fix(rome_js_parser): Crash at empty default export #4670

CHANGELOG.md

@@ -20,6 +20,7 @@
 
 #### Other changes
 
+- Fix [#4670](https://github.com/rome/tools/issues/4670), don't crash at empty default export.
 - Fix [#4556](https://github.com/rome/tools/issues/4556), which correctly handles new lines in the
 `.gitignore` file across OS.
 - Add a new option to ignore unknown files `--files-ignore-unknown`:

crates/rome_js_parser/src/syntax/module.rs

@@ -1425,6 +1425,12 @@ fn parse_export_default_expression_clause(
     start: TextSize,
 ) -> ParsedSyntax {
     if !is_at_expression(p) {
+        // test_err js export_default_expression_broken
+        // export default ;
+        // export default @decorator
+        // export default
+        // export default @decorator
+        m.abandon(p);
         return Absent;
     }
 

crates/rome_js_parser/test_data/inline/err/export_default_expression_broken.js

@@ -0,0 +1,4 @@
+export default ;
+export default @decorator
+export default
+export default @decorator

crates/rome_js_parser/test_data/inline/err/export_default_expression_broken.rast

@@ -0,0 +1,203 @@
+JsModule {
+    interpreter_token: missing (optional),
+    directives: JsDirectiveList [],
+    items: JsModuleItemList [
+        JsBogusStatement {
+            items: [
+                JsDecoratorList [],
+                EXPORT_KW@0..7 "export" [] [Whitespace(" ")],
+                DEFAULT_KW@7..15 "default" [] [Whitespace(" ")],
+            ],
+        },
+        JsEmptyStatement {
+            semicolon_token: SEMICOLON@15..16 ";" [] [],
+        },
+        JsBogusStatement {
+            items: [
+                JsDecoratorList [],
+                EXPORT_KW@16..24 "export" [Newline("\n")] [Whitespace(" ")],
+                DEFAULT_KW@24..32 "default" [] [Whitespace(" ")],
+                JsBogusStatement {
+                    items: [
+                        JsDecorator {
+                            at_token: AT@32..33 "@" [] [],
+                            expression: JsIdentifierExpression {
+                                name: JsReferenceIdentifier {
+                                    value_token: IDENT@33..42 "decorator" [] [],
+                                },
+                            },
+                        },
+                    ],
+                },
+            ],
+        },
+        JsBogusStatement {
+            items: [
+                JsDecoratorList [],
+                EXPORT_KW@42..50 "export" [Newline("\n")] [Whitespace(" ")],
+                DEFAULT_KW@50..57 "default" [] [],
+            ],
+        },
+        JsBogusStatement {
+            items: [
+                JsDecoratorList [],
+                EXPORT_KW@57..65 "export" [Newline("\n")] [Whitespace(" ")],
+                DEFAULT_KW@65..73 "default" [] [Whitespace(" ")],
+                JsBogusStatement {
+                    items: [
+                        JsDecorator {
+                            at_token: AT@73..74 "@" [] [],
+                            expression: JsIdentifierExpression {
+                                name: JsReferenceIdentifier {
+                                    value_token: IDENT@74..83 "decorator" [] [],
+                                },
+                            },
+                        },
+                    ],
+                },
+            ],
+        },
+    ],
+    eof_token: EOF@83..84 "" [Newline("\n")] [],
+}
+
+0: JS_MODULE@0..84
+  0: (empty)
+  1: JS_DIRECTIVE_LIST@0..0
+  2: JS_MODULE_ITEM_LIST@0..83
+    0: JS_BOGUS_STATEMENT@0..15
+      0: JS_DECORATOR_LIST@0..0
+      1: EXPORT_KW@0..7 "export" [] [Whitespace(" ")]
+      2: DEFAULT_KW@7..15 "default" [] [Whitespace(" ")]
+    1: JS_EMPTY_STATEMENT@15..16
+      0: SEMICOLON@15..16 ";" [] []
+    2: JS_BOGUS_STATEMENT@16..42
