diff --git a/estree.ts b/estree.ts
new file mode 100644
index 0000000000..819a195104
--- /dev/null
+++ b/estree.ts
@@ -0,0 +1,571 @@
+// Type definitions for ESTree AST specification
+// Project: https://github.com/estree/estree
+// Definitions by: RReverser <https://github.com/RReverser>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+// This definition file follows a somewhat unusual format. ESTree allows
+// runtime type checks based on the `type` parameter. In order to explain this
+// to typescript we want to use discriminated union types:
+// https://github.com/Microsoft/TypeScript/pull/9163
+//
+// For ESTree this is a bit tricky because the high level interfaces like
+// Node or Function are pulling double duty. We want to pass common fields down
+// to the interfaces that extend them (like Identifier or
+// ArrowFunctionExpression), but you can't extend a type union or enforce
+// common fields on them. So we've split the high level interfaces into two
+// types, a base type which passes down inhereted fields, and a type union of
+// all types which extend the base type. Only the type union is exported, and
+// the union is how other types refer to the collection of inheriting types.
+//
+// This makes the definitions file here somewhat more difficult to maintain,
+// but it has the notable advantage of making ESTree much easier to use as
+// an end user.
+
+interface BaseNodeWithoutComments {
+  // Every leaf interface that extends BaseNode must specify a type property.
+  // The type property should be a string literal. For example, Identifier
+  // has: `type: "Identifier"`
+  type: string;
+  loc?: SourceLocation | null;
+  range?: [number, number];
+}
+
+interface BaseNode extends BaseNodeWithoutComments {
+  leadingComments?: Array<Comment>;
+  trailingComments?: Array<Comment>;
+}
+
+export type Node =
+    Identifier | Literal | Program | Function | SwitchCase | CatchClause |
+    VariableDeclarator | Statement | Expression | Property |
+    AssignmentProperty | Super | TemplateElement | SpreadElement | Pattern |
+    ClassBody | Class | MethodDefinition | ModuleDeclaration | ModuleSpecifier;
+
+export interface Comment extends BaseNodeWithoutComments {
+  type: "Line" | "Block";
+  value: string;
+}
+
+interface SourceLocation {
+  source?: string | null;
+  start: Position;
+  end: Position;
+}
+
+export interface Position {
+  /** >= 1 */
+  line: number;
+  /** >= 0 */
+  column: number;
+}
+
+export interface Program extends BaseNode {
+  type: "Program";
+  sourceType: "script" | "module";
+  body: Array<Directive | Statement | ModuleDeclaration>;
+  comments?: Array<Comment>;
+}
+
+export interface Directive extends BaseNode {
+  type: "ExpressionStatement";
+  expression: Literal;
+  directive: string;
+}
+
+interface BaseFunction extends BaseNode {
+  params: Array<Pattern>;
+  generator?: boolean;
+  async?: boolean;
+  // The body is either BlockStatement or Expression because arrow functions
+  // can have a body that's either. FunctionDeclarations and
+  // FunctionExpressions have only BlockStatement bodies.
