feat: add InferOk and InferErr utility types for Result type inference

EpicenterHQ · Dec 23, 2024 · 043d624 · 043d624
1 parent b4a0bc4
commit 043d624
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diff --git a/.changeset/spotty-rice-roll.md b/.changeset/spotty-rice-roll.md
@@ -0,0 +1,5 @@
+---
+"@epicenterhq/result": patch
+---
+
+Add InferOk and InferErr utility types for Result type inference
diff --git a/src/result.ts b/src/result.ts
@@ -2,12 +2,24 @@ export type Ok<T> = {
 	ok: true;
 	data: T;
 };
+
 export type Err<E> = {
 	ok: false;
 	error: E;
 };
+
 export type Result<T, E> = Ok<T> | Err<E>;
 
+export type InferOk<R extends Result<unknown, unknown>> = R extends Ok<infer U>
+	? U
+	: never;
+
+export type InferErr<R extends Result<unknown, unknown>> = R extends Err<
+	infer U
+>
+	? U
+	: never;
+
 export const Ok = <T>(data: T): Ok<T> => ({ ok: true, data });
 export const Err = <E>(error: E): Err<E> => ({ ok: false, error });