Improve RUF006 detection

crates/ruff_linter/resources/test/fixtures/ruff/RUF006.py

@@ -162,3 +162,26 @@ async def f(x: bool):
         T = asyncio.create_task(asyncio.sleep(1))
     else:
         T = None
+
+
+# Error
+def f():
+    loop = asyncio.new_event_loop()
+    loop.create_task(main()) # Error
+
+# Error
+def f():
+    loop = asyncio.get_event_loop()
+    loop.create_task(main()) # Error
+
+# OK
+def f():
+    global task
+    loop = asyncio.new_event_loop()
+    task = loop.create_task(main()) # Error
+
+# OK
+def f():
+    global task
+    loop = asyncio.get_event_loop()
+    task = loop.create_task(main()) # Error

crates/ruff_linter/src/rules/ruff/rules/asyncio_dangling_task.rs

@@ -52,14 +52,15 @@ use ruff_text_size::Ranged;
 /// - [The Python Standard Library](https://docs.python.org/3/library/asyncio-task.html#asyncio.create_task)
 #[violation]
 pub struct AsyncioDanglingTask {
+    expr: &'static str,
     method: Method,
 }
 
 impl Violation for AsyncioDanglingTask {
     #[derive_message_formats]
     fn message(&self) -> String {
-        let AsyncioDanglingTask { method } = self;
-        format!("Store a reference to the return value of `asyncio.{method}`")
+        let AsyncioDanglingTask { expr, method } = self;
+        format!("Store a reference to the return value of `{expr}.{method}`")
     }
 }
 
@@ -80,19 +81,29 @@ pub(crate) fn asyncio_dangling_task(expr: &Expr, semantic: &SemanticModel) -> Op
             })
     {
         return Some(Diagnostic::new(
-            AsyncioDanglingTask { method },
+            AsyncioDanglingTask {
+                expr: "asyncio",
+                method,
+            },
             expr.range(),
         ));
     }
 
-    // Ex) `loop = asyncio.get_running_loop(); loop.create_task(...)`
+    // Ex) `loop = ...; loop.create_task(...)`
     if let Expr::Attribute(ast::ExprAttribute { attr, value, .. }) = func.as_ref() {
         if attr == "create_task" {
             if typing::resolve_assignment(value, semantic).is_some_and(|call_path| {
-                matches!(call_path.as_slice(), ["asyncio", "get_running_loop"])
+                matches!(
+                    call_path.as_slice(),
+                    [
+                        "asyncio",
+                        "get_event_loop" | "get_running_loop" | "new_event_loop"
+                    ]
+                )
             }) {
                 return Some(Diagnostic::new(
                     AsyncioDanglingTask {
+                        expr: "loop", // TODO: How can you turn `value` into a string?
                         method: Method::CreateTask,
                     },
                     expr.range(),

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF006_RUF006.py.snap

@@ -25,20 +25,40 @@ RUF006.py:68:12: RUF006 Store a reference to the return value of `asyncio.create
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ RUF006
    |
 
-RUF006.py:74:26: RUF006 Store a reference to the return value of `asyncio.create_task`
+RUF006.py:74:26: RUF006 Store a reference to the return value of `loop.create_task`
    |
 72 | def f():
 73 |     loop = asyncio.get_running_loop()
 74 |     task: asyncio.Task = loop.create_task(coordinator.ws_connect())
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ RUF006
    |
 
-RUF006.py:97:5: RUF006 Store a reference to the return value of `asyncio.create_task`
+RUF006.py:97:5: RUF006 Store a reference to the return value of `loop.create_task`
    |
 95 | def f():
 96 |     loop = asyncio.get_running_loop()
 97 |     loop.create_task(coordinator.ws_connect())  # Error
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ RUF006
    |
 
+RUF006.py:170:5: RUF006 Store a reference to the return value of `loop.create_task`
+    |
+168 | def f():
+169 |     loop = asyncio.new_event_loop()
+170 |     loop.create_task(main()) # Error
+    |     ^^^^^^^^^^^^^^^^^^^^^^^^ RUF006
+171 | 
+172 | # Error
+    |
+
+RUF006.py:175:5: RUF006 Store a reference to the return value of `loop.create_task`
+    |
+173 | def f():
+174 |     loop = asyncio.get_event_loop()
+175 |     loop.create_task(main()) # Error
+    |     ^^^^^^^^^^^^^^^^^^^^^^^^ RUF006
+176 | 
+177 | # OK
+    |
+