feat(parser): improve error message for missing closing tokens that may be followed by a rest element

crates/oxc_parser/src/cursor.rs

@@ -473,6 +473,7 @@ impl<'a> ParserImpl<'a> {
     pub(crate) fn parse_delimited_list_with_rest<E, A, D>(
         &mut self,
         close: Kind,
+        opening_span: Span,
         parse_element: E,
         rest_last_diagnostic: D,
     ) -> (Vec<'a, A>, Option<BindingRestElement<'a>>)
@@ -497,8 +498,13 @@ impl<'a> ParserImpl<'a> {
             } else {
                 let comma_span = self.cur_token().span();
                 if kind != Kind::Comma {
-                    let error =
-                        diagnostics::expect_token(Kind::Comma.to_str(), kind.to_str(), comma_span);
+                    let error = diagnostics::expect_closing_or_separator(
+                        close.to_str(),
+                        Kind::Comma.to_str(),
+                        kind.to_str(),
+                        comma_span,
+                        opening_span,
+                    );
                     self.set_fatal_error(error);
                     break;
                 }

crates/oxc_parser/src/js/binding.rs

@@ -41,9 +41,11 @@ impl<'a> ParserImpl<'a> {
     /// Section 14.3.3 Object Binding Pattern
     fn parse_object_binding_pattern(&mut self) -> BindingPatternKind<'a> {
         let span = self.start_span();
+        let opening_span = self.cur_token().span();
         self.expect(Kind::LCurly);
         let (list, rest) = self.parse_delimited_list_with_rest(
             Kind::RCurly,
+            opening_span,
             Self::parse_binding_property,
             diagnostics::binding_rest_element_last,
         );
@@ -67,9 +69,11 @@ impl<'a> ParserImpl<'a> {
     /// Section 14.3.3 Array Binding Pattern
     fn parse_array_binding_pattern(&mut self) -> BindingPatternKind<'a> {
         let span = self.start_span();
+        let opening_span = self.cur_token().span();
         self.expect(Kind::LBrack);
         let (list, rest) = self.parse_delimited_list_with_rest(
             Kind::RBrack,
+            opening_span,
             Self::parse_array_binding_element,
             diagnostics::binding_rest_element_last,
         );

crates/oxc_parser/src/js/function.rs

@@ -46,6 +46,7 @@ impl<'a> ParserImpl<'a> {
         params_kind: FormalParameterKind,
     ) -> (Option<TSThisParameter<'a>>, Box<'a, FormalParameters<'a>>) {
         let span = self.start_span();
+        let opening_span = self.cur_token().span();
         self.expect(Kind::LParen);
         let this_param = if self.is_ts && self.at(Kind::This) {
             let param = self.parse_ts_this_parameter();
@@ -56,6 +57,7 @@ impl<'a> ParserImpl<'a> {
         };
         let (list, rest) = self.parse_delimited_list_with_rest(
             Kind::RParen,
+            opening_span,
             |p| p.parse_formal_parameter(func_kind),
             diagnostics::rest_parameter_last,
         );

tasks/coverage/snapshots/formatter_babel.snap

@@ -24,9 +24,9 @@ Unexpected token. Did you mean `{'>'}` or `>`?
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/explicit-resource-management/valid-for-using-declaration-binding-of/input.js
 Unexpected token
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param/input.ts
-Expected `,` but found `extends`
+Expected `,` or `)` but found `extends`
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param-babel-7/input.ts
-Expected `,` but found `extends`
+Expected `,` or `)` but found `extends`
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/type-arguments-bit-shift-left-like/class-heritage/input.ts
 Expected `{` but found `<<`
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/type-arguments-bit-shift-left-like/class-heritage-babel-7/input.ts

tasks/coverage/snapshots/parser_babel.snap

@@ -679,20 +679,22 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
 
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param/input.ts
 
-  × Expected `,` but found `extends`
+  × Expected `,` or `)` but found `extends`
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param/input.ts:1:31]
  1 │ type Equals = A extends (x: B extends C ? D : E) => 0 ? F : G;
-   ·                               ───┬───
-   ·                                  ╰── `,` expected
+   ·                         ┬     ───┬───
+   ·                         │        ╰── `,` or `)` expected
+   ·                         ╰── Opened here
    ╰────
 
