The generated parser TypeScript types currently declare BindingIdentifier.typeAnnotation as always null, but the parser can emit a real TSTypeAnnotation for binding identifiers.

Reference discussion: https://discord.com/channels/1079625926024900739/1080712024683708466/1500159726980432084

AI disclosure: this issue text was drafted with AI assistance and reviewed before filing.

Reproduction

Parse a TypeScript binding identifier with a type annotation, for example:

const x: string = "foo";

The parsed AST includes a BindingIdentifier whose typeAnnotation is populated:

{
  type: "Identifier",
  name: "x",
  typeAnnotation: {
    type: "TSTypeAnnotation",
    typeAnnotation: {
      type: "TSStringKeyword"
    }
  }
}

Current Type Definition

In types.d.ts, BindingIdentifier is currently generated as:

export interface BindingIdentifier extends Span {
  type: "Identifier";
  decorators?: [];
  name: string;
  optional?: false;
  typeAnnotation?: null;
  parent?: Node;
}

Expected

IdentifierReference.typeAnnotation should remain null, because annotations are not valid on identifier references:

const y = x: string; // invalid

But BindingIdentifier.typeAnnotation should allow a real TypeScript annotation, because bindings can be annotated:

const x: string = "foo";

Expected type:

export interface BindingIdentifier extends Span {
  type: "Identifier";
  decorators?: [];
  name: string;
  optional?: false;
  typeAnnotation?: TSTypeAnnotation | null;
  parent?: Node;
}

Notes

This appears to be a generated type mismatch rather than a parser AST output issue. The generated files point to:

tasks/ast_tools/src/generators/typescript.rs

as the source for types.d.ts generation.