feat: add no-drafts-import rule

docs/rules/no-drafts-import.md

@@ -0,0 +1,23 @@
+# Disallow use of the drafts endpoint in primer/react (no-drafts-import)
+
+🔧 The `--fix` option on the [ESLint CLI](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems) can automatically fix some of the problems reported by this rule.
+
+The `/drafts` endpoint in `@primer/react` has been deprecated in favor of
+`@primer/react/experimental`.
+
+## Rule details
+
+This rule disallows the use of importing from `@primer/react/drafts` as
+`@primer/react/experimental` is now the preferred entrypoint.
+
+👎 Examples of **incorrect** code for this rule:
+
+```tsx
+import {UnderlineNav} from '@primer/react/drafts'
+```
+
+👍 Examples of **correct** code for this rule:
+
+```tsx
+import {UnderlineNav} from '@primer/react/experimental'
+```

src/rules/__tests__/no-drafts-import.test.js

@@ -0,0 +1,41 @@
+'use strict'
+
+const rule = require('../no-drafts-import')
+const {RuleTester} = require('eslint')
+
+const ruleTester = new RuleTester({
+  parserOptions: {
+    ecmaVersion: 'latest',
+    sourceType: 'module',
+    ecmaFeatures: {
+      jsx: true
+    }
+  }
+})
+
+ruleTester.run('no-drafts-import', rule, {
+  valid: [
+    `import {UnderlineNav} from '@primer/react/experimental'`,
+    `import {TreeView, UnderlineNav} from '@primer/react/experimental'`
+  ],
+  invalid: [
+    {
+      code: `import {UnderlineNav} from '@primer/react/drafts'`,
+      output: `import {UnderlineNav} from '@primer/react/experimental'`,
+      errors: [
+        {
+          messageId: 'entrypoint-error'
+        }
+      ]
+    },
+    {
+      code: `import {TreeView, UnderlineNav} from '@primer/react/drafts'`,
+      output: `import {TreeView, UnderlineNav} from '@primer/react/experimental'`,
+      errors: [
+        {
+          messageId: 'entrypoint-error'
+        }
+      ]
+    }
+  ]
+})

src/rules/no-drafts-import.js

@@ -0,0 +1,38 @@
+'use strict'
+
+/**
+ * @type {import('eslint').Rule.RuleModule}
+ */
+module.exports = {
+  meta: {
+    docs: {
+      description: '',
+      url: require('../url')(module)
+    },
+    type: 'suggestion',
+    hasSuggestions: true,
+    fixable: true,
+    schema: [],
+    messages: {
+      'entrypoint-error': 'The drafts entrypoint is deprecated. Use the experimental entrypoint instead.'
+    }
+  },
+  create(context) {
+    return {
+      ImportDeclaration(node) {
+        const source = node.source.value
+        if (source !== '@primer/react/drafts') {
+          return
+        }
+
+        context.report({
+          node,
+          messageId: 'entrypoint-error',
+          fix(fixer) {
+            return fixer.replaceText(node.source, `'@primer/react/experimental'`)
+          }
+        })
+      }
+    }
+  }
+}