Fix stale state if sCU returned false

preactjs · Mar 7, 2019 · 661dbfb · 661dbfb
1 parent 27e4e22
commit 661dbfb
Show file tree

Hide file tree

Showing 2 changed files with 35 additions and 0 deletions.
diff --git a/src/diff/index.js b/src/diff/index.js
@@ -106,6 +106,7 @@ export function diff(dom, parentDom, newVNode, oldVNode, context, isSvg, excessD
 
 				if (!c._force && c.shouldComponentUpdate!=null && c.shouldComponentUpdate(newVNode.props, s, cctx)===false) {
 					c.props = newVNode.props;
+					c.state = s;
 					c._dirty = false;
 					break outer;
 				}

diff --git a/test/browser/lifecycle.test.js b/test/browser/lifecycle.test.js
@@ -1705,6 +1705,40 @@ describe('Lifecycle methods', () => {
 
 			expect(spy).to.be.calledOnce;
 		});
+
+		it('should update state reference when sCU returns false', () => {
+			let spy = sinon.spy();
+
+			let updateState;
+			class Foo extends Component {
+				constructor() {
+					super();
+					this.state = { foo: 1 };
+					updateState = () => this.setState({ foo: 2 });
+				}
+
+				shouldComponentUpdate(_, nextState) {
+					if (nextState !== this.state) {
+						spy(this.state, nextState);
+						return false;
+					}
+					return true;
+				}
+			}
+
+			render(<Foo />, scratch);
+			updateState();
+			rerender();
+
+			expect(spy).to.be.calledOnce;
+			expect(spy).to.be.calledWithMatch({ foo: 1 }, { foo: 2 });
+
+			updateState();
+			rerender();
+
+			expect(spy).to.be.calledWithMatch({ foo: 2 }, { foo: 2 });
+			expect(spy).to.be.calledTwice;
+		});
 	});