feat!: enable noUncheckedIndexedAccess and exactOptionalPropertyTypes

As recommended in TS 5.9: microsoft/TypeScript#61813

Author: haoqunjiang

tsconfig.json

@@ -31,6 +31,11 @@
     "noImplicitThis": true,
     "strict": true,
 
+    // See <https://www.semver-ts.org/formal-spec/5-compiler-considerations.html#strictness>
+    // These 2 options are also part of the recommended tsconfig as of TS 5.9
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+
     // <https://devblogs.microsoft.com/typescript/announcing-typescript-5-0/#verbatimmodulesyntax>
     // Any imports or exports without a type modifier are left around. This is important for `<script setup>`.
     // Anything that uses the type modifier is dropped entirely.

tsconfig.lib.json

@@ -9,7 +9,5 @@
     // For example, its types must be compatible with the Vue types.
     // So we don't want to skip the type checking of its dependencies.
     "skipLibCheck": false,
-
-    "noUncheckedIndexedAccess": true
   }
 }