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param-babel-7/input.ts
 
-  × Expected `,` but found `extends`
+  × Expected `,` or `)` but found `extends`
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param-babel-7/input.ts:1:31]
  1 │ type Equals = A extends (x: B extends C ? D : E) => 0 ? F : G;
-   ·                               ───┬───
-   ·                                  ╰── `,` expected
+   ·                         ┬     ───┬───
+   ·                         │        ╰── `,` or `)` expected
+   ·                         ╰── Opened here
    ╰────
 
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/type-arguments-bit-shift-left-like/class-heritage/input.ts
@@ -3165,11 +3167,12 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
    ╰────
   help: Replace this operator with `=`.
 
-  × Expected `,` but found `(`
+  × Expected `,` or `}` but found `(`
    ╭─[babel/packages/babel-parser/test/fixtures/es2015/destructuring/invalid-object-method/input.js:1:12]
  1 │ const { foo() {} } = foo();
-   ·            ┬
-   ·            ╰── `,` expected
+   ·       ┬    ┬
+   ·       │    ╰── `,` or `}` expected
+   ·       ╰── Opened here
    ╰────
 
   × Cannot assign to this expression
@@ -5538,11 +5541,12 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
    ╰────
   help: Did you mean to use a ':'? An '=' can only follow a property name when the containing object literal is part of a destructuring pattern.
 
-  × Expected `,` but found `?`
+  × Expected `,` or `)` but found `?`
    ╭─[babel/packages/babel-parser/test/fixtures/es2017/async-call/with-optional-operator/input.js:1:8]
  1 │ async(x?)
-   ·        ┬
-   ·        ╰── `,` expected
+   ·      ┬ ┬
+   ·      │ ╰── `,` or `)` expected
+   ·      ╰── Opened here
    ╰────
 
   × Expected a semicolon or an implicit semicolon after a statement, but found none

tasks/coverage/snapshots/parser_typescript.snap

@@ -6943,21 +6943,23 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ╰────
   help: Remove the duplicate modifier.
 
-  × Expected `,` but found `:`
+  × Expected `,` or `)` but found `:`
    ╭─[typescript/tests/cases/compiler/decoratorInJsFile.ts:3:10]
  2 │ class SomeClass {
  3 │     foo(x: number) {
-   ·          ┬
-   ·          ╰── `,` expected
+   ·        ┬ ┬
+   ·        │ ╰── `,` or `)` expected
+   ·        ╰── Opened here
  4 │ 
    ╰────
 
-  × Expected `,` but found `:`
+  × Expected `,` or `)` but found `:`
    ╭─[typescript/tests/cases/compiler/decoratorInJsFile1.ts:3:10]
  2 │ class SomeClass {
  3 │     foo(x: number) {
-   ·          ┬
-   ·          ╰── `,` expected
+   ·        ┬ ┬
+   ·        │ ╰── `,` or `)` expected
+   ·        ╰── Opened here
  4 │ 
    ╰────
 
@@ -8454,12 +8456,19 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
  15 │ }
     ╰────
 
-  × Expected `,` but found `var`
+  × Expected `,` or `)` but found `var`
+   ╭─[typescript/tests/cases/compiler/functionTypesLackingReturnTypes.ts:2:11]
+ 1 │ // Error (no '=>')
+ 2 │ function f(x: ()) {
+   ·           ┬
+   ·           ╰── Opened here
+ 3 │ }
+   ╰────
    ╭─[typescript/tests/cases/compiler/functionTypesLackingReturnTypes.ts:6:1]
  5 │ // Error (no '=>')
  6 │ var g: (param);
    · ─┬─
-   ·  ╰── `,` expected
+   ·  ╰── `,` or `)` expected
  7 │ 
    ╰────
 
