fix: array handling in SchemaOf type (#1169)

- Move array before object so that inference works correctly
- Include lazy as part of array type, to match the class definition

src/index.ts

@@ -6,7 +6,7 @@ import DateSchema, { create as dateCreate } from './date';
 import ObjectSchema, { AnyObject, create as objectCreate } from './object';
 import ArraySchema, { create as arrayCreate } from './array';
 import { create as refCreate } from './Reference';
-import { create as lazyCreate } from './Lazy';
+import Lazy, { create as lazyCreate } from './Lazy';
 import ValidationError from './ValidationError';
 import reach from './util/reach';
 import isSchema from './util/isSchema';
@@ -39,20 +39,20 @@ function addMethod(schemaType: any, name: string, fn: any) {
 
 type ObjectSchemaOf<T extends AnyObject> = ObjectSchema<
   {
-    [k in keyof T]-?: T[k] extends AnyObject
+    [k in keyof T]-?: T[k] extends Array<infer E>
+      ? ArraySchema<SchemaOf<E>>
+      : T[k] extends AnyObject
       ? // we can't use  ObjectSchema<{ []: SchemaOf<T[k]> }> b/c TS produces a union of two schema
         ObjectSchemaOf<T[k]>
-      : T[k] extends Array<infer E>
-      ? ArraySchema<SchemaOf<E>>
       : BaseSchema<Maybe<T[k]>, AnyObject, T[k]>;
   }
 >;
 
-type SchemaOf<T> = T extends AnyObject
-  ? ObjectSchemaOf<T>
-  : T extends Array<infer E>
-  ? ArraySchema<SchemaOf<E>>
-  : BaseSchema<Maybe<T>, AnyObject, T>;
+type SchemaOf<T> = T extends Array<infer E>
+    ? ArraySchema<SchemaOf<E> | Lazy<SchemaOf<E>>>
+    : T extends AnyObject
+    ? ObjectSchemaOf<T>
+    : BaseSchema<Maybe<T>, AnyObject, T>;
 
 export type AnyObjectSchema = ObjectSchema<any, any, any, any>;