Discriminated union pattern

typescript

type Success = { kind: "success"; data: string };
type Failure = { kind: "error"; message: string };
type Result = Success | Failure;

Explanation

Discriminated unions pair especially well with narrowing in control flow.

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Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.

Same sheet · prioritizing Mapped and Conditional Types

Create a type by iterating over keys.

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Choose a type based on another type relationship.

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Use `infer` inside a conditional type.

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Use a type parameter for reusable function typing.

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Get a union of property names from a type.

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Make every property optional.

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