@@ -9126,11 +9135,12 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ╰────
   help: Try inserting a semicolon here
 
-  × Expected `,` but found `?`
+  × Expected `,` or `)` but found `?`
    ╭─[typescript/tests/cases/compiler/jsFileCompilationOptionalParameter.ts:1:13]
  1 │ function F(p?) { }
-   ·             ┬
-   ·             ╰── `,` expected
+   ·           ┬ ┬
+   ·           │ ╰── `,` or `)` expected
+   ·           ╰── Opened here
    ╰────
 
   × TS(8012): Parameter modifiers can only be used in TypeScript files.
@@ -9173,11 +9183,12 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ·         ─
    ╰────
 
-  × Expected `,` but found `:`
+  × Expected `,` or `)` but found `:`
    ╭─[typescript/tests/cases/compiler/jsFileCompilationTypeOfParameter.ts:1:13]
  1 │ function F(a: number) { }
-   ·             ┬
-   ·             ╰── `,` expected
+   ·           ┬ ┬
+   ·           │ ╰── `,` or `)` expected
+   ·           ╰── Opened here
    ╰────
 
   × Expected `{` but found `<`
@@ -11001,12 +11012,13 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
  3 │     }
    ╰────
 
-  × Expected `,` but found `:`
+  × Expected `,` or `)` but found `:`
    ╭─[typescript/tests/cases/compiler/parametersSyntaxErrorNoCrash1.ts:3:28]
  2 │ 
  3 │ function identity<T>(arg: T: T {
-   ·                            ┬
-   ·                            ╰── `,` expected
+   ·                     ┬      ┬
+   ·                     │      ╰── `,` or `)` expected
+   ·                     ╰── Opened here
  4 │     return arg;
    ╰────
 
@@ -12069,12 +12081,13 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ·                ──────
    ╰────
 
-  × Expected `,` but found `Identifier`
+  × Expected `,` or `)` but found `Identifier`
    ╭─[typescript/tests/cases/compiler/restParamModifier.ts:2:27]
  1 │ class C {
  2 │     constructor(...public rest: string[]) {}
-   ·                           ──┬─
-   ·                             ╰── `,` expected
+   ·                ┬          ──┬─
+   ·                │            ╰── `,` or `)` expected
+   ·                ╰── Opened here
  3 │ }
    ╰────
 
@@ -16802,12 +16815,13 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
  5 │ }
    ╰────
 
-  × Expected `,` but found `@`
+  × Expected `,` or `)` but found `@`
    ╭─[typescript/tests/cases/conformance/decorators/class/constructor/parameter/decoratorOnClassConstructorParameter4.ts:4:24]
  3 │ class C {
  4 │     constructor(public @dec p: number) {}
-   ·                        ┬
-   ·                        ╰── `,` expected
+   ·                ┬       ┬
+   ·                │       ╰── `,` or `)` expected
+   ·                ╰── Opened here
  5 │ }
    ╰────
 
@@ -17489,12 +17503,13 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ╰────
   help: Add an initializer (e.g. ` = undefined`) here
 
-  × Expected `,` but found `?`
+  × Expected `,` or `}` but found `?`
    ╭─[typescript/tests/cases/conformance/es6/destructuring/destructuringObjectBindingPatternAndAssignment3.ts:2:7]
  1 │ // Error
  2 │ var {h?} = { h?: 1 };
-   ·       ┬
-   ·       ╰── `,` expected
+   ·     ┬ ┬
+   ·     │ ╰── `,` or `}` expected
+   ·     ╰── Opened here
  3 │ var {i}: string | number = { i: 2 };
    ╰────
 
@@ -22579,11 +22594,12 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ·                 ──
    ╰────
 
