Eslint: Add rule to prohibit unsafe APIs

packages/eslint-plugin/configs/custom.js

@@ -7,6 +7,7 @@ module.exports = {
 		'@wordpress/no-global-active-element': 'error',
 		'@wordpress/no-global-get-selection': 'error',
 		'@wordpress/no-global-event-listener': 'warn',
+		'@wordpress/no-unsafe-wp-apis': 'error',
 	},
 	overrides: [
 		{

packages/eslint-plugin/docs/rules/no-unsafe-wp-apis.md

@@ -0,0 +1,44 @@
+# Prevent unsafe API usage (no-unsafe-wp-apis)
+
+Prevent unsafe APIs from `@wordpress/*` packages from being imported.
+
+This includes experimental and unstable APIs which are expected to change and likely to cause issues in application code.
+See the [documentation](https://github.com/WordPress/gutenberg/blob/master/docs/contributors/coding-guidelines.md#experimental-and-unstable-apis).
+
+> **There is no support commitment for experimental and unstable APIs.** They can and will be removed or changed without advance warning, including as part of a minor or patch release. As an external consumer, you should avoid these APIs.
+> …
+>
+> -   An **experimental API** is one which is planned for eventual public availability, but is subject to further experimentation, testing, and discussion.
+> -   An **unstable API** is one which serves as a means to an end. It is not desired to ever be converted into a public API.
+
+## Rule details
+
+Examples of **incorrect** code for this rule:
+
+```js
+import { __experimentalFeature } from '@wordpress/foo';
+import { __unstableFeature } from '@wordpress/bar';
+```
+
+Examples of **correct** code for this rule:
+
+```js
+import { registerBlockType } from '@wordpress/blocks';
+```
+
+## Options
+
+The rule can be configured via an object.
+This should be an object where the keys are import package names and the values are arrays of allowed experimental imports.
+Note that `unstable` features are not intended for public use and the rule cannot be configured to allow them.
+
+#### Example configuration
+
+```json
+{
+	"wpcalypso/wp-no-unsafe-features": [
+		"error",
+		{ "@wordpress/block-editor": [ "__experimentalBlock" ] }
+	]
+}
+```

packages/eslint-plugin/rules/__tests__/no-unsafe-wp-apis.js

@@ -0,0 +1,112 @@
+/**
+ * External dependencies
+ */
+import { RuleTester } from 'eslint';
+
+/**
+ * Internal dependencies
+ */
+import rule from '../no-unsafe-wp-apis';
+
+const ruleTester = new RuleTester( {
+	parserOptions: {
+		sourceType: 'module',
+		ecmaVersion: 6,
+	},
+} );
+
+const options = [ { '@wordpress/safe': [ '__experimentalSafe' ] } ];
+
+ruleTester.run( 'wp-no-unsafe-features', rule, {
+	valid: [
+		{ code: "import _ from 'lodash';", options },
+		{ code: "import { map } from 'lodash';", options },
+		{ code: "import { __experimentalFoo } from 'lodash';", options },
+		{ code: "import { __unstableFoo } from 'lodash';", options },
+		{ code: "import _, { __unstableFoo } from 'lodash';", options },
+		{ code: "import * as _ from 'lodash';", options },
+
+		{ code: "import _ from './x';", options },
+		{ code: "import { map } from './x';", options },
+		{ code: "import { __experimentalFoo } from './x';", options },
+		{ code: "import { __unstableFoo } from './x';", options },
+		{ code: "import _, { __unstableFoo } from './x';", options },
+		{ code: "import * as _ from './x';", options },
+
+		{ code: "import s from '@wordpress/safe';", options },
+		{ code: "import { feature } from '@wordpress/safe';", options },
+		{
+			code: "import { __experimentalSafe } from '@wordpress/safe';",
+			options,
+		},
+		{
+			code:
+				"import { feature, __experimentalSafe } from '@wordpress/safe';",
+			options,
+		},
+		{
+			code: "import s, { __experimentalSafe } from '@wordpress/safe';",
+			options,
+		},
+		{ code: "import * as s from '@wordpress/safe';", options },
+	],
+
+	invalid: [
+		{
+			code: "import { __experimentalUnsafe } from '@wordpress/safe';",
+			options,
+			errors: [
+				{
+					message:
+						'Usage of `__experimentalUnsafe` from `@wordpress/safe` is not allowed',
+					type: 'ImportSpecifier',
+				},
+			],
+		},
+		{
+			code: "import { __experimentalSafe } from '@wordpress/unsafe';",
+			options,
+			errors: [
+				{
+					message:
+						'Usage of `__experimentalSafe` from `@wordpress/unsafe` is not allowed',
+					type: 'ImportSpecifier',
+				},
+			],
+		},
+		{
+			code:
+				"import { feature, __experimentalSafe } from '@wordpress/unsafe';",
+			options,
+			errors: [
+				{
+					message:
+						'Usage of `__experimentalSafe` from `@wordpress/unsafe` is not allowed',
+					type: 'ImportSpecifier',
+				},
+			],
+		},
+		{
+			code: "import s, { __experimentalUnsafe } from '@wordpress/safe';",
+			options,
+			errors: [
+				{
+					message:
+						'Usage of `__experimentalUnsafe` from `@wordpress/safe` is not allowed',
+					type: 'ImportSpecifier',
+				},
+			],
+		},
+		{
+			code: "import { __unstableIsNeverSafe } from '@wordpress/safe';",
+			options,
+			errors: [
+				{
+					message:
+						'Usage of `__unstableIsNeverSafe` from `@wordpress/safe` is not allowed',
+					type: 'ImportSpecifier',
+				},
+			],
+		},
+	],
+} );

