added context hook to allow the override of the default binder

scm-ui/ui-extensions/src/useBinder.test.tsx

@@ -0,0 +1,29 @@
+import useBinder, { BinderContext } from "./useBinder";
+import { Binder } from "./binder";
+import { mount } from "enzyme";
+import "@scm-manager/ui-tests/enzyme";
+import React from "react";
+
+describe("useBinder tests", () => {
+  const BinderName = () => {
+    const binder = useBinder();
+    return <>{binder.name}</>;
+  };
+
+  it("should return default binder", () => {
+    const rendered = mount(<BinderName />);
+    expect(rendered.text()).toBe("default");
+  });
+
+  it("should return binder from context", () => {
+    const binder = new Binder("from-context");
+    const app = (
+      <BinderContext.Provider value={binder}>
+        <BinderName />
+      </BinderContext.Provider>
+    );
+
+    const rendered = mount(app);
+    expect(rendered.text()).toBe("from-context");
+  });
+});