diff --git a/.gitignore b/.gitignore
index 7aa75b29f4..3d1322c33e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+.idea
 .DS_Store
 .nyc_output
 node_modules
diff --git a/package-lock.json b/package-lock.json
index 28ecb0eedb..f87b3610df 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "svelte",
-  "version": "3.4.1",
+  "version": "3.4.2",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -4179,9 +4179,9 @@
       "dev": true
     },
     "typescript": {
-      "version": "3.2.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.2.4.tgz",
-      "integrity": "sha512-0RNDbSdEokBeEAkgNbxJ+BLwSManFy9TeXz8uW+48j/xhEXv1ePME60olyzw2XzUqUBNAYFeJadIqAgNqIACwg==",
+      "version": "3.4.5",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.4.5.tgz",
+      "integrity": "sha512-YycBxUb49UUhdNMU5aJ7z5Ej2XGmaIBL0x34vZ82fn3hGvD+bgrMrVDpatgz2f7YxUMJxMkbWxJZeAvDxVe7Vw==",
       "dev": true
     },
     "uglify-js": {
diff --git a/package.json b/package.json
index 90ec6d27ec..b32e19786f 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,8 @@
     "pretest": "npm run build",
     "posttest": "agadoo src/internal/index.js",
     "prepublishOnly": "export PUBLISH=true && npm run lint && npm test",
-    "tsd": "tsc -d src/store.ts --outDir ."
+    "tsd": "tsc -d src/store.ts --outDir .",
+    "typecheck": "tsc --noEmit"
   },
   "repository": {
     "type": "git",
@@ -84,7 +85,7 @@
     "tiny-glob": "^0.2.1",
     "ts-node": "^8.0.2",
     "tslib": "^1.8.0",
-    "typescript": "^3.0.1"
+    "typescript": "^3.4.0"
   },
   "nyc": {
     "include": [
diff --git a/src/compile/Component.ts b/src/compile/Component.ts
index a429db41f6..a8145e6b2c 100644
--- a/src/compile/Component.ts
+++ b/src/compile/Component.ts
@@ -1,4 +1,5 @@
 import MagicString, { Bundle } from 'magic-string';
+// @ts-ignore
 import { walk, childKeys } from 'estree-walker';
 import { getLocator } from 'locate-character';
 import Stats from '../Stats';
@@ -21,6 +22,7 @@ import { remove_indentation, add_indentation } from '../utils/indentation';
 import get_object from './utils/get_object';
 import unwrap_parens from './utils/unwrap_parens';
 import Slot from './nodes/Slot';
+import { Node as ESTreeNode } from 'estree';
 
 type ComponentOptions = {
 	namespace?: string;
@@ -758,7 +760,7 @@ export default class Component {
 					});
 				}
 
-				if (is_reference(node, parent)) {
+				if (is_reference(node as ESTreeNode, parent as ESTreeNode)) {
 					const object = get_object(node);
 					const { name } = object;
 
@@ -776,7 +778,7 @@ export default class Component {
 		});
 	}
 
-	invalidate(name, value) {
+	invalidate(name, value?) {
 		const variable = this.var_lookup.get(name);
 
 		if (variable && (variable.subscribable && variable.reassigned)) {
@@ -1022,7 +1024,7 @@ export default class Component {
 						scope = map.get(node);
 					}
 
-					if (is_reference(node, parent)) {
+					if (is_reference(node as ESTreeNode, parent as ESTreeNode)) {
 						const { name } = flatten_reference(node);
 						const owner = scope.find_owner(name);
 
@@ -1113,7 +1115,7 @@ export default class Component {
 						} else if (node.type === 'UpdateExpression') {
 							const identifier = get_object(node.argument);
 							assignees.add(identifier.name);
-						} else if (is_reference(node, parent)) {
+						} else if (is_reference(node as ESTreeNode, parent as ESTreeNode)) {
 							const identifier = get_object(node);
 							if (!assignee_nodes.has(identifier)) {
 								const { name } = identifier;
diff --git a/src/compile/index.ts b/src/compile/index.ts
index e80a937932..526d8abaeb 100644
--- a/src/compile/index.ts
+++ b/src/compile/index.ts
@@ -55,7 +55,7 @@ function validate_options(options: CompileOptions, warnings: Warning[]) {
 	}
 }
 
-function get_name(filename) {
+function get_name(filename: string) {
 	if (!filename) return null;
 	const parts = filename.split(/[\/\\]/);
 
@@ -105,4 +105,4 @@ export default function compile(source: string, options: CompileOptions = {}) {
 			: render_dom(component, options);
 
 	return component.generate(js);
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/Attribute.ts b/src/compile/nodes/Attribute.ts
index c07960ce47..0b2d3a3700 100644
--- a/src/compile/nodes/Attribute.ts
+++ b/src/compile/nodes/Attribute.ts
@@ -67,6 +67,7 @@ export default class Attribute extends Node {
 
 			this.should_cache = this.is_dynamic
 				? this.chunks.length === 1
+					// @ts-ignore todo: probably error
 					? this.chunks[0].node.type !== 'Identifier' || scope.names.has(this.chunks[0].node.name)
 					: true
 				: false;
@@ -91,8 +92,10 @@ export default class Attribute extends Node {
 		if (this.chunks.length === 0) return `""`;
 
 		if (this.chunks.length === 1) {
+
 			return this.chunks[0].type === 'Text'
-				? stringify(this.chunks[0].data)
+				? stringify((this.chunks[0] as Text).data)
+				// @ts-ignore todo: probably error
 				: this.chunks[0].render(block);
 		}
 
@@ -102,6 +105,7 @@ export default class Attribute extends Node {
 					if (chunk.type === 'Text') {
 						return stringify(chunk.data);
 					} else {
+						// @ts-ignore todo: probably error
 						return chunk.get_precedence() <= 13 ? `(${chunk.render()})` : chunk.render();
 					}
 				})
@@ -114,7 +118,8 @@ export default class Attribute extends Node {
 		return this.is_true
 			? true
 			: this.chunks[0]
-				? this.chunks[0].data
+				// method should be called only when `is_static = true`
+				? (this.chunks[0] as Text).data
 				: '';
 	}
 }
diff --git a/src/compile/nodes/AwaitBlock.ts b/src/compile/nodes/AwaitBlock.ts
index f8e6896b5d..cd57750d29 100644
--- a/src/compile/nodes/AwaitBlock.ts
+++ b/src/compile/nodes/AwaitBlock.ts
@@ -5,6 +5,7 @@ import CatchBlock from './CatchBlock';
 import Expression from './shared/Expression';
 
 export default class AwaitBlock extends Node {
+	type: 'AwaitBlock';
 	expression: Expression;
 	value: string;
 	error: string;
diff --git a/src/compile/nodes/Binding.ts b/src/compile/nodes/Binding.ts
index b03eba0c36..0d666a543f 100644
--- a/src/compile/nodes/Binding.ts
+++ b/src/compile/nodes/Binding.ts
@@ -5,6 +5,7 @@ import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
 
 export default class Binding extends Node {
+	type: 'Binding';
 	name: string;
 	expression: Expression;
 	is_contextual: boolean;
diff --git a/src/compile/nodes/CatchBlock.ts b/src/compile/nodes/CatchBlock.ts
index 23c08a494c..0edc0f76d8 100644
--- a/src/compile/nodes/CatchBlock.ts
+++ b/src/compile/nodes/CatchBlock.ts
@@ -3,6 +3,7 @@ import TemplateScope from './shared/TemplateScope';
 import AbstractBlock from './shared/AbstractBlock';
 
 export default class CatchBlock extends AbstractBlock {
+	type: 'CatchBlock';
 	scope: TemplateScope;
 
 	constructor(component, parent, scope, info) {
diff --git a/src/compile/nodes/DebugTag.ts b/src/compile/nodes/DebugTag.ts
index 4d2c3f6ae4..0fbfa592ad 100644
--- a/src/compile/nodes/DebugTag.ts
+++ b/src/compile/nodes/DebugTag.ts
@@ -2,6 +2,7 @@ import Node from './shared/Node';
 import Expression from './shared/Expression';
 
 export default class DebugTag extends Node {
+	type: 'DebugTag';
 	expressions: Expression[];
 
 	constructor(component, parent, scope, info) {
@@ -11,4 +12,4 @@ export default class DebugTag extends Node {
 			return new Expression(component, parent, scope, node);
 		});
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/EachBlock.ts b/src/compile/nodes/EachBlock.ts
index b58c023ac9..2f18373137 100644
--- a/src/compile/nodes/EachBlock.ts
+++ b/src/compile/nodes/EachBlock.ts
@@ -6,8 +6,15 @@ import TemplateScope from './shared/TemplateScope';
 import AbstractBlock from './shared/AbstractBlock';
 import { Node as INode } from '../../interfaces';
 import { new_tail } from '../utils/tail';
+import Element from './Element';
 
-function unpack_destructuring(contexts: Array<{ name: string, tail: string }>, node: INode, tail: string) {
+type Context = {
+	key: INode,
+	name?: string,
+	tail: string
+};
+
+function unpack_destructuring(contexts: Array<Context>, node: INode, tail: string) {
 	if (!node) return;
 
 	if (node.type === 'Identifier' || node.type === 'RestIdentifier') {
@@ -53,7 +60,7 @@ export default class EachBlock extends AbstractBlock {
 	context: string;
 	key: Expression;
 	scope: TemplateScope;
-	contexts: Array<{ name: string, tail: string }>;
+	contexts: Array<Context>;
 	has_animation: boolean;
 	has_binding = false;
 
@@ -82,7 +89,7 @@ export default class EachBlock extends AbstractBlock {
 
 		if (this.index) {
 			// index can only change if this is a keyed each block
-			const dependencies = this.key ? this.expression.dependencies : [];
+			const dependencies = this.key ? this.expression.dependencies : new Set([]);
 			this.scope.add(this.index, dependencies, this);
 		}
 
