fix(semantic): disallow let as destructured catch param in sloppy mode

crates/oxc_semantic/src/checker/javascript.rs

@@ -105,6 +105,13 @@ fn invalid_let_declaration(x0: &str, span1: Span) -> OxcDiagnostic {
     .with_label(span1)
 }
 
+fn invalid_let_catch_param(span1: Span) -> OxcDiagnostic {
+    OxcDiagnostic::error(
+        "`let` cannot be declared as a variable name inside of a destructured catch parameter",
+    )
+    .with_label(span1)
+}
+
 pub fn check_binding_identifier(ident: &BindingIdentifier, ctx: &SemanticBuilder<'_>) {
     if ctx.strict_mode() {
         // In strict mode, `eval` and `arguments` are banned as identifiers.
@@ -161,6 +168,7 @@ pub fn check_binding_identifier(ident: &BindingIdentifier, ctx: &SemanticBuilder
         // LexicalDeclaration : LetOrConst BindingList ;
         // * It is a Syntax Error if the BoundNames of BindingList contains "let".
         if ident.name == "let" {
+            let mut is_grandparent_or_above = false;
             for node_kind in ctx.nodes.ancestor_kinds(ctx.current_node_id) {
                 match node_kind {
                     AstKind::VariableDeclarator(decl) => {
@@ -171,8 +179,17 @@ pub fn check_binding_identifier(ident: &BindingIdentifier, ctx: &SemanticBuilder
                     }
                     // `let` is permitted as function name or function param (including arrow functions)
                     AstKind::Function(_) | AstKind::FormalParameter(_) => break,
+                    // `try {} catch (let) {}` is permitted.
+                    // `try {} catch ({let}) {}` and `try {} catch ([let]) {}` are not.
+                    AstKind::CatchParameter(_) => {
+                        if is_grandparent_or_above {
+                            ctx.error(invalid_let_catch_param(ident.span));
+                        }
+                        break;
+                    }
                     _ => {}
                 }
+                is_grandparent_or_above = true;
             }
         }
     }

tasks/coverage/misc/fail/oxc-12306.cjs

@@ -0,0 +1,8 @@
+// Sloppy mode
+
+try {} catch ({let}) {}
+try {} catch ([let]) {}
+try {} catch ({x: let}) {}
+try {} catch ({...let}) {}
+try {} catch ([...let]) {}
+try {} catch ({x: {y: [{...let}]}}) {}

tasks/coverage/misc/pass/oxc-12306.cjs

@@ -0,0 +1,3 @@
+// Sloppy mode
+
+try {} catch (let) {}

tasks/coverage/snapshots/codegen_misc.snap

@@ -1,3 +1,3 @@
 codegen_misc Summary:
-AST Parsed     : 45/45 (100.00%)
-Positive Passed: 45/45 (100.00%)
+AST Parsed     : 46/46 (100.00%)
+Positive Passed: 46/46 (100.00%)

tasks/coverage/snapshots/parser_misc.snap

@@ -1,7 +1,7 @@
 parser_misc Summary:
-AST Parsed     : 45/45 (100.00%)
-Positive Passed: 45/45 (100.00%)
-Negative Passed: 48/48 (100.00%)
+AST Parsed     : 46/46 (100.00%)
+Positive Passed: 46/46 (100.00%)
+Negative Passed: 49/49 (100.00%)
 
   × Cannot assign to 'arguments' in strict mode
    ╭─[misc/fail/arguments-eval.ts:1:10]
@@ -188,6 +188,53 @@ Negative Passed: 48/48 (100.00%)
    ·              ──────────
    ╰────
 
+  × `let` cannot be declared as a variable name inside of a destructured catch parameter
+   ╭─[misc/fail/oxc-12306.cjs:3:16]
+ 2 │ 
+ 3 │ try {} catch ({let}) {}
+   ·                ───
+ 4 │ try {} catch ([let]) {}
+   ╰────
+
+  × `let` cannot be declared as a variable name inside of a destructured catch parameter
+   ╭─[misc/fail/oxc-12306.cjs:4:16]
+ 3 │ try {} catch ({let}) {}
+ 4 │ try {} catch ([let]) {}
+   ·                ───
+ 5 │ try {} catch ({x: let}) {}
+   ╰────
+
+  × `let` cannot be declared as a variable name inside of a destructured catch parameter
+   ╭─[misc/fail/oxc-12306.cjs:5:19]
+ 4 │ try {} catch ([let]) {}
+ 5 │ try {} catch ({x: let}) {}
+   ·                   ───
+ 6 │ try {} catch ({...let}) {}
+   ╰────
+
+  × `let` cannot be declared as a variable name inside of a destructured catch parameter
+   ╭─[misc/fail/oxc-12306.cjs:6:19]
+ 5 │ try {} catch ({x: let}) {}
+ 6 │ try {} catch ({...let}) {}
+   ·                   ───
+ 7 │ try {} catch ([...let]) {}
+   ╰────
+
+  × `let` cannot be declared as a variable name inside of a destructured catch parameter
+   ╭─[misc/fail/oxc-12306.cjs:7:19]
+ 6 │ try {} catch ({...let}) {}
+ 7 │ try {} catch ([...let]) {}
+   ·                   ───
+ 8 │ try {} catch ({x: {y: [{...let}]}}) {}
+   ╰────
+
+  × `let` cannot be declared as a variable name inside of a destructured catch parameter
+   ╭─[misc/fail/oxc-12306.cjs:8:28]
+ 7 │ try {} catch ([...let]) {}
+ 8 │ try {} catch ({x: {y: [{...let}]}}) {}
+   ·                            ───
+   ╰────
+
   × Unexpected token
    ╭─[misc/fail/oxc-169.js:2:1]
  1 │ 1<(V=82<<t-j0<(V=$<LBI<(V=ut<I<(V=$<LBI<(V=uIV=82<<t-j0<(V=$<LBI<(V=ut<I<(V=$<LBI<(V<II>

tasks/coverage/snapshots/semantic_misc.snap

@@ -1,6 +1,6 @@
 semantic_misc Summary:
-AST Parsed     : 45/45 (100.00%)
-Positive Passed: 29/45 (64.44%)
+AST Parsed     : 46/46 (100.00%)
+Positive Passed: 30/46 (65.22%)
 semantic Error: tasks/coverage/misc/pass/oxc-11593.ts
 Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]

tasks/coverage/snapshots/transformer_misc.snap

@@ -1,3 +1,3 @@
 transformer_misc Summary:
-AST Parsed     : 45/45 (100.00%)
-Positive Passed: 45/45 (100.00%)
+AST Parsed     : 46/46 (100.00%)
+Positive Passed: 46/46 (100.00%)