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[Fast Refresh] Fix crashes caused by rogue Proxies (facebook#20030)
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kri committed Oct 17, 2020
1 parent 2eb3181 commit 202dd0b
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Showing 2 changed files with 30 additions and 2 deletions.
14 changes: 12 additions & 2 deletions packages/react-refresh/src/ReactFreshRuntime.js
Original file line number Diff line number Diff line change
Expand Up @@ -178,6 +178,16 @@ function cloneSet<T>(set: Set<T>): Set<T> {
return clone;
}

// This is a safety mechanism to protect against rogue getters and Proxies.
function getProperty(object, property) {
try {
return object[property];
} catch (err) {
// Intentionally ignore.
return undefined;
}
}

export function performReactRefresh(): RefreshUpdate | null {
if (!__DEV__) {
throw new Error(
Expand Down Expand Up @@ -322,7 +332,7 @@ export function register(type: any, id: string): void {

// Visit inner types because we might not have registered them.
if (typeof type === 'object' && type !== null) {
switch (type.$$typeof) {
switch (getProperty(type, '$$typeof')) {
case REACT_FORWARD_REF_TYPE:
register(type.render, id + '$render');
break;
Expand Down Expand Up @@ -676,7 +686,7 @@ export function isLikelyComponentType(type: any): boolean {
}
case 'object': {
if (type != null) {
switch (type.$$typeof) {
switch (getProperty(type, '$$typeof')) {
case REACT_FORWARD_REF_TYPE:
case REACT_MEMO_TYPE:
// Definitely React components.
Expand Down
18 changes: 18 additions & 0 deletions packages/react-refresh/src/__tests__/ReactFresh-test.js
Original file line number Diff line number Diff line change
Expand Up @@ -3612,20 +3612,38 @@ describe('ReactFresh', () => {
const useStore = () => {};
expect(ReactFreshRuntime.isLikelyComponentType(useStore)).toBe(false);
expect(ReactFreshRuntime.isLikelyComponentType(useTheme)).toBe(false);
const rogueProxy = new Proxy({}, {
get(target, property) {
throw new Error();
}
});
expect(ReactFreshRuntime.isLikelyComponentType(rogueProxy)).toBe(false);

// These seem like function components.
const Button = () => {};
expect(ReactFreshRuntime.isLikelyComponentType(Button)).toBe(true);
expect(ReactFreshRuntime.isLikelyComponentType(Widget)).toBe(true);
const ProxyButton = new Proxy(Button, {
get(target, property) {
return target[property];
}
});
expect(ReactFreshRuntime.isLikelyComponentType(ProxyButton)).toBe(true);
const anon = (() => () => {})();
anon.displayName = 'Foo';
expect(ReactFreshRuntime.isLikelyComponentType(anon)).toBe(true);

// These seem like class components.
class Btn extends React.Component {}
class PureBtn extends React.PureComponent {}
const ProxyBtn = new Proxy(Btn, {
get(target, property) {
return target[property];
}
});
expect(ReactFreshRuntime.isLikelyComponentType(Btn)).toBe(true);
expect(ReactFreshRuntime.isLikelyComponentType(PureBtn)).toBe(true);
expect(ReactFreshRuntime.isLikelyComponentType(ProxyBtn)).toBe(true);
expect(
ReactFreshRuntime.isLikelyComponentType(
createReactClass({render() {}}),
Expand Down

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