16457e2adb
Summary: You need to use a type guard when narrowing types in a filter. Reviewed By: danielbuechele Differential Revision: D17163782 fbshipit-source-id: aa78bdd392653ebf1080a04e62e131b607e5181b
13 lines
397 B
TypeScript
13 lines
397 B
TypeScript
/**
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* Copyright 2018-present Facebook.
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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* @format
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*/
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// Typescript doesn't know Array.filter(Boolean) won't contain nulls.
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// So use Array.filter(notNull) instead.
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export function notNull<T>(x: T | null | undefined): x is T {
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return x !== null && x !== undefined;
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}
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