		routes: string;
+		output: string;
+		ext: string;
 	}) => {
 		console.log(`> Building...`);
 
@@ -208,21 +208,21 @@ prog.command('export [dest]')
 	.option('--ext', 'Custom page route extensions (space separated)', '.svelte .html')
 	.option('--entry', 'Custom entry points (space separated)', '/')
 	.action(async (dest = '__sapper__/export', opts: {
-		build: boolean,
-		legacy: boolean,
-		bundler?: 'rollup' | 'webpack',
-		basepath?: string,
-		host?: string,
-		concurrent: number,
-		timeout: number | false,
-		cwd: string,
-		src: string,
-		routes: string,
-		static: string,
-		output: string,
-		'build-dir': string,
-		ext: string
-		entry: string
+		build: boolean;
+		legacy: boolean;
+		bundler?: 'rollup' | 'webpack';
+		basepath?: string;
+		host?: string;
+		concurrent: number;
+		timeout: number | false;
+		cwd: string;
+		src: string;
+		routes: string;
+		static: string;
+		output: string;
+		'build-dir': string;
+		ext: string;
+		entry: string;
 	}) => {
 		try {
 			if (opts.build) {
diff --git a/src/config/rollup.ts b/src/config/rollup.ts
index bb04b6334..8735b94bf 100644
--- a/src/config/rollup.ts
+++ b/src/config/rollup.ts
@@ -8,7 +8,7 @@ export default {
 
 	client: {
 		input: (): InputOption => {
-			return `${src}/client.js`
+			return `${src}/client.js`;
 		},
 
 		output: (): OutputOptions => {
@@ -51,7 +51,7 @@ export default {
 				file: `${dest}/service-worker.js`,
 				format: 'iife',
 				sourcemap
-			}
+			};
 		}
 	}
 };
\ No newline at end of file
diff --git a/src/config/webpack.ts b/src/config/webpack.ts
index 78a753584..0dc748c1d 100644
--- a/src/config/webpack.ts
+++ b/src/config/webpack.ts
@@ -50,7 +50,7 @@ export default {
 				path: dest,
 				filename: '[name].js',
 				chunkFilename: '[name].[id].[hash].js'
-			}
+			};
 		}
 	}
 };
\ No newline at end of file
diff --git a/src/core/create_app.ts b/src/core/create_app.ts
index 7dcd7f03c..680c6dd98 100644
--- a/src/core/create_app.ts
+++ b/src/core/create_app.ts
@@ -14,7 +14,7 @@ export function create_app({
 	routes,
 	output
 }: {
-	bundler: string,
+	bundler: string;
 	manifest_data: ManifestData;
 	dev_port?: number;
 	dev: boolean;
@@ -22,7 +22,7 @@ export function create_app({
 	src: string;
 	dest: string;
 	routes: string;
-	output: string
+	output: string;
 }) {
 	if (!fs.existsSync(output)) fs.mkdirSync(output);
 
@@ -55,7 +55,7 @@ export function create_serviceworker_manifest({ manifest_data, output, client_fi
 		}
 	}
 
-	let code = `
+	const code = `
 		// This file is generated by Sapper — do not edit it!
 		export const timestamp = ${Date.now()};
 
@@ -73,7 +73,7 @@ export function create_serviceworker_manifest({ manifest_data, output, client_fi
 function create_param_match(param: string, i: number) {
 	return /^\.{3}.+$/.test(param)
 		? `${param.replace(/.{3}/, '')}: d(match[${i + 1}]).split('/')`
-		: `${param}: d(match[${i + 1}])`
+		: `${param}: d(match[${i + 1}])`;
 }
 
 function generate_client_manifest(
@@ -132,7 +132,7 @@ function generate_client_manifest(
 	]`.replace(/^\t/gm, '');
 
 	if (needs_decode) {
-		routes = `(d => ${routes})(decodeURIComponent)`
+		routes = `(d => ${routes})(decodeURIComponent)`;
 	}
 
 	return `
@@ -178,7 +178,7 @@ function generate_server_manifest(
 		component_lookup[component.name] = i;
 	});
 
