feat(es/lints): Mark catch params as binding patterns while checking …

…duplicates (#3981)

crates/swc/tests/errors/lints/duplicate-bindings/catch-clause/1/input.js

@@ -0,0 +1,4 @@
+try {
+} catch (foo) {
+    let foo;
+}

crates/swc/tests/errors/lints/duplicate-bindings/catch-clause/1/output.swc-stderr

@@ -0,0 +1,8 @@
+error: the name `foo` is defined multiple times
+
+  |
+2 | } catch (foo) {
+  |          --- previous definition of `foo` here
+3 |     let foo;
+  |         ^^^ `foo` redefined here
+

crates/swc_ecma_lints/src/rules/duplicate_bindings.rs

@@ -84,23 +84,6 @@ impl DuplicateBindings {
 impl Visit for DuplicateBindings {
     noop_visit_type!();
 
-    fn visit_module(&mut self, m: &Module) {
-        m.visit_with(&mut TypeCollector {
-            type_bindings: &mut self.type_bindings,
-        });
-
-        self.is_module = true;
-        m.visit_children_with(self);
-    }
-
-    fn visit_script(&mut self, s: &Script) {
-        s.visit_with(&mut TypeCollector {
-            type_bindings: &mut self.type_bindings,
-        });
-
-        s.visit_children_with(self);
-    }
-
     fn visit_assign_pat_prop(&mut self, p: &AssignPatProp) {
         p.visit_children_with(self);
 
@@ -109,6 +92,19 @@ impl Visit for DuplicateBindings {
         }
     }
 
+    fn visit_catch_clause(&mut self, c: &CatchClause) {
+        let old_var_decl_kind = self.var_decl_kind.take();
+        let old_is_pat_decl = self.is_pat_decl;
+
+        self.var_decl_kind = Some(VarDeclKind::Var);
+        self.is_pat_decl = true;
+
+        c.visit_children_with(self);
+
+        self.is_pat_decl = old_is_pat_decl;
+        self.var_decl_kind = old_var_decl_kind;
+    }
+
     fn visit_class_decl(&mut self, d: &ClassDecl) {
         self.add(&d.ident, true);
 
@@ -160,6 +156,15 @@ impl Visit for DuplicateBindings {
         }
     }
 
+    fn visit_module(&mut self, m: &Module) {
+        m.visit_with(&mut TypeCollector {
+            type_bindings: &mut self.type_bindings,
+        });
+
+        self.is_module = true;
+        m.visit_children_with(self);
+    }
+
     fn visit_pat(&mut self, p: &Pat) {
         p.visit_children_with(self);
 
@@ -170,6 +175,14 @@ impl Visit for DuplicateBindings {
         }
     }
 
+    fn visit_script(&mut self, s: &Script) {
+        s.visit_with(&mut TypeCollector {
+            type_bindings: &mut self.type_bindings,
+        });
+
+        s.visit_children_with(self);
+    }
+
     fn visit_var_decl(&mut self, d: &VarDecl) {
         let old_var_decl_kind = self.var_decl_kind.take();
         let old_is_pat_decl = self.is_pat_decl;

crates/swc_ecma_lints/tests/fixture.rs

@@ -4,6 +4,7 @@ use swc_common::{input::SourceFileInput, Mark, SyntaxContext};
 use swc_ecma_ast::{EsVersion, Program};
 use swc_ecma_lints::{
     config::LintConfig,
+    rule::Rule,
     rules::{all, LintParams},
 };
 use swc_ecma_parser::{lexer::Lexer, Parser, Syntax};
@@ -53,19 +54,20 @@ fn pass(input: PathBuf) {
 
         let config = LintConfig::default();
 
-        let rules = all(LintParams {
+        let mut rules = all(LintParams {
             program: &program,
             lint_config: &config,
             top_level_ctxt,
             es_version,
             source_map: cm,
         });
 
-        HANDLER.set(handler, || {
-            if let Program::Module(m) = &program {
-                for mut rule in rules {
-                    rule.lint_module(m);
-                }
+        HANDLER.set(handler, || match &program {
+            Program::Module(m) => {
+                rules.lint_module(m);
+            }
+            Program::Script(s) => {
+                rules.lint_script(s);
             }
         });