TypeScript support in core

.eslintrc

@@ -8,7 +8,7 @@
     "mocha": true,
     "jasmine": true
   },
-  "parser": "babel-eslint",
+  "parser": "@babel/eslint-parser",
   "parserOptions": {
     "ecmaVersion": 6,
     "sourceType": "module",
@@ -38,14 +38,37 @@
           ["@package", "./src"],
           ["@root", "./src"]
         ],
-        "extensions": [".js", ".jsx", ".json"]
+        "extensions": [".js", ".jsx", ".ts", ".tsx", ".json"]
       },
       "babel-plugin-root-import": {
         "rootPathSuffix": "src"
       }
     },
-    "import/core-modules": ["load-volto-addons"]
+    "import/core-modules": ["load-volto-addons"],
+    "react": {
+      "version": "detect"
+    }
   },
+  "overrides": [
+    {
+      "files": ["**/*.ts", "**/*.tsx"],
+      // "react-app" already loads plugin:@typescript-eslint/eslint-plugin
+      // and it complains on having two different versions around.
+      // Re-add it if at some point, we stop relying on it
+      "extends": ["react-app", "prettier", "plugin:jsx-a11y/recommended"],
+      "plugins": ["prettier", "react-hooks", "jsx-a11y"],
+      "parser": "@typescript-eslint/parser"
+    },
+    {
+      "files": [
+        "**/*.stories.js",
+        "**/*.stories.jsx"
+      ],
+      "rules": {
+        "import/no-anonymous-default-export": "off"
+      }
+    }
+  ],
   "globals": {
     "root": true,
     "__DEVELOPMENT__": true,

addon-registry.js

@@ -6,6 +6,12 @@ const debug = require('debug')('shadowing');
 const { map } = require('lodash');
 const { DepGraph } = require('dependency-graph');
 
+const excludedCompilerOptionsPaths = [
+  '@plone/volto/*',
+  '@plone/volto-slate/*',
+  '@root/*',
+];
+
 function getPackageBasePath(base) {
   while (!fs.existsSync(`${base}/package.json`)) {
     base = path.join(base, '../');
@@ -197,7 +203,10 @@ class AddonConfigurationRegistry {
           addons: require(packageJsonPath).addons || [],
         };
 
-        this.packages[name] = Object.assign(this.packages[name] || {}, pkg);
+        // Removed excluded paths from CompilerOptions
+        if (!excludedCompilerOptionsPaths.includes(name)) {
+          this.packages[name] = Object.assign(this.packages[name] || {}, pkg);
+        }
       });
     }
     this.initPackagesFolder();

docs/source/contributing/typescript.md

@@ -9,14 +9,131 @@ myst:
 
