Split checks and plugins into source-related modules (#447)

src/pyupgrade/plugins/useless_object_inheritance.rs

@@ -0,0 +1,29 @@
+use rustpython_ast::{Expr, Keyword, Stmt};
+
+use crate::autofix::{fixer, fixes};
+use crate::check_ast::Checker;
+use crate::pyupgrade::checks;
+
+pub fn useless_object_inheritance(
+    checker: &mut Checker,
+    stmt: &Stmt,
+    name: &str,
+    bases: &[Expr],
+    keywords: &[Keyword],
+) {
+    let scope = checker.current_scope();
+    if let Some(mut check) = checks::useless_object_inheritance(name, bases, scope) {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            if let Some(fix) = fixes::remove_class_def_base(
+                &mut checker.locator,
+                &stmt.location,
+                check.location,
+                bases,
+                keywords,
+            ) {
+                check.amend(fix);
+            }
+        }
+        checker.add_check(check);
+    }
+}