feat: doc tags (same as blog tags) (#3646)

* [v2] tags to doc, same as tags to blog - [IN PROGRESS]

- Addition of plugin-content-docs

- Addition of DocTagsListPage in `docusaurus-theme-classic`

! Error exists for this commit towards the theme aspect and help required.

Commit towards #3434

* docs: make tags list page work

* temp: disable onBrokenLinks

* theme bootstrap: create DocTagsListPage

* DocTagsPage added and functionality too

- individual doc tag page added to show docs for that specific tag

* Added all Docs Tags Link

* add some shared tag utils

* move tag tests to _dogfooding

* fix type

* fix some tests

* fix blog test

* refactor blog post tags handling

* better yaml tag examples

* better dogfood md files

* refactor and factorize theme tag components

* finish DocTagDocListPage

* Extract DocItemFooter + add inline tag list

* minor fix

* better typings

* fix versions.test.ts tests

* add tests for doc tags

* fix tests

* test toTagDocListProp

* move shared theme code to tagUtils

* Add new theme translation keys

* move common theme code to tagUtils + add tests

* update-code-translations should handle theme-common

* update french translation

* revert add translation

* fix pluralization problem in theme.docs.tagDocListPageTitle

* add theme component configuration options

* add more tags tests

* add documentation for docs tagging

Co-authored-by: slorber <lorber.sebastien@gmail.com>

packages/docusaurus-utils-validation/src/JoiFrontMatter.ts

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import Joi from './Joi';
+
+// Enhance the default Joi.string() type so that it can convert number to strings
+// If user use frontmatter "tag: 2021", we shouldn't need to ask the user to write "tag: '2021'"
+// Also yaml tries to convert patterns like "2019-01-01" to dates automatically
+// see https://github.com/facebook/docusaurus/issues/4642
+// see https://github.com/sideway/joi/issues/1442#issuecomment-823997884
+const JoiFrontMatterString: Joi.Extension = {
+  type: 'string',
+  base: Joi.string(),
+  // Fix Yaml that tries to auto-convert many things to string out of the box
+  prepare: (value) => {
+    if (typeof value === 'number' || value instanceof Date) {
+      return {value: value.toString()};
+    }
+    return {value};
+  },
+};
+export const JoiFrontMatter: typeof Joi = Joi.extend(JoiFrontMatterString);

packages/docusaurus-utils-validation/src/__tests__/validationUtils.test.ts

@@ -6,7 +6,8 @@
  */
 
 import Joi from '../Joi';
-import {JoiFrontMatter, validateFrontMatter} from '../validationUtils';
+import {JoiFrontMatter} from '../JoiFrontMatter';
+import {validateFrontMatter} from '../validationUtils';
 
 describe('validateFrontMatter', () => {
   test('should accept good values', () => {

packages/docusaurus-utils-validation/src/index.ts

@@ -7,6 +7,7 @@
 
 // /!\ don't remove this export, as we recommend plugin authors to use it
 export {default as Joi} from './Joi';
+export {JoiFrontMatter} from './JoiFrontMatter';
 
 export * from './validationUtils';
 export * from './validationSchemas';

packages/docusaurus-utils-validation/src/validationSchemas.ts

@@ -6,6 +6,8 @@
  */
 import Joi from './Joi';
 import {isValidPathname} from '@docusaurus/utils';
+import type {Tag} from '@docusaurus/utils';
+import {JoiFrontMatter} from './JoiFrontMatter';
 
 export const PluginIdSchema = Joi.string()
   .regex(/^[a-zA-Z_-]+$/)
@@ -55,3 +57,13 @@ export const PathnameSchema = Joi.string()
   .message(
     '{{#label}} is not a valid pathname. Pathname should start with slash and not contain any domain or query string.',
   );
+
+export const FrontMatterTagsSchema = JoiFrontMatter.array().items(
+  JoiFrontMatter.alternatives().try(
+    JoiFrontMatter.string().required(),
+    JoiFrontMatter.object<Tag>({
+      label: JoiFrontMatter.string().required(),
+      permalink: JoiFrontMatter.string().required(),
+    }).required(),
+  ),
+);

packages/docusaurus-utils-validation/src/validationUtils.ts

@@ -99,24 +99,6 @@ export function normalizeThemeConfig<T>(
   return value;
 }
 
-// Enhance the default Joi.string() type so that it can convert number to strings
-// If user use frontmatter "tag: 2021", we shouldn't need to ask the user to write "tag: '2021'"
-// Also yaml tries to convert patterns like "2019-01-01" to dates automatically
-// see https://github.com/facebook/docusaurus/issues/4642
-// see https://github.com/sideway/joi/issues/1442#issuecomment-823997884
-const JoiFrontMatterString: Joi.Extension = {
-  type: 'string',
-  base: Joi.string(),
-  // Fix Yaml that tries to auto-convert many things to string out of the box
-  prepare: (value) => {
-    if (typeof value === 'number' || value instanceof Date) {
-      return {value: value.toString()};
-    }
-    return {value};
-  },
-};
-export const JoiFrontMatter: typeof Joi = Joi.extend(JoiFrontMatterString);
-
 export function validateFrontMatter<T>(
   frontMatter: Record<string, unknown>,
   schema: Joi.ObjectSchema<T>,