refactor(pages): refine Article pages

* use rehype to update code blocks class names
* fix widget heading level (after a level 1 it should always be a level
2 and not 3)
* replace Spinner with LoadingPage and LoadingPageComments components to
keep layout coherent
* refactor useArticle and useComments hooks
* fix URLs in JSON LD schema
* add Cypress tests

8 files changed, 175 insertions, 67 deletions

diff --git a/src/utils/hooks/use-article.ts b/src/utils/hooks/use-article.ts
deleted file mode 100644
index 5e54ee4..0000000
--- a/src/utils/hooks/use-article.ts
+++ /dev/null
@@ -1,35 +0,0 @@
-import { useEffect, useState } from 'react';
-import useSWR from 'swr';
-import { convertPostToArticle, fetchPost } from '../../services/graphql';
-import type { Article, Maybe } from '../../types';
-
-export type UseArticleConfig = {
-  /**
-   * A fallback article
-   */
-  fallback?: Article;
-  /**
-   * The article slug
-   */
-  slug?: string;
-};
-
-/**
- * Retrieve an article by slug.
- *
- * @param {UseArticleConfig} config - The config.
- * @returns {Article|undefined} The matching article if it exists.
- */
-export const useArticle = ({
-  slug,
-  fallback,
-}: UseArticleConfig): Article | undefined => {
-  const { data } = useSWR(slug, fetchPost, {});
-  const [article, setArticle] = useState<Maybe<Article>>(fallback);
-
-  useEffect(() => {
-    if (data) convertPostToArticle(data).then((post) => setArticle(post));
-  }, [data]);
-
-  return article;
-};
diff --git a/src/utils/hooks/use-article/index.ts b/src/utils/hooks/use-article/index.ts
new file mode 100644
index 0000000..459fc6d
--- /dev/null
+++ b/src/utils/hooks/use-article/index.ts
@@ -0,0 +1 @@
+export * from './use-article';
diff --git a/src/utils/hooks/use-article/use-article.test.ts b/src/utils/hooks/use-article/use-article.test.ts
new file mode 100644
index 0000000..7c9574c
--- /dev/null
+++ b/src/utils/hooks/use-article/use-article.test.ts
@@ -0,0 +1,54 @@
+import {
+  afterEach,
+  beforeEach,
+  describe,
+  expect,
+  it,
+  jest,
+} from '@jest/globals';
+import { renderHook, waitFor } from '@testing-library/react';
+import { wpPostsFixture } from '../../../../tests/fixtures';
+import { ROUTES } from '../../constants';
+import { useArticle } from './use-article';
+
+describe('useArticle', () => {
+  beforeEach(() => {
+    /* Not sure why it is needed, but without it Jest was complaining with
+     * `Jest worker encountered 4 child process exceptions`... Maybe because of
+     * useSWR? */
+    jest.useFakeTimers({
+      doNotFake: ['queueMicrotask'],
+    });
+  });
+
+  afterEach(() => {
+    jest.runOnlyPendingTimers();
+    jest.useRealTimers();
+  });
+
+  /* eslint-disable max-statements */
+  it('fetch the requested article', async () => {
+    const { result } = renderHook(() => useArticle(wpPostsFixture[0].slug));
+
+    // Inaccurate assertions count because of waitFor...
+    //expect.assertions(8);
+    expect.hasAssertions();
+
+    expect(result.current.article).toBeUndefined();
+    expect(result.current.isError).toBe(false);
+    expect(result.current.isLoading).toBe(true);
+    expect(result.current.isValidating).toBe(true);
+
+    jest.advanceTimersToNextTimer();
+
+    await waitFor(() =>
+      expect(result.current.article?.slug).toBe(
+        `${ROUTES.ARTICLE}/${wpPostsFixture[0].slug}`
+      )
+    );
+    expect(result.current.isError).toBe(false);
+    expect(result.current.isLoading).toBe(false);
+    expect(result.current.isValidating).toBe(false);
+  });
+  /* eslint-enable max-statements */
+});
diff --git a/src/utils/hooks/use-article/use-article.ts b/src/utils/hooks/use-article/use-article.ts
new file mode 100644
index 0000000..fbbc6bd
--- /dev/null
+++ b/src/utils/hooks/use-article/use-article.ts
@@ -0,0 +1,28 @@
+import useSWR from 'swr';
+import { convertPostToArticle, fetchPost } from '../../../services/graphql';
+import type { Article, Maybe, WPPost } from '../../../types';
+
+export type UseArticleReturn<T extends Maybe<WPPost>> = {
+  article: T extends undefined ? Maybe<Article> : Article;
+  isError: boolean;
+  isLoading: boolean;
+  isValidating: boolean;
+};
+
+export const useArticle = <T extends Maybe<WPPost>>(
+  slug: string,
+  fallback?: T
+): UseArticleReturn<T> => {
+  const { data, error, isLoading, isValidating } = useSWR(slug, fetchPost, {
+    fallbackData: fallback,
+  });
+
+  if (error) console.error(error);
+
+  return {
