Prefer type to interface and add an ESLint rule

.eslintrc.js

@@ -95,6 +95,36 @@ const rules = {
 
   // Upgrade from a warning
   '@typescript-eslint/explicit-module-boundary-types': 'error',
+
+  'no-restricted-syntax': [
+    'error',
+    {
+      selector: 'TSInterfaceDeclaration',
+      message:
+        'Prefer `type`. Interfaces are mutable and less powerful, so we prefer `type` for simplicity.',
+    },
+    // Defaults
+    {
+      selector: 'ForInStatement',
+      message:
+        'for..in loops iterate over the entire prototype chain, which is virtually never what you want. Use Object.{keys,values,entries}, and iterate over the resulting array.',
+    },
+    {
+      selector: 'ForOfStatement',
+      message:
+        'iterators/generators require regenerator-runtime, which is too heavyweight for this guide to allow them. Separately, loops should be avoided in favor of array iterations.',
+    },
+    {
+      selector: 'LabeledStatement',
+      message:
+        'Labels are a form of GOTO; using them makes code confusing and hard to maintain and understand.',
+    },
+    {
+      selector: 'WithStatement',
+      message:
+        '`with` is disallowed in strict mode because it makes code impossible to predict and optimize.',
+    },
+  ],
 };
 
 module.exports = {