Fix renderer crashing with effecful hooks

Author: marvinhagemeister

src/index.js

@@ -76,7 +76,8 @@ function renderToString(vnode, context, opts, inner, isSvgMode, selectValue) {
 		else {
 			let rendered;
 
-			let c = vnode.__c = { __v: vnode, context, props: vnode.props };
+			let c = vnode.__c = { __v: vnode, context, props: vnode.props, __h: [] };
+
 			// options.render
 			if (options.__r) options.__r(vnode);
 
@@ -101,8 +102,6 @@ function renderToString(vnode, context, opts, inner, isSvgMode, selectValue) {
 				c.__v = vnode;
 				// turn off stateful re-rendering:
 				c._dirty = c.__d = true;
-				// required by hooks
-				c._renderCallbacks = [];
 				c.props = props;
 				if (c.state==null) c.state = {};
 				c.context = cctx;

test/render.js

@@ -1,6 +1,6 @@
 import { render, shallowRender } from '../src';
 import { h, Component, createContext, Fragment } from 'preact';
-import { useState, useContext, useEffect } from 'preact/hooks';
+import { useState, useContext, useEffect, useLayoutEffect } from 'preact/hooks';
 import chai, { expect } from 'chai';
 import { spy, stub, match } from 'sinon';
 import sinonChai from 'sinon-chai';
@@ -711,6 +711,25 @@ describe('render', () => {
 			}).to.not.throw();
 		});
 
+		it('should not crash with effectful hooks', () => {
+			function Foo() {
+				useEffect(() => {
+					// Nothing
+				}, []);
+
+				useLayoutEffect(() => {
+					// Nothing
+				}, []);
+
+				return <div />;
+			}
+
+			// eslint-disable-next-line prefer-arrow-callback
+			expect(function() {
+				render(<Foo />);
+			}).to.not.throw();
+		});
+
 		it('should work with useContext and default value', () => {
 			let Ctx = createContext('foo');
 			function Foo() {