28 lines
939 B
JavaScript
28 lines
939 B
JavaScript
/**
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* Calls the given async function only when the returned promise-like object is
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* awaited. Afterwards, it provides the resolved value synchronously as `value`
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* property.
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*/ export function createLazyResult(fn) {
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let pendingResult;
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const result = {
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then (onfulfilled, onrejected) {
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if (!pendingResult) {
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pendingResult = fn();
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}
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pendingResult.then((value)=>{
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result.value = value;
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}).catch(()=>{
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// The externally awaited result will be rejected via `onrejected`. We
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// don't need to handle it here. But we do want to avoid an unhandled
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// rejection.
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});
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return pendingResult.then(onfulfilled, onrejected);
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}
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};
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return result;
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}
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export function isResolvedLazyResult(result) {
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return result.hasOwnProperty('value');
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}
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//# sourceMappingURL=lazy-result.js.map
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