Add test

src/components/InputElements.tsx

@@ -3,7 +3,6 @@ import React, {
   ChangeEvent,
   useEffect,
   InputHTMLAttributes,
-  SyntheticEvent,
 } from "react";
 import { Converters, Converter } from "../core/Converters";
 import { FormContext, FormContextContent } from "./Form";
@@ -21,7 +20,10 @@ export interface BoundComponentProps
   validate?(value: any): Promise<ValidationResult>;
 
   /** onChange event handler has been extended to also receive the formContext */
-  onChange?(event: SyntheticEvent, formContext: FormContextContent): void;
+  onChange?(
+    event: ChangeEvent<HTMLInputElement>,
+    formContext: FormContextContent
+  ): void;
 }
 
 export interface InputProps extends BoundComponentProps {

test/InputElementsTest.tsx

@@ -225,4 +225,19 @@ describe("Input", function () {
     expect(form.toJSON()).toMatchSnapshot();
     expect(onSubmit).toHaveBeenCalledTimes(1);
   });
+
+  it("has access to formContext from onChange", async function () {
+    mount(
+      <Input
+        type="checkbox"
+        name="foo"
+        onChange={(e, formContext) => {
+          const value = e.target.checked;
+          expect(value).toBe(formContext.getValue("foo"));
+        }}
+      />,
+      { foo: true }
+    );
+    triggerChange({ value: "xxx", checked: true });
+  });
 });