fix(parser): forbid readonly in parser instead of semantic (#13905)

Closes #13883

This also fixes duplicate essentially same diagnostics coming from
parser and semantic each.

Author: ulrichstark

crates/oxc_parser/src/js/function.rs

@@ -70,12 +70,11 @@ impl<'a> ParserImpl<'a> {
         let decorators = self.parse_decorators();
         let modifiers = self.parse_modifiers(false, false);
         if self.is_ts {
-            let mut allowed_modifiers = ModifierFlags::READONLY;
-            if func_kind == FunctionKind::Constructor {
-                allowed_modifiers = allowed_modifiers
-                    .union(ModifierFlags::ACCESSIBILITY)
-                    .union(ModifierFlags::OVERRIDE);
-            }
+            let allowed_modifiers = if func_kind == FunctionKind::Constructor {
+                ModifierFlags::ACCESSIBILITY | ModifierFlags::OVERRIDE | ModifierFlags::READONLY
+            } else {
+                ModifierFlags::empty()
+            };
             self.verify_modifiers(
                 &modifiers,
                 allowed_modifiers,

crates/oxc_semantic/src/checker/typescript.rs

@@ -77,32 +77,19 @@ fn required_parameter_after_optional_parameter(span: Span) -> OxcDiagnostic {
         .with_label(span)
 }
 
-fn parameter_property_outside_constructor(span: Span) -> OxcDiagnostic {
-    OxcDiagnostic::error("A parameter property is only allowed in a constructor implementation.")
-        .with_label(span)
-}
-
 pub fn check_formal_parameters(params: &FormalParameters, ctx: &SemanticBuilder<'_>) {
     if params.kind == FormalParameterKind::Signature && params.items.len() > 1 {
         check_duplicate_bound_names(params, ctx);
     }
 
-    let is_inside_constructor =
-        !params.kind.is_signature() && ctx.current_scope_flags().is_constructor();
     let mut has_optional = false;
 
     for param in &params.items {
         // function a(optional?: number, required: number) { }
-        if has_optional && !param.pattern.optional && !param.pattern.kind.is_assignment_pattern() {
-            ctx.error(required_parameter_after_optional_parameter(param.span));
-        }
         if param.pattern.optional {
             has_optional = true;
-        }
-
-        // function a(public x: number) { }
-        if !is_inside_constructor && param.has_modifier() {
-            ctx.error(parameter_property_outside_constructor(param.span));
+        } else if has_optional && !param.pattern.kind.is_assignment_pattern() {
+            ctx.error(required_parameter_after_optional_parameter(param.span));
         }
     }
 }

tasks/coverage/snapshots/parser_babel.snap

@@ -12870,6 +12870,14 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
  9 │   readonly *[e?.e]?() { }
    ╰────
 
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:3:9]
+ 2 │     not_constructor(
+ 3 │         readonly r,
+   ·         ────────
+ 4 │         public pu: number,
+   ╰────
+
   × TS(1090): 'public' modifier cannot appear on a parameter.
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:4:9]
  3 │         readonly r,
@@ -12902,78 +12910,38 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
  8 │         // Also works on AssignmentPattern
    ╰────
 
-  × TS(1090): 'public' modifier cannot appear on a parameter.
-    ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:10:9]
-  9 │         readonly x = 0,
- 10 │         public y?: number = 0) {}
-    ·         ──────
- 11 │ }
-    ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:3:9]
- 2 │     not_constructor(
- 3 │         readonly r,
-   ·         ──────────
- 4 │         public pu: number,
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:4:9]
- 3 │         readonly r,
- 4 │         public pu: number,
-   ·         ─────────────────
- 5 │         protected po?,
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:5:9]
- 4 │         public pu: number,
- 5 │         protected po?,
-   ·         ─────────────
- 6 │         private pi?: number,
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:6:9]
- 5 │         protected po?,
- 6 │         private pi?: number,
-   ·         ───────────────────
- 7 │         public readonly pur,
-   ╰────
-
-  × A required parameter cannot follow an optional parameter.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:7:9]
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:7:16]
  6 │         private pi?: number,
  7 │         public readonly pur,
-   ·         ───────────────────
- 8 │         // Also works on AssignmentPattern
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:7:9]
- 6 │         private pi?: number,
- 7 │         public readonly pur,
-   ·         ───────────────────
+   ·                ────────
  8 │         // Also works on AssignmentPattern
    ╰────
 
-  × A parameter property is only allowed in a constructor implementation.
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
     ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:9:9]
   8 │         // Also works on AssignmentPattern
   9 │         readonly x = 0,
-    ·         ──────────────
+    ·         ────────
  10 │         public y?: number = 0) {}
     ╰────
 