+  body: BlockStatement | Expression;
+}
+
+export type Function =
+    FunctionDeclaration | FunctionExpression | ArrowFunctionExpression;
+
+export type Statement =
+    ExpressionStatement | BlockStatement | EmptyStatement |
+    DebuggerStatement | WithStatement | ReturnStatement | LabeledStatement |
+    BreakStatement | ContinueStatement | IfStatement | SwitchStatement |
+    ThrowStatement | TryStatement | WhileStatement | DoWhileStatement |
+    ForStatement | ForInStatement | ForOfStatement | Declaration;
+
+interface BaseStatement extends BaseNode { }
+
+export interface EmptyStatement extends BaseStatement {
+  type: "EmptyStatement";
+}
+
+export interface BlockStatement extends BaseStatement {
+  type: "BlockStatement";
+  body: Array<Statement>;
+  innerComments?: Array<Comment>;
+}
+
+export interface ExpressionStatement extends BaseStatement {
+  type: "ExpressionStatement";
+  expression: Expression;
+}
+
+export interface IfStatement extends BaseStatement {
+  type: "IfStatement";
+  test: Expression;
+  consequent: Statement;
+  alternate?: Statement | null;
+}
+
+export interface LabeledStatement extends BaseStatement {
+  type: "LabeledStatement";
+  label: Identifier;
+  body: Statement;
+}
+
+export interface BreakStatement extends BaseStatement {
+  type: "BreakStatement";
+  label?: Identifier | null;
+}
+
+export interface ContinueStatement extends BaseStatement {
+  type: "ContinueStatement";
+  label?: Identifier | null;
+}
+
+export interface WithStatement extends BaseStatement {
+  type: "WithStatement";
+  object: Expression;
+  body: Statement;
+}
+
+export interface SwitchStatement extends BaseStatement {
+  type: "SwitchStatement";
+  discriminant: Expression;
+  cases: Array<SwitchCase>;
+}
+
+export interface ReturnStatement extends BaseStatement {
+  type: "ReturnStatement";
+  argument?: Expression | null;
+}
+
+export interface ThrowStatement extends BaseStatement {
+  type: "ThrowStatement";
+  argument: Expression;
+}
+
+export interface TryStatement extends BaseStatement {
+  type: "TryStatement";
+  block: BlockStatement;
+  handler?: CatchClause | null;
+  finalizer?: BlockStatement | null;
+}
+
+export interface WhileStatement extends BaseStatement {
+  type: "WhileStatement";
+  test: Expression;
+  body: Statement;
+}
+
+export interface DoWhileStatement extends BaseStatement {
+  type: "DoWhileStatement";
+  body: Statement;
+  test: Expression;
+}
+
+export interface ForStatement extends BaseStatement {
+  type: "ForStatement";
+  init?: VariableDeclaration | Expression | null;
+  test?: Expression | null;
+  update?: Expression | null;
+  body: Statement;
+}
+
+interface BaseForXStatement extends BaseStatement {
+  left: VariableDeclaration | Pattern;
+  right: Expression;
+  body: Statement;
+}
+
+export interface ForInStatement extends BaseForXStatement {
+  type: "ForInStatement";
+}
+
+export interface DebuggerStatement extends BaseStatement {
+  type: "DebuggerStatement";
+}
+
+export type Declaration =
+      FunctionDeclaration | VariableDeclaration | ClassDeclaration;
+
+interface BaseDeclaration extends BaseStatement { }
+
+export interface FunctionDeclaration extends BaseFunction, BaseDeclaration {
+  type: "FunctionDeclaration";
+  /** It is null when a function declaration is a part of the `export default function` statement */
+  id: Identifier | null;
+  body: BlockStatement;
+}
+
+export interface VariableDeclaration extends BaseDeclaration {
+  type: "VariableDeclaration";
+  declarations: Array<VariableDeclarator>;
