Allow mapError to map entire error type (except for its tag) so its a…

…nalagous to mapError on DFs

src/composable/composable.ts

@@ -111,9 +111,9 @@ function map<T extends Composable, R>(
 ) {
   return (async (...args) => {
     const res = await fn(...args)
-    if(!res.success) return error(res.errors)
+    if (!res.success) return error(res.errors)
     const mapped = await composable(mapper)(res.data)
-    if(!mapped.success) return error(mapped.errors)
+    if (!mapped.success) return error(mapped.errors)
     return mapped
   }) as Composable<(...args: Parameters<T>) => R>
 }
@@ -135,20 +135,20 @@ function map<T extends Composable, R>(
  */
 function mapError<T extends Composable, R>(
   fn: T,
-  mapper: (err: ErrorWithMessage) => ErrorWithMessage,
+  mapper: (err: Omit<Failure, 'success'>) => Omit<Failure, 'success'>,
 ) {
   return (async (...args) => {
     const res = await fn(...args)
-    return !res.success ? error(res.errors.map(mapper)) : success(res.data)
+    return !res.success ? error(mapper(res).errors) : success(res.data)
   }) as T
 }
 
 export {
   all,
+  collect,
   composable,
   composable as cf,
   composable as λ,
-  collect,
   error,
   map,
   mapError,

src/composable/index.test.ts

@@ -1,8 +1,4 @@
-import {
-  assertEquals,
-  describe,
-  it,
-} from '../test-prelude.ts'
+import { assertEquals, describe, it } from '../test-prelude.ts'
 import { map, mapError, pipe, sequence } from './index.ts'
 import type { Composable, ErrorWithMessage, Result } from './index.ts'
 import { Equal, Expect } from './types.test.ts'
@@ -257,10 +253,7 @@ describe('map', () => {
   })
 
   it('maps over a composition', async () => {
-    const fn = map(
-      pipe(λ(add), λ(toString)),
-      (a) => typeof a === 'string',
-    )
+    const fn = map(pipe(λ(add), λ(toString)), (a) => typeof a === 'string')
     const res = await fn(1, 2)
 
     type _FN = Expect<
@@ -290,7 +283,9 @@ const cleanError = (err: ErrorWithMessage) => ({
 })
 describe('mapError', () => {
   it('maps over the error results of an Composable function', async () => {
-    const fn = mapError(λ(faultyAdd), cleanError)
+    const fn = mapError(λ(faultyAdd), ({ errors }) => ({
+      errors: errors.map(cleanError),
+    }))
     const res = await fn(1, 2)
 
     type _FN = Expect<