+    article: data ? convertPostToArticle(data) : undefined,
+    isError: !!error,
+    isLoading,
+    isValidating,
+  } as UseArticleReturn<T>;
+};
diff --git a/src/utils/hooks/use-comments.ts b/src/utils/hooks/use-comments.ts
deleted file mode 100644
index 94a2d7e..0000000
--- a/src/utils/hooks/use-comments.ts
+++ /dev/null
@@ -1,32 +0,0 @@
-import useSWR from 'swr';
-import {
-  type FetchCommentsListInput,
-  fetchCommentsList,
-  convertWPCommentToComment,
-  buildCommentsTree,
-} from '../../services/graphql';
-import type { SingleComment } from '../../types';
-
-export type UseCommentsConfig = FetchCommentsListInput & {
-  fallback?: SingleComment[];
-};
-
-/**
- * Retrieve the comments of a page/article.
- *
- * @param {string | number} contentId - A page/article id.
- * @returns {SingleComment[]|undefined}
- */
-export const useComments = ({
-  fallback,
-  ...input
-}: UseCommentsConfig): SingleComment[] | undefined => {
-  const { data } = useSWR(input, fetchCommentsList, {});
-
-  if (!data) return fallback;
-
-  const comments = data.map(convertWPCommentToComment);
-  const commentsTree = buildCommentsTree(comments);
-
-  return commentsTree;
-};
diff --git a/src/utils/hooks/use-comments/index.ts b/src/utils/hooks/use-comments/index.ts
new file mode 100644
index 0000000..8f69ffd
--- /dev/null
+++ b/src/utils/hooks/use-comments/index.ts
@@ -0,0 +1 @@
+export * from './use-comments';
diff --git a/src/utils/hooks/use-comments/use-comments.test.ts b/src/utils/hooks/use-comments/use-comments.test.ts
new file mode 100644
index 0000000..f05f9eb
--- /dev/null
+++ b/src/utils/hooks/use-comments/use-comments.test.ts
@@ -0,0 +1,49 @@
+import {
+  afterEach,
+  beforeEach,
+  describe,
+  expect,
+  it,
+  jest,
+} from '@jest/globals';
+import { renderHook, waitFor } from '@testing-library/react';
+import { useComments } from './use-comments';
+
+describe('useComments', () => {
+  beforeEach(() => {
+    /* Not sure why it is needed, but without it Jest was complaining with
+     * `Jest worker encountered 4 child process exceptions`... Maybe because of
+     * useSWR? */
+    jest.useFakeTimers({
+      doNotFake: ['queueMicrotask'],
+    });
+  });
+
+  afterEach(() => {
+    jest.runOnlyPendingTimers();
+    jest.useRealTimers();
+  });
+
+  /* eslint-disable max-statements */
+  it('fetch the requested comments', async () => {
+    const { result } = renderHook(() => useComments({}));
+
+    // Inaccurate assertions count because of waitFor...
+    //expect.assertions(8);
+    expect.hasAssertions();
+
+    expect(result.current.comments).toBeUndefined();
+    expect(result.current.isError).toBe(false);
+    expect(result.current.isLoading).toBe(true);
+    expect(result.current.isValidating).toBe(true);
+
+    jest.advanceTimersToNextTimer();
+
+    await waitFor(() => expect(result.current.comments).toBeDefined());
+
+    expect(result.current.isError).toBe(false);
+    expect(result.current.isLoading).toBe(false);
+    expect(result.current.isValidating).toBe(false);
+  });
+  /* eslint-enable max-statements */
+});
diff --git a/src/utils/hooks/use-comments/use-comments.ts b/src/utils/hooks/use-comments/use-comments.ts
new file mode 100644
index 0000000..cb967a5
--- /dev/null
+++ b/src/utils/hooks/use-comments/use-comments.ts
@@ -0,0 +1,42 @@
+import useSWR from 'swr';
+import {
+  type FetchCommentsListInput,
+  buildCommentsTree,
+  convertWPCommentToComment,
+  fetchCommentsList,
+} from '../../../services/graphql';
+import type { Maybe, SingleComment, WPComment } from '../../../types';
+
+export type UseCommentsReturn<T extends Maybe<WPComment[]>> = {
+  comments: T extends undefined ? Maybe<SingleComment[]> : SingleComment[];
+  isError: boolean;
+  isLoading: boolean;
+  isValidating: boolean;
+};
+
+export type UseCommentsConfig<T extends Maybe<WPComment[]>> =
+  FetchCommentsListInput & {
+    fallback?: T;
+  };
+
+export const useComments = <T extends Maybe<WPComment[]>>({
+  fallback,
+  ...input
+}: UseCommentsConfig<T>): UseCommentsReturn<T> => {
+  const { data, error, isLoading, isValidating } = useSWR(
+    input,
+    fetchCommentsList,
+    { fallbackData: fallback }
+  );
+
+  if (error) console.error(error);
+
+  return {
+    comments: data
+      ? buildCommentsTree(data.map(convertWPCommentToComment))
+      : undefined,
+    isError: !!error,
+    isLoading,
+    isValidating,
+  } as UseCommentsReturn<T>;
+};