From c0cb36c9d61045315fab20faa2d1769e56ffabd8 Mon Sep 17 00:00:00 2001
From: Tom Ratcliffe <tom.ratcliffe@grafana.com>
Date: Fri, 5 Apr 2024 17:32:16 +0100
Subject: [PATCH] Add initial test-utils file with render helper, wrapping in
 (most) required providers

---
 public/test/test-utils.tsx | 111 +++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 public/test/test-utils.tsx

diff --git a/public/test/test-utils.tsx b/public/test/test-utils.tsx
new file mode 100644
index 00000000000..2fa8c63daa5
--- /dev/null
+++ b/public/test/test-utils.tsx
@@ -0,0 +1,111 @@
+import { ToolkitStore } from '@reduxjs/toolkit/dist/configureStore';
+import { render, RenderOptions } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { KBarProvider } from 'kbar';
+import React from 'react';
+import { Provider } from 'react-redux';
+import { MemoryRouter } from 'react-router-dom';
+import { PreloadedState } from 'redux';
+import { getGrafanaContextMock } from 'test/mocks/getGrafanaContextMock';
+
+import { config } from '@grafana/runtime';
+import { ErrorBoundaryAlert } from '@grafana/ui';
+import { GrafanaContext, GrafanaContextType } from 'app/core/context/GrafanaContext';
+import { ModalsContextProvider } from 'app/core/context/ModalsContextProvider';
+import { ThemeProvider } from 'app/core/utils/ConfigProvider';
+import { configureStore } from 'app/store/configureStore';
+import { StoreState } from 'app/types/store';
+
+interface ExtendedRenderOptions extends RenderOptions {
+  /**
+   * Partial state to use for preloading store when rendering tests
+   */
+  preloadedState?: PreloadedState<StoreState>;
+  /**
+   * Optional
+   */
+  store?: ToolkitStore;
+  renderWithRouter?: boolean;
+}
+
+/**
+ * Wraps children in empty fragment - used to conditionally render in a router or not,
+ * as needed by tests
+ */
+const FragmentWrapper = ({ children }: { children: React.ReactNode }) => {
+  return children;
+};
+
+/**
+ * Get a wrapper component that implements all of the providers that components
+ * within the app will need
+ */
+const getWrapper = ({
+  store,
+  renderWithRouter,
+  grafanaContext,
+}: {
+  store?: ToolkitStore;
+  /**
+   * Should the wrapper be generated with a wrapping Router component?
+   * Useful if you're testing something that needs more nuanced routing behaviour
+   * and you want full control over it instead
+   */
+  renderWithRouter?: boolean;
+  grafanaContext?: GrafanaContextType;
+}): React.FC<{ children: React.ReactNode }> => {
+  const reduxStore = store || configureStore();
+  /**
+   * Conditional router - either a MemoryRouter or just a Fragment
+   */
+  const PotentialRouter = renderWithRouter ? MemoryRouter : FragmentWrapper;
+
+  const context = {
+    ...getGrafanaContextMock(),
+    ...grafanaContext,
+  };
+
+  /**
+   * Returns a wrapper that should (closely) match the main `AppWrapper`, so any tests are rendering
+   * in mostly the same providers as a "real" hierarchy
+   */
+  return function Wrapper({ children }: { children?: React.ReactNode }) {
+    return (
+      <Provider store={reduxStore}>
+        <ErrorBoundaryAlert style="page">
+          <GrafanaContext.Provider value={context}>
+            <ThemeProvider value={config.theme2}>
+              <KBarProvider>
+                <PotentialRouter>
+                  <ModalsContextProvider>{children}</ModalsContextProvider>
+                </PotentialRouter>
+              </KBarProvider>
+            </ThemeProvider>
+          </GrafanaContext.Provider>
+        </ErrorBoundaryAlert>
+      </Provider>
+    );
+  };
+};
+
+/**
+ * Extended [@testing-library/react render](https://testing-library.com/docs/react-testing-library/api/#render)
+ * method which wraps the passed element in all of the necessary Providers,
+ * so it can render correctly in the context of the application
+ */
+const customRender = (
+  ui: React.ReactElement,
+  { renderWithRouter = true, ...renderOptions }: ExtendedRenderOptions = {}
+) => {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const store = renderOptions.preloadedState ? configureStore(renderOptions?.preloadedState as any) : undefined;
+  const AllTheProviders = renderOptions.wrapper || getWrapper({ store, renderWithRouter });
+
+  return {
+    ...render(ui, { wrapper: AllTheProviders, ...renderOptions }),
+    store,
+  };
+};
+
+export * from '@testing-library/react';
+export { customRender as render, getWrapper, userEvent };