this is undefined in bound functions when shallow rendering #1756
Description
Describe the bug
The following test passes in 3.4.1 but fails in 3.4.2.
class Comp extends Component {
state = {
key: "",
}
componentDidMount() {
this.instanceFunction();
}
instanceFunction = () => this.setState(() => ({ key: "value" }));
render() {
const { key } = this.state;
return null;
}
}
it("should work", () => {
shallow(<Comp />);
});The error in 3.4.2 is:
FAIL src/test.js
✕ should work (16ms)
● should work
Method “setState” is only meant to be run on a single node. undefined found instead.
11 | }
12 |
> 13 | instanceFunction = () => this.setState(() => ({ key: "value" }));
| ^
14 |
15 | render() {
16 | const { key } = this.state;
at ShallowWrapper.single (node_modules/enzyme/build/ShallowWrapper.js:1718:17)
at ShallowWrapper.setState (node_modules/enzyme/build/ShallowWrapper.js:499:14)
at Comp.ShallowWrapper.instance.setState (node_modules/enzyme/build/ShallowWrapper.js:184:33)
at Comp.setState [as instanceFunction] (src/test.js:13:33)
at Comp.instanceFunction [as componentDidMount] (src/test.js:10:10)
at node_modules/enzyme/build/ShallowWrapper.js:189:20
at Object.batchedUpdates (node_modules/enzyme-adapter-react-16/build/ReactSixteenAdapter.js:392:22)
at new ShallowWrapper (node_modules/enzyme/build/ShallowWrapper.js:188:24)
at shallow (node_modules/enzyme/build/shallow.js:21:10)
at Object.<anonymous> (src/test.js:22:3)
Test Suites: 1 failed, 1 total
Tests: 1 failed, 1 total
Snapshots: 0 total
Time: 2.147s
Ran all test suites matching /src\/test.js/i.
error Command failed with exit code 1.To Reproduce
Steps to reproduce the behavior:
- Run the above test with
enzyme@3.4.2
Expected behavior
The test should pass.
Desktop (please complete the following information):
- OS: Mac OSX (but also fails in Windows)
- Browser n/a
- Version n/a