@@ -92,8 +99,8 @@ export default class EachBlock extends AbstractBlock {
 
 		if (this.has_animation) {
 			if (this.children.length !== 1) {
-				const child = this.children.find(child => !!child.animation);
-				component.error(child.animation, {
+				const child = this.children.find(child => !!(child as Element).animation);
+				component.error((child as Element).animation, {
 					code: `invalid-animation`,
 					message: `An element that use the animate directive must be the sole child of a keyed each block`
 				});
diff --git a/src/compile/nodes/Element.ts b/src/compile/nodes/Element.ts
index 2b76d68e6d..1b2d82188c 100644
--- a/src/compile/nodes/Element.ts
+++ b/src/compile/nodes/Element.ts
@@ -15,6 +15,7 @@ import fuzzymatch from '../../utils/fuzzymatch';
 import list from '../../utils/list';
 import Let from './Let';
 import TemplateScope from './shared/TemplateScope';
+import { INode } from './interfaces';
 
 const svg = /^(?:altGlyph|altGlyphDef|altGlyphItem|animate|animateColor|animateMotion|animateTransform|circle|clipPath|color-profile|cursor|defs|desc|discard|ellipse|feBlend|feColorMatrix|feComponentTransfer|feComposite|feConvolveMatrix|feDiffuseLighting|feDisplacementMap|feDistantLight|feDropShadow|feFlood|feFuncA|feFuncB|feFuncG|feFuncR|feGaussianBlur|feImage|feMerge|feMergeNode|feMorphology|feOffset|fePointLight|feSpecularLighting|feSpotLight|feTile|feTurbulence|filter|font|font-face|font-face-format|font-face-name|font-face-src|font-face-uri|foreignObject|g|glyph|glyphRef|hatch|hatchpath|hkern|image|line|linearGradient|marker|mask|mesh|meshgradient|meshpatch|meshrow|metadata|missing-glyph|mpath|path|pattern|polygon|polyline|radialGradient|rect|set|solidcolor|stop|svg|switch|symbol|text|textPath|tref|tspan|unknown|use|view|vkern)$/;
 
@@ -101,7 +102,7 @@ export default class Element extends Node {
 	intro?: Transition = null;
 	outro?: Transition = null;
 	animation?: Animation = null;
-	children: Node[];
+	children: INode[];
 	namespace: string;
 
 	constructor(component, parent, scope, info: any) {
@@ -136,7 +137,7 @@ export default class Element extends Node {
 			// Special case — treat these the same way:
 			//   <option>{foo}</option>
 			//   <option value={foo}>{foo}</option>
-			const value_attribute = info.attributes.find((attribute: Node) => attribute.name === 'value');
+			const value_attribute = info.attributes.find(attribute => attribute.name === 'value');
 
 			if (!value_attribute) {
 				info.attributes.push({
@@ -228,7 +229,7 @@ export default class Element extends Node {
 			let is_figure_parent = false;
 
 			while (parent) {
-				if (parent.name === 'figure') {
+				if ((parent as Element).name === 'figure') {
 					is_figure_parent = true;
 					break;
 				}
@@ -253,7 +254,7 @@ export default class Element extends Node {
 				return true;
 			});
 
-			const index = children.findIndex(child => child.name === 'figcaption');
+			const index = children.findIndex(child => (child as Element).name === 'figcaption');
 
 			if (index !== -1 && (index !== 0 && index !== children.length - 1)) {
 				this.component.warn(children[index], {
@@ -320,7 +321,9 @@ export default class Element extends Node {
 				}
 
 				const value = attribute.get_static_value();
+				// @ts-ignore
 				if (value && !aria_role_set.has(value)) {
+					// @ts-ignore
 					const match = fuzzymatch(value, aria_roles);
 					let message = `A11y: Unknown role '${value}'`;
 					if (match) message += ` (did you mean '${match}'?)`;
@@ -359,6 +362,7 @@ export default class Element extends Node {
 			// tabindex-no-positive
 			if (name === 'tabindex') {
 				const value = attribute.get_static_value();
+				// @ts-ignore todo is tabindex=true correct case?
 				if (!isNaN(value) && +value > 0) {
 					component.warn(attribute, {
 						code: `a11y-positive-tabindex`,
diff --git a/src/compile/nodes/ElseBlock.ts b/src/compile/nodes/ElseBlock.ts
index 61c1aa5455..5f3aa29529 100644
--- a/src/compile/nodes/ElseBlock.ts
+++ b/src/compile/nodes/ElseBlock.ts
@@ -1,10 +1,11 @@
 import map_children from './shared/map_children';
 import AbstractBlock from './shared/AbstractBlock';
+import Component from '../Component';
 
 export default class ElseBlock extends AbstractBlock {
 	type: 'ElseBlock';
 
-	constructor(component, parent, scope, info) {
+	constructor(component: Component, parent, scope, info) {
 		super(component, parent, scope, info);
 		this.children = map_children(component, this, scope, info.children);
 
diff --git a/src/compile/nodes/EventHandler.ts b/src/compile/nodes/EventHandler.ts
index f5e7e0e898..dab60858d5 100644
--- a/src/compile/nodes/EventHandler.ts
+++ b/src/compile/nodes/EventHandler.ts
@@ -5,6 +5,7 @@ import deindent from '../utils/deindent';
 import Block from '../render-dom/Block';
 
 export default class EventHandler extends Node {
+	type: 'EventHandler';
 	name: string;
 	modifiers: Set<string>;
 	expression: Expression;
@@ -65,4 +66,4 @@ export default class EventHandler extends Node {
 		// this.component.add_reference(this.handler_name);
 		return `ctx.${this.handler_name}`;
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/Fragment.ts b/src/compile/nodes/Fragment.ts
index ec25d41a1c..6025b036a6 100644
--- a/src/compile/nodes/Fragment.ts
+++ b/src/compile/nodes/Fragment.ts
@@ -3,10 +3,12 @@ import Component from '../Component';
 import map_children from './shared/map_children';
 import Block from '../render-dom/Block';
 import TemplateScope from './shared/TemplateScope';
+import { INode } from './interfaces';
 
 export default class Fragment extends Node {
+	type: 'Fragment';
 	block: Block;
-	children: Node[];
+	children: INode[];
 	scope: TemplateScope;
 
 	constructor(component: Component, info: any) {
@@ -16,4 +18,4 @@ export default class Fragment extends Node {
 		this.scope = scope;
 		this.children = map_children(component, this, scope, info.children);
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/Head.ts b/src/compile/nodes/Head.ts
index bc6e9bde40..2c08dcd595 100644
--- a/src/compile/nodes/Head.ts
+++ b/src/compile/nodes/Head.ts
@@ -1,5 +1,4 @@
 import Node from './shared/Node';
-import Block from '../render-dom/Block';
 import map_children from './shared/map_children';
 
 export default class Head extends Node {
diff --git a/src/compile/nodes/InlineComponent.ts b/src/compile/nodes/InlineComponent.ts
index 3359e981ed..8b6cd77282 100644
--- a/src/compile/nodes/InlineComponent.ts
+++ b/src/compile/nodes/InlineComponent.ts
@@ -7,6 +7,7 @@ import Expression from './shared/Expression';
 import Component from '../Component';
 import Let from './Let';
 import TemplateScope from './shared/TemplateScope';
+import { INode } from './interfaces';
 
 export default class InlineComponent extends Node {
 	type: 'InlineComponent';
@@ -16,7 +17,7 @@ export default class InlineComponent extends Node {
 	bindings: Binding[] = [];
 	handlers: EventHandler[] = [];
 	lets: Let[] = [];
-	children: Node[];
+	children: INode[];
 	scope: TemplateScope;
 
 	constructor(component: Component, parent, scope, info) {
diff --git a/src/compile/nodes/MustacheTag.ts b/src/compile/nodes/MustacheTag.ts
index e668987a9c..ac6688d503 100644
--- a/src/compile/nodes/MustacheTag.ts
+++ b/src/compile/nodes/MustacheTag.ts
@@ -1,3 +1,5 @@
 import Tag from './shared/Tag';
 
-export default class MustacheTag extends Tag {}
\ No newline at end of file
+export default class MustacheTag extends Tag {
+	type: 'MustacheTag';
+}
diff --git a/src/compile/nodes/PendingBlock.ts b/src/compile/nodes/PendingBlock.ts
index 0fd71c0221..5ff7352558 100644
--- a/src/compile/nodes/PendingBlock.ts
+++ b/src/compile/nodes/PendingBlock.ts
@@ -2,7 +2,7 @@ import map_children from './shared/map_children';
 import AbstractBlock from './shared/AbstractBlock';
 
 export default class PendingBlock extends AbstractBlock {
-
+  type: 'PendingBlock';
 	constructor(component, parent, scope, info) {
 		super(component, parent, scope, info);
 		this.children = map_children(component, parent, scope, info.children);
diff --git a/src/compile/nodes/RawMustacheTag.ts b/src/compile/nodes/RawMustacheTag.ts
index ada3123410..fc63885942 100644
--- a/src/compile/nodes/RawMustacheTag.ts
+++ b/src/compile/nodes/RawMustacheTag.ts
@@ -1,3 +1,5 @@
 import Tag from './shared/Tag';
 
-export default class RawMustacheTag extends Tag {}
\ No newline at end of file
+export default class RawMustacheTag extends Tag {
+	type: 'RawMustacheTag'
+}
diff --git a/src/compile/nodes/Slot.ts b/src/compile/nodes/Slot.ts
index dbb502b41a..a03fe8c026 100644
--- a/src/compile/nodes/Slot.ts
+++ b/src/compile/nodes/Slot.ts
@@ -1,17 +1,17 @@
-import Node from './shared/Node';
 import Element from './Element';
 import Attribute from './Attribute';
 import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
+import { INode } from './interfaces';
 
 export default class Slot extends Element {
 	type: 'Element';
 	name: string;
-	children: Node[];
+	children: INode[];
 	slot_name: string;
 	values: Map<string, Attribute> = new Map();
 
-	constructor(component: Component, parent: Node, scope: TemplateScope, info: any) {
+	constructor(component: Component, parent: INode, scope: TemplateScope, info: any) {
 		super(component, parent, scope, info);
 
 		info.attributes.forEach(attr => {
@@ -68,4 +68,4 @@ export default class Slot extends Element {
 
 		component.slots.set(this.slot_name, this);
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/Text.ts b/src/compile/nodes/Text.ts
index 1c31c9d83d..7500f5ff30 100644
--- a/src/compile/nodes/Text.ts
+++ b/src/compile/nodes/Text.ts
@@ -1,13 +1,14 @@
 import Node from './shared/Node';
 import Component from '../Component';
 import TemplateScope from './shared/TemplateScope';
+import { INode } from './interfaces';
 
 export default class Text extends Node {
 	type: 'Text';
 	data: string;
 	use_space = false;
 