+  kind: "var" | "let" | "const";
+}
+
+export interface VariableDeclarator extends BaseNode {
+  type: "VariableDeclarator";
+  id: Pattern;
+  init?: Expression | null;
+}
+
+// BOOKMARK(@littledivy) - we had to manipulate estree source :eyes:
+export type Expression =
+    ThisExpression | ArrayExpression | ObjectExpression | FunctionExpression |
+    ArrowFunctionExpression | YieldExpression | Literal | UnaryExpression |
+    UpdateExpression | BinaryExpression | AssignmentExpression |
+    LogicalExpression | MemberExpression | ConditionalExpression |
+    CallExpression | NewExpression | SequenceExpression | TemplateLiteral |
+    TaggedTemplateExpression | ClassExpression | MetaProperty | Identifier |
+    AwaitExpression | ImportExpression | ChainExpression;
+
+export interface BaseExpression extends BaseNode { }
+
+type ChainElement = SimpleCallExpression | MemberExpression;
+
+export interface ChainExpression extends BaseExpression {
+  type: "ChainExpression";
+  expression: ChainElement;
+}
+
+export interface ThisExpression extends BaseExpression {
+  type: "ThisExpression";
+}
+
+export interface ArrayExpression extends BaseExpression {
+  type: "ArrayExpression";
+  elements: Array<Expression | SpreadElement>;
+}
+
+export interface ObjectExpression extends BaseExpression {
+  type: "ObjectExpression";
+  properties: Array<Property | SpreadElement>;
+}
+
+export interface Property extends BaseNode {
+  type: "Property";
+  key: Expression;
+  value: Expression | Pattern; // Could be an AssignmentProperty
+  kind: "init" | "get" | "set";
+  method: boolean;
+  shorthand: boolean;
+  computed: boolean;
+}
+
+export interface FunctionExpression extends BaseFunction, BaseExpression {
+  id?: Identifier | null;
+  type: "FunctionExpression";
+  body: BlockStatement;
+}
+
+export interface SequenceExpression extends BaseExpression {
+  type: "SequenceExpression";
+  expressions: Array<Expression>;
+}
+
+export interface UnaryExpression extends BaseExpression {
+  type: "UnaryExpression";
+  operator: UnaryOperator;
+  prefix: true;
+  argument: Expression;
+}
+
+export interface BinaryExpression extends BaseExpression {
+  type: "BinaryExpression";
+  operator: BinaryOperator;
+  left: Expression;
+  right: Expression;
+}
+
+export interface AssignmentExpression extends BaseExpression {
+  type: "AssignmentExpression";
+  operator: AssignmentOperator;
+  left: Pattern | MemberExpression;
+  right: Expression;
+}
+
+export interface UpdateExpression extends BaseExpression {
+  type: "UpdateExpression";
+  operator: UpdateOperator;
+  argument: Expression;
+  prefix: boolean;
+}
+
+export interface LogicalExpression extends BaseExpression {
+  type: "LogicalExpression";
+  operator: LogicalOperator;
+  left: Expression;
+  right: Expression;
+}
+
+export interface ConditionalExpression extends BaseExpression {
+  type: "ConditionalExpression";
+  test: Expression;
+  alternate: Expression;
+  consequent: Expression;
+}
+
+interface BaseCallExpression extends BaseExpression {
+  callee: Expression | Super;
+  arguments: Array<Expression | SpreadElement>;
+}
+export type CallExpression = SimpleCallExpression | NewExpression;
+
+export interface SimpleCallExpression extends BaseCallExpression {
+  type: "CallExpression";
+  optional: boolean;
+}
+
+export interface NewExpression extends BaseCallExpression {
+  type: "NewExpression";
+}
+
+export interface MemberExpression extends BaseExpression, BasePattern {
+  type: "MemberExpression";
+  object: Expression | Super;
+  property: Expression;
