feat: add ResultValue and ResultError helper types

src/index.ts

@@ -1,9 +1,11 @@
-export { Result, ok, Ok, err, Err, fromThrowable, safeTry } from './result'
+export { Err, Ok, Result, err, fromThrowable, ok, safeTry } from './result'
 export {
   ResultAsync,
-  okAsync,
   errAsync,
   fromAsyncThrowable,
   fromPromise,
   fromSafePromise,
+  okAsync,
 } from './result-async'
+export type { ResultError } from './result-error'
+export type { ResultValue } from './result-value'

src/result-error.ts

@@ -0,0 +1,12 @@
+import { Result } from 'result'
+import { ResultAsync } from 'result-async'
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type ResultError<T extends Result<any, any> | ResultAsync<any, any>> = T extends Result<
+  infer _,
+  infer E
+>
+  ? E
+  : T extends ResultAsync<infer _, infer E>
+  ? E
+  : never

src/result-value.ts

@@ -0,0 +1,12 @@
+import { Result } from 'result'
+import { ResultAsync } from 'result-async'
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type ResultValue<T extends Result<any, any> | ResultAsync<any, any>> = T extends Result<
+  infer U,
+  infer _
+>
+  ? U
+  : T extends ResultAsync<infer U, infer _>
+  ? U
+  : never