-	constructor(component: Component, parent: Node, scope: TemplateScope, info: any) {
+	constructor(component: Component, parent: INode, scope: TemplateScope, info: any) {
 		super(component, parent, scope, info);
 		this.data = info.data;
 
@@ -23,4 +24,4 @@ export default class Text extends Node {
 			this.use_space = true;
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/ThenBlock.ts b/src/compile/nodes/ThenBlock.ts
index 7e4ed0e5da..7f9bbde0f0 100644
--- a/src/compile/nodes/ThenBlock.ts
+++ b/src/compile/nodes/ThenBlock.ts
@@ -3,6 +3,7 @@ import TemplateScope from './shared/TemplateScope';
 import AbstractBlock from './shared/AbstractBlock';
 
 export default class ThenBlock extends AbstractBlock {
+	type: 'ThenBlock';
 	scope: TemplateScope;
 
 	constructor(component, parent, scope, info) {
diff --git a/src/compile/nodes/Title.ts b/src/compile/nodes/Title.ts
index fd58d3043d..6ac0848053 100644
--- a/src/compile/nodes/Title.ts
+++ b/src/compile/nodes/Title.ts
@@ -1,12 +1,13 @@
 import Node from './shared/Node';
-import map_children from './shared/map_children';
+import map_children, { Children } from './shared/map_children';
+import Component from '../Component';
 
 export default class Title extends Node {
 	type: 'Title';
-	children: any[]; // TODO
+	children: Children;
 	should_cache: boolean;
 
-	constructor(component, parent, scope, info) {
+	constructor(component: Component, parent, scope, info) {
 		super(component, parent, scope, info);
 		this.children = map_children(component, parent, scope, info.children);
 
@@ -33,4 +34,4 @@ export default class Title extends Node {
 			)
 			: true;
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/interfaces.ts b/src/compile/nodes/interfaces.ts
new file mode 100644
index 0000000000..434b09e5aa
--- /dev/null
+++ b/src/compile/nodes/interfaces.ts
@@ -0,0 +1,64 @@
+import Tag from './shared/Tag';
+
+import Action from './Action';
+import Animation from './Animation';
+import Attribute from './Attribute';
+import AwaitBlock from './AwaitBlock';
+import Binding from './Binding';
+import Body from './Body';
+import CatchBlock from './CatchBlock';
+import Class from './Class';
+import Comment from './Comment';
+import DebugTag from './DebugTag';
+import EachBlock from './EachBlock';
+import Element from './Element';
+import ElseBlock from './ElseBlock';
+import EventHandler from './EventHandler';
+import Fragment from './Fragment';
+import Head from './Head';
+import IfBlock from './IfBlock';
+import InlineComponent from './InlineComponent';
+import Let from './Let';
+import MustacheTag from './MustacheTag';
+import Options from './Options';
+import PendingBlock from './PendingBlock';
+import RawMustacheTag from './RawMustacheTag';
+import Slot from './Slot';
+import Text from './Text';
+import ThenBlock from './ThenBlock';
+import Title from './Title';
+import Transition from './Transition';
+import Window from './Window';
+
+// note: to write less types each of types in union below should have type defined as literal
+// https://www.typescriptlang.org/docs/handbook/advanced-types.html#discriminated-unions
+export type INode = Action
+ | Animation
+ | Attribute
+ | AwaitBlock
+ | Binding
+ | Body
+ | CatchBlock
+ | Class
+ | Comment
+ | DebugTag
+ | EachBlock
+ | Element
+ | ElseBlock
+ | EventHandler
+ | Fragment
+ | Head
+ | IfBlock
+ | InlineComponent
+ | Let
+ | MustacheTag
+ | Options
+ | PendingBlock
+ | RawMustacheTag
+ | Slot
+ | Tag
+ | Text
+ | ThenBlock
+ | Title
+ | Transition
+ | Window;
diff --git a/src/compile/nodes/shared/AbstractBlock.ts b/src/compile/nodes/shared/AbstractBlock.ts
index 1dfebd51f0..e1104e4928 100644
--- a/src/compile/nodes/shared/AbstractBlock.ts
+++ b/src/compile/nodes/shared/AbstractBlock.ts
@@ -1,10 +1,11 @@
 import Block from '../../render-dom/Block';
 import Component from './../../Component';
 import Node from './Node';
+import { INode } from '../interfaces';
 
 export default class AbstractBlock extends Node {
 	block: Block;
-	children: Node[];
+	children: INode[];
 
 	constructor(component: Component, parent, scope, info: any) {
 		super(component, parent, scope, info);
diff --git a/src/compile/nodes/shared/Expression.ts b/src/compile/nodes/shared/Expression.ts
index fc188e9673..e7c63dfec2 100644
--- a/src/compile/nodes/shared/Expression.ts
+++ b/src/compile/nodes/shared/Expression.ts
@@ -12,6 +12,7 @@ import TemplateScope from './TemplateScope';
 import get_object from '../../utils/get_object';
 import { nodes_match } from '../../../utils/nodes_match';
 import Block from '../../render-dom/Block';
+import { INode } from '../interfaces';
 
 const binary_operators: Record<string, number> = {
 	'**': 15,
@@ -61,10 +62,12 @@ const precedence: Record<string, (node?: Node) => number> = {
 	SequenceExpression: () => 0
 };
 
+type Owner = Wrapper | INode;
+
 export default class Expression {
-	type = 'Expression';
+	type: 'Expression' = 'Expression';
 	component: Component;
-	owner: Wrapper;
+	owner: Owner;
 	node: any;
 	snippet: string;
 	references: Set<string>;
@@ -81,7 +84,8 @@ export default class Expression {
 
 	rendered: string;
 
-	constructor(component: Component, owner: Wrapper, template_scope: TemplateScope, info) {
+	// todo: owner type
+	constructor(component: Component, owner: Owner, template_scope: TemplateScope, info) {
 		// TODO revert to direct property access in prod?
 		Object.defineProperties(this, {
 			component: {
@@ -92,6 +96,7 @@ export default class Expression {
 		this.node = info;
 		this.template_scope = template_scope;
 		this.owner = owner;
+		// @ts-ignore
 		this.is_synthetic = owner.is_synthetic;
 
 		const { dependencies, contextual_dependencies } = this;
@@ -218,7 +223,7 @@ export default class Expression {
 	}
 
 	// TODO move this into a render-dom wrapper?
-	render(block: Block) {
+	render(block?: Block) {
 		if (this.rendered) return this.rendered;
 
 		const {
@@ -510,4 +515,4 @@ function is_contextual(component: Component, scope: TemplateScope, name: string)
 
 	// assume contextual
 	return true;
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/shared/Node.ts b/src/compile/nodes/shared/Node.ts
index b6eaf9965d..b647e3a158 100644
--- a/src/compile/nodes/shared/Node.ts
+++ b/src/compile/nodes/shared/Node.ts
@@ -1,15 +1,17 @@
 import Attribute from './../Attribute';
 import Component from './../../Component';
+import { INode } from '../interfaces';
+import Text from '../Text';
 
 export default class Node {
 	readonly start: number;
 	readonly end: number;
 	readonly component: Component;
-	readonly parent: Node;
+	readonly parent: INode;
 	readonly type: string;
 
-	prev?: Node;
-	next?: Node;
+	prev?: INode;
+	next?: INode;
 
 	can_use_innerhtml: boolean;
 	var: string;
@@ -55,7 +57,7 @@ export default class Node {
 		if (attribute.chunks.length === 0) return '';
 
 		if (attribute.chunks.length === 1 && attribute.chunks[0].type === 'Text') {
-			return attribute.chunks[0].data;
+			return (attribute.chunks[0] as Text).data;
 		}
 
 		return null;
diff --git a/src/compile/nodes/shared/Tag.ts b/src/compile/nodes/shared/Tag.ts
index 94971bef11..bc826458d9 100644
--- a/src/compile/nodes/shared/Tag.ts
+++ b/src/compile/nodes/shared/Tag.ts
@@ -2,6 +2,7 @@ import Node from './Node';
 import Expression from './Expression';
 
 export default class Tag extends Node {
+	type: 'MustacheTag' | 'RawMustacheTag';
 	expression: Expression;
 	should_cache: boolean;
 
@@ -14,4 +15,4 @@ export default class Tag extends Node {
 			(this.expression.dependencies.size && scope.names.has(info.expression.name))
 		);
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/shared/TemplateScope.ts b/src/compile/nodes/shared/TemplateScope.ts
index abd366642e..5f30d0c883 100644
--- a/src/compile/nodes/shared/TemplateScope.ts
+++ b/src/compile/nodes/shared/TemplateScope.ts
@@ -2,6 +2,7 @@ import EachBlock from '../EachBlock';
 import ThenBlock from '../ThenBlock';
 import CatchBlock from '../CatchBlock';
 import InlineComponent from '../InlineComponent';
+import Element from '../Element';
 
 type NodeWithScope = EachBlock | ThenBlock | CatchBlock | InlineComponent | Element;
 
@@ -41,4 +42,4 @@ export default class TemplateScope {
 		const owner = this.get_owner(name);
 		return owner && (owner.type === 'Element' || owner.type === 'InlineComponent');
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/nodes/shared/map_children.ts b/src/compile/nodes/shared/map_children.ts
index b903853016..71d764a889 100644
--- a/src/compile/nodes/shared/map_children.ts
+++ b/src/compile/nodes/shared/map_children.ts
@@ -14,9 +14,11 @@ import Slot from '../Slot';
 import Text from '../Text';
 import Title from '../Title';
 import Window from '../Window';
-import Node from './Node';
+import { Node } from '../../../interfaces';
 
-function get_constructor(type): typeof Node {
+export type Children = ReturnType<typeof map_children>;
+
+function get_constructor(type) {
 	switch (type) {
 		case 'AwaitBlock': return AwaitBlock;
 		case 'Body': return Body;
@@ -38,7 +40,7 @@ function get_constructor(type): typeof Node {
 	}
 }
 