+  computed: boolean;
+  optional: boolean;
+}
+
+export type Pattern =
+    Identifier | ObjectPattern | ArrayPattern | RestElement |
+    AssignmentPattern | MemberExpression;
+
+// BOOKMARK(@littledivy): Had to manipulate estree source
+export interface BasePattern extends BaseNode { }
+
+export interface SwitchCase extends BaseNode {
+  type: "SwitchCase";
+  test?: Expression | null;
+  consequent: Array<Statement>;
+}
+
+export interface CatchClause extends BaseNode {
+  type: "CatchClause";
+  param: Pattern | null;
+  body: BlockStatement;
+}
+
+export interface Identifier extends BaseNode, BaseExpression, BasePattern {
+  type: "Identifier";
+  name: string;
+}
+
+export type Literal = SimpleLiteral | RegExpLiteral;
+
+export interface SimpleLiteral extends BaseNode, BaseExpression {
+  type: "Literal";
+  value: string | boolean | number | null;
+  raw?: string;
+}
+
+export interface RegExpLiteral extends BaseNode, BaseExpression {
+  type: "Literal";
+  value?: RegExp | null;
+  regex: {
+    pattern: string;
+    flags: string;
+  };
+  raw?: string;
+}
+
+export type UnaryOperator =
+    "-" | "+" | "!" | "~" | "typeof" | "void" | "delete";
+
+export type BinaryOperator =
+    "==" | "!=" | "===" | "!==" | "<" | "<=" | ">" | ">=" | "<<" |
+    ">>" | ">>>" | "+" | "-" | "*" | "/" | "%" | "**" | "|" | "^" | "&" | "in" |
+    "instanceof";
+
+export type LogicalOperator = "||" | "&&" | "??";
+
+export type AssignmentOperator =
+    "=" | "+=" | "-=" | "*=" | "/=" | "%=" | "**=" | "<<=" | ">>=" | ">>>=" |
+    "|=" | "^=" | "&=";
+
+export type UpdateOperator = "++" | "--";
+
+export interface ForOfStatement extends BaseForXStatement {
+  type: "ForOfStatement";
+  await: boolean;
+}
+
+export interface Super extends BaseNode {
+  type: "Super";
+}
+
+export interface SpreadElement extends BaseNode {
+  type: "SpreadElement";
+  argument: Expression;
+}
+
+export interface ArrowFunctionExpression extends BaseExpression, BaseFunction {
+  type: "ArrowFunctionExpression";
+  expression: boolean;
+  body: BlockStatement | Expression;
+}
+
+export interface YieldExpression extends BaseExpression {
+  type: "YieldExpression";
+  argument?: Expression | null;
+  delegate: boolean;
+}
+
+export interface TemplateLiteral extends BaseExpression {
+  type: "TemplateLiteral";
+  quasis: Array<TemplateElement>;
+  expressions: Array<Expression>;
+}
+
+export interface TaggedTemplateExpression extends BaseExpression {
+  type: "TaggedTemplateExpression";
+  tag: Expression;
+  quasi: TemplateLiteral;
+}
+
+export interface TemplateElement extends BaseNode {
+  type: "TemplateElement";
+  tail: boolean;
+  value: {
+    cooked: string;
+    raw: string;
+  };
+}
+
+export interface AssignmentProperty extends Property {
+  value: Pattern;
+  kind: "init";
+  method: boolean; // false
+}
+
+export interface ObjectPattern extends BasePattern {
+  type: "ObjectPattern";
+  properties: Array<AssignmentProperty | RestElement>;
+}
+
+export interface ArrayPattern extends BasePattern {
+  type: "ArrayPattern";
+  elements: Array<Pattern>;
+}
+
+export interface RestElement extends BasePattern {
+  type: "RestElement";
+  argument: Pattern;
+}
+
+export interface AssignmentPattern extends BasePattern {
+  type: "AssignmentPattern";
+  left: Pattern;
+  right: Expression;
+}
+
+export type Class = ClassDeclaration | ClassExpression;
+interface BaseClass extends BaseNode {
+  superClass?: Expression | null;
+  body: ClassBody;
+}
+
+export interface ClassBody extends BaseNode {
+  type: "ClassBody";
