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Merge the keys of a union or intersection of objects into a single type.
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| /** | |
| * Merge the keys of a union or intersection of objects into a single type. | |
| * | |
| * @example | |
| * ```ts | |
| * type GetBlockOptions = { | |
| * includeTransactions?: boolean | undefined | |
| * } & ( | |
| * | { | |
| * blockHash?: string | undefined; | |
| * blockNumber?: never | undefined; | |
| * blockTag?: never | undefined; | |
| * } | |
| * | { | |
| * blockHash?: never | undefined; | |
| * blockNumber?: bigint | undefined; | |
| * blockTag?: never | undefined; | |
| * } | |
| * | { | |
| * blockHash?: never | undefined; | |
| * blockNumber?: never | undefined; | |
| * blockTag?: string | undefined; | |
| * } | |
| * ) | |
| * | |
| * type Merged = MergeKeys<GetBlockOptions>; | |
| * // { | |
| * // includeTransactions?: boolean | undefined; | |
| * // blockHash?: string | undefined; | |
| * // blockNumber?: bigint | undefined; | |
| * // blockTag?: string | undefined; | |
| * // } | |
| * ``` | |
| */ | |
| export type MergeKeys<T> = | |
| UnionToIntersection<T> extends infer I | |
| ? { | |
| // Each key of the intersection is first checked against the union type, | |
| // T. If it exists in every member of T, then T[K] will be a union of | |
| // the value types. Otherwise, I[K] is used. I[K] is the value type of | |
| // the key in the intersection which will be `never` for keys with | |
| // conflicting value types. | |
| [K in keyof I]: K extends keyof T ? T[K] : I[K]; | |
| } | |
| : never; | |
| // https://gist.github.com/ryangoree/e816db56e5fc12aab14e64cea415436c | |
| type UnionToIntersection<T> = ( | |
| T extends any ? (member: T) => any : never | |
| ) extends (member: infer R) => any | |
| ? R | |
| : never; |
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