-export default function map_children(component, parent, scope, children: any[]) {
+export default function map_children(component, parent, scope, children: Node[]) {
 	let last = null;
 	return children.map(child => {
 		const constructor = get_constructor(child.type);
diff --git a/src/compile/render-dom/Block.ts b/src/compile/render-dom/Block.ts
index e40b3ceb55..531826edcb 100644
--- a/src/compile/render-dom/Block.ts
+++ b/src/compile/render-dom/Block.ts
@@ -9,7 +9,7 @@ export interface BlockOptions {
 	renderer?: Renderer;
 	comment?: string;
 	key?: string;
-	bindings?: Map<string, () => { object: string, property: string, snippet: string }>;
+	bindings?: Map<string, { object: string, property: string, snippet: string }>;
 	dependencies?: Set<string>;
 }
 
diff --git a/src/compile/render-dom/Renderer.ts b/src/compile/render-dom/Renderer.ts
index 1d766c6345..ea07c1544f 100644
--- a/src/compile/render-dom/Renderer.ts
+++ b/src/compile/render-dom/Renderer.ts
@@ -3,7 +3,6 @@ import { CompileOptions } from '../../interfaces';
 import Component from '../Component';
 import FragmentWrapper from './wrappers/Fragment';
 import CodeBuilder from '../utils/CodeBuilder';
-import SlotWrapper from './wrappers/Slot';
 
 export default class Renderer {
 	component: Component; // TODO Maybe Renderer shouldn't know about Component?
@@ -18,6 +17,7 @@ export default class Renderer {
 	fragment: FragmentWrapper;
 
 	file_var: string;
+	locate: (c: number) => { line: number; column: number; };
 
 	constructor(component: Component, options: CompileOptions) {
 		this.component = component;
@@ -58,4 +58,4 @@ export default class Renderer {
 
 		this.fragment.render(this.block, null, 'nodes');
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-dom/wrappers/EachBlock.ts b/src/compile/render-dom/wrappers/EachBlock.ts
index fe5d5746e5..9208c838ad 100644
--- a/src/compile/render-dom/wrappers/EachBlock.ts
+++ b/src/compile/render-dom/wrappers/EachBlock.ts
@@ -8,7 +8,7 @@ import deindent from '../../utils/deindent';
 import ElseBlock from '../../nodes/ElseBlock';
 import { attach_head } from '../../utils/tail';
 
-class ElseBlockWrapper extends Wrapper {
+export class ElseBlockWrapper extends Wrapper {
 	node: ElseBlock;
 	block: Block;
 	fragment: FragmentWrapper;
@@ -83,6 +83,7 @@ export default class EachBlockWrapper extends Wrapper {
 		this.block = block.child({
 			comment: create_debugging_comment(this.node, this.renderer.component),
 			name: renderer.component.get_unique_name('create_each_block'),
+			// @ts-ignore todo: probably error
 			key: node.key as string,
 
 			bindings: new Map(block.bindings)
@@ -310,7 +311,9 @@ export default class EachBlockWrapper extends Wrapper {
 		}
 
 		block.builders.init.add_block(deindent`
-			const ${get_key} = ctx => ${this.node.key.render()};
+			const ${get_key} = ctx => ${
+			// @ts-ignore todo: probably error
+			this.node.key.render()};
 
 			for (var #i = 0; #i < ${this.vars.each_block_value}.${length}; #i += 1) {
 				let child_ctx = ${this.vars.get_each_context}(ctx, ${this.vars.each_block_value}, #i);
diff --git a/src/compile/render-dom/wrappers/Element/Attribute.ts b/src/compile/render-dom/wrappers/Element/Attribute.ts
index 5007724f34..876496e2f6 100644
--- a/src/compile/render-dom/wrappers/Element/Attribute.ts
+++ b/src/compile/render-dom/wrappers/Element/Attribute.ts
@@ -4,6 +4,7 @@ import fix_attribute_casing from './fix_attribute_casing';
 import ElementWrapper from './index';
 import { stringify } from '../../../utils/stringify';
 import deindent from '../../../utils/deindent';
+import Expression from '../../../nodes/shared/Expression';
 
 export default class AttributeWrapper {
 	node: Attribute;
@@ -21,7 +22,9 @@ export default class AttributeWrapper {
 			// special case — <option value={foo}> — see below
 			if (this.parent.node.name === 'option' && node.name === 'value') {
 				let select: ElementWrapper = this.parent;
-				while (select && (select.node.type !== 'Element' || select.node.name !== 'select')) select = select.parent;
+				while (select && (select.node.type !== 'Element' || select.node.name !== 'select'))
+					// @ts-ignore todo: doublecheck this, but looks to be correct
+					select = select.parent;
 
 				if (select && select.select_binding_dependencies) {
 					select.select_binding_dependencies.forEach(prop => {
@@ -47,7 +50,7 @@ export default class AttributeWrapper {
 			(element.node.name === 'option' || // TODO check it's actually bound
 				(element.node.name === 'input' &&
 					element.node.bindings.find(
-						(binding: Binding) =>
+						(binding) =>
 							/checked|group/.test(binding.name)
 						)));
 
@@ -78,13 +81,13 @@ export default class AttributeWrapper {
 			// DRY it out if that's possible without introducing crazy indirection
 			if (this.node.chunks.length === 1) {
 				// single {tag} — may be a non-string
-				value = this.node.chunks[0].render(block);
+				value = (this.node.chunks[0] as Expression).render(block);
 			} else {
 				// '{foo} {bar}' — treat as string concatenation
 				value =
 					(this.node.chunks[0].type === 'Text' ? '' : `"" + `) +
 					this.node.chunks
-						.map((chunk: Node) => {
+						.map((chunk) => {
 							if (chunk.type === 'Text') {
 								return stringify(chunk.data);
 							} else {
diff --git a/src/compile/render-dom/wrappers/Element/StyleAttribute.ts b/src/compile/render-dom/wrappers/Element/StyleAttribute.ts
index 8d59585cad..64de2921b3 100644
--- a/src/compile/render-dom/wrappers/Element/StyleAttribute.ts
+++ b/src/compile/render-dom/wrappers/Element/StyleAttribute.ts
@@ -1,14 +1,15 @@
 import Attribute from '../../../nodes/Attribute';
 import Block from '../../Block';
 import AttributeWrapper from './Attribute';
-import Node from '../../../nodes/shared/Node';
 import ElementWrapper from '.';
 import { stringify } from '../../../utils/stringify';
 import add_to_set from '../../../utils/add_to_set';
+import Expression from '../../../nodes/shared/Expression';
+import Text from '../../../nodes/Text';
 
 export interface StyleProp {
 	key: string;
-	value: Node[];
+	value: (Text|Expression)[];
 }
 
 export default class StyleAttributeWrapper extends AttributeWrapper {
@@ -28,7 +29,7 @@ export default class StyleAttributeWrapper extends AttributeWrapper {
 				value =
 					((prop.value.length === 1 || prop.value[0].type === 'Text') ? '' : `"" + `) +
 					prop.value
-						.map((chunk: Node) => {
+						.map((chunk) => {
 							if (chunk.type === 'Text') {
 								return stringify(chunk.data);
 							} else {
@@ -54,7 +55,7 @@ export default class StyleAttributeWrapper extends AttributeWrapper {
 					);
 				}
 			} else {
-				value = stringify(prop.value[0].data);
+				value = stringify((prop.value[0] as Text).data);
 			}
 
 			block.builders.hydrate.add_line(
@@ -64,8 +65,8 @@ export default class StyleAttributeWrapper extends AttributeWrapper {
 	}
 }
 
-function optimize_style(value: Node[]) {
-	const props: { key: string, value: Node[] }[] = [];
+function optimize_style(value: (Text|Expression)[]) {
+	const props: StyleProp[] = [];
 	let chunks = value.slice();
 
 	while (chunks.length) {
@@ -87,7 +88,7 @@ function optimize_style(value: Node[]) {
 				end: chunk.end,
 				type: 'Text',
 				data: remaining_data
-			};
+			} as Text;
 		} else {
 			chunks.shift();
 		}
@@ -101,8 +102,8 @@ function optimize_style(value: Node[]) {
 	return props;
 }
 
-function get_style_value(chunks: Node[]) {
-	const value: Node[] = [];
+function get_style_value(chunks: (Text | Expression)[]) {
+	const value: (Text|Expression)[] = [];
 
 	let in_url = false;
 	let quote_mark = null;
@@ -141,7 +142,7 @@ function get_style_value(chunks: Node[]) {
 					start: chunk.start,
 					end: chunk.start + c,
 					data: chunk.data.slice(0, c)
-				});
+				} as Text);
 			}
 
 			while (/[;\s]/.test(chunk.data[c])) c += 1;
@@ -153,7 +154,7 @@ function get_style_value(chunks: Node[]) {
 					end: chunk.end,
 					type: 'Text',
 					data: remaining_data
-				});
+				} as Text);
 
 				break;
 			}
@@ -170,6 +171,6 @@ function get_style_value(chunks: Node[]) {
 	};
 }
 
