Apply a joi.array.min to non-optional file upload fields (#308)

* Apply a joi.array.min to non-optional file upload fields

* Add test to assert schema applies a default min items for the file upload

Author: davidjamesstone

src/server/plugins/engine/components/FileUploadField.test.ts

@@ -648,6 +648,29 @@ describe('FileUploadField', () => {
           }
         ]
       },
+      {
+        description: 'Schema default min',
+        component: {
+          title: 'Example file upload field',
+          name: 'myComponent',
+          type: ComponentType.FileUploadField,
+          options: {},
+          schema: {}
+        } satisfies FileUploadFieldComponent,
+        assertions: [
+          {
+            input: getFormData([]),
+            output: {
+              value: getFormData([]),
+              errors: [
+                expect.objectContaining({
+                  text: 'Example file upload field must contain at least 1 items'
+                })
+              ]
+            }
+          }
+        ]
+      },
       {
         description: 'Schema length',
         component: {

src/server/plugins/engine/components/FileUploadField.ts

@@ -134,6 +134,8 @@ export class FileUploadField extends FormComponent {
 
       if (typeof schema.min === 'number') {
         formSchema = formSchema.min(schema.min)
+      } else if (options.required !== false) {
+        formSchema = formSchema.min(1)
       }
     } else {
       formSchema = formSchema.length(schema.length)