feat(codegen): preserve comments between CatchClause's param and body

crates/oxc_codegen/src/gen.rs

@@ -607,6 +607,12 @@ impl Gen for CatchClause<'_> {
             p.print_str(")");
         }
         p.print_soft_space();
+        p.print_comments_at(self.body.span.start);
+        // Consume the space flag set by comment printing to ensure proper spacing before the opening brace
+        if !p.options.minify && p.print_next_indent_as_space {
+            p.print_hard_space();
+            p.print_next_indent_as_space = false;
+        }
         p.print_block_statement(&self.body, ctx);
     }
 }

crates/oxc_codegen/tests/integration/comments.rs

@@ -181,6 +181,19 @@ catch(e) {
   // should never happen
 }
 ",
+            // Inline comment between catch param and body
+            "try { console.log('test'); }
+catch (err) /* v8 ignore next */ { console.error(err); }",
+            // Multiple comments between catch param and body
+            "try { something(); }
+catch (err) /* c8 ignore next */ /* istanbul ignore next */ { handle(err); }",
+            // Line comment between catch param and body.
+            // NOTE: Line comments after `)` are classified as trailing comments by the parser,
+            // so they are not preserved. Use block comments instead.
+            // See: https://github.com/oxc-project/oxc/pull/16167#discussion_r2567604139
+            "try { something(); }
+catch (err) // v8 ignore next
+{ handle(err); }",
         ];
 
         snapshot("coverage", &cases);

crates/oxc_codegen/tests/integration/js.rs

@@ -144,6 +144,10 @@ fn do_while_stmt() {
     test_minify("do throw x; while (true)", "do throw x;while(true);");
     test_minify("do with(x); while (true)", "do with(x);while(true);");
     test_minify("do try{} catch{} while (true)", "do try{}catch{}while(true);");
+    test_minify(
+        "try { x } catch (err) /* v8 ignore next */ { y }",
+        "try{x}catch(err)/* v8 ignore next */{y}",
+    );
     test_minify("do do ; while(true) while (true)", "do do;while(true);while(true);");
 }
 

crates/oxc_codegen/tests/integration/snapshots/coverage.snap

@@ -109,3 +109,35 @@ try {
 } 
 /* istanbul ignore next */
 catch (e) {}
+
+########## 20
+try { console.log('test'); }
+catch (err) /* v8 ignore next */ { console.error(err); }
+----------
+try {
+	console.log('test');
+} catch (err) /* v8 ignore next */ {
+	console.error(err);
+}
+
+########## 21
+try { something(); }
+catch (err) /* c8 ignore next */ /* istanbul ignore next */ { handle(err); }
+----------
+try {
+	something();
+} catch (err) /* c8 ignore next *//* istanbul ignore next */ {
+	handle(err);
+}
+
+########## 22
+try { something(); }
+catch (err) // v8 ignore next
+{ handle(err); }
+----------
+try {
+	something();
+} catch (err) {
+	handle(err);
+}
+