-function is_dynamic(value: Node[]) {
+function is_dynamic(value: (Text|Expression)[]) {
 	return value.length > 1 || value[0].type !== 'Text';
 }
diff --git a/src/compile/render-dom/wrappers/Element/index.ts b/src/compile/render-dom/wrappers/Element/index.ts
index c20e10a82f..41db1c03a0 100644
--- a/src/compile/render-dom/wrappers/Element/index.ts
+++ b/src/compile/render-dom/wrappers/Element/index.ts
@@ -20,20 +20,19 @@ import add_event_handlers from '../shared/add_event_handlers';
 import add_actions from '../shared/add_actions';
 import create_debugging_comment from '../shared/create_debugging_comment';
 import { get_context_merger } from '../shared/get_context_merger';
-import Slot from '../../../nodes/Slot';
 
 const events = [
 	{
 		event_names: ['input'],
 		filter: (node: Element, name: string) =>
 			node.name === 'textarea' ||
-			node.name === 'input' && !/radio|checkbox|range/.test(node.get_static_attribute_value('type'))
+			node.name === 'input' && !/radio|checkbox|range/.test(node.get_static_attribute_value('type') as string)
 	},
 	{
 		event_names: ['change'],
 		filter: (node: Element, name: string) =>
 			node.name === 'select' ||
-			node.name === 'input' && /radio|checkbox/.test(node.get_static_attribute_value('type'))
+			node.name === 'input' && /radio|checkbox/.test(node.get_static_attribute_value('type') as string)
 	},
 	{
 		event_names: ['change', 'input'],
@@ -141,7 +140,7 @@ export default class ElementWrapper extends Wrapper {
 				}
 
 				if (owner && owner.node.type === 'InlineComponent') {
-					const name = attribute.get_static_value();
+					const name = attribute.get_static_value() as string;
 
 					if (!(owner as InlineComponentWrapper).slots.has(name)) {
 						const child_block = block.child({
@@ -281,6 +280,7 @@ export default class ElementWrapper extends Wrapper {
 		if (!this.node.namespace && this.can_use_innerhtml && this.fragment.nodes.length > 0) {
 			if (this.fragment.nodes.length === 1 && this.fragment.nodes[0].node.type === 'Text') {
 				block.builders.create.add_line(
+					 // @ts-ignore todo: should it be this.fragment.nodes[0].node.data instead?
 					`${node}.textContent = ${stringify(this.fragment.nodes[0].data)};`
 				);
 			} else {
@@ -330,7 +330,7 @@ export default class ElementWrapper extends Wrapper {
 
 		function to_html(wrapper: ElementWrapper | TextWrapper) {
 			if (wrapper.node.type === 'Text') {
-				const { parent } = wrapper.node;
+				const parent = wrapper.node.parent as Element;
 
 				const raw = parent && (
 					parent.name === 'script' ||
@@ -355,7 +355,7 @@ export default class ElementWrapper extends Wrapper {
 
 			if (is_void(wrapper.node.name)) return open + '>';
 
-			return `${open}>${wrapper.fragment.nodes.map(to_html).join('')}</${wrapper.node.name}>`;
+			return `${open}>${(wrapper as ElementWrapper).fragment.nodes.map(to_html).join('')}</${wrapper.node.name}>`;
 		}
 
 		if (renderer.options.dev) {
@@ -382,8 +382,8 @@ export default class ElementWrapper extends Wrapper {
 
 	get_claim_statement(nodes: string) {
 		const attributes = this.node.attributes
-			.filter((attr: Node) => attr.type === 'Attribute')
-			.map((attr: Node) => `${quote_name_if_necessary(attr.name)}: true`)
+			.filter((attr) => attr.type === 'Attribute')
+			.map((attr) => `${quote_name_if_necessary(attr.name)}: true`)
 			.join(', ');
 
 		const name = this.node.namespace
@@ -559,12 +559,13 @@ export default class ElementWrapper extends Wrapper {
 	}
 
 	add_attributes(block: Block) {
+		// @ts-ignore todo:
 		if (this.node.attributes.find(attr => attr.type === 'Spread')) {
 			this.add_spread_attributes(block);
 			return;
 		}
 
-		this.attributes.forEach((attribute: Attribute) => {
+		this.attributes.forEach((attribute) => {
 			if (attribute.node.name === 'class' && attribute.node.is_dynamic) {
 				this.class_dependencies.push(...attribute.node.dependencies);
 			}
@@ -820,27 +821,28 @@ export default class ElementWrapper extends Wrapper {
 		});
 	}
 
-	add_css_class(class_name = this.component.stylesheet.id) {
-		const class_attribute = this.attributes.find(a => a.name === 'class');
-		if (class_attribute && !class_attribute.is_true) {
-			if (class_attribute.chunks.length === 1 && class_attribute.chunks[0].type === 'Text') {
-				(class_attribute.chunks[0] as Text).data += ` ${class_name}`;
-			} else {
-				(class_attribute.chunks as Node[]).push(
-					new Text(this.component, this, this.scope, {
-						type: 'Text',
-						data: ` ${class_name}`
-					})
-				);
-			}
-		} else {
-			this.attributes.push(
-				new Attribute(this.component, this, this.scope, {
-					type: 'Attribute',
-					name: 'class',
-					value: [{ type: 'Text', data: class_name }]
-				})
-			);
-		}
-	}
+	// todo: looks to be dead code copypasted from Element.add_css_class in src/compile/nodes/Element.ts
+	// add_css_class(class_name = this.component.stylesheet.id) {
+	// 	const class_attribute = this.attributes.find(a => a.name === 'class');
+	// 	if (class_attribute && !class_attribute.is_true) {
+	// 		if (class_attribute.chunks.length === 1 && class_attribute.chunks[0].type === 'Text') {
+	// 			(class_attribute.chunks[0] as Text).data += ` ${class_name}`;
+	// 		} else {
+	// 			(class_attribute.chunks as Node[]).push(
+	// 				new Text(this.component, this, this.scope, {
+	// 					type: 'Text',
+	// 					data: ` ${class_name}`
+	// 				})
+	// 			);
+	// 		}
+	// 	} else {
+	// 		this.attributes.push(
+	// 			new Attribute(this.component, this, this.scope, {
+	// 				type: 'Attribute',
+	// 				name: 'class',
+	// 				value: [{ type: 'Text', data: class_name }]
+	// 			})
+	// 		);
+	// 	}
+	// }
 }
diff --git a/src/compile/render-dom/wrappers/Fragment.ts b/src/compile/render-dom/wrappers/Fragment.ts
index 8d955b6d01..21a6704548 100644
--- a/src/compile/render-dom/wrappers/Fragment.ts
+++ b/src/compile/render-dom/wrappers/Fragment.ts
@@ -13,7 +13,7 @@ import Slot from './Slot';
 import Text from './Text';
 import Title from './Title';
 import Window from './Window';
-import Node from '../../nodes/shared/Node';
+import { INode } from '../../nodes/interfaces';
 import TextWrapper from './Text';
 import Renderer from '../Renderer';
 import Block from '../Block';
@@ -49,7 +49,7 @@ export default class FragmentWrapper {
 	constructor(
 		renderer: Renderer,
 		block: Block,
-		nodes: Node[],
+		nodes: INode[],
 		parent: Wrapper,
 		strip_whitespace: boolean,
 		next_sibling: Wrapper
@@ -85,6 +85,7 @@ export default class FragmentWrapper {
 				// *unless* there is no whitespace between this node and its next sibling
 				if (this.nodes.length === 0) {
 					const should_trim = (
+						// @ts-ignore todo: probably error, should it be next_sibling.node.data?
 						next_sibling ? (next_sibling.node.type === 'Text' && /^\s/.test(next_sibling.data)) : !child.has_ancestor('EachBlock')
 					);
 
@@ -96,6 +97,7 @@ export default class FragmentWrapper {
 
 				// glue text nodes (which could e.g. be separated by comments) together
 				if (last_child && last_child.node.type === 'Text') {
+					// @ts-ignore todo: probably error, should it be last_child.node.data?
 					last_child.data = data + last_child.data;
 					continue;
 				}
diff --git a/src/compile/render-dom/wrappers/IfBlock.ts b/src/compile/render-dom/wrappers/IfBlock.ts
index f3b5c7f2b2..0d56ea85b2 100644
--- a/src/compile/render-dom/wrappers/IfBlock.ts
+++ b/src/compile/render-dom/wrappers/IfBlock.ts
@@ -96,7 +96,7 @@ export default class IfBlockWrapper extends Wrapper {
 			if (branch.block.has_outros) has_outros = true;
 
 			if (is_else_if(node.else)) {
-				create_branches(node.else.children[0]);
+				create_branches(node.else.children[0] as IfBlock);
 			} else if (node.else) {
 				const branch = new IfBlockBranch(
 					renderer,
@@ -452,4 +452,4 @@ export default class IfBlockWrapper extends Wrapper {
 
 		block.builders.destroy.add_line(`${if_name}${name}.d(${parent_node ? '' : 'detaching'});`);
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-dom/wrappers/InlineComponent/index.ts b/src/compile/render-dom/wrappers/InlineComponent/index.ts
index f9d79d2693..049c21e256 100644
--- a/src/compile/render-dom/wrappers/InlineComponent/index.ts
+++ b/src/compile/render-dom/wrappers/InlineComponent/index.ts
@@ -142,7 +142,7 @@ export default class InlineComponentWrapper extends Wrapper {
 		if (this.fragment) {
 			const default_slot = this.slots.get('default');
 
-			this.fragment.nodes.forEach((child: Wrapper) => {
+			this.fragment.nodes.forEach((child) => {
 				child.render(default_slot.block, null, 'nodes');
 			});
 		}
@@ -505,4 +505,4 @@ export default class InlineComponentWrapper extends Wrapper {
 			);
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-dom/wrappers/MustacheTag.ts b/src/compile/render-dom/wrappers/MustacheTag.ts
index f42d0c1de0..71faf91cb2 100644
--- a/src/compile/render-dom/wrappers/MustacheTag.ts
+++ b/src/compile/render-dom/wrappers/MustacheTag.ts
@@ -1,13 +1,14 @@
 import Renderer from '../Renderer';
 import Block from '../Block';
-import Node from '../../nodes/shared/Node';
 import Tag from './shared/Tag';
 import Wrapper from './shared/Wrapper';
+import MustacheTag from '../../nodes/MustacheTag';
+import RawMustacheTag from '../../nodes/RawMustacheTag';
 
 export default class MustacheTagWrapper extends Tag {
 	var = 't';
 
