Prettier Config: Add type-checking (#21053)

* Prettier Config: Add type-checking

* Prettier Config: Disable ESLint validation for union type

package.json

@@ -89,6 +89,7 @@
 		"@storybook/react": "5.3.2",
 		"@types/jest": "24.0.25",
 		"@types/lodash": "4.14.149",
+		"@types/prettier": "1.19.0",
 		"@types/qs": "6.9.1",
 		"@types/requestidlecallback": "0.3.1",
 		"@types/sprintf-js": "1.1.2",

packages/prettier-config/lib/index.js

@@ -1,4 +1,18 @@
-module.exports = {
+/** @typedef {import('prettier').Options} PrettierOptions */
+
+/**
+ * @typedef WPPrettierOptions
+ *
+ * @property {boolean} [parenSpacing=true] Insert spaces inside parentheses.
+ */
+
+// Disable reason: The current JSDoc tooling does not yet understand TypeScript
+// union types.
+
+/* eslint-disable jsdoc/valid-types */
+/** @type {PrettierOptions & WPPrettierOptions} */
+/* eslint-enable jsdoc/valid-types */
+const config = {
 	useTabs: true,
 	tabWidth: 4,
 	printWidth: 80,
@@ -10,3 +24,5 @@ module.exports = {
 	semi: true,
 	arrowParens: 'always',
 };
+
+module.exports = config;

packages/prettier-config/package.json

@@ -25,6 +25,7 @@
 		"lib/index.js"
 	],
 	"main": "lib/index.js",
+	"types": "build-types",
 	"publishConfig": {
 		"access": "public"
 	}

packages/prettier-config/tsconfig.json

@@ -0,0 +1,8 @@
+{
+	"extends": "../../tsconfig.base.json",
+	"compilerOptions": {
+		"rootDir": "lib",
+		"declarationDir": "build-types"
+	},
+	"include": [ "lib/**/*" ]
+}