From 3d1e5676fbb8fce0b4351a94289f54e22f0fefa4 Mon Sep 17 00:00:00 2001
From: David Peter <sharkdp@users.noreply.github.com>
Date: Mon, 31 Mar 2025 12:52:23 +0200
Subject: [PATCH] [red-knot] Add `ParamSpecArgs` and `ParamSpecKwargs` as
 `KnownClass` (#17086)

## Summary

In preparation for #17017, where we will need them to suppress new false
positives (once we understand the `ParamSpec.args`/`ParamSpec.kwargs`
properties).

## Test Plan

Tested on branch #17017
---
 .../annotations/unsupported_special_forms.md  |  2 +-
 crates/red_knot_python_semantic/src/types.rs  |  6 ++---
 .../src/types/class.rs                        | 23 ++++++++++++++++---
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md b/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md
index bed5c4a56f..175ada1236 100644
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md
@@ -56,7 +56,7 @@ def _(
     reveal_type(d)  # revealed: Unknown
 
     def foo(a_: e) -> None:
-        reveal_type(a_)  # revealed: @Todo(Support for `typing.ParamSpec` instances in type expressions)
+        reveal_type(a_)  # revealed: @Todo(Support for `typing.ParamSpec`)
 ```
 
 ## Inheritance
diff --git a/crates/red_knot_python_semantic/src/types.rs b/crates/red_knot_python_semantic/src/types.rs
index c8b9c31182..d45ec530d8 100644
--- a/crates/red_knot_python_semantic/src/types.rs
+++ b/crates/red_knot_python_semantic/src/types.rs
@@ -3089,9 +3089,9 @@ impl<'db> Type<'db> {
                 Some(KnownClass::TypeVar) => Ok(todo_type!(
                     "Support for `typing.TypeVar` instances in type expressions"
                 )),
-                Some(KnownClass::ParamSpec) => Ok(todo_type!(
-                    "Support for `typing.ParamSpec` instances in type expressions"
-                )),
+                Some(
+                    KnownClass::ParamSpec | KnownClass::ParamSpecArgs | KnownClass::ParamSpecKwargs,
+                ) => Ok(todo_type!("Support for `typing.ParamSpec`")),
                 Some(KnownClass::TypeVarTuple) => Ok(todo_type!(
                     "Support for `typing.TypeVarTuple` instances in type expressions"
                 )),
diff --git a/crates/red_knot_python_semantic/src/types/class.rs b/crates/red_knot_python_semantic/src/types/class.rs
index fec4e8bf06..33e14acd24 100644
--- a/crates/red_knot_python_semantic/src/types/class.rs
+++ b/crates/red_knot_python_semantic/src/types/class.rs
@@ -844,6 +844,8 @@ pub enum KnownClass {
     SpecialForm,
     TypeVar,
     ParamSpec,
+    ParamSpecArgs,
+    ParamSpecKwargs,
     TypeVarTuple,
     TypeAliasType,
     NoDefaultType,
@@ -893,6 +895,8 @@ impl<'db> KnownClass {
             | Self::TypeAliasType
             | Self::TypeVar
             | Self::ParamSpec
+            | Self::ParamSpecArgs
+            | Self::ParamSpecKwargs
             | Self::TypeVarTuple
             | Self::WrapperDescriptorType
             | Self::MethodWrapperType => Truthiness::AlwaysTrue,
@@ -969,6 +973,8 @@ impl<'db> KnownClass {
             Self::SpecialForm => "_SpecialForm",
             Self::TypeVar => "TypeVar",
             Self::ParamSpec => "ParamSpec",
+            Self::ParamSpecArgs => "ParamSpecArgs",
+            Self::ParamSpecKwargs => "ParamSpecKwargs",
             Self::TypeVarTuple => "TypeVarTuple",
             Self::TypeAliasType => "TypeAliasType",
             Self::NoDefaultType => "_NoDefaultType",
@@ -1149,9 +1155,12 @@ impl<'db> KnownClass {
             | Self::StdlibAlias
             | Self::SupportsIndex
             | Self::Sized => KnownModule::Typing,
-            Self::TypeAliasType | Self::TypeVarTuple | Self::ParamSpec | Self::NewType => {
-                KnownModule::TypingExtensions
-            }
+            Self::TypeAliasType
+            | Self::TypeVarTuple
+            | Self::ParamSpec
+            | Self::ParamSpecArgs
+            | Self::ParamSpecKwargs
+            | Self::NewType => KnownModule::TypingExtensions,
             Self::NoDefaultType => {
                 let python_version = Program::get(db).python_version(db);
 
@@ -1227,6 +1236,8 @@ impl<'db> KnownClass {
             | Self::StdlibAlias
             | Self::TypeVar
             | Self::ParamSpec
+            | Self::ParamSpecArgs
+            | Self::ParamSpecKwargs
             | Self::TypeVarTuple
             | Self::Sized
             | Self::Enum
@@ -1282,6 +1293,8 @@ impl<'db> KnownClass {
             | Self::Classmethod
             | Self::TypeVar
             | Self::ParamSpec
+            | Self::ParamSpecArgs
+            | Self::ParamSpecKwargs
             | Self::TypeVarTuple
             | Self::Sized
             | Self::Enum
@@ -1328,6 +1341,8 @@ impl<'db> KnownClass {
             "TypeAliasType" => Self::TypeAliasType,
             "TypeVar" => Self::TypeVar,
             "ParamSpec" => Self::ParamSpec,
+            "ParamSpecArgs" => Self::ParamSpecArgs,
+            "ParamSpecKwargs" => Self::ParamSpecKwargs,
             "TypeVarTuple" => Self::TypeVarTuple,
             "ChainMap" => Self::ChainMap,
             "Counter" => Self::Counter,
@@ -1405,6 +1420,8 @@ impl<'db> KnownClass {
             | Self::NoDefaultType
             | Self::SupportsIndex
             | Self::ParamSpec
+            | Self::ParamSpecArgs
+            | Self::ParamSpecKwargs
             | Self::TypeVarTuple
             | Self::Sized
             | Self::NewType => matches!(module, KnownModule::Typing | KnownModule::TypingExtensions),