-	constructor(renderer: Renderer, block: Block, parent: Wrapper, node: Node) {
+	constructor(renderer: Renderer, block: Block, parent: Wrapper, node: MustacheTag | RawMustacheTag) {
 		super(renderer, block, parent, node);
 		this.cannot_use_innerhtml();
 	}
@@ -25,4 +26,4 @@ export default class MustacheTagWrapper extends Tag {
 			parent_node
 		);
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-dom/wrappers/RawMustacheTag.ts b/src/compile/render-dom/wrappers/RawMustacheTag.ts
index eb71e16de9..d8f863c674 100644
--- a/src/compile/render-dom/wrappers/RawMustacheTag.ts
+++ b/src/compile/render-dom/wrappers/RawMustacheTag.ts
@@ -1,9 +1,10 @@
 import Renderer from '../Renderer';
 import Block from '../Block';
-import Node from '../../nodes/shared/Node';
 import Tag from './shared/Tag';
 import Wrapper from './shared/wrapper';
 import deindent from '../../utils/deindent';
+import MustacheTag from '../../nodes/MustacheTag';
+import RawMustacheTag from '../../nodes/RawMustacheTag';
 
 export default class RawMustacheTagWrapper extends Tag {
 	var = 'raw';
@@ -12,7 +13,7 @@ export default class RawMustacheTagWrapper extends Tag {
 		renderer: Renderer,
 		block: Block,
 		parent: Wrapper,
-		node: Node
+		node: MustacheTag | RawMustacheTag
 	) {
 		super(renderer, block, parent, node);
 		this.cannot_use_innerhtml();
@@ -100,4 +101,4 @@ export default class RawMustacheTagWrapper extends Tag {
 			add_anchor_after();
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-dom/wrappers/Slot.ts b/src/compile/render-dom/wrappers/Slot.ts
index 31bb4853b1..8a9dc7aca2 100644
--- a/src/compile/render-dom/wrappers/Slot.ts
+++ b/src/compile/render-dom/wrappers/Slot.ts
@@ -9,7 +9,6 @@ import add_to_set from '../../utils/add_to_set';
 import get_slot_data from '../../utils/get_slot_data';
 import { stringify_props } from '../../utils/stringify_props';
 import Expression from '../../nodes/shared/Expression';
-import Attribute from '../../nodes/Attribute';
 
 export default class SlotWrapper extends Wrapper {
 	node: Slot;
diff --git a/src/compile/render-dom/wrappers/Title.ts b/src/compile/render-dom/wrappers/Title.ts
index eff1d2523b..f24e2926e0 100644
--- a/src/compile/render-dom/wrappers/Title.ts
+++ b/src/compile/render-dom/wrappers/Title.ts
@@ -4,6 +4,7 @@ import Block from '../Block';
 import Title from '../../nodes/Title';
 import { stringify } from '../../utils/stringify';
 import add_to_set from '../../utils/add_to_set';
+import Text from '../../nodes/Text';
 
 export default class TitleWrapper extends Wrapper {
 	node: Title;
@@ -31,6 +32,7 @@ export default class TitleWrapper extends Wrapper {
 			// DRY it out if that's possible without introducing crazy indirection
 			if (this.node.children.length === 1) {
 				// single {tag} — may be a non-string
+				// @ts-ignore todo: check this
 				const { expression } = this.node.children[0];
 				value = expression.render(block);
 				add_to_set(all_dependencies, expression.dependencies);
@@ -39,16 +41,18 @@ export default class TitleWrapper extends Wrapper {
 				value =
 					(this.node.children[0].type === 'Text' ? '' : `"" + `) +
 					this.node.children
-						.map((chunk: Node) => {
+						.map((chunk) => {
 							if (chunk.type === 'Text') {
 								return stringify(chunk.data);
 							} else {
+								// @ts-ignore todo: check this
 								const snippet = chunk.expression.render(block);
-
+								// @ts-ignore todo: check this
 								chunk.expression.dependencies.forEach(d => {
 									all_dependencies.add(d);
 								});
 
+								// @ts-ignore todo: check this
 								return chunk.expression.get_precedence() <= 13 ? `(${snippet})` : snippet;
 							}
 						})
@@ -88,8 +92,8 @@ export default class TitleWrapper extends Wrapper {
 				);
 			}
 		} else {
-			const value = stringify(this.node.children[0].data);
+			const value = stringify((this.node.children[0] as Text).data);
 			block.builders.hydrate.add_line(`document.title = ${value};`);
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-dom/wrappers/Window.ts b/src/compile/render-dom/wrappers/Window.ts
index 2b58153d95..56c63adb3d 100644
--- a/src/compile/render-dom/wrappers/Window.ts
+++ b/src/compile/render-dom/wrappers/Window.ts
@@ -6,6 +6,7 @@ import deindent from '../../utils/deindent';
 import add_event_handlers from './shared/add_event_handlers';
 import Window from '../../nodes/Window';
 import add_actions from './shared/add_actions';
+import { INode } from '../../nodes/interfaces';
 
 const associated_events = {
 	innerWidth: 'resize',
@@ -33,7 +34,7 @@ const readonly = new Set([
 export default class WindowWrapper extends Wrapper {
 	node: Window;
 
-	constructor(renderer: Renderer, block: Block, parent: Wrapper, node: Node) {
+	constructor(renderer: Renderer, block: Block, parent: Wrapper, node: INode) {
 		super(renderer, block, parent, node);
 	}
 
diff --git a/src/compile/render-dom/wrappers/shared/Wrapper.ts b/src/compile/render-dom/wrappers/shared/Wrapper.ts
index 2a9394415f..3315b6b483 100644
--- a/src/compile/render-dom/wrappers/shared/Wrapper.ts
+++ b/src/compile/render-dom/wrappers/shared/Wrapper.ts
@@ -1,11 +1,11 @@
 import Renderer from '../../Renderer';
-import Node from '../../../nodes/shared/Node';
 import Block from '../../Block';
+import { INode } from '../../../nodes/interfaces';
 
 export default class Wrapper {
 	renderer: Renderer;
 	parent: Wrapper;
-	node: Node;
+	node: INode;
 
 	prev: Wrapper | null;
 	next: Wrapper | null;
@@ -17,7 +17,7 @@ export default class Wrapper {
 		renderer: Renderer,
 		block: Block,
 		parent: Wrapper,
-		node: Node
+		node: INode
 	) {
 		this.node = node;
 
@@ -75,4 +75,8 @@ export default class Wrapper {
 			this.node.type === 'MustacheTag'
 		);
 	}
-}
\ No newline at end of file
+
+	render(block: Block, parent_node: string, parent_nodes: string){
+		throw Error('Wrapper class is not renderable');
+	}
+}
diff --git a/src/compile/render-dom/wrappers/shared/create_debugging_comment.ts b/src/compile/render-dom/wrappers/shared/create_debugging_comment.ts
index b32d25c1a4..df1ae9ff8e 100644
--- a/src/compile/render-dom/wrappers/shared/create_debugging_comment.ts
+++ b/src/compile/render-dom/wrappers/shared/create_debugging_comment.ts
@@ -1,8 +1,8 @@
 import Component from '../../../Component';
-import { Node } from '../../../../interfaces';
+import { INode } from '../../../nodes/interfaces';
 
 export default function create_debugging_comment(
-	node: Node,
+	node: INode,
 	component: Component
 ) {
 	const { locate, source } = component;
@@ -19,6 +19,7 @@ export default function create_debugging_comment(
 		d = node.children.length ? node.children[0].start : node.start;
 		while (source[d - 1] !== '>') d -= 1;
 	} else {
+		// @ts-ignore
 		d = node.expression ? node.expression.node.end : c;
 		while (source[d] !== '}') d += 1;
 		while (source[d] === '}') d += 1;
diff --git a/src/compile/render-ssr/Renderer.ts b/src/compile/render-ssr/Renderer.ts
index c97965de14..ef1d16429e 100644
--- a/src/compile/render-ssr/Renderer.ts
+++ b/src/compile/render-ssr/Renderer.ts
@@ -12,6 +12,7 @@ import Tag from './handlers/Tag';
 import Text from './handlers/Text';
 import Title from './handlers/Title';
 import { AppendTarget, CompileOptions } from '../../interfaces';
+import { INode } from '../nodes/interfaces';
 
 type Handler = (node: any, renderer: Renderer, options: CompileOptions) => void;
 
@@ -36,6 +37,10 @@ const handlers: Record<string, Handler> = {
 	Window: noop
 };
 
+export interface RenderOptions extends CompileOptions{
+	locate: (c: number) => { line: number; column: number; };
+};
+
 export default class Renderer {
 	has_bindings = false;
 	code = '';
@@ -51,7 +56,7 @@ export default class Renderer {
 		}
 	}
 
-	render(nodes, options) {
+	render(nodes: INode[], options: RenderOptions) {
 		nodes.forEach(node => {
 			const handler = handlers[node.type];
 
diff --git a/src/compile/render-ssr/handlers/AwaitBlock.ts b/src/compile/render-ssr/handlers/AwaitBlock.ts
index bbc4a15e05..85bf7b3135 100644
--- a/src/compile/render-ssr/handlers/AwaitBlock.ts
+++ b/src/compile/render-ssr/handlers/AwaitBlock.ts
@@ -1,8 +1,8 @@
-import Renderer from '../Renderer';
-import { CompileOptions } from '../../../interfaces';
+import Renderer, { RenderOptions } from '../Renderer';
 import { snip } from '../../utils/snip';
+import AwaitBlock from '../../nodes/AwaitBlock';
 
-export default function(node, renderer: Renderer, options: CompileOptions) {
+export default function(node: AwaitBlock, renderer: Renderer, options: RenderOptions) {
 	renderer.append('${(function(__value) { if(@is_promise(__value)) return `');
 
 	renderer.render(node.pending.children, options);
@@ -13,4 +13,4 @@ export default function(node, renderer: Renderer, options: CompileOptions) {
 
 	const snippet = snip(node.expression);
 	renderer.append(`\`;}(__value);}(${snippet})) }`);
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/Comment.ts b/src/compile/render-ssr/handlers/Comment.ts
index 4517faace5..237c260230 100644
--- a/src/compile/render-ssr/handlers/Comment.ts
+++ b/src/compile/render-ssr/handlers/Comment.ts
@@ -1,8 +1,8 @@
-import Renderer from '../Renderer';
-import { CompileOptions } from '../../../interfaces';
+import Renderer, { RenderOptions } from '../Renderer';
+import Comment from '../../nodes/Comment';
 
-export default function(node, renderer: Renderer, options: CompileOptions) {
+export default function(node: Comment, renderer: Renderer, options: RenderOptions) {
 	if (options.preserveComments) {
 		renderer.append(`<!--${node.data}-->`);
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/DebugTag.ts b/src/compile/render-ssr/handlers/DebugTag.ts
index b04d541105..3fd7584d57 100644
--- a/src/compile/render-ssr/handlers/DebugTag.ts
+++ b/src/compile/render-ssr/handlers/DebugTag.ts
@@ -1,9 +1,10 @@
 import { stringify } from '../../utils/stringify';
-
-export default function(node, renderer, options) {
+import DebugTag from '../../nodes/DebugTag';
+import Renderer, { RenderOptions } from '../Renderer';
+export default function(node: DebugTag, renderer: Renderer, options: RenderOptions) {
 	if (!options.dev) return;
 
