Add strict to tsconfig.json

Author: wooorm

index.js

@@ -16,11 +16,11 @@ const max = 6
  * @returns {T}
  */
 export function normalizeHeadings(tree) {
-  /** @type {boolean} */
+  /** @type {boolean|undefined} */
   let multiple
-  /** @type {Heading} */
+  /** @type {Heading|undefined} */
   let first
-  /** @type {Heading} */
+  /** @type {Heading|undefined} */
   let title
 
   visit(

tsconfig.json

@@ -10,6 +10,7 @@
     "declaration": true,
     "emitDeclarationOnly": true,
     "allowSyntheticDefaultImports": true,
-    "skipLibCheck": true
+    "skipLibCheck": true,
+    "strict": true
   }
 }