From 55f5a1f6decc0993b1a1d1a6a62460fe6d7fdfe2 Mon Sep 17 00:00:00 2001
From: Nathan Hagen <nathan@nh.run>
Date: Fri, 2 Apr 2021 15:34:43 -0400
Subject: [PATCH] feat(partial): add support for returning type from partial if
 passed a type

---
 docs/reference/utilities.md              |  2 +-
 src/structs/utilities.ts                 |  4 ++--
 src/utils.ts                             |  2 +-
 test/validation/partial/composed-type.ts | 18 ++++++++++++++++++
 4 files changed, 22 insertions(+), 4 deletions(-)
 create mode 100644 test/validation/partial/composed-type.ts

diff --git a/docs/reference/utilities.md b/docs/reference/utilities.md
index 6ff77eff..37dc26ec 100644
--- a/docs/reference/utilities.md
+++ b/docs/reference/utilities.md
@@ -92,7 +92,7 @@ partial(
 { name: 'Jane' }
 ```
 
-`partial` allows you to create a new struct based on an existing object struct, but with all of its properties being optional.
+`partial` allows you to create a new struct based on an existing object or type struct, but with all of its properties being optional.
 
 ### `pick`
 
diff --git a/src/structs/utilities.ts b/src/structs/utilities.ts
index 1d444c05..c2112561 100644
--- a/src/structs/utilities.ts
+++ b/src/structs/utilities.ts
@@ -170,7 +170,7 @@ export function omit<S extends ObjectSchema, K extends keyof S>(
 }
 
 /**
- * Create a new struct based on an existing object struct, but with all of its
+ * Create a new struct based on an existing object or type struct, but with all of its
  * properties allowed to be `undefined`.
  *
  * Like TypeScript's `Partial` utility.
@@ -186,7 +186,7 @@ export function partial<S extends ObjectSchema>(
     schema[key] = optional(schema[key])
   }
 
-  return object(schema) as any
+  return (struct.type === 'type' ? type : object)(schema) as any
 }
 
 /**
diff --git a/src/utils.ts b/src/utils.ts
index ff587244..b0815aca 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -277,7 +277,7 @@ export type Optionalize<S extends object> = OmitBy<S, undefined> &
   Partial<PickBy<S, undefined>>
 
 /**
- * Transform an object schema type to represent a partial.
+ * Transform an object or type schema type to represent a partial.
  */
 
 export type PartialObjectSchema<S extends ObjectSchema> = {
diff --git a/test/validation/partial/composed-type.ts b/test/validation/partial/composed-type.ts
new file mode 100644
index 00000000..55466867
--- /dev/null
+++ b/test/validation/partial/composed-type.ts
@@ -0,0 +1,18 @@
+import { partial, type, string, number } from '../../..'
+
+export const Struct = partial(
+  type({
+    name: string(),
+    age: number(),
+  })
+)
+
+export const data = {
+  name: 'john',
+  location: 'mars',
+}
+
+export const output = {
+  name: 'john',
+  location: 'mars',
+}