From aebaf7965face5d46dd06fa3ef7bc65fd295836b Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Sun, 16 Mar 2025 23:34:03 +0800
Subject: [PATCH 1/2] feat!: turn on noUncheckedIndexedAccess for libraries

See https://www.semver-ts.org/formal-spec/5-compiler-considerations.html#strictness
for the arguments for turning on noUncheckedIndexedAccess for libraries.

In short, it helps prevent shipping accidental breaking type changes to
library consumers.

(Note the link also suggests turning on `exactOptionalPropertyTypes`,
but I still have doubts about it, as it would not be helpful without
a specific coding style, which is hard to enforce.)
---
 tsconfig.lib.json | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tsconfig.lib.json b/tsconfig.lib.json
index 964598a..3ce7121 100644
--- a/tsconfig.lib.json
+++ b/tsconfig.lib.json
@@ -8,6 +8,8 @@
     // Libraries generally require more strict type accuracy.
     // 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
+    "skipLibCheck": false,
+
+    "noUncheckedIndexedAccess": true
   }
 }

From b5f50c1cf34636dcf03aa5b3c6f0836806b6e047 Mon Sep 17 00:00:00 2001
From: Haoqun Jiang <haoqunjiang@gmail.com>
Date: Thu, 17 Jul 2025 17:27:15 +0800
Subject: [PATCH 2/2] feat!: enable `noUncheckedIndexedAccess` and
 `exactOptionalPropertyTypes`

As recommended in TS 5.9: https://github.com/microsoft/TypeScript/pull/61813
---
 tsconfig.json     | 5 +++++
 tsconfig.lib.json | 2 --
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/tsconfig.json b/tsconfig.json
index 56402e7..ea3f593 100644
--- a/tsconfig.json
+++ b/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.
diff --git a/tsconfig.lib.json b/tsconfig.lib.json
index 3ce7121..1810eeb 100644
--- a/tsconfig.lib.json
+++ b/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
   }
 }