{
  "context": "Evaluates whether the solution configures Babel for syntax-only parsing of experimental features, using @babel/core with the correct @babel/plugin-syntax-* plugins to accept or reject code while returning unaltered output and meaningful AST data. Checks focus exclusively on using Babel's syntax-only facilities to honor per-compiler allowlists and report unsupported features clearly.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Syntax plugins",
      "description": "Allowlist entries resolve to the matching @babel/plugin-syntax-* modules (e.g., @babel/plugin-syntax-pipeline-operator, @babel/plugin-syntax-do-expressions) and are passed to @babel/core via the plugins array without introducing transform plugins.",
      "max_score": 30
    },
    {
      "name": "Passthrough code",
      "description": "Uses @babel/core (parseSync/transformSync/transform) to process input while keeping the emitted code identical to the source, avoiding presets or transform plugins that would change syntax.",
      "max_score": 20
    },
    {
      "name": "AST availability",
      "description": "Returns the Babel AST (File/Program) from the @babel/core result so callers can inspect parsed nodes from syntax-only compilation.",
      "max_score": 15
    },
    {
      "name": "Missing feature errors",
      "description": "Compilation attempts for features not in the allowlist surface a clear error that names the absent feature rather than silently enabling it or passing invalid code through.",
      "max_score": 20
    },
    {
      "name": "Isolated configs",
      "description": "Each compiler instance builds its own plugins array from the provided allowlist so different instances keep their syntax scopes independent (no shared global plugin state).",
      "max_score": 15
    }
  ]
}