{
  "context": "This criteria evaluates the engineer's ability to use Babel's experimental features API to build a plugin that parses and transforms cutting-edge JavaScript proposals. It focuses on proper usage of parser plugins, plugin development patterns, AST transformation, and configuration options.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Parser plugin configuration",
      "description": "Uses @babel/parser with experimental syntax plugins (e.g., 'pipelineOperator', 'decorators', 'doExpressions') configured via parserOpts to enable parsing of proposal syntax",
      "max_score": 25
    },
    {
      "name": "Babel plugin structure",
      "description": "Returns a proper Babel plugin object from the main function with a 'visitor' property containing visitor methods for AST traversal, following the plugin API pattern",
      "max_score": 20
    },
    {
      "name": "AST node transformation",
      "description": "Uses @babel/types builders (e.g., t.identifier, t.callExpression, t.blockStatement) and visitor methods to transform experimental syntax AST nodes into backward-compatible JavaScript",
      "max_score": 30
    },
    {
      "name": "Plugin options handling",
      "description": "Accepts and uses the options parameter to conditionally enable/disable experimental features, allowing configuration of which syntax proposals to support",
      "max_score": 15
    },
    {
      "name": "@babel/core integration",
      "description": "Uses transformSync or transform from @babel/core to process source code with the plugin, properly passing the plugin and its configuration through Babel's transformation pipeline",
      "max_score": 10
    }
  ]
}