-	let code = `
+	const code = `
 		`.replace(/^\t\t/gm, '').trim();
 
 	const build_dir = posixify(path.normalize(path.relative(cwd, dest)));
diff --git a/src/core/create_compilers/RollupCompiler.ts b/src/core/create_compilers/RollupCompiler.ts
index 6822abadc..c755ae858 100644
--- a/src/core/create_compilers/RollupCompiler.ts
+++ b/src/core/create_compilers/RollupCompiler.ts
@@ -17,7 +17,7 @@ export default class RollupCompiler {
 	warnings: any[];
 	errors: any[];
 	chunks: any[];
-	css_files: Array<{ id: string, code: string }>;
+	css_files: Array<{ id: string; code: string }>;
 
 	constructor(config: any) {
 		this._ = this.get_config(config);
@@ -191,7 +191,7 @@ export function handleError(err: RollupError, recover = false) {
 	}
 
 	if (err.loc) {
-		stderr(`${(err.loc.file || err.id)!} (${err.loc.line}:${err.loc.column})`);
+		stderr(`${err.loc.file || err.id} (${err.loc.line}:${err.loc.column})`);
 	} else if (err.id) {
 		stderr(err.id);
 	}
diff --git a/src/core/create_compilers/RollupResult.ts b/src/core/create_compilers/RollupResult.ts
index f3d33b844..5eb43fab6 100644
--- a/src/core/create_compilers/RollupResult.ts
+++ b/src/core/create_compilers/RollupResult.ts
@@ -17,15 +17,15 @@ export default class RollupResult implements CompileResult {
 	dependencies: Record<string, string[]>;
 	css_files: CssFile[];
 	css: {
-		main: string,
-		chunks: Record<string, string[]>
+		main: string;
+		chunks: Record<string, string[]>;
 	};
 	sourcemap: boolean | 'inline';
 	summary: string;
 
 	constructor(duration: number, compiler: RollupCompiler, sourcemap: boolean | 'inline') {
 		this.duration = duration;
-		this.sourcemap = sourcemap
+		this.sourcemap = sourcemap;
 
 		this.errors = compiler.errors.map(munge_warning_or_error);
 		this.warnings = compiler.warnings.map(munge_warning_or_error);
diff --git a/src/core/create_compilers/extract_css.ts b/src/core/create_compilers/extract_css.ts
index 57fc48067..5bec128c0 100644
--- a/src/core/create_compilers/extract_css.ts
+++ b/src/core/create_compilers/extract_css.ts
@@ -4,7 +4,7 @@ import hash from 'string-hash';
 import * as codec from 'sourcemap-codec';
 import { PageComponent, Dirs } from '../../interfaces';
 import { CompileResult, Chunk } from './interfaces';
-import { normalize_path, posixify } from '../../utils'
+import { normalize_path, posixify } from '../../utils';
 
 const inline_sourcemap_header = 'data:application/json;charset=utf-8;base64,';
 
@@ -111,7 +111,7 @@ export default function extract_css(
 ) {
 	const result: {
 		main: string | null;
-		chunks: Record<string, string[]>
+		chunks: Record<string, string[]>;
 	} = {
 		main: null,
 		chunks: {}
@@ -155,7 +155,7 @@ export default function extract_css(
 		}
 
 		if (sourcemap === 'inline') {
-			const base64 = Buffer.from(JSON.stringify(map), 'utf8').toString('base64')
+			const base64 = Buffer.from(JSON.stringify(map), 'utf8').toString('base64');
 			code += `\n/*# sourceMappingURL=${inline_sourcemap_header}${base64} */`;
 		}
 
@@ -270,7 +270,7 @@ export default function extract_css(
 		}
 
 		if (sourcemap === 'inline') {
-			const base64 = Buffer.from(JSON.stringify(map), 'utf8').toString('base64')
+			const base64 = Buffer.from(JSON.stringify(map), 'utf8').toString('base64');
 			code += `\n/*# sourceMappingURL=${inline_sourcemap_header}${base64} */`;
 		}
 
diff --git a/src/core/create_compilers/interfaces.ts b/src/core/create_compilers/interfaces.ts
index b7afb604d..afe22ed0b 100644
--- a/src/core/create_compilers/interfaces.ts
+++ b/src/core/create_compilers/interfaces.ts
@@ -25,7 +25,7 @@ export interface CompileResult {
 	css_files: CssFile[];
 	print: () => void;
 