+  body: Array<MethodDefinition>;
+}
+
+export interface MethodDefinition extends BaseNode {
+  type: "MethodDefinition";
+  key: Expression;
+  value: FunctionExpression;
+  kind: "constructor" | "method" | "get" | "set";
+  computed: boolean;
+  static: boolean;
+}
+
+export interface ClassDeclaration extends BaseClass, BaseDeclaration {
+  type: "ClassDeclaration";
+  /** It is null when a class declaration is a part of the `export default class` statement */
+  id: Identifier | null;
+}
+
+export interface ClassExpression extends BaseClass, BaseExpression {
+  type: "ClassExpression";
+  id?: Identifier | null;
+}
+
+export interface MetaProperty extends BaseExpression {
+  type: "MetaProperty";
+  meta: Identifier;
+  property: Identifier;
+}
+
+export type ModuleDeclaration =
+    ImportDeclaration | ExportNamedDeclaration | ExportDefaultDeclaration |
+    ExportAllDeclaration;
+interface BaseModuleDeclaration extends BaseNode { }
+
+export type ModuleSpecifier =
+    ImportSpecifier | ImportDefaultSpecifier | ImportNamespaceSpecifier |
+    ExportSpecifier;
+interface BaseModuleSpecifier extends BaseNode {
+  local: Identifier;
+}
+
+export interface ImportDeclaration extends BaseModuleDeclaration {
+  type: "ImportDeclaration";
+  specifiers: Array<ImportSpecifier | ImportDefaultSpecifier | ImportNamespaceSpecifier>;
+  source: Literal;
+}
+
+export interface ImportSpecifier extends BaseModuleSpecifier {
+  type: "ImportSpecifier";
+  imported: Identifier;
+}
+
+export interface ImportExpression extends BaseExpression {
+  type: "ImportExpression";
+  source: Expression;
+}
+
+export interface ImportDefaultSpecifier extends BaseModuleSpecifier {
+  type: "ImportDefaultSpecifier";
+}
+
+export interface ImportNamespaceSpecifier extends BaseModuleSpecifier {
+  type: "ImportNamespaceSpecifier";
+}
+
+export interface ExportNamedDeclaration extends BaseModuleDeclaration {
+  type: "ExportNamedDeclaration";
+  declaration?: Declaration | null;
+  specifiers: Array<ExportSpecifier>;
+  source?: Literal | null;
+}
+
+export interface ExportSpecifier extends BaseModuleSpecifier {
+  type: "ExportSpecifier";
+  exported: Identifier;
+}
+
+export interface ExportDefaultDeclaration extends BaseModuleDeclaration {
+  type: "ExportDefaultDeclaration";
+  declaration: Declaration | Expression;
+}
+
+export interface ExportAllDeclaration extends BaseModuleDeclaration {
+  type: "ExportAllDeclaration";
+  source: Literal;
+}
+
+export interface AwaitExpression extends BaseExpression {
+  type: "AwaitExpression";
+  argument: Expression;
+}
diff --git a/import_map.json b/import_map.json
index 71a09da0dc..9eba665b4e 100644
--- a/import_map.json
+++ b/import_map.json
@@ -1,13 +1,14 @@
 {
    "imports": {
-      "acorn": "https://cdn.skypack.dev/acorn",
-      "estree": "https://cdn.skypack.dev/@types/estree?dts",
+      "acorn": "https://cdn.skypack.dev/acorn?dts",
+      "estree": "./estree.ts",
       "estree-walker": "https://cdn.skypack.dev/estree-walker",
-      "magic-string": "https://cdn.skypack.dev/magic-string",
-      "code-red": "https://cdn.skypack.dev/code-red",
+      "magic-string": "https://cdn.skypack.dev/magic-string?dts",
+      "code-red": "https://esm.sh/code-red",
       "is-reference": "https://cdn.skypack.dev/is-reference",
       "locate-character": "https://cdn.skypack.dev/locate-character",
       "periscopic": "https://cdn.skypack.dev/periscopic",
-      "css-tree": "https://esm.sh/css-tree@1.0.0-alpha22"
+      "css-tree": "https://esm.sh/css-tree@1.0.0-alpha22",
