generatePolicy

const generatePolicy = function(principalId, effect, resource) {
    const authResponse = {};
    authResponse.principalId = principalId;
    if (effect && resource) {
        const policyDocument = {};
        policyDocument.Version = '2012-10-17'; // default version
        policyDocument.Statement = [];
        const statementOne = {};
        statementOne.Action = 'execute-api:Invoke'; // default action
        statementOne.Effect = effect;
        statementOne.Resource = [
            // resource,
            "arn:aws:execute-api:ap-northeast-1:s:todo/todo/*",
        ];
        policyDocument.Statement[0] = statementOne;
        authResponse.policyDocument = policyDocument;
    }

    return authResponse;
};