-	const filename = options.file || null;
+	const filename = options.filename || null;
 	const { line, column } = options.locate(node.start + 1);
 
 	const obj = node.expressions.length === 0
@@ -15,4 +16,4 @@ export default function(node, renderer, options) {
 	const str = '${@debug(' + `${filename && stringify(filename)}, ${line}, ${column}, ${obj})}`;
 
 	renderer.append(str);
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/EachBlock.ts b/src/compile/render-ssr/handlers/EachBlock.ts
index 3731093a9b..5ed27dff15 100644
--- a/src/compile/render-ssr/handlers/EachBlock.ts
+++ b/src/compile/render-ssr/handlers/EachBlock.ts
@@ -1,6 +1,8 @@
 import { snip } from '../../utils/snip';
+import Renderer, { RenderOptions } from '../Renderer';
+import EachBlock from '../../nodes/EachBlock';
 
-export default function(node, renderer, options) {
+export default function(node: EachBlock, renderer: Renderer, options: RenderOptions) {
 	const snippet = snip(node.expression);
 
 	const { start, end } = node.context_node;
@@ -24,4 +26,4 @@ export default function(node, renderer, options) {
 	}
 
 	renderer.append('}');
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/Element.ts b/src/compile/render-ssr/handlers/Element.ts
index 7717be48e3..fc6bc5b969 100644
--- a/src/compile/render-ssr/handlers/Element.ts
+++ b/src/compile/render-ssr/handlers/Element.ts
@@ -5,6 +5,9 @@ import Node from '../../nodes/shared/Node';
 import { snip } from '../../utils/snip';
 import { stringify_attribute } from '../../utils/stringify_attribute';
 import { get_slot_scope } from './shared/get_slot_scope';
+import Renderer, { RenderOptions } from '../Renderer';
+import Element from '../../nodes/Element';
+import Text from '../../nodes/Text';
 
 // source: https://gist.github.com/ArjanSchouten/0b8574a6ad7f5065a5e7
 const boolean_attributes = new Set([
@@ -47,15 +50,17 @@ const boolean_attributes = new Set([
 	'translate'
 ]);
 
-export default function(node, renderer, options) {
+export default function(node: Element, renderer: Renderer, options: RenderOptions & {
+	slot_scopes: Map<any, any>;
+}) {
 	let opening_tag = `<${node.name}`;
 	let textarea_contents; // awkward special case
 
 	const slot = node.get_static_attribute_value('slot');
 	const component = node.find_nearest(/InlineComponent/);
 	if (slot && component) {
-		const slot = node.attributes.find((attribute: Node) => attribute.name === 'slot');
-		const slot_name = slot.chunks[0].data;
+		const slot = node.attributes.find((attribute) => attribute.name === 'slot');
+		const slot_name = (slot.chunks[0] as Text).data;
 		const target = renderer.targets[renderer.targets.length - 1];
 		target.slot_stack.push(slot_name);
 		target.slots[slot_name] = '';
@@ -160,4 +165,4 @@ export default function(node, renderer, options) {
 	if (!is_void(node.name)) {
 		renderer.append(`</${node.name}>`);
 	}
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/Head.ts b/src/compile/render-ssr/handlers/Head.ts
index 656759af3c..ecd32cc0ef 100644
--- a/src/compile/render-ssr/handlers/Head.ts
+++ b/src/compile/render-ssr/handlers/Head.ts
@@ -1,7 +1,10 @@
-export default function(node, renderer, options) {
+import Renderer, { RenderOptions } from '../Renderer';
+import Head from '../../nodes/Head';
+
+export default function(node: Head, renderer: Renderer, options: RenderOptions) {
 	renderer.append('${($$result.head += `');
 
 	renderer.render(node.children, options);
 
 	renderer.append('`, "")}');
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/HtmlTag.ts b/src/compile/render-ssr/handlers/HtmlTag.ts
index 7562186a4b..84e2e1f573 100644
--- a/src/compile/render-ssr/handlers/HtmlTag.ts
+++ b/src/compile/render-ssr/handlers/HtmlTag.ts
@@ -1,5 +1,7 @@
 import { snip } from '../../utils/snip';
+import Renderer, { RenderOptions } from '../Renderer';
+import RawMustacheTag from '../../nodes/RawMustacheTag';
 
-export default function(node, renderer, options) {
+export default function(node: RawMustacheTag, renderer: Renderer, options: RenderOptions) {
 	renderer.append('${' + snip(node.expression) + '}');
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/IfBlock.ts b/src/compile/render-ssr/handlers/IfBlock.ts
index cbe505fef8..c841f1d593 100644
--- a/src/compile/render-ssr/handlers/IfBlock.ts
+++ b/src/compile/render-ssr/handlers/IfBlock.ts
@@ -1,6 +1,7 @@
 import { snip } from '../../utils/snip';
-
-export default function(node, renderer, options) {
+import IfBlock from '../../nodes/IfBlock';
+import Renderer, { RenderOptions } from '../Renderer';
+export default function(node: IfBlock, renderer: Renderer, options: RenderOptions) {
 	const snippet = snip(node.expression);
 
 	renderer.append('${ ' + snippet + ' ? `');
@@ -14,4 +15,4 @@ export default function(node, renderer, options) {
 	}
 
 	renderer.append('` }');
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/InlineComponent.ts b/src/compile/render-ssr/handlers/InlineComponent.ts
index bc58be5df9..94fdcfd434 100644
--- a/src/compile/render-ssr/handlers/InlineComponent.ts
+++ b/src/compile/render-ssr/handlers/InlineComponent.ts
@@ -1,14 +1,17 @@
 import { escape, escape_template, stringify } from '../../utils/stringify';
 import { quote_name_if_necessary } from '../../../utils/names';
 import { snip } from '../../utils/snip';
-import Renderer from '../Renderer';
+import Renderer, { RenderOptions } from '../Renderer';
 import { stringify_props } from '../../utils/stringify_props';
 import { get_slot_scope } from './shared/get_slot_scope';
 import { AppendTarget } from '../../../interfaces';
+import InlineComponent from '../../nodes/InlineComponent';
+import { INode } from '../../nodes/interfaces';
+import Text from '../../nodes/Text';
 
-function stringify_attribute(chunk: Node) {
+function stringify_attribute(chunk: INode) {
 	if (chunk.type === 'Text') {
-		return escape_template(escape(chunk.data));
+		return escape_template(escape((chunk as Text).data));
 	}
 
 	return '${@escape(' + snip(chunk) + ')}';
@@ -30,7 +33,7 @@ function get_attribute_value(attribute) {
 	return '`' + attribute.chunks.map(stringify_attribute).join('') + '`';
 }
 
-export default function(node, renderer: Renderer, options) {
+export default function(node: InlineComponent, renderer: Renderer, options: RenderOptions) {
 	const binding_props = [];
 	const binding_fns = [];
 
diff --git a/src/compile/render-ssr/handlers/Slot.ts b/src/compile/render-ssr/handlers/Slot.ts
index b2e67f9e79..087519979b 100644
--- a/src/compile/render-ssr/handlers/Slot.ts
+++ b/src/compile/render-ssr/handlers/Slot.ts
@@ -1,7 +1,9 @@
 import { quote_prop_if_necessary } from '../../../utils/names';
 import get_slot_data from '../../utils/get_slot_data';
+import Renderer, { RenderOptions } from '../Renderer';
+import Slot from '../../nodes/Slot';
 
-export default function(node, renderer, options) {
+export default function(node: Slot, renderer: Renderer, options: RenderOptions) {
 	const prop = quote_prop_if_necessary(node.slot_name);
 
 	const slot_data = get_slot_data(node.values, true);
@@ -13,4 +15,4 @@ export default function(node, renderer, options) {
 	renderer.render(node.children, options);
 
 	renderer.append(`\`}`);
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/Tag.ts b/src/compile/render-ssr/handlers/Tag.ts
index eb887b8688..d03f46fe0a 100644
--- a/src/compile/render-ssr/handlers/Tag.ts
+++ b/src/compile/render-ssr/handlers/Tag.ts
@@ -1,6 +1,6 @@
 import { snip } from '../../utils/snip';
-
-export default function(node, renderer, options) {
+import Renderer, { RenderOptions } from '../Renderer';
+export default function(node, renderer: Renderer, options: RenderOptions) {
 	const snippet = snip(node.expression);
 
 	renderer.append(
@@ -10,4 +10,4 @@ export default function(node, renderer, options) {
 			? '${' + snippet + '}'
 			: '${@escape(' + snippet + ')}'
 	);
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/Text.ts b/src/compile/render-ssr/handlers/Text.ts
index e794025370..1d2906d10a 100644
--- a/src/compile/render-ssr/handlers/Text.ts
+++ b/src/compile/render-ssr/handlers/Text.ts
@@ -1,14 +1,17 @@
 import { escape_html, escape_template, escape } from '../../utils/stringify';
+import Renderer, { RenderOptions } from '../Renderer';
+import Text from '../../nodes/Text';
+import Element from '../../nodes/Element';
 
-export default function(node, renderer, options) {
+export default function(node: Text, renderer: Renderer, options: RenderOptions) {
 	let text = node.data;
 	if (
 		!node.parent ||
 		node.parent.type !== 'Element' ||
-		(node.parent.name !== 'script' && node.parent.name !== 'style')
+		((node.parent as Element).name !== 'script' && (node.parent as Element).name !== 'style')
 	) {
 		// unless this Text node is inside a <script> or <style> element, escape &,<,>
 		text = escape_html(text);
 	}
 	renderer.append(escape(escape_template(text)));
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/handlers/Title.ts b/src/compile/render-ssr/handlers/Title.ts
index 456d4215f1..e5792ec81f 100644
--- a/src/compile/render-ssr/handlers/Title.ts
+++ b/src/compile/render-ssr/handlers/Title.ts
@@ -1,7 +1,10 @@
-export default function(node, renderer, options) {
+import Renderer, { RenderOptions } from '../Renderer';
+import Title from '../../nodes/Title';
+
+export default function(node: Title, renderer: Renderer, options: RenderOptions) {
 	renderer.append(`<title>`);
 
 	renderer.render(node.children, options);
 
 	renderer.append(`</title>`);
-}
\ No newline at end of file
+}
diff --git a/src/compile/render-ssr/index.ts b/src/compile/render-ssr/index.ts
index 10f82beb5e..c63bd5d457 100644
--- a/src/compile/render-ssr/index.ts
+++ b/src/compile/render-ssr/index.ts
@@ -4,6 +4,8 @@ import { CompileOptions } from '../../interfaces';
 import { stringify } from '../utils/stringify';
 import Renderer from './Renderer';
 import { extract_names } from '../utils/scope';
+import { INode } from '../nodes/interfaces';
+import Text from '../nodes/Text';
 
 export default function ssr(
 	component: Component,
@@ -151,10 +153,10 @@ export default function ssr(
 	`).trim();
 }
 
