Test for HOC at https://gist.github.com/mikebridge/3b1746a3208e0eb6bc3e1a00275ad941

withQueryString.test.tsx

import * as React from "react";
import {shallow, mount} from "enzyme";
import withQueryString from "./withQueryString";
import {IQueryStringProps} from "./withQueryString";
import {MemoryRouter} from "react-router";

interface ITestComponentOwnProps {}

class TestComponent extends React.Component<IQueryStringProps & ITestComponentOwnProps, {}> {

    public render(): JSX.Element {
        const qsProps = JSON.stringify(this.props.params);
        return (<div>{qsProps}</div>);
    }

}


describe("withQueryString", () => {

    const TestComponentWithQueryString = withQueryString(TestComponent);

    it("injects the query string into the component as an object", () => {
        const wrapper = shallow(
            <MemoryRouter  initialEntries={["/test?foo=bar"]}>
                <TestComponentWithQueryString />
            </MemoryRouter>);
        expect(wrapper.html()).toContain("{&quot;foo&quot;:&quot;bar&quot;}");
    });

    it("injects an empty object when no query string", () => {
        const wrapper = shallow(
            <MemoryRouter  initialEntries={["/test"]}>
                <TestComponentWithQueryString />
            </MemoryRouter>);
        expect(wrapper.html()).toContain("{}");
    });


});