From f6f2c2f38f226afabca59e4aaf960926406c0592 Mon Sep 17 00:00:00 2001
From: Diogo Biazus <diogo@biazus.ca>
Date: Tue, 28 Nov 2023 22:37:04 -0500
Subject: [PATCH] Added missing default generic parameters when parsers are not
 given. Also remove the validation from our default undefined parser and
 simply ignore the input, since that seems more useful on compositions than
 erroring in case something is passed.

---
 src/constructor.test.ts |  9 +++++----
 src/constructor.ts      | 12 +++---------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/src/constructor.test.ts b/src/constructor.test.ts
index 0db58c9a..78a13b41 100644
--- a/src/constructor.test.ts
+++ b/src/constructor.test.ts
@@ -32,13 +32,14 @@ describe('makeDomainFunction', () => {
     })
 
     it('fails gracefully if gets something other than undefined', async () => {
-      const handler = mdf()(() => 'no input!')
-      type _R = Expect<Equal<typeof handler, DomainFunction<string>>>
+      const handler = mdf()((args) => args)
+      type _R = Expect<Equal<typeof handler, DomainFunction<undefined>>>
 
       assertEquals(await handler('some input'), {
-        success: false,
+        success: true,
+        data: undefined,
         errors: [],
-        inputErrors: [{ path: [], message: 'Expected undefined' }],
+        inputErrors: [],
         environmentErrors: [],
       })
     })
diff --git a/src/constructor.ts b/src/constructor.ts
index 08b7a8a5..2bcacd7d 100644
--- a/src/constructor.ts
+++ b/src/constructor.ts
@@ -87,7 +87,7 @@ async function safeResult<T>(fn: () => T): Promise<Result<T>> {
  *   return { message: `${greeting} ${user.name}` }
  * })
  */
-function makeDomainFunction<I, E>(
+function makeDomainFunction<I = undefined, E = Record<PropertyKey, unknown>>(
   inputSchema?: ParserSchema<I>,
   environmentSchema?: ParserSchema<E>,
 ) {
@@ -131,14 +131,8 @@ const objectSchema: ParserSchema<Record<PropertyKey, unknown>> = {
 }
 
 const undefinedSchema: ParserSchema<undefined> = {
-  safeParseAsync: (data: unknown) => {
-    if (data !== undefined) {
-      return Promise.resolve({
-        success: false,
-        error: { issues: [{ path: [], message: 'Expected undefined' }] },
-      })
-    }
-    return Promise.resolve({ success: true, data })
+  safeParseAsync: (_data: unknown) => {
+    return Promise.resolve({ success: true, data: undefined })
   },
 }