 # TypeScript
 
+```{versionadded} 17.0.0-alpha.27
+```
+
+TypeScript support has been added to Volto core.
+ESlint has been configured in order to accept code base written both in JavaScript and in TypeScript.
+TypeScript in projects and add-ons has been supported since Volto 14.
+It is now supported in the project generator by default.
+
+## TypeScript in core
+
+The internal policy for TypeScript support in Volto core will be as follows.
+
+-   No existing code has been migrated.
+    Volto 17.0.0 has no TypeScript code present.
+    Only *support* for TypeScript has been added.
+-   Code in core can be written in either JavaScript or TypeScript, or both.
+-   You are not forced to migrate existing code to TypeScript.
+    It's your choice which one to use.
+-   If you need to backport code to a version of Volto before 17.0.0, you must make the code compatible without TypeScript.
+
+## TypeScript learning resources
+
+-   [TypeScript Official Handbook](https://www.typescriptlang.org/docs/handbook/intro.html)
+
+-   [TotalTypeScript React with TypeScript Free course](https://www.totaltypescript.com/tutorials/react-with-typescript)
+
+-   [TotalTypeScript Beginner's TypeScript Free course](https://www.totaltypescript.com/tutorials/beginners-typescript)
+
+## TypeScript in projects and add-ons
+
+You can enable TypeScript support when developing your project in Volto.
+If you use the Volto generator, TypeScript is enabled by default, and you can already start using TypeScript in it.
+
+### Enable it in your Volto 17 project
+
+If you already use Volto 17 in your projects, using a boilerplate generated before Volto 17.0.0-alpha.27 and the generator 7.0.0-alpha.7, you can enable TypeScript support as follows:
+
+Edit your {file}`package.json`:
+
+```diff
+-    "lint": "./node_modules/eslint/bin/eslint.js --max-warnings=0 'src/**/*.{js,jsx}'",
+-    "lint:fix": "./node_modules/eslint/bin/eslint.js --max-warnings=0 --fix 'src/**/*.{js,jsx}'",
+-    "lint:ci": "./node_modules/eslint/bin/eslint.js --max-warnings=0 -f checkstyle 'src/**/*.{js,jsx}' > eslint.xml",
++    "lint": "./node_modules/eslint/bin/eslint.js --max-warnings=0 'src/**/*.{js,jsx,ts,tsx,json}'",
++    "lint:fix": "./node_modules/eslint/bin/eslint.js --fix 'src/**/*.{js,jsx,ts,tsx,json}'",
++    "lint:ci": "./node_modules/eslint/bin/eslint.js --max-warnings=0 -f checkstyle 'src/**/*.{js,jsx,ts,tsx,json}' > eslint.xml",
+```
+
+```diff
+"devDependencies": {
++     "@plone/scripts": ^3.0.0,
++     "@typescript-eslint/eslint-plugin": "6.7.0",
++     "@typescript-eslint/parser": "6.7.0",
++     "stylelint-prettier": "1.1.2",
++     "ts-jest": "^26.4.2",
++     "ts-loader": "9.4.4",
++     "typescript": "5.2.2"
+}
+```
+
 ```{note}
-This feature is available since Volto 14. Please note that TypeScript is *not* allowed in Volto core, that's why it's not enabled in the core by default. This feature enables the use of TypeScript (as opt-in) in projects and in add-ons.
+After making this change, you might experience hoisting problems and some packages can't be found on start.
+In that case, make sure you reset your `yarn.lock` by deleting it and start with a clean environment.
+```
+
+To use TypeScript in your projects, you'll need to introduce a TypeScript configuration file {file}`tsconfig.json`, and remove the existing file {file}`jsconfig.json`.
+You can use the one provided by the generator as a template, or use your own:
+
+```json
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "lib": ["DOM", "DOM.Iterable", "ESNext"],
+    "module": "commonjs",
+    "allowJs": true,
+    "skipLibCheck": true,
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true,
+    "strict": true,
+    "forceConsistentCasingInFileNames": true,
+    "moduleResolution": "Node",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "paths": {},
+    "baseUrl": "src"
+  },
+  "include": ["src"],
+  "exclude": [
+    "node_modules",
+    "build",
+    "public",
+    "coverage",
+    "src/**/*.test.{js,jsx,ts,tsx}",
+    "src/**/*.spec.{js,jsx,ts,tsx}",
+    "src/**/*.stories.{js,jsx,ts,tsx}"
+  ]
+}
+```
+
+If you use `mrs-developer` in your project, update the command in {file}`Makefile`:
+
+```diff
+--- a/Makefile
++++ b/Makefile
+@@ -59,7 +59,8 @@ preinstall: ## Preinstall task, checks if missdev (mrs-developer) is present and runs it
+
+ .PHONY: develop
+ develop: ## Runs missdev in the local project (mrs.developer.json should be present)
+-       npx -p mrs-developer missdev --config=jsconfig.json --output=addons --fetch-https
++       if [ -f $$(pwd)/jsconfig.json ]; then npx -p mrs-developer missdev --config=jsconfig.json --output=addons --fetch-https; fi
++       if [ ! -f $$(pwd)/jsconfig.json ]; then npx -p mrs-developer missdev --output=addons --fetch-https; fi
+```
+
+````{note}
+After editing your {file}`Makefile`, run `mrs-developer` with the following command, so the configuration gets in the right place ({file}`tsconfig.json`).
+```shell
+make develop
 ```
+````
 
-It is possible to enable TypeScript support when developing you project with Volto.
-Volto itself is not written in TypeScript, but it is ready to use it if you want.
+### Enable it in a project not using Volto 17 yet
 
