Avoid synchronously adding setState callbacks

mangle.json

@@ -44,6 +44,7 @@
       "$_force": "__e",
       "$_nextState": "__s",
       "$_renderCallbacks": "__h",
+      "$_stateCallbacks": "_sb",
       "$_vnode": "__v",
       "$_children": "__k",
       "$_pendingSuspensionCount": "__u",

src/component.js

@@ -47,7 +47,9 @@ Component.prototype.setState = function(update, callback) {
 	if (update == null) return;
 
 	if (this._vnode) {
-		if (callback) this._renderCallbacks.push(callback);
+		if (callback) {
+			this._stateCallbacks.push(callback);
+		}
 		enqueueRender(this);
 	}
 };

src/diff/index.js

@@ -89,6 +89,7 @@ export function diff(
 				c._globalContext = globalContext;
 				isNew = c._dirty = true;
 				c._renderCallbacks = [];
+				c._stateCallbacks = [];
 			}
 
 			// Invoke getDerivedStateFromProps
@@ -109,6 +110,11 @@ export function diff(
 			oldProps = c.props;
 			oldState = c.state;
 
+			for (tmp = 0; tmp < c._stateCallbacks.length; tmp++) {
+				c._renderCallbacks.push(c._stateCallbacks[tmp]);
+				c._stateCallbacks = [];
+			}
+
 			// Invoke pre-render lifecycle methods
 			if (isNew) {
 				if (

src/internal.d.ts

@@ -133,6 +133,7 @@ export interface Component<P = {}, S = {}> extends preact.Component<P, S> {
 	_dirty: boolean;
 	_force?: boolean;
 	_renderCallbacks: Array<() => void>; // Only class components
+	_stateCallbacks: Array<() => void>; // Only class components
 	_globalContext?: any;
 	_vnode?: VNode<P> | null;
 	_nextState?: S | null; // Only class components

test/browser/lifecycles/componentDidUpdate.test.js

@@ -381,5 +381,55 @@ describe('Lifecycle methods', () => {
 			expect(Inner.prototype.componentDidUpdate).to.have.been.called;
 			expect(outerChildText).to.equal(`Outer: ${newValue.toString()}`);
 		});
+
+		it('should not interfere with setState callbacks', () => {
+			let invocation;
+
+			class Child extends Component {
+				componentDidMount() {
+					this.props.setValue(10);
+				}
+				render() {
+					return <p>Hello world</p>;
+				}
+			}
+
+			class App extends Component {
+				constructor(props) {
+					super(props);
+					this.state = {
+						show: false,
+						count: null
+					};
+				}
+
+				componentDidMount() {
+					// eslint-disable-next-line
+					this.setState({ show: true });
+				}
+
+				componentDidUpdate() {}
+
+				render() {
+					if (this.state.show) {
+						return (
+							<Child
+								setValue={i =>
+									this.setState({ count: i }, () => {
+										invocation = this.state;
+									})
+								}
+							/>
+						);
+					}
+					return null;
+				}
+			}
+
+			render(<App />, scratch);
+
+			rerender();
+			expect(invocation.count).to.equal(10);
+		});
 	});
 });