add lint for bitwise parity check

crates/cairo-lint-core/src/lints/bitwise_for_parity_check.rs

@@ -0,0 +1,21 @@
+use cairo_lang_defs::plugin::PluginDiagnostic;
+use cairo_lang_diagnostics::Severity;
+use cairo_lang_syntax::node::ast::StatementLet;
+use cairo_lang_syntax::node::db::SyntaxGroup;
+use cairo_lang_syntax::node::kind::SyntaxKind;
+use cairo_lang_syntax::node::TypedSyntaxNode;
+
+pub const BITWISE_FOR_PARITY: &str =
+    "you seem to be trying to use `&` for parity check. Consider using `DivRem::div_rem()` instead.";
+
+pub fn check_bitwise_for_parity(db: &dyn SyntaxGroup, node: StatementLet, diagnostics: &mut Vec<PluginDiagnostic>) {
+    let is_bitwise_for_parity_check = node.rhs(db);
+
+    //     if is_bitwise_for_parity_check {
+    //     diagnostics.push(PluginDiagnostic {
+    //         stable_ptr: node.as_syntax_node().stable_ptr(),
+    //         message: BITWISE_FOR_PARITY.to_string(),
+    //         severity: Severity::Warning,
+    //     });
+    // }
+}

crates/cairo-lint-core/src/lints/mod.rs

@@ -1,3 +1,4 @@
+pub mod bitwise_for_parity_check;
 pub mod bool_comparison;
 pub mod breaks;
 pub mod double_parens;

crates/cairo-lint-core/src/plugin.rs

@@ -3,11 +3,11 @@ use cairo_lang_defs::plugin::PluginDiagnostic;
 use cairo_lang_semantic::db::SemanticGroup;
 use cairo_lang_semantic::plugin::{AnalyzerPlugin, PluginSuite};
 use cairo_lang_semantic::Expr;
-use cairo_lang_syntax::node::ast::{Expr as AstExpr, ExprBinary};
+use cairo_lang_syntax::node::ast::{Expr as AstExpr, ExprBinary, StatementLet};
 use cairo_lang_syntax::node::kind::SyntaxKind;
 use cairo_lang_syntax::node::{TypedStablePtr, TypedSyntaxNode};
 
-use crate::lints::{bool_comparison, breaks, double_parens, loops, single_match};
+use crate::lints::{bitwise_for_parity_check, bool_comparison, breaks, double_parens, loops, single_match};
 
 pub fn cairo_lint_plugin_suite() -> PluginSuite {
     let mut suite = PluginSuite::default();
@@ -88,6 +88,11 @@ impl AnalyzerPlugin for CairoLint {
                         let expr_binary = ExprBinary::from_syntax_node(db.upcast(), node);
                         bool_comparison::check_bool_comparison(db.upcast(), expr_binary, &mut diags);
                     }
+                    SyntaxKind::StatementLet => bitwise_for_parity_check::check_bitwise_for_parity(
+                        db.upcast(),
+                        StatementLet::from_syntax_node(db.upcast(), node),
+                        &mut diags,
+                    ),
                     _ => continue,
                 }
             }

crates/cairo-lint-core/tests/test_files/bitwise_for_parity_check/bitwise_for_parity_check

@@ -0,0 +1,6 @@
+//! > Test name
+
+//! > cairo_code
+fn main() {
+    let a: Option<felt252> = Option::Some(1);
+}

crates/cairo-lint-core/tests/tests.rs

@@ -92,3 +92,5 @@ test_file!(
     "Negated comparison with false",
     "Negated comparison with false on LHS"
 );
+
+test_file!(bitwise_for_parity_check, bitwise_for_parity_check, "Test name");