32 lines
811 B
JavaScript
32 lines
811 B
JavaScript
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//@ts-check
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/**
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* Utility: use it at the end of switch statements to make sure all matches are covered.
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* Only useful in an editor that supports JSDOC strong typing.
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*
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* Use it like so
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* ```js
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* switch(data):
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* case A:
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* doThing();
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* break;
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* case B:
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* doOtherThing();
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* break;
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* default:
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* throw new UnreachableCaseError(state);
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* ```
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* It `data` may be more options, then `state` will be underlined with the error
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* ```
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* Argument of type 'T' is not assignable to parameter of type 'never'
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* ```
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* Where `T` is the type of `data`.
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* To remove the error, handle all cases.
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*/
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export class UnreachableCaseError extends Error {
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constructor(/** @type {never} */ value) {
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super(`Unreachable case: ${JSON.stringify(value)}`);
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}
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}
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export default UnreachableCaseError
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