Allow underscore names in N803 (#622)

resources/test/fixtures/N803.py

@@ -1,7 +1,7 @@
-def func(a, A):
-    return a, A
+def func(_, a, A):
+    return _, a, A
 
 
 class Class:
-    def method(self, a, A):
-        return a, A
+    def method(self, _, a, A):
+        return _, a, A

src/check_ast.rs

@@ -1717,7 +1717,7 @@ where
 
         if self.settings.enabled.contains(&CheckCode::N803) {
             if let Some(check) =
-                pep8_naming::checks::invalid_argument_name(Range::from_located(arg), &arg.node.arg)
+                pep8_naming::checks::invalid_argument_name(&arg.node.arg, Range::from_located(arg))
             {
                 self.checks.push(check);
             }

src/pep8_naming/checks.rs

@@ -25,7 +25,7 @@ pub fn invalid_class_name(class_def: &Stmt, name: &str) -> Option<Check> {
 
 /// N802
 pub fn invalid_function_name(func_def: &Stmt, name: &str, settings: &Settings) -> Option<Check> {
-    if !is_lower(name)
+    if name.to_lowercase() != name
         && !settings
             .ignore_names
             .iter()
@@ -40,8 +40,8 @@ pub fn invalid_function_name(func_def: &Stmt, name: &str, settings: &Settings) -
 }
 
 /// N803
-pub fn invalid_argument_name(location: Range, name: &str) -> Option<Check> {
-    if !is_lower(name) {
+pub fn invalid_argument_name(name: &str, location: Range) -> Option<Check> {
+    if name.to_lowercase() != name {
         return Some(Check::new(
             CheckKind::InvalidArgumentName(name.to_string()),
             location,
@@ -164,7 +164,7 @@ pub fn lowercase_imported_as_non_lowercase(
     name: &str,
     asname: &str,
 ) -> Option<Check> {
-    if is_lower(name) && asname.to_lowercase() != asname {
+    if !is_upper(name) && is_lower(name) && asname.to_lowercase() != asname {
         return Some(Check::new(
             CheckKind::LowercaseImportedAsNonLowercase(name.to_string(), asname.to_string()),
             Range::from_located(import_from),
@@ -194,7 +194,7 @@ pub fn camelcase_imported_as_constant(
     name: &str,
     asname: &str,
 ) -> Option<Check> {
-    if is_camelcase(name) && is_upper(asname) && !is_acronym(name, asname) {
+    if is_camelcase(name) && !is_lower(asname) && is_upper(asname) && !is_acronym(name, asname) {
         return Some(Check::new(
             CheckKind::CamelcaseImportedAsConstant(name.to_string(), asname.to_string()),
             Range::from_located(import_from),
@@ -241,7 +241,7 @@ pub fn camelcase_imported_as_acronym(
     name: &str,
     asname: &str,
 ) -> Option<Check> {
-    if is_camelcase(name) && is_upper(asname) && is_acronym(name, asname) {
+    if is_camelcase(name) && !is_lower(asname) && is_upper(asname) && is_acronym(name, asname) {
         return Some(Check::new(
             CheckKind::CamelcaseImportedAsAcronym(name.to_string(), asname.to_string()),
             Range::from_located(import_from),
@@ -290,7 +290,7 @@ fn is_upper(s: &str) -> bool {
     for c in s.chars() {
         if c.is_lowercase() {
             return false;
-        } else if (!cased) && c.is_uppercase() {
+        } else if !cased && c.is_uppercase() {
             cased = true;
         }
     }

src/snapshots/ruff__linter__tests__N803_N803.py.snap

@@ -6,18 +6,18 @@ expression: checks
     InvalidArgumentName: A
   location:
     row: 1
-    column: 12
+    column: 15
   end_location:
     row: 1
-    column: 13
+    column: 16
   fix: ~
 - kind:
     InvalidArgumentName: A
   location:
     row: 6
-    column: 24
+    column: 27
   end_location:
     row: 6
-    column: 25
+    column: 28
   fix: ~