'use strict';

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

const msg = 'Please use common.expectsError(fn, err) instead of ' +
            'assert.throws(fn, common.expectsError(err)).';

function isAssertThrows(node) {
  return node &&
         node.callee &&
         node.callee.object &&
         node.callee.object.name === 'assert' &&
         node.callee.property &&
         node.callee.property.name === 'throws';
}


function isFunction(arg) {
  return arg && (arg.type === 'ArrowFunctionExpression' ||
                 arg.type === 'FunctionExpression' ||
                 arg.type === 'CallExpression');
}

function isCommonExpectsError(node) {
  return node &&
         node.callee &&
         node.callee.object &&
         node.callee.object.name === 'common' &&
         node.callee.property &&
         node.callee.property.name === 'expectsError';
}

module.exports = function(context) {
  return {
    CallExpression(node) {
      if (isAssertThrows(node) &&
          isFunction(node.arguments[0]) &&
          isCommonExpectsError(node.arguments[1]) &&
          !node.arguments[2]) {
        context.report(node, msg);
      }
    }
  };
};