feat: Add useTopics model hook and query for topics listing

 - This commit adds a new `useTopics` model hook, which makes GraphQL
requests to the server to administer Kafka topics.
 - The hook returns a set of sub-hooks, with just the `useGetTopics`
sub-hook implemented for now. `useGetTopics` returns the list of topics
(including name, number of partitions and number of replicas).

Contributes to: #124

Signed-off-by: Andrew Borley <[email protected]>

Author: ajborley

client/Bootstrap/index.tsx

@@ -8,9 +8,12 @@ import { init } from 'i18n';
 import { ApolloProvider } from '@apollo/client';
 
 import { apolloClient } from 'Bootstrap/GraphQLClient';
-import { ConfigFeatureFlagProvider, FeatureFlag } from 'Contexts';
+import {
+  ConfigFeatureFlagProvider,
+  FeatureFlag,
+  LoggingProvider,
+} from 'Contexts';
 import { Home } from 'Panels/Home';
-import { LoggingProvider } from 'Contexts';
 
 init(); //Bootstrap i18next support
 ReactDOM.render(

client/Models/README.md

@@ -0,0 +1,37 @@
+# Models
+
+This directory contains custom [React Hooks](https://reactjs.org/docs/hooks-intro.html#motivation). Unlike the [Hooks](../Hooks/README.md), these hooks encapsulate specific business logic for views to utilise.
+
+## Test approach
+
+Elements should be tested in a functional manor. See [Test Driven Development](../../docs/Test.md#style-of-test).
+
+## Expected files
+
+For a given model `useFoo`, the expected files are as follows:
+
+```
+Models/
+  index.ts
+  types.ts
+  useFoo/
+    README.md
+    useFoo.ts
+    useFoo.spec.ts
+    useFoo.assets.ts
+    useFoo.types.ts
+```
+
+Where:
+
+- index.ts acts as a barrel file, exporting the hooks defined in the Hooks directory
+- types.ts acts as a barrel file, exporting all the public types of each context
+- README.md is the readme for this hook, detailing design choices and usage
+- useFoo.ts is the hook implementation
+- useFoo.spec.ts are the tests for this hook
+- useFoo.assets.ts are the test assets for this hook
+- useFoo.types.ts are the types for this hook
+
+## Implemented hooks
+
+- [`useTopics`](./useTopics/README.md) - a hook providing sub-hooks to administer Kafka topics via GraphQL queries.

client/Models/index.ts

@@ -0,0 +1,5 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+export * from './useTopics';

client/Models/useTopics/Hook.ts

@@ -0,0 +1,14 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+import { GET_TOPICS } from 'Queries/Topics';
+import { useQuery } from '@apollo/client';
+import { useTopicsType } from './useTopics.types';
+
+export const useTopics = (): useTopicsType => {
+  const useGetTopics = () => useQuery(GET_TOPICS);
+  return {
+    useGetTopics,
+  };
+};

client/Models/useTopics/README.md

@@ -0,0 +1,5 @@
+# useTopics
+
+The `useTopics` hook returns sub-hooks to administer Kafka topics via GraphQL queries to the server `/api` endpoint. The sub-hooks returned by the `useTopics` hook are:
+
+- `useGetTopics()` - returns the list of topics, including name, partitions count and replicas count, as an [Apollo `QueryResult` object](https://www.apollographql.com/docs/react/api/react/hooks/#result).

client/Models/useTopics/index.ts

@@ -0,0 +1,7 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+export * from './Hook';
+export * from './useTopics.types';
+export * from './useTopics.assets';

client/Models/useTopics/useTopics.assets.ts

@@ -0,0 +1,24 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+import { generateMockDataResponseForGQLRequest } from 'utils/test/withApollo/withApollo.util';
+import { topicsType } from './useTopics.types';
+import { GET_TOPICS } from 'Queries/Topics';
+
+export const mockGetTopicsResponse: topicsType = {
+  topics: [
+    { name: 'testtopic1', partitions: 1, replicas: 1 },
+    { name: 'testtopic2', partitions: 2, replicas: 2 },
+    { name: 'testtopic3', partitions: 3, replicas: 3 },
+  ],
+};
+
+const successRequest = generateMockDataResponseForGQLRequest(
+  GET_TOPICS,
+  mockGetTopicsResponse
+);
+
+export const mockGetTopicsRequests = {
+  successRequest,
+};