-  × A parameter property is only allowed in a constructor implementation.
+  × TS(1090): 'public' modifier cannot appear on a parameter.
     ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:10:9]
   9 │         readonly x = 0,
  10 │         public y?: number = 0) {}
-    ·         ─────────────────────
+    ·         ──────
  11 │ }
     ╰────
 
+  × A required parameter cannot follow an optional parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/parameter-properties-not-constructor/input.ts:7:9]
+ 6 │         private pi?: number,
+ 7 │         public readonly pur,
+   ·         ───────────────────
+ 8 │         // Also works on AssignmentPattern
+   ╰────
+
   × TS(18010): An accessibility modifier cannot be used with a private identifier.
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/class/private-fields-modifier-private/input.ts:2:3]
  1 │ class A {
@@ -13158,6 +13126,14 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
    ·             ──
    ╰────
 
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:2:3]
+ 1 │ function foo(
+ 2 │   readonly r,
+   ·   ────────
+ 3 │   public pu: number,
+   ╰────
+
   × TS(1090): 'public' modifier cannot appear on a parameter.
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:3:3]
  2 │   readonly r,
@@ -13190,78 +13166,38 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typesc
  7 │   readonly x = 0,
    ╰────
 
-  × TS(1090): 'public' modifier cannot appear on a parameter.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:8:3]
- 7 │   readonly x = 0,
- 8 │   public y?: number = 0
-   ·   ──────
- 9 │ ) {}
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:2:3]
- 1 │ function foo(
- 2 │   readonly r,
-   ·   ──────────
- 3 │   public pu: number,
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:3:3]
- 2 │   readonly r,
- 3 │   public pu: number,
-   ·   ─────────────────
- 4 │   protected po?,
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:4:3]
- 3 │   public pu: number,
- 4 │   protected po?,
-   ·   ─────────────
- 5 │   private pi?: number,
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:5:3]
- 4 │   protected po?,
- 5 │   private pi?: number,
-   ·   ───────────────────
- 6 │   public readonly pur,
-   ╰────
-
-  × A required parameter cannot follow an optional parameter.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:6:3]
- 5 │   private pi?: number,
- 6 │   public readonly pur,
-   ·   ───────────────────
- 7 │   readonly x = 0,
-   ╰────
-
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:6:3]
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:6:10]
  5 │   private pi?: number,
  6 │   public readonly pur,
-   ·   ───────────────────
+   ·          ────────
  7 │   readonly x = 0,
    ╰────
 
-  × A parameter property is only allowed in a constructor implementation.
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:7:3]
  6 │   public readonly pur,
  7 │   readonly x = 0,
-   ·   ──────────────
+   ·   ────────
  8 │   public y?: number = 0
    ╰────
 
-  × A parameter property is only allowed in a constructor implementation.
+  × TS(1090): 'public' modifier cannot appear on a parameter.
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:8:3]
  7 │   readonly x = 0,
  8 │   public y?: number = 0
-   ·   ─────────────────────
+   ·   ──────
  9 │ ) {}
    ╰────
 
+  × A required parameter cannot follow an optional parameter.
+   ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/parameter-properties/input.ts:6:3]
+ 5 │   private pi?: number,
+ 6 │   public readonly pur,
+   ·   ───────────────────
+ 7 │   readonly x = 0,
+   ╰────
+
   × A required parameter cannot follow an optional parameter.
    ╭─[babel/packages/babel-parser/test/fixtures/typescript/function/pattern-optional-parameters/input.ts:1:17]
  1 │ function f([]?, {}) {}

tasks/coverage/snapshots/parser_misc.snap

@@ -309,16 +309,16 @@ Negative Passed: 90/90 (100.00%)
  3 │ }
    ╰────
 
-  × A parameter property is only allowed in a constructor implementation.
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
    ╭─[misc/fail/oxc-11713-26.ts:1:14]
  1 │ function foo(readonly parameter) {}
-   ·              ──────────────────
+   ·              ────────
    ╰────
 
-  × A parameter property is only allowed in a constructor implementation.
+  × TS(1090): 'readonly' modifier cannot appear on a parameter.
    ╭─[misc/fail/oxc-11713-27.ts:1:20]
  1 │ class Foo { method(readonly parameter) {} }
-   ·                    ──────────────────
+   ·                    ────────
    ╰────
 
   × TS(1090): 'private' modifier cannot appear on a parameter.
@@ -327,12 +327,6 @@ Negative Passed: 90/90 (100.00%)
    ·              ───────
    ╰────
 
-  × A parameter property is only allowed in a constructor implementation.
-   ╭─[misc/fail/oxc-11713-3.ts:1:14]
- 1 │ function foo(private parameter) {}
-   ·              ─────────────────
-   ╰────
-
   × 'declare' modifier cannot be used here.
    ╭─[misc/fail/oxc-11713-4.ts:2:2]
  1 │ class Foo {