60 lines
1.2 KiB
TypeScript
60 lines
1.2 KiB
TypeScript
import {RequiredKeysOf} from './required-keys-of';
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/**
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Creates a type that represents `true` or `false` depending on whether the given type has any required fields.
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This is useful when you want to create an API whose behavior depends on the presence or absence of required fields.
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@example
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```
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import type {HasRequiredKeys} from 'type-fest';
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type GeneratorOptions<Template extends object> = {
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prop1: number;
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prop2: string;
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} & (HasRequiredKeys<Template> extends true
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? {template: Template}
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: {template?: Template});
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interface Template1 {
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optionalSubParam?: string;
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}
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interface Template2 {
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requiredSubParam: string;
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}
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type Options1 = GeneratorOptions<Template1>;
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type Options2 = GeneratorOptions<Template2>;
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const optA: Options1 = {
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prop1: 0,
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prop2: 'hi'
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};
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const optB: Options1 = {
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prop1: 0,
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prop2: 'hi',
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template: {}
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};
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const optC: Options1 = {
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prop1: 0,
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prop2: 'hi',
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template: {
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optionalSubParam: 'optional value'
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}
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};
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const optD: Options2 = {
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prop1: 0,
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prop2: 'hi',
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template: {
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requiredSubParam: 'required value'
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}
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};
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```
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@category Utilities
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*/
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export type HasRequiredKeys<BaseType extends object> = RequiredKeysOf<BaseType> extends never ? false : true;
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