Merge bitcoin/bitcoin#30553: lint: Find function calls in default arguments

fac7b7ff7f lint: Find function calls in default arguments (MarcoFalke)

Pull request description:

  This type of bug in the test code keeps biting back regularly, is hard to debug, and wastes review cycles: https://github.com/bitcoin/bitcoin/issues/30543#issuecomment-2259260024 .

  Fix all issues by catching it with a linter that checks for rule B008: https://docs.astral.sh/ruff/rules/function-call-in-default-argument/

  This also allows to drop the hand-written linter that checks for rule B006: https://docs.astral.sh/ruff/rules/mutable-argument-default/

ACKs for top commit:
  davidgumberg:
    reACK fac7b7ff7f

Tree-SHA512: a47a28a35ec9c81947cb8c3e625f1eb8c0d7e780a4d768491ef94b2beed43b9710bf6c1044da18c7fd677ea5576fb9077c7f77b4465033fedfdca9920c185bf7

ci/lint/04_install.sh

@@ -53,6 +53,7 @@ ${CI_RETRY_EXE} pip3 install \
   lief==0.13.2 \
   mypy==1.4.1 \
   pyzmq==25.1.0 \
+  ruff==0.5.5 \
   vulture==2.6
 
 SHELLCHECK_VERSION=v0.8.0

test/lint/lint-python-mutable-default-parameters.py

@@ -1,72 +0,0 @@
-#!/usr/bin/env python3
-#
-# Copyright (c) 2019-2022 The Bitcoin Core developers
-# Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-"""
-Detect when a mutable list or dict is used as a default parameter value in a Python function.
-"""
-
-import subprocess
-import sys
-
-
-def main():
-    command = [
-        "git",
-        "grep",
-        "-E",
-        r"^\s*def [a-zA-Z0-9_]+\(.*=\s*(\[|\{)",
-        "--",
-        "*.py",
-    ]
-    output = subprocess.run(command, stdout=subprocess.PIPE, text=True)
-    if len(output.stdout) > 0:
-        error_msg = (
-            "A mutable list or dict seems to be used as default parameter value:\n\n"
-            f"{output.stdout}\n"
-            f"{example()}"
-        )
-        print(error_msg)
-        sys.exit(1)
-    else:
-        sys.exit(0)
-
-
-def example():
-    return """This is how mutable list and dict default parameter values behave:
-
->>> def f(i, j=[], k={}):
-...     j.append(i)
-...     k[i] = True
-...     return j, k
-...
->>> f(1)
-([1], {1: True})
->>> f(1)
-([1, 1], {1: True})
->>> f(2)
-([1, 1, 2], {1: True, 2: True})
-
-The intended behaviour was likely:
-
->>> def f(i, j=None, k=None):
-...     if j is None:
-...         j = []
-...     if k is None:
-...         k = {}
-...     j.append(i)
-...     k[i] = True
-...     return j, k
-...
->>> f(1)
-([1], {1: True})
->>> f(1)
-([1], {1: True})
->>> f(2)
-([2], {2: True})"""
-
-
-if __name__ == "__main__":
-    main()

test/lint/test_runner/src/main.rs

@@ -35,6 +35,11 @@ fn get_linter_list() -> Vec<&'static Linter> {
             name: "markdown",
             lint_fn: lint_markdown
         },
+        &Linter {
+            description: "Check the default arguments in python",
+            name: "py_mut_arg_default",
+            lint_fn: lint_py_mut_arg_default,
+        },
         &Linter {
             description: "Check that std::filesystem is not used directly",
             name: "std_filesystem",
@@ -180,6 +185,35 @@ fn lint_subtree() -> LintResult {
     }
 }
 
+fn lint_py_mut_arg_default() -> LintResult {
+    let bin_name = "ruff";
+    let checks = ["B006", "B008"]
+        .iter()
+        .map(|c| format!("--select={}", c))
+        .collect::<Vec<_>>();
+    let files = check_output(
+        git()
+            .args(["ls-files", "--", "*.py"])
+            .args(get_pathspecs_exclude_subtrees()),
+    )?;
+
+    let mut cmd = Command::new(bin_name);
+    cmd.arg("check").args(checks).args(files.lines());
+
+    match cmd.status() {
+        Ok(status) if status.success() => Ok(()),
+        Ok(_) => Err(format!("`{}` found errors!", bin_name)),
+        Err(e) if e.kind() == ErrorKind::NotFound => {
+            println!(
+                "`{}` was not found in $PATH, skipping those checks.",
+                bin_name
+            );
+            Ok(())
+        }
+        Err(e) => Err(format!("Error running `{}`: {}", bin_name, e)),
+    }
+}
+
 fn lint_std_filesystem() -> LintResult {
     let found = git()
         .args([