+      "events@3.2.0/": "https://esm.sh/events/"
    }
 }
diff --git a/src/compiler/Stats.ts b/src/compiler/Stats.ts
index 200fa448e9..bd04d2d929 100644
--- a/src/compiler/Stats.ts
+++ b/src/compiler/Stats.ts
@@ -1,9 +1,4 @@
-const now = (typeof process !== 'undefined' && process.hrtime)
-	? () => {
-		const t = process.hrtime();
-		return t[0] * 1e3 + t[1] / 1e6;
-	}
-	: () => self.performance.now();
+const now = performance.now;
 
 interface Timing {
 	label: string;
diff --git a/src/compiler/compile/Component.ts b/src/compiler/compile/Component.ts
index 16d814a1d4..ce60e1787f 100644
--- a/src/compiler/compile/Component.ts
+++ b/src/compiler/compile/Component.ts
@@ -123,9 +123,9 @@ export default class Component {
 
 		this.file =
 			compile_options.filename &&
-			(typeof process !== 'undefined'
+			(typeof Deno !== 'undefined'
 				? compile_options.filename
-					.replace(process.cwd(), '')
+					.replace(Deno.cwd(), '')
 					.replace(/^[/\\]/, '')
 				: compile_options.filename);
 		this.locate = getLocator(this.source, { offsetLine: 1 });
diff --git a/test/css/css_test.ts b/test/css/css_test.ts
new file mode 100644
index 0000000000..c461c6abca
--- /dev/null
+++ b/test/css/css_test.ts
@@ -0,0 +1,92 @@
+import * as svelte from '../../src/compiler/index.ts';
+import { assertEquals } from 'https://deno.land/std/testing/asserts.ts';
+async function try_require(file) {
+	try {
+		const mod = await import(file);
+		return mod.default || mod;
+	} catch (err) {
+		return null;
+	}
+}
+
+function normalize_warning(warning) {
+	warning.frame = warning.frame
+		.replace(/^\n/, '')
+		.replace(/^\t+/gm, '')
+		.replace(/\s+$/gm, '');
+	delete warning.filename;
+	delete warning.toString;
+	return warning;
+}
+
+	const __dirname = new URL('.', import.meta.url).pathname;
+	const files = Deno.readDirSync(`${__dirname}/samples`);
+	for (const dir of files) {
+
+		if (dir[0] === '.') continue;
+		// add .solo to a sample directory name to only run that test
+		const solo = /\.solo/.test(dir.name);
+		const skip = /\.skip/.test(dir.name);
+
+		if (solo && Deno.env.get("CI")) {
+			throw new Error('Forgot to remove `solo: true` from test');
+		}
+		Deno.test({ name: dir.name, only: skip, fn: async () => {
+				const config = await try_require(`./samples/${dir.name}/_config.js`) || {};
+				const input = Deno
+					.readTextFileSync(`${__dirname}/samples/${dir.name}/input.svelte`)
+					.replace(/\s+$/, '')
+					.replace(/\r/g, '');
+
+				const expected_warnings = (config.warnings || []).map(normalize_warning);
+
+				const dom = svelte.compile(
+					input,
+					Object.assign(config.compileOptions || {}, { format: 'cjs' })
+				);
+
+				const ssr = svelte.compile(
+					input,
+					Object.assign(config.compileOptions || {}, { format: 'cjs', generate: 'ssr' })
+				);
+
+				assertEquals(dom.css.code, ssr.css.code);
+
+				const dom_warnings = dom.warnings.map(normalize_warning);
+				const ssr_warnings = ssr.warnings.map(normalize_warning);
+
+				assertEquals(dom_warnings, ssr_warnings);
+				assertEquals(dom_warnings.map(normalize_warning), expected_warnings);
+
+				await Deno.writeTextFile(`${__dirname}/samples/${dir.name}/_actual.css`, dom.css.code);
+				const expected = {
+					html: read(`${__dirname}/samples/${dir.name}/expected.html`),
+					css: read(`${__dirname}/samples/${dir.name}/expected.css`)
+				};
+
+				const actual_css = dom.css.code.replace(/svelte(-ref)?-[a-z0-9]+/g, (m, $1) => $1 ? m : 'svelte-xyz');
+				try {
+					assertEquals(actual_css, expected.css);
+				} catch (error) {
