From 81e202ed523b2f2e5ddb69b3da3015b112328263 Mon Sep 17 00:00:00 2001
From: Micha Reiser <micha@reiser.io>
Date: Fri, 14 Feb 2025 07:15:24 +0000
Subject: [PATCH] Make `CallBinding::callable_ty` required (#16135)

## Summary

The `callable_ty` is always known except in some TODO code where we can
use a `TODO` type instead.

## Test Plan

`cargo test`
---
 crates/red_knot_python_semantic/src/types.rs         |  2 +-
 .../red_knot_python_semantic/src/types/call/bind.rs  | 12 ++++++------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/crates/red_knot_python_semantic/src/types.rs b/crates/red_knot_python_semantic/src/types.rs
index 6d10b10131..e1fe29359c 100644
--- a/crates/red_knot_python_semantic/src/types.rs
+++ b/crates/red_knot_python_semantic/src/types.rs
@@ -1942,7 +1942,7 @@ impl<'db> Type<'db> {
     fn call(self, db: &'db dyn Db, arguments: &CallArguments<'_, 'db>) -> CallOutcome<'db> {
         match self {
             Type::FunctionLiteral(function_type) => {
-                let mut binding = bind_call(db, arguments, function_type.signature(db), Some(self));
+                let mut binding = bind_call(db, arguments, function_type.signature(db), self);
                 match function_type.known(db) {
                     Some(KnownFunction::RevealType) => {
                         let revealed_ty = binding.one_parameter_type().unwrap_or(Type::unknown());
diff --git a/crates/red_knot_python_semantic/src/types/call/bind.rs b/crates/red_knot_python_semantic/src/types/call/bind.rs
index 4a20987ce3..f2fb125d33 100644
--- a/crates/red_knot_python_semantic/src/types/call/bind.rs
+++ b/crates/red_knot_python_semantic/src/types/call/bind.rs
@@ -5,7 +5,7 @@ use crate::types::diagnostic::{
     TOO_MANY_POSITIONAL_ARGUMENTS, UNKNOWN_ARGUMENT,
 };
 use crate::types::signatures::Parameter;
-use crate::types::UnionType;
+use crate::types::{todo_type, UnionType};
 use ruff_python_ast as ast;
 
 /// Bind a [`CallArguments`] against a callable [`Signature`].
@@ -16,7 +16,7 @@ pub(crate) fn bind_call<'db>(
     db: &'db dyn Db,
     arguments: &CallArguments<'_, 'db>,
     signature: &Signature<'db>,
-    callable_ty: Option<Type<'db>>,
+    callable_ty: Type<'db>,
 ) -> CallBinding<'db> {
     let parameters = signature.parameters();
     // The type assigned to each parameter at this call site.
@@ -138,7 +138,7 @@ pub(crate) fn bind_call<'db>(
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub(crate) struct CallBinding<'db> {
     /// Type of the callable object (function, class...)
-    callable_ty: Option<Type<'db>>,
+    callable_ty: Type<'db>,
 
     /// Return type of the call.
     return_ty: Type<'db>,
@@ -154,7 +154,7 @@ impl<'db> CallBinding<'db> {
     // TODO remove this constructor and construct always from `bind_call`
     pub(crate) fn from_return_type(return_ty: Type<'db>) -> Self {
         Self {
-            callable_ty: None,
+            callable_ty: todo_type!("CallBinding::from_return_type"),
             return_ty,
             parameter_tys: Box::default(),
             errors: vec![],
@@ -189,8 +189,8 @@ impl<'db> CallBinding<'db> {
 
     fn callable_name(&self, db: &'db dyn Db) -> Option<&str> {
         match self.callable_ty {
-            Some(Type::FunctionLiteral(function)) => Some(function.name(db)),
-            Some(Type::ClassLiteral(class_type)) => Some(class_type.class.name(db)),
+            Type::FunctionLiteral(function) => Some(function.name(db)),
+            Type::ClassLiteral(class_type) => Some(class_type.class.name(db)),
             _ => None,
         }
     }