fix(parser): validate accessor parameters in interface method signatures (#18391)

## Summary

Add validation for getter/setter accessor parameters in TypeScript interface method signatures:

- A 'get' accessor cannot have parameters (TS1054)
- A 'set' accessor must have exactly one parameter (TS1049)
- A 'set' accessor cannot have an optional parameter (TS1051)
- A 'set' accessor cannot have rest parameter (TS1053)
- 'get' and 'set' accessors cannot declare 'this' parameters (TS2784)

This fixes 5 failing Babel conformance tests:
- `interface/get-set-invalid-optional-parameter`
- `interface/get-set-invalid-parameters`
- `interface/get-set-invalid-reset-parameter`
- `interface/get-set-invalid-reset-parameter-babel-7`
- `interface/get-set-invalid-this-parameters`

🤖 Generated with [Claude Code](https://claude.ai/code)

crates/oxc_parser/src/diagnostics.rs

@@ -1144,6 +1144,16 @@ pub fn getter_parameters(span: Span) -> OxcDiagnostic {
         .with_help("Remove these parameters here")
 }
 
+#[cold]
+pub fn setter_with_optional_parameter(span: Span) -> OxcDiagnostic {
+    ts_error("1051", "A 'set' accessor cannot have an optional parameter.").with_label(span)
+}
+
+#[cold]
+pub fn accessor_cannot_have_this_parameter(span: Span) -> OxcDiagnostic {
+    ts_error("2784", "'get' and 'set' accessors cannot declare 'this' parameters.").with_label(span)
+}
+
 #[cold]
 pub fn variable_declarator_definite(span: Span) -> OxcDiagnostic {
     ts_error(

crates/oxc_parser/src/ts/types.rs

@@ -1213,13 +1213,40 @@ impl<'a> ParserImpl<'a> {
             self.parse_formal_parameters(FunctionKind::Declaration, FormalParameterKind::Signature);
         let return_type = self.parse_ts_return_type_annotation();
         self.parse_type_member_semicolon();
-        if kind == TSMethodSignatureKind::Set
-            && let Some(return_type) = return_type.as_ref()
-        {
-            self.error(diagnostics::a_set_accessor_cannot_have_a_return_type_annotation(
-                return_type.span,
-            ));
+
+        if let Some(this_param) = &this_param {
+            self.error(diagnostics::accessor_cannot_have_this_parameter(this_param.span));
         }
+
+        match kind {
+            TSMethodSignatureKind::Get => {
+                if !params.items.is_empty() {
+                    self.error(diagnostics::getter_parameters(params.span));
+                }
+            }
+            TSMethodSignatureKind::Set => {
+                if let Some(return_type) = return_type.as_ref() {
+                    self.error(diagnostics::a_set_accessor_cannot_have_a_return_type_annotation(
+                        return_type.span,
+                    ));
+                }
+                if let Some(rest) = &params.rest {
+                    self.error(diagnostics::setter_with_rest_parameter(rest.span));
+                }
+                if params.items.len() != 1 {
+                    self.error(diagnostics::setter_with_parameters(
+                        params.span,
+                        params.items.len(),
+                    ));
+                } else if let Some(param) = params.items.first()
+                    && param.optional
+                {
+                    self.error(diagnostics::setter_with_optional_parameter(param.span));
+                }
+            }
+            TSMethodSignatureKind::Method => {}
+        }
+
         self.ast.ts_signature_method_signature(
             self.end_span(span),
             key,

tasks/coverage/snapshots/parser_babel.snap

@@ -3,7 +3,7 @@ commit: fc58af40
 parser_babel Summary:
 AST Parsed     : 2217/2223 (99.73%)
 Positive Passed: 2204/2223 (99.15%)
-Negative Passed: 1649/1689 (97.63%)
+Negative Passed: 1654/1689 (97.93%)
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/es2026/explicit-resource-management/invalid-for-using-of-no-initializer/input.js
 
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/cast/unparenthesized-assert-and-assign/input.ts
@@ -56,16 +56,6 @@ Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/ty
 
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/import/equals-require-in-script/input.ts
 
-Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-optional-parameter/input.ts
-
-Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-parameters/input.ts
-
-Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-reset-parameter/input.ts
-
-Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-reset-parameter-babel-7/input.ts
-
-Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-this-parameters/input.ts
-
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/module-namespace/module-identifier-invalid/input.ts
 
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/regression/keyword-qualified-type-2/input.ts
@@ -13323,6 +13313,66 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
    ·                          ─
    ╰────
 
+  × TS(1051): A 'set' accessor cannot have an optional parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-optional-parameter/input.ts:2:11]
+ 1 │ interface Foo {
+ 2 │   set bar(foo?: string);
+   ·           ────────────
+ 3 │ }
+   ╰────
+
+  × A 'get' accessor must not have any formal parameters.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-parameters/input.ts:2:10]
+ 1 │ interface Foo {
+ 2 │   get foo(param): string;
+   ·          ───────
+ 3 │   set foo();
+   ╰────
+  help: Remove these parameters here
+
+  × A 'set' accessor must have exactly one parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-parameters/input.ts:3:10]
+ 2 │   get foo(param): string;
+ 3 │   set foo();
+   ·          ──
+ 4 │ }
+   ╰────
+  help: Add a parameter here
+
+  × A 'set' accessor cannot have rest parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-reset-parameter/input.ts:2:11]
+ 1 │ interface Foo {
+ 2 │   set bar(...v);
+   ·           ────
+ 3 │ }
+   ╰────
+
+  × A 'set' accessor must have exactly one parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-reset-parameter/input.ts:2:10]
+ 1 │ interface Foo {
+ 2 │   set bar(...v);
+   ·          ──────
+ 3 │ }
+   ╰────
+  help: Add a parameter here
+
+  × A 'set' accessor cannot have rest parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-reset-parameter-babel-7/input.ts:2:11]
+ 1 │ interface Foo {
+ 2 │   set bar(...v);
+   ·           ────
+ 3 │ }
+   ╰────
+
+  × A 'set' accessor must have exactly one parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-reset-parameter-babel-7/input.ts:2:10]
+ 1 │ interface Foo {
+ 2 │   set bar(...v);
+   ·          ──────
+ 3 │ }
+   ╰────
+  help: Add a parameter here
+
   × TS(1095): A 'set' accessor cannot have a return type annotation.
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-return-types/input.ts:2:17]
  1 │ interface Foo {
@@ -13331,6 +13381,31 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
  3 │ }
    ╰────
 
+  × TS(2784): 'get' and 'set' accessors cannot declare 'this' parameters.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-this-parameters/input.ts:2:11]
+ 1 │ interface Foo {
+ 2 │   get bar(this: Foo);
+   ·           ─────────
+ 3 │   set bar(this: Foo);
+   ╰────
+
+  × TS(2784): 'get' and 'set' accessors cannot declare 'this' parameters.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-this-parameters/input.ts:3:11]
+ 2 │   get bar(this: Foo);
+ 3 │   set bar(this: Foo);
+   ·           ─────────
+ 4 │ }
+   ╰────
+
+  × A 'set' accessor must have exactly one parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-this-parameters/input.ts:3:10]
+ 2 │   get bar(this: Foo);
+ 3 │   set bar(this: Foo);
+   ·          ───────────
+ 4 │ }
+   ╰────
+  help: Add a parameter here
+
   × Expected `(` but found `<`
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/interface/get-set-type-parameters/input.ts:2:10]
  1 │ interface Foo {