+					if (shouldUpdateExpected()) {
+						await Deno.writeTextFile(`${__dirname}/samples/${dir}/expected.css`, actual_css);
+						console.log(`Updated ${dir}/expected.css.`);
+					} else {
+						throw error;
+					}
+				}
+		}})
+
+}
+
+function shouldUpdateExpected() {
+	return Deno.args.includes('--update');
+}
+
+function read(file) {
+	try {
+		return Deno.readTextFileSync(file);
+	} catch (err) {
+		return null;
+	}
+}
diff --git a/test/css/index.ts b/test/css/index.ts
deleted file mode 100644
index 65b43322b1..0000000000
--- a/test/css/index.ts
+++ /dev/null
@@ -1,159 +0,0 @@
-import * as fs from 'fs';
-import { assert, env, svelte, setupHtmlEqual, shouldUpdateExpected } from '../helpers';
-
-function try_require(file) {
-	try {
-		const mod = require(file);
-		return mod.default || mod;
-	} catch (err) {
-		if (err.code !== 'MODULE_NOT_FOUND') throw err;
-		return null;
-	}
-}
-
-function normalize_warning(warning) {
-	warning.frame = warning.frame
-		.replace(/^\n/, '')
-		.replace(/^\t+/gm, '')
-		.replace(/\s+$/gm, '');
-	delete warning.filename;
-	delete warning.toString;
-	return warning;
-}
-
-function create(code) {
-	const fn = new Function('module', 'exports', 'require', code);
-
-	const module = { exports: {} };
-	fn(module, module.exports, id => {
-		if (id === 'svelte') return require('../../index.js');
-		if (id.startsWith('svelte/')) return require(id.replace('svelte', '../../'));
-
-		return require(id);
-	});
-
-	return module.exports.default;
-}
-
-describe('css', () => {
-	before(() => {
-		setupHtmlEqual();
-	});
-
-	fs.readdirSync(`${__dirname}/samples`).forEach(dir => {
-		if (dir[0] === '.') return;
-
-		// add .solo to a sample directory name to only run that test
-		const solo = /\.solo/.test(dir);
-		const skip = /\.skip/.test(dir);
-
-		if (solo && process.env.CI) {
-			throw new Error('Forgot to remove `solo: true` from test');
-		}
-
-		(solo ? it.only : skip ? it.skip : it)(dir, () => {
-			const config = try_require(`./samples/${dir}/_config.js`) || {};
-			const input = fs
-				.readFileSync(`${__dirname}/samples/${dir}/input.svelte`, 'utf-8')
-				.replace(/\s+$/, '')
-				.replace(/\r/g, '');
-
-			const expected_warnings = (config.warnings || []).map(normalize_warning);
-
-			const dom = svelte.compile(
-				input,
-				Object.assign(config.compileOptions || {}, { format: 'cjs' })
-			);
-
-			const ssr = svelte.compile(
-				input,
-				Object.assign(config.compileOptions || {}, { format: 'cjs', generate: 'ssr' })
-			);
-
-			assert.equal(dom.css.code, ssr.css.code);
-
-			const dom_warnings = dom.warnings.map(normalize_warning);
-			const ssr_warnings = ssr.warnings.map(normalize_warning);
-
-			assert.deepEqual(dom_warnings, ssr_warnings);
-			assert.deepEqual(dom_warnings.map(normalize_warning), expected_warnings);
-
-			fs.writeFileSync(`${__dirname}/samples/${dir}/_actual.css`, dom.css.code);
-			const expected = {
-				html: read(`${__dirname}/samples/${dir}/expected.html`),
-				css: read(`${__dirname}/samples/${dir}/expected.css`)
-			};
-
-			const actual_css = dom.css.code.replace(/svelte(-ref)?-[a-z0-9]+/g, (m, $1) => $1 ? m : 'svelte-xyz');
-			try {
-				assert.equal(actual_css, expected.css);
-			} catch (error) {
-				if (shouldUpdateExpected()) {
-					fs.writeFileSync(`${__dirname}/samples/${dir}/expected.css`, actual_css);
-					console.log(`Updated ${dir}/expected.css.`);
-				} else {
-					throw error;
-				}
-			}
-
-			let ClientComponent;
-			let ServerComponent;
-
-			// we do this here, rather than in the expected.html !== null
