Fix isErr for unknown

package.json

@@ -8,7 +8,7 @@
     "error",
     "error-handling"
   ],
-  "version": "1.0.21",
+  "version": "1.0.22",
   "author": "Alex Shelkovskiy <alexshelkov@gmail.com>",
   "repository": "https://github.com/alexshelkov/result",
   "license": "MIT",

src/checks.ts

@@ -1,14 +1,12 @@
 import { Err } from './err';
 import { Failure, Success } from './result';
 
-export const isUnknownErr = (input: unknown): input is Err => {
+export const isErr = <Error = Err>(
+  input: Error | unknown
+): input is Error extends Err ? Error : never => {
   return typeof input === 'object' && input !== null && 'type' in input;
 };
 
-export const isErr = <Error = Err>(input: Error): input is Error extends Err ? Error : never => {
-  return isUnknownErr(input);
-};
-
 export const isErrType = <
   Type extends string,
   Fail,

src/index.ts

@@ -2,7 +2,7 @@ export { ErrUtil as Err, Err as ErrInfo, ErrLevel, Errs } from './err';
 
 export { Success, Failure, Result, Response } from './result';
 
-export { isUnknownErr, isErr, isErrType, isSuccessLike, isFailureLike } from './checks';
+export { isErr, isErrType, isSuccessLike, isFailureLike } from './checks';
 
 export {
   ok,

src/utils.ts

@@ -9,14 +9,7 @@ import {
   Response,
 } from './result';
 
-import {
-  isPromise,
-  isHaveStatus,
-  isSuccessLike,
-  isFailureLike,
-  isErr,
-  isUnknownErr,
-} from './checks';
+import { isPromise, isHaveStatus, isSuccessLike, isFailureLike, isErr } from './checks';
 
 import { Err, ErrUtil } from './err';
 
@@ -63,7 +56,7 @@ const maybeFailToResult = <Data, Fail>(
         prevResult.message,
         prevResult.code
       );
-    } else if (isUnknownErr(result)) {
+    } else if (isErr(result)) {
       exception = new FailureException(
         result.type,
         result as unknown as Fail,