client/Models/useTopics/useTopics.spec.tsx

@@ -0,0 +1,40 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+import React from 'react';
+import { renderHook, act } from '@testing-library/react-hooks';
+import { withApolloProviderReturning, apolloMockResponse } from 'utils/test';
+import { useTopics } from './Hook';
+import {
+  mockGetTopicsRequests,
+  mockGetTopicsResponse,
+} from './useTopics.assets';
+
+describe('`useTopics` hook', () => {
+  describe('`useGetTopics` hook', () => {
+    it('returns the expected content', async () => {
+      const { result, rerender } = renderHook(
+        () => useTopics().useGetTopics(),
+        {
+          wrapper: ({ children }) =>
+            withApolloProviderReturning(
+              [mockGetTopicsRequests.successRequest],
+              <React.Fragment>{children}</React.Fragment>
+            ),
+        }
+      );
+
+      expect(result.current.loading).toBe(true);
+      expect(result.current.data).toBeUndefined();
+
+      await act(async () => {
+        await apolloMockResponse();
+      });
+      rerender();
+
+      expect(result.current.loading).toBe(false);
+      expect(result.current.data).toEqual(mockGetTopicsResponse);
+    });
+  });
+});

client/Models/useTopics/useTopics.types.ts

@@ -0,0 +1,21 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+import { QueryResult } from '@apollo/client';
+
+/** the shape of the object returned by the useTopics hook */
+export type useTopicsType = {
+  useGetTopics: () => QueryResult<topicsType>;
+};
+
+/** the shape of the `data` returned by the useGetTopics hook */
+export type topicsType = {
+  topics: topicType[];
+};
+
+export type topicType = {
+  name: string;
+  partitions: number;
+  replicas: number;
+};

client/Panels/Home/Home.steps.tsx

@@ -5,7 +5,12 @@
 import { Given, When, Then, Fusion } from 'jest-cucumber-fusion';
 import { RenderResult } from '@testing-library/react';
 import merge from 'lodash.merge';
-import { renderWithCustomConfigFeatureFlagContext } from 'utils/test';
+import {
+  renderWithCustomConfigFeatureFlagContext,
+  withApolloProviderReturning,
+  apolloMockResponse,
+} from 'utils/test';
+import { mockGetTopicsRequests } from 'Models';
 import { Home } from '.';
 import React, { ReactElement } from 'react';
 
@@ -31,7 +36,10 @@ Given('a Home component', () => {
 When('it is rendered', () => {
   renderResult = renderWithCustomConfigFeatureFlagContext(
     coreConfigFromContext,
-    component
+    withApolloProviderReturning(
+      [mockGetTopicsRequests.successRequest],
+      component
+    )
   );
   showVersionSet = true;
 });
@@ -47,18 +55,28 @@ When('it is rendered with no version', () => {
         },
       },
     }),
-    component
+    withApolloProviderReturning(
+      [mockGetTopicsRequests.successRequest],
+      component
+    )
   );
   showVersionSet = false;
 });
 
-Then('it should display the expected text', () => {
+Then('it should display the expected text', async () => {
   const { getByText, queryByText } = renderResult;
   expect(getByText('Welcome to the Strimzi UI')).toBeInTheDocument();
   const versionString = `Version: ${coreConfigFromContext.client.about.version}`;
   showVersionSet
     ? expect(getByText(versionString)).toBeInTheDocument()
     : expect(queryByText(versionString)).not.toBeInTheDocument();
+
+  const loadingTopicsString = 'Loading...';
+  expect(getByText(loadingTopicsString)).toBeInTheDocument();
+
+  await apolloMockResponse();
+  expect(queryByText(loadingTopicsString)).not.toBeInTheDocument();
+  expect(getByText('Number of topics: 3')).toBeInTheDocument();
 });
 
 Fusion('Home.feature');

client/Panels/Home/Home.tsx

@@ -7,6 +7,7 @@ import get from 'lodash.get';
 import image from 'Images/logo.png';
 import './style.scss';
 import { useConfigFeatureFlag, useLogger } from 'Hooks';
+import { useTopics } from 'Models';
 
 const Home: FunctionComponent = ({ children }) => {
   const { client, featureFlags, isComplete } = useConfigFeatureFlag();
@@ -17,11 +18,19 @@ const Home: FunctionComponent = ({ children }) => {
   const { debug } = useLogger('Home');
   debug(`Client version to display: ${version}`);
 
+  const { useGetTopics } = useTopics();
+  const { data, loading } = useGetTopics();
+
   return (
     <div className='home'>
       <img src={image} alt='Strimzi logo' />
       <p>Welcome to the Strimzi UI</p>
       {showVersion && isComplete && <p>{`Version: ${version}`}</p>}
+      {loading || !data ? (
+        <p>Loading...</p>
+      ) : (
+        <p>{`Number of topics: ${data.topics.length}`}</p>
+      )}
       {children}
     </div>
   );

client/Queries/Topics/index.ts

@@ -0,0 +1,15 @@
+/*
+ * Copyright Strimzi authors.
+ * License: Apache License 2.0 (see the file LICENSE or http://apache.org/licenses/LICENSE-2.0.html).
+ */
+import gql from 'graphql-tag';
+
+export const GET_TOPICS = gql`
+  query {
+    topics {
+      name
+      partitions
+      replicas
+    }
+  }
+`;