-	to_json: (manifest_data: ManifestData, dirs: Dirs) => BuildInfo
+	to_json: (manifest_data: ManifestData, dirs: Dirs) => BuildInfo;
 }
 
 export type BuildInfo = {
@@ -35,7 +35,7 @@ export type BuildInfo = {
 	dependencies?: Record<string, string[]>;
 	legacy_assets?: Record<string, string>;
 	css: {
-		main: string | null,
-		chunks: Record<string, string[]>
-	}
+		main: string | null;
+		chunks: Record<string, string[]>;
+	};
 }
diff --git a/src/core/create_manifest_data.ts b/src/core/create_manifest_data.ts
index 3d720bd3b..99aa3e758 100644
--- a/src/core/create_manifest_data.ts
+++ b/src/core/create_manifest_data.ts
@@ -19,7 +19,7 @@ export default function create_manifest_data(cwd: string, extensions: string = '
 		return ext
 			? {
 				name: component_name,
-				file: file
+				file
 			}
 			: null;
 	}
@@ -47,8 +47,8 @@ export default function create_manifest_data(cwd: string, extensions: string = '
 		parent_segments: Part[][],
 		parent_params: string[],
 		stack: Array<{
-			component: PageComponent,
-			params: string[]
+			component: PageComponent;
+			params: string[];
 		}>
 	) {
 		const items = fs.readdirSync(dir)
@@ -151,7 +151,7 @@ export default function create_manifest_data(cwd: string, extensions: string = '
 
 				const parts = (item.is_index && stack[stack.length - 1] === null)
 					? stack.slice(0, -1).concat({ component, params })
-					: stack.concat({ component, params })
+					: stack.concat({ component, params });
 
 				pages.push({
 					pattern: get_pattern(segments, true),
@@ -223,8 +223,8 @@ function is_spread(path: string) {
 }
 
 function comparator(
-	a: { basename: string, parts: Part[], file: string, is_index: boolean },
-	b: { basename: string, parts: Part[], file: string, is_index: boolean }
+	a: { basename: string; parts: Part[]; file: string; is_index: boolean; },
+	b: { basename: string; parts: Part[]; file: string; is_index: boolean; }
 ) {
 	if (a.is_index !== b.is_index) {
 		if (a.is_index) return is_spread(a.file) ? 1 : -1;
@@ -243,7 +243,7 @@ function comparator(
 
 		// if spread && index, order later
 		if (a_sub_part.spread && b_sub_part.spread) {
-			return a.is_index ? 1 : -1
+			return a.is_index ? 1 : -1;
 		}
 
 		// If one is ...spread order it later
@@ -287,7 +287,7 @@ function get_parts(part: string): Part[] {
 
 			const [, content, qualifier] = dynamic
 				? /([^(]+)(\(.+\))?$/.exec(str)
-				: [, str, null];
+				: [null, str, null];
 
 			return {
 				content,
@@ -301,12 +301,12 @@ function get_parts(part: string): Part[] {
 
 function get_slug(file: string) {
 	let name = file
-		.replace(/[\\\/]index/, '')
-		.replace(/[\/\\]/g, '_')
+		.replace(/[\\/]index/, '')
+		.replace(/[/\\]/g, '_')
 		.replace(/\.\w+$/, '')
 		.replace(/\[([^(]+)(?:\([^(]+\))?\]/, '$$$1')
 		.replace(/[^a-zA-Z0-9_$]/g, c => {
-			return c === '.' ? '_' : `$${c.charCodeAt(0)}`
+			return c === '.' ? '_' : `$${c.charCodeAt(0)}`;
 		});
 
 	if (reserved_words.has(name)) name += '_';
diff --git a/src/interfaces.ts b/src/interfaces.ts
index 1f124b357..631ac997f 100644
--- a/src/interfaces.ts
+++ b/src/interfaces.ts
@@ -3,10 +3,10 @@ import { CompileResult } from './core/create_compilers/interfaces';
 
 export type Route = {
 	id: string;
-	handlers: {
+	handlers: Array<{
 		type: 'page' | 'route';
 		file: string;
-	}[];
+	}>;
 	pattern: RegExp;
 	test: (url: string) => boolean;
 	exec: (url: string) => Record<string, string>;
@@ -37,7 +37,7 @@ export type Page = {
 	parts: Array<{
 		component: PageComponent;
 		params: string[];
-	}>
+	}>;
 };
 
 export type ServerRoute = {
@@ -48,9 +48,9 @@ export type ServerRoute = {
 };
 
 export type Dirs = {
-	dest: string,
-	src: string,
-	routes: string
+	dest: string;
+	src: string;
+	routes: string;
 };
 
 export type ManifestData = {
@@ -89,13 +89,13 @@ export type InvalidEvent = {
 		client: boolean;
 		server: boolean;
 		serviceworker: boolean;
-	}
+	};
 };
 
 export type BuildEvent = {
 	type: string;
-	errors: Array<{ file: string, message: string, duplicate: boolean }>;
-	warnings: Array<{ file: string, message: string, duplicate: boolean }>;
+	errors: Array<{ file: string; message: string; duplicate: boolean }>;
+	warnings: Array<{ file: string; message: string; duplicate: boolean }>;
 	duration: number;
 	result: CompileResult;
 };