From 80dc44788a8d3c499433dd86d1a7fbcab77f9d9b Mon Sep 17 00:00:00 2001
From: soaring0616 <30642533+soaring0616@users.noreply.github.com>
Date: Sat, 14 Nov 2026 11:44:39 +0800
Subject: [PATCH] Respect model-level strict config in synthesized RootModel
 __init__

Fixes #5242
---
 pyrefly/lib/alt/class/dataclass.rs      |  6 +++++-
 pyrefly/lib/test/pydantic/root_model.rs | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/pyrefly/lib/alt/class/dataclass.rs b/pyrefly/lib/alt/class/dataclass.rs
index d4bbc1e50f..9e6deaca5b 100644
--- a/pyrefly/lib/alt/class/dataclass.rs
+++ b/pyrefly/lib/alt/class/dataclass.rs
@@ -153,7 +153,11 @@ impl<'ctx, 'answer, Ans: LookupAnswer> AnswersSolver<'ctx, 'answer, Ans> {
             let init_method = if let Some((root_model_type, has_strict)) =
                 self.get_pydantic_root_model_type_via_mro(cls, metadata)
             {
-                self.get_pydantic_root_model_init(cls, root_model_type, has_strict)
+                self.get_pydantic_root_model_init(
+                    cls,
+                    root_model_type,
+                    has_strict || dataclass.kws.strict,
+                )
             } else if metadata.is_pydantic_model() {
                 // Pydantic models with RootModel fields need type expansion
                 let transform_type: &dyn Fn(Type) -> Type = &|ty: Type| {
diff --git a/pyrefly/lib/test/pydantic/root_model.rs b/pyrefly/lib/test/pydantic/root_model.rs
index 2186f8c112..70fc0d9f9c 100644
--- a/pyrefly/lib/test/pydantic/root_model.rs
+++ b/pyrefly/lib/test/pydantic/root_model.rs
@@ -350,3 +350,24 @@ def serialize(d: InnerModelDict) -> OuterModel:
     return OuterModel(data=d)
     "#,
 );
+
+pydantic_testcase!(
+    test_root_model_config_strict,
+    r#"
+from pydantic import ConfigDict, RootModel
+
+class Text(RootModel[str]):
+    model_config = ConfigDict(strict=True)
+
+class Text2(RootModel[str], strict=True): ...
+
+class Child(Text): ...
+
+class Lax(RootModel[str]): ...
+
+Text(b"hello")  # E: Argument `Literal[b'hello']` is not assignable to parameter `root` with type `str`
+Text2(b"hello")  # E: Argument `Literal[b'hello']` is not assignable to parameter `root` with type `str`
+Child(b"hello")  # E: Argument `Literal[b'hello']` is not assignable to parameter `root` with type `str`
+Lax(b"hello")
+"#,
+);