+      0: JS_DECORATOR_LIST@16..16
+      1: EXPORT_KW@16..24 "export" [Newline("\n")] [Whitespace(" ")]
+      2: DEFAULT_KW@24..32 "default" [] [Whitespace(" ")]
+      3: JS_BOGUS_STATEMENT@32..42
+        0: JS_DECORATOR@32..42
+          0: AT@32..33 "@" [] []
+          1: JS_IDENTIFIER_EXPRESSION@33..42
+            0: JS_REFERENCE_IDENTIFIER@33..42
+              0: IDENT@33..42 "decorator" [] []
+    3: JS_BOGUS_STATEMENT@42..57
+      0: JS_DECORATOR_LIST@42..42
+      1: EXPORT_KW@42..50 "export" [Newline("\n")] [Whitespace(" ")]
+      2: DEFAULT_KW@50..57 "default" [] []
+    4: JS_BOGUS_STATEMENT@57..83
+      0: JS_DECORATOR_LIST@57..57
+      1: EXPORT_KW@57..65 "export" [Newline("\n")] [Whitespace(" ")]
+      2: DEFAULT_KW@65..73 "default" [] [Whitespace(" ")]
+      3: JS_BOGUS_STATEMENT@73..83
+        0: JS_DECORATOR@73..83
+          0: AT@73..74 "@" [] []
+          1: JS_IDENTIFIER_EXPRESSION@74..83
+            0: JS_REFERENCE_IDENTIFIER@74..83
+              0: IDENT@74..83 "decorator" [] []
+  3: EOF@83..84 "" [Newline("\n")] []
+--
+export_default_expression_broken.js:1:16 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × expected a class, a function, or a variable declaration but instead found ';'
+
+  > 1 │ export default ;
+      │                ^
+    2 │ export default @decorator
+    3 │ export default
+
+  i Expected a class, a function, or a variable declaration here
+
+  > 1 │ export default ;
+      │                ^
+    2 │ export default @decorator
+    3 │ export default
+
+--
+export_default_expression_broken.js:2:16 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × Decorators are not valid here.
+
+    1 │ export default ;
+  > 2 │ export default @decorator
+      │                ^^^^^^^^^^
+    3 │ export default
+    4 │ export default @decorator
+
+  i Decorators are only valid on class declarations, class expressions, and class methods.
+
+--
+export_default_expression_broken.js:3:1 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × expected a class, a function, or a variable declaration but instead found 'export'
+
+    1 │ export default ;
+    2 │ export default @decorator
+  > 3 │ export default
+      │ ^^^^^^
+    4 │ export default @decorator
+    5 │ 
+
+  i Expected a class, a function, or a variable declaration here
+
+    1 │ export default ;
+    2 │ export default @decorator
+  > 3 │ export default
+      │ ^^^^^^
+    4 │ export default @decorator
+    5 │ 
+
+--
+export_default_expression_broken.js:4:1 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × expected a class, a function, or a variable declaration but instead found 'export'
+
+    2 │ export default @decorator
+    3 │ export default
+  > 4 │ export default @decorator
+      │ ^^^^^^
+    5 │ 
+
+  i Expected a class, a function, or a variable declaration here
+
+    2 │ export default @decorator
+    3 │ export default
+  > 4 │ export default @decorator
+      │ ^^^^^^
+    5 │ 
+
+--
+export_default_expression_broken.js:4:16 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × Decorators are not valid here.
+
+    2 │ export default @decorator
+    3 │ export default
+  > 4 │ export default @decorator
+      │                ^^^^^^^^^^
+    5 │ 
+
+  i Decorators are only valid on class declarations, class expressions, and class methods.
+
+--
+export_default_expression_broken.js:5:1 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  × expected a class, a function, or a variable declaration but instead found the end of the file
+
+    3 │ export default
+    4 │ export default @decorator
+  > 5 │ 
+      │ 
+
+  i Expected a class, a function, or a variable declaration here
+
+    3 │ export default
+    4 │ export default @decorator
+  > 5 │ 
+      │ 
+
+--
+export default ;
+export default @decorator
+export default
+export default @decorator