-In order to enable TypeScript, you need to install these additional dependencies in your project:
+To use TypeScript for an existing project in Volto versions 14.x-16.x, you need to install these additional dependencies in your project:
 
 ```shell
 yarn add --dev typescript @typescript-eslint/parser @typescript-eslint/eslint-plugin @types/react @types/react-dom concurrently

docs/source/upgrade-guide/index.md

@@ -53,6 +53,120 @@ or use Webpack plugins, you might need to make adjustments.
 Razzle has been upgraded to version `4.2.18`.
 It is recommended that you update your project's dependency on Razzle to this version in order to avoid duplication.
 
+### TypeScript support in Volto
+
+```{versionadded} 17.0.0-alpha.27
+```
+
+We added full support of TypeScript in Volto core.
+
+No existing code has been migrated.
+You may write code in either JavaScript or TypeScript.
+The choice is yours.
+
+Previously developers had the option to support TypeScript only in their Volto add-ons.
+Now it's available in Volto projects, as long as you upgrade your project dependencies.
+
+To support TypeScript in your projects, you must update your project as follows.
+
+Edit your {file}`package.json`:
+
+```diff
+"scripts": {
+-    "lint": "./node_modules/eslint/bin/eslint.js --max-warnings=0 'src/**/*.{js,jsx}'",
+-    "lint:fix": "./node_modules/eslint/bin/eslint.js --max-warnings=0 --fix 'src/**/*.{js,jsx}'",
+-    "lint:ci": "./node_modules/eslint/bin/eslint.js --max-warnings=0 -f checkstyle 'src/**/*.{js,jsx}' > eslint.xml",
++    "lint": "./node_modules/eslint/bin/eslint.js --max-warnings=0 'src/**/*.{js,jsx,ts,tsx,json}'",
++    "lint:fix": "./node_modules/eslint/bin/eslint.js --fix 'src/**/*.{js,jsx,ts,tsx,json}'",
++    "lint:ci": "./node_modules/eslint/bin/eslint.js --max-warnings=0 -f checkstyle 'src/**/*.{js,jsx,ts,tsx,json}' > eslint.xml",
+}
+```
+
+```diff
+"devDependencies": {
++     "@plone/scripts": ^3.0.0,
++     "@typescript-eslint/eslint-plugin": "6.7.0",
++     "@typescript-eslint/parser": "6.7.0",
++     "stylelint-prettier": "1.1.2",
++     "ts-jest": "^26.4.2",
++     "ts-loader": "9.4.4",
++     "typescript": "5.2.2"
+}
+```
+
+```{note}
+After making this change, you might experience hoisting problems and some packages can't be found on start.
+In that case, make sure you reset your `yarn.lock` by deleting it and start with a clean environment.
+```
+
+To use TypeScript in your projects, you'll need to introduce a TypeScript configuration file {file}`tsconfig.json`, and remove the existing file {file}`jsconfig.json`.
+You can use the one provided by the generator as a template, or use your own:
+
+```json
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "lib": ["DOM", "DOM.Iterable", "ESNext"],
+    "module": "commonjs",
+    "allowJs": true,
+    "skipLibCheck": true,
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true,
+    "strict": true,
+    "forceConsistentCasingInFileNames": true,
+    "moduleResolution": "Node",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "paths": {},
+    "baseUrl": "src"
+  },
+  "include": ["src"],
+  "exclude": [
+    "node_modules",
+    "build",
+    "public",
+    "coverage",
+    "src/**/*.test.{js,jsx,ts,tsx}",
+    "src/**/*.spec.{js,jsx,ts,tsx}",
+    "src/**/*.stories.{js,jsx,ts,tsx}"
+  ]
+}
+```
+
+If you use `mrs-developer` in your project, update the command in {file}`Makefile`:
+
+```diff
+--- a/Makefile
++++ b/Makefile
+preinstall: ## Preinstall task, checks if missdev (mrs-developer) is present and runs it
+
+ .PHONY: develop
+ develop: ## Runs missdev in the local project (mrs.developer.json should be present)
+-       npx -p mrs-developer missdev --config=jsconfig.json --output=addons --fetch-https
++       if [ -f $$(pwd)/jsconfig.json ]; then npx -p mrs-developer missdev --config=jsconfig.json --output=addons --fetch-https; fi
++       if [ ! -f $$(pwd)/jsconfig.json ]; then npx -p mrs-developer missdev --output=addons --fetch-https; fi
+```
+
+````{note}
+After editing your {file}`Makefile`, run `mrs-developer` with the following command, so the configuration gets in the right place ({file}`tsconfig.json`).
+```shell
+make develop
+```
+````
+
+### Upgrade ESlint and use `@babel/eslint-parser`
+
+```{versionchanged} 17.0.0-alpha.27
+```
+
+ESlint uses a library to parse the language under analysis.
+The one used was long deprecated and didn't supported both TypeScript and JavaScript.
+We upgraded the ESlint parser to use `@babel/eslint-parser`.
+This means when you upgrade your project, some new violations may appear.
+Once upgraded, run the linters again to make sure that your code is free of violations.
+
 ### `BlockChooser` component now uses `popperjs` internally
 
 Technically not a breaking, the API nor the component contract has changed, but it's worth noting this change in here.

news/4662.feature

@@ -0,0 +1 @@
+TypeScript support in core @sneridagh @ninanoleto