-  × Expected `,` but found `:`
+  × Expected `,` or `)` but found `:`
    ╭─[typescript/tests/cases/conformance/parser/ecmascript5/ArrowFunctionExpressions/parserArrowFunctionExpression14.ts:1:9]
  1 │ a() ? (b: number, c?: string): void => d() : e; // Not legal JS; "Unexpected token ':'" at first colon
-   ·         ┬
-   ·         ╰── `,` expected
+   ·       ┬ ┬
+   ·       │ ╰── `,` or `)` expected
+   ·       ╰── Opened here
    ╰────
 
   × Expected a semicolon or an implicit semicolon after a statement, but found none
@@ -23218,11 +23234,12 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ·       ╰── `:` expected
    ╰────
 
-  × Expected `,` but found `{`
+  × Expected `,` or `)` but found `{`
    ╭─[typescript/tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ParameterLists/parserErrorRecovery_ParameterList1.ts:1:14]
  1 │ function f(a {
-   ·              ┬
-   ·              ╰── `,` expected
+   ·           ┬  ┬
+   ·           │  ╰── `,` or `)` expected
+   ·           ╰── Opened here
  2 │ }
    ╰────
 
@@ -23239,11 +23256,12 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
  2 │ }
    ╰────
 
-  × Expected `,` but found `=>`
+  × Expected `,` or `)` but found `=>`
    ╭─[typescript/tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ParameterLists/parserErrorRecovery_ParameterList5.ts:1:11]
  1 │ (a:number => { }
-   ·           ─┬
-   ·            ╰── `,` expected
+   · ┬         ─┬
+   · │          ╰── `,` or `)` expected
+   · ╰── Opened here
    ╰────
 
   × Unexpected token
@@ -23318,11 +23336,12 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ╰────
   help: Function name is required in function declaration or named export
 
-  × Expected `,` but found `=>`
+  × Expected `,` or `)` but found `=>`
    ╭─[typescript/tests/cases/conformance/parser/ecmascript5/ErrorRecovery/parserEqualsGreaterThanAfterFunction2.ts:1:13]
  1 │ function (a => b;
-   ·             ─┬
-   ·              ╰── `,` expected
+   ·          ┬  ─┬
+   ·          │   ╰── `,` or `)` expected
+   ·          ╰── Opened here
    ╰────
 
   × Expected a semicolon or an implicit semicolon after a statement, but found none

tasks/coverage/snapshots/semantic_babel.snap

@@ -1565,10 +1565,10 @@ after transform: ScopeId(0): [ScopeId(1), ScopeId(2)]
 rebuilt        : ScopeId(0): []
 
 semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param/input.ts
-Expected `,` but found `extends`
+Expected `,` or `)` but found `extends`
 
 semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-param-babel-7/input.ts
-Expected `,` but found `extends`
+Expected `,` or `)` but found `extends`
 
 semantic Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/nested-extends-in-arrow-type-return/input.ts
 Scope children mismatch:

tasks/track_memory_allocations/allocs_parser.snap

@@ -1,14 +1,14 @@
 File                       | File size      || Sys allocs     | Sys reallocs   || Arena allocs   | Arena reallocs | Arena bytes    
 -------------------------------------------------------------------------------------------------------------------------------------------
-checker.ts                 | 2.92 MB        ||           9671 |             21 ||         267681 |          22847
+checker.ts                 | 2.92 MB        ||           9672 |             21 ||         267681 |          22847
 
-cal.com.tsx                | 1.06 MB        ||           2197 |             62 ||         138162 |          13699
+cal.com.tsx                | 1.06 MB        ||           2212 |             62 ||         138162 |          13699
 
 RadixUIAdoptionSection.jsx | 2.52 kB        ||              1 |              0 ||            365 |             66
 
-pdf.mjs                    | 567.30 kB      ||            701 |             75 ||          90678 |           8148
+pdf.mjs                    | 567.30 kB      ||            703 |             75 ||          90678 |           8148
 
-antd.js                    | 6.69 MB        ||           6997 |            235 ||         528505 |          55357
+antd.js                    | 6.69 MB        ||           7132 |            235 ||         528505 |          55357
 
 binder.ts                  | 193.08 kB      ||            530 |              7 ||          16791 |           1467