-function trim(nodes) {
+function trim(nodes: INode[]) {
 	let start = 0;
 	for (; start < nodes.length; start += 1) {
-		const node = nodes[start];
+		const node = nodes[start] as Text;
 		if (node.type !== 'Text') break;
 
 		node.data = node.data.replace(/^\s+/, '');
@@ -163,7 +165,7 @@ function trim(nodes) {
 
 	let end = nodes.length;
 	for (; end > start; end -= 1) {
-		const node = nodes[end - 1];
+		const node = nodes[end - 1] as Text;
 		if (node.type !== 'Text') break;
 
 		node.data = node.data.replace(/\s+$/, '');
diff --git a/src/compile/utils/add_to_set.ts b/src/compile/utils/add_to_set.ts
index 262d7d32e7..b37e0db931 100644
--- a/src/compile/utils/add_to_set.ts
+++ b/src/compile/utils/add_to_set.ts
@@ -1,5 +1,6 @@
-export default function add_to_set(a: Set<any>, b: Set<any>) {
+export default function add_to_set<T>(a: Set<T>, b: Set<T> | Array<T>) {
+	// @ts-ignore
 	b.forEach(item => {
 		a.add(item);
 	});
-}
\ No newline at end of file
+}
diff --git a/src/compile/utils/scope.ts b/src/compile/utils/scope.ts
index 6488986d83..1303d205a0 100644
--- a/src/compile/utils/scope.ts
+++ b/src/compile/utils/scope.ts
@@ -1,6 +1,7 @@
 import { walk } from 'estree-walker';
 import is_reference from 'is-reference';
 import { Node } from '../../interfaces';
+import { Node as ESTreeNode } from 'estree';
 
 export function create_scopes(expression: Node) {
 	const map = new WeakMap();
@@ -9,7 +10,7 @@ export function create_scopes(expression: Node) {
 	let scope = new Scope(null, false);
 
 	walk(expression, {
-		enter(node: Node, parent: Node) {
+		enter(node, parent) {
 			if (node.type === 'ImportDeclaration') {
 				node.specifiers.forEach(specifier => {
 					scope.declarations.set(specifier.local.name, specifier);
@@ -25,7 +26,7 @@ export function create_scopes(expression: Node) {
 					if (node.id) scope.declarations.set(node.id.name, node);
 				}
 
-				node.params.forEach((param: Node) => {
+				node.params.forEach((param) => {
 					extract_names(param).forEach(name => {
 						scope.declarations.set(name, node);
 					});
@@ -38,7 +39,7 @@ export function create_scopes(expression: Node) {
 				map.set(node, scope);
 			} else if (/(Class|Variable)Declaration/.test(node.type)) {
 				scope.add_declaration(node);
-			} else if (node.type === 'Identifier' && is_reference(node, parent)) {
+			} else if (node.type === 'Identifier' && is_reference(node as ESTreeNode, parent as ESTreeNode)) {
 				if (!scope.has(node.name) && !globals.has(node.name)) {
 					globals.set(node.name, node);
 				}
diff --git a/src/compile/utils/stringify_attribute.ts b/src/compile/utils/stringify_attribute.ts
index 9df2d18344..ee3450edbb 100644
--- a/src/compile/utils/stringify_attribute.ts
+++ b/src/compile/utils/stringify_attribute.ts
@@ -1,11 +1,10 @@
 import Attribute from '../nodes/Attribute';
-import Node from '../nodes/shared/Node';
 import { escape_template, escape } from './stringify';
 import { snip } from './snip';
 
 export function stringify_attribute(attribute: Attribute, is_ssr: boolean) {
 	return attribute.chunks
-		.map((chunk: Node) => {
+		.map((chunk) => {
 			if (chunk.type === 'Text') {
 				return escape_template(escape(chunk.data).replace(/"/g, '&quot;'));
 			}
@@ -15,4 +14,4 @@ export function stringify_attribute(attribute: Attribute, is_ssr: boolean) {
 				: '${' + snip(chunk) + '}';
 		})
 		.join('');
-}
\ No newline at end of file
+}
diff --git a/src/interfaces.ts b/src/interfaces.ts
index 68fef7472e..90ee60d1be 100644
--- a/src/interfaces.ts
+++ b/src/interfaces.ts
@@ -1,10 +1,51 @@
-export interface Node {
+interface BaseNode {
 	start: number;
 	end: number;
 	type: string;
+	children?: Node[];
 	[prop_name: string]: any;
 }
 
+export interface Text extends BaseNode {
+	type: 'Text',
+	data: string;
+}
+
+export interface MustacheTag extends BaseNode {
+	type: 'MustacheTag',
+	expresion: Node;
+}
+
+export type DirectiveType = 'Action'
+	| 'Animation'
+	| 'Binding'
+	| 'Class'
+	| 'EventHandler'
+	| 'Let'
+	| 'Ref'
+	| 'Transition';
+
+interface BaseDirective extends BaseNode {
+	type: DirectiveType;
+	expression: null|Node;
+	name: string;
+	modifiers: string[]
+}
+
+export interface Transition extends BaseDirective{
+	type: 'Transition',
+	intro: boolean;
+	outro: boolean;
+}
+
+export type Directive = BaseDirective | Transition;
+
+export type Node = Text
+	| MustacheTag
+	| BaseNode
+	| Directive
+	| Transition;
+
 export interface Parser {
 	readonly template: string;
 	readonly filename?: string;
@@ -92,4 +133,4 @@ export interface Var {
 	initialised?: boolean;
 	hoistable?: boolean;
 	subscribable?: boolean;
-}
\ No newline at end of file
+}
diff --git a/src/parse/read/expression.ts b/src/parse/read/expression.ts
index 4d1de89fe7..615f270112 100644
--- a/src/parse/read/expression.ts
+++ b/src/parse/read/expression.ts
@@ -1,9 +1,10 @@
 import { parse_expression_at } from '../acorn';
 import { Parser } from '../index';
+import { Identifier, Node, SimpleLiteral } from 'estree';
 
 const literals = new Map([['true', true], ['false', false], ['null', null]]);
 
-export default function read_expression(parser: Parser) {
+export default function read_expression(parser: Parser): Node {
 	const start = parser.index;
 
 	const name = parser.read_until(/\s*}/);
@@ -17,7 +18,7 @@ export default function read_expression(parser: Parser) {
 				end,
 				value: literals.get(name),
 				raw: name,
-			};
+			} as SimpleLiteral;
 		}
 
 		return {
@@ -25,7 +26,7 @@ export default function read_expression(parser: Parser) {
 			start,
 			end: start + name.length,
 			name,
-		};
+		} as Identifier;
 	}
 
 	parser.index = start;
@@ -34,7 +35,7 @@ export default function read_expression(parser: Parser) {
 		const node = parse_expression_at(parser.template, parser.index);
 		parser.index = node.end;
 
-		return node;
+		return node as Node;
 	} catch (err) {
 		parser.acorn_error(err);
 	}
diff --git a/src/parse/state/tag.ts b/src/parse/state/tag.ts
index 56195549d8..f7f5a93574 100644
--- a/src/parse/state/tag.ts
+++ b/src/parse/state/tag.ts
@@ -4,7 +4,7 @@ import read_style from '../read/style';
 import { decode_character_references } from '../utils/html';
 import { is_void } from '../../utils/names';
 import { Parser } from '../index';
-import { Node } from '../../interfaces';
+import { Directive, DirectiveType, Node, Text } from '../../interfaces';
 import fuzzymatch from '../../utils/fuzzymatch';
 import list from '../../utils/list';
 
@@ -401,7 +401,7 @@ function read_attribute(parser: Parser, unique_names: Set<string>) {
 		}
 
 		if (value[0]) {
-			if (value.length > 1 || value[0].type === 'Text') {
+			if ((value as Array<any>).length > 1 || value[0].type === 'Text') {
 				parser.error({
 					code: `invalid-directive-value`,
 					message: `Directive value must be a JavaScript expression enclosed in curly braces`
@@ -409,7 +409,7 @@ function read_attribute(parser: Parser, unique_names: Set<string>) {
 			}
 		}
 
-		const directive = {
+		const directive: Directive = {
 			start,
 			end,
 			type,
@@ -445,7 +445,7 @@ function read_attribute(parser: Parser, unique_names: Set<string>) {
 	};
 }
 
-function get_directive_type(name) {
+function get_directive_type(name: string):DirectiveType {
 	if (name === 'use') return 'Action';
 	if (name === 'animate') return 'Animation';
 	if (name === 'bind') return 'Binding';
@@ -471,15 +471,15 @@ function read_attribute_value(parser: Parser) {
 	return value;
 }
 
-function read_sequence(parser: Parser, done: () => boolean) {
-	let current_chunk: Node = {
+function read_sequence(parser: Parser, done: () => boolean): Node[] {
+	let current_chunk: Text = {
 		start: parser.index,
 		end: null,
 		type: 'Text',
 		data: '',
 	};
 
-	const chunks = [];
+	const chunks: Node[] = [];
 
 	while (parser.index < parser.template.length) {
 		const index = parser.index;
diff --git a/src/preprocess/index.ts b/src/preprocess/index.ts
index 2666e5fb7f..a9dad9f05b 100644
--- a/src/preprocess/index.ts
+++ b/src/preprocess/index.ts
@@ -74,6 +74,7 @@ export default async function preprocess(
 	preprocessor: PreprocessorGroup | PreprocessorGroup[],
 	options?: { filename?: string }
 ) {
+	// @ts-ignore todo: doublecheck
 	const filename = (options && options.filename) || preprocessor.filename; // legacy
 	const dependencies = [];