-			// block, to verify that valid code was generated
-			try {
-				ClientComponent = create(dom.js.code);
-			} catch (err) {
-				console.log(dom.js.code);
-				throw err;
-			}
-
-			try {
-				ServerComponent = create(ssr.js.code);
-			} catch (err) {
-				console.log(dom.js.code);
-				throw err;
-			}
-
-			// verify that the right elements have scoping selectors
-			if (expected.html !== null) {
-				const window = env();
-
-				// dom
-				try {
-					const target = window.document.querySelector('main');
-
-					new ClientComponent({ target, props: config.props });
-					const html = target.innerHTML;
-
-					fs.writeFileSync(`${__dirname}/samples/${dir}/_actual.html`, html);
-
-					const actual_html = html.replace(/svelte(-ref)?-[a-z0-9]+/g, (m, $1) => $1 ? m : 'svelte-xyz');
-					assert.htmlEqual(actual_html, expected.html);
-
-					window.document.head.innerHTML = ''; // remove added styles
-				} catch (err) {
-					console.log(dom.js.code);
-					throw err;
-				}
-
-				// ssr
-				try {
-					const actual_ssr = ServerComponent.render(config.props).html.replace(/svelte(-ref)?-[a-z0-9]+/g, (m, $1) => $1 ? m : 'svelte-xyz');
-					assert.htmlEqual(actual_ssr, expected.html);
-				} catch (err) {
-					console.log(ssr.js.code);
-					throw err;
-				}
-			}
-		});
-	});
-});
-
-function read(file) {
-	try {
-		return fs.readFileSync(file, 'utf-8');
-	} catch (err) {
-		return null;
-	}
-}
diff --git a/test/helpers.ts b/test/helpers.js
similarity index 89%
rename from test/helpers.ts
rename to test/helpers.js
index 78f000c274..a6f708355c 100644
--- a/test/helpers.ts
+++ b/test/helpers.js
@@ -1,23 +1,13 @@
-import * as assert$1 from 'assert';
-import * as jsdom from 'jsdom';
-import glob from 'tiny-glob/sync';
-import * as path from 'path';
-import * as fs from 'fs';
-import * as colors from 'kleur';
-export const assert = (assert$1 as unknown) as typeof assert$1 & { htmlEqual: (actual, expected, message?) => void };
-
-// for coverage purposes, we need to test source files,
-// but for sanity purposes, we need to test dist files
-export function loadSvelte(test) {
-	process.env.TEST = test ? 'true' : '';
-
-	const resolved = require.resolve('../compiler.js');
-
-	delete require.cache[resolved];
-	return require(resolved);
-}
+import * as assert from 'https://esm.sh/assert';
+import * as jsdom from 'https://esm.sh/jsdom';
+import glob from 'https://esm.sh/tiny-glob/sync';
+import * as path from 'https://deno.land/std@0.75.0/node/path.ts';
+import * as fs from 'https://deno.land/std@0.75.0/node/fs.ts';
+import * as colors from 'https://esm.sh/kleur';
+// @ts-ignore
+import * as svelte from "../src/compiler/index.ts";
+
 
-export const svelte = loadSvelte();
 
 export function exists(path) {
 	try {
diff --git a/tsconfig.json b/tsconfig.json
index 39476f3dd1..aed65f55c4 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,27 +2,9 @@
 	"include": [],
 
 	"compilerOptions": {
-		"rootDir": "src",
-
-		// target node v8+ (https://node.green/)
-		// the only missing feature is Array.prototype.values
-		"lib": ["es2017"],
-		"target": "es2017",
-
-		"declaration": true,
-		"declarationDir": "types",
-
-		"noEmitOnError": true,
 		"noErrorTruncation": true,
-
-		// rollup takes care of these
-		"module": "esnext",
-		"moduleResolution": "node",
-		"resolveJsonModule": true,
-		"allowSyntheticDefaultImports": true,
-
 		// TODO: error all the things
-		//"strict": true,
+		"strict": false,
 		"noImplicitThis": true,
 		"noUnusedLocals": true,
 		"noUnusedParameters": true