Replace return statements in a JavaScript syntax tree

gistfile1.js

function replaceReturnedValue(returnStatement) {
  returnStatement.type = 'ExpressionStatement',
  returnStatement.expression = {
    type: 'CallExpression',
    callee: {
      type: 'MemberExpression',
      computed: false,
      object: {
        type: 'Identifier',
        name: '_map'
      },
      property: {
        type: 'Identifier',
        name: 'push'
      }
    },
    arguments: [returnStatement.argument]
  };
  delete returnStatement.argument;
  return returnStatement;
}

function replaceReturnStatement(returnStatement) {
  returnStatement.type = 'ExpressionStatement',
  returnStatement.expression = {
    type: 'Literal',
    value: 'noop',
    raw: '"noop"'
  };
  return returnStatement;
}

function handleReturnStatement(returnStatement) {
  var returnHasValue = !! returnStatement.argument;
  return returnHasValue ? replaceReturnedValue(returnStatement) : replaceReturnStatement(returnStatement);
}