packages/eslint-plugin/rules/dependency-group.js

@@ -1,7 +1,8 @@
 /** @typedef {import('estree').Comment} Comment */
 /** @typedef {import('estree').Node} Node */
 
-module.exports = /** @type {import('eslint').Rule.RuleModule} */ ( {
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
 	meta: {
 		type: 'layout',
 		docs: {
@@ -254,4 +255,4 @@ module.exports = /** @type {import('eslint').Rule.RuleModule} */ ( {
 			},
 		};
 	},
-} );
+};

packages/eslint-plugin/rules/no-unsafe-wp-apis.js

@@ -0,0 +1,95 @@
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+	type: 'problem',
+	meta: {
+		messages: {
+			noUnsafeFeatures:
+				'Usage of `{{importedName}}` from `{{sourceModule}}` is not allowed',
+		},
+		schema: [
+			{
+				type: 'object',
+				additionalProperties: false,
+				patternProperties: {
+					'^@wordpress\\/[a-zA-Z0-9_-]+$': {
+						type: 'array',
+						uniqueItems: true,
+						minItems: 1,
+						items: {
+							type: 'string',
+							pattern: '^__experimental',
+						},
+					},
+				},
+			},
+		],
+	},
+	create( context ) {
+		/** @type {AllowedImportsMap} */
+		const allowedImports =
+			( context.options &&
+				typeof context.options[ 0 ] === 'object' &&
+				context.options[ 0 ] ) ||
+			{};
+		const reporter = makeListener( { allowedImports, context } );
+
+		return { ImportDeclaration: reporter };
+	},
+};
+
+/**
+ * @param {Object} _
+ * @param {AllowedImportsMap} _.allowedImports
+ * @param {import('eslint').Rule.RuleContext} _.context
+ *
+ * @return {(node: Node) => void} Listener function
+ */
+function makeListener( { allowedImports, context } ) {
+	return function reporter( node ) {
+		if ( node.type !== 'ImportDeclaration' ) {
+			return;
+		}
+		if ( typeof node.source.value !== 'string' ) {
+			return;
+		}
+
+		const sourceModule = node.source.value.trim();
+
+		// Only interested in @wordpress/* packages
+		if ( ! sourceModule.startsWith( '@wordpress/' ) ) {
+			return;
+		}
+
+		const allowedImportNames = allowedImports[ sourceModule ] || [];
+
+		node.specifiers.forEach( ( specifierNode ) => {
+			if ( specifierNode.type !== 'ImportSpecifier' ) {
+				return;
+			}
+
+			const importedName = specifierNode.imported.name;
+
+			const data = {
+				sourceModule,
+				importedName,
+			};
+
+			if (
+				// Unstable is never allowed
+				importedName.startsWith( '__unstable' ) ||
+				// Experimental may be allowed
+				( importedName.startsWith( '__experimental' ) &&
+					! allowedImportNames.includes( importedName ) )
+			) {
+				context.report( {
+					messageId: 'noUnsafeFeatures',
+					node: specifierNode,
+					data,
+				} );
+			}
+		} );
+	};
+}
+
+/** @typedef {import('estree').Node} Node */
+/** @typedef {Record<string, string[]|undefined>} AllowedImportsMap */

packages/eslint-plugin/tsconfig.json

@@ -1,13 +1,12 @@
 {
 	"extends": "../../tsconfig.base.json",
 	"compilerOptions": {
+		"module": "CommonJS",
 		"rootDir": "rules",
 		"declarationDir": "build-types"
 	},
 	// NOTE: This package is being progressively typed. You are encouraged to
 	// expand this array with files which can be type-checked. At some point in
 	// the future, this can be simplified to an `includes` of `src/**/*`.
-	"files": [
-		"rules/dependency-group.js"
-	]
+	"files": [ "rules/dependency-group.js", "rules/no-unsafe-wp-apis.js" ]
 }