From f670f9b22c213a721577fb3df62c7f7134b3aff9 Mon Sep 17 00:00:00 2001
From: Harutaka Kawamura <hkawamura0130@gmail.com>
Date: Wed, 11 Oct 2023 22:53:48 +0900
Subject: [PATCH] [SIM115] Allow `open` followed by `close` (#7916)

---
 .../test/fixtures/flake8_simplify/SIM115.py   |  4 +++
 .../rules/open_file_with_context_handler.rs   | 29 +++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM115.py b/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM115.py
index 388b1fd670..6a6925c45a 100644
--- a/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM115.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM115.py
@@ -42,3 +42,7 @@ with contextlib.ExitStack():
 with contextlib.ExitStack() as exit_stack:
     exit_stack_ = exit_stack
     f = exit_stack_.enter_context(open("filename"))
+
+# OK (quick one-liner to clear file contents)
+open("filename", "w").close()
+pathlib.Path("filename").open("w").close()
diff --git a/crates/ruff_linter/src/rules/flake8_simplify/rules/open_file_with_context_handler.rs b/crates/ruff_linter/src/rules/flake8_simplify/rules/open_file_with_context_handler.rs
index a55c49d880..49e7826217 100644
--- a/crates/ruff_linter/src/rules/flake8_simplify/rules/open_file_with_context_handler.rs
+++ b/crates/ruff_linter/src/rules/flake8_simplify/rules/open_file_with_context_handler.rs
@@ -127,12 +127,41 @@ fn is_open(checker: &mut Checker, func: &Expr) -> bool {
     }
 }
 
+/// Return `true` if the current expression is followed by a `close` call.
+fn is_closed(semantic: &SemanticModel) -> bool {
+    let Some(expr) = semantic.current_expression_grandparent() else {
+        return false;
+    };
+
+    let Expr::Call(ast::ExprCall {
+        func, arguments, ..
+    }) = expr
+    else {
+        return false;
+    };
+
+    if !arguments.is_empty() {
+        return false;
+    }
+
+    let Expr::Attribute(ast::ExprAttribute { attr, .. }) = func.as_ref() else {
+        return false;
+    };
+
+    attr.as_str() == "close"
+}
+
 /// SIM115
 pub(crate) fn open_file_with_context_handler(checker: &mut Checker, func: &Expr) {
     if !is_open(checker, func) {
         return;
     }
 
+    // Ex) `open("foo.txt").close()`
+    if is_closed(checker.semantic()) {
+        return;
+    }
+
     // Ex) `with open("foo.txt") as f: ...`
     if checker.semantic().current_statement().is_with_stmt() {
         return;