optionsFromArguments.js

const DEFAULT_S3_REGION = 'us-east-1';

function requiredOrFromEnvironment(options, key, env) {
  const opts = Object.assign({}, options);
  opts[key] = options[key] || process.env[env];
  if (!opts[key]) {
    throw new Error(`S3Adapter requires option '${key}' or env. variable ${env}`);
  }
  return opts;
}

function fromEnvironmentOrDefault(options, key, env, defaultValue) {
  const opts = Object.assign({}, options);
  opts[key] = options[key] || process.env[env] || defaultValue;
  // If we used the overrides,
  // make sure they take priority
  if (opts.s3overrides) {
    if (opts.s3overrides[key]) {
      opts[key] = opts.s3overrides[key];
    } else if (opts.s3overrides.params && opts.s3overrides.params.Bucket) {
      opts.bucket = opts.s3overrides.params.Bucket;
    }
  }
  return opts;
}

function fromOptionsDictionaryOrDefault(options, key, defaultValue) {
  const opts = Object.assign({}, options);
  opts[key] = options[key] || defaultValue;
  return opts;
}

const optionsFromArguments = function optionsFromArguments(args) {
  const stringOrOptions = args[0];
  let options = {};
  let s3overrides = {};
  let otherOptions;

  if (typeof stringOrOptions === 'string') {
    if (args.length === 1) {
      options.bucket = stringOrOptions;
    } else if (args.length === 2) {
      options.bucket = stringOrOptions;
      if (typeof args[1] !== 'object') {
        throw new Error("Failed to configure S3Adapter. Arguments don't make sense");
      }
      otherOptions = args[1];
    } else if (args.length > 2) {
      if (typeof args[1] !== 'string' || typeof args[2] !== 'string') {
        throw new Error("Failed to configure S3Adapter. Arguments don't make sense");
      }
      options.accessKey = args[0];
      options.secretKey = args[1];
      options.bucket = args[2];
      otherOptions = args[3];
    }

    if (otherOptions) {
      options.bucketPrefix = otherOptions.bucketPrefix;
      options.credentials = otherOptions.credentials;
      options.directAccess = otherOptions.directAccess;
      options.fileAcl = otherOptions.fileAcl;
      options.baseUrl = otherOptions.baseUrl;
      options.baseUrlDirect = otherOptions.baseUrlDirect;
      options.signatureVersion = otherOptions.signatureVersion;
      options.globalCacheControl = otherOptions.globalCacheControl;
      options.presignedUrl = otherOptions.presignedUrl;
      options.presignedUrlExpires = otherOptions.presignedUrlExpires;
      options.ServerSideEncryption = otherOptions.ServerSideEncryption;
      options.generateKey = otherOptions.generateKey;
      options.validateFilename = otherOptions.validateFilename;
      s3overrides = otherOptions.s3overrides;
    }
  } else if (args.length === 1) {
    Object.assign(options, stringOrOptions);
  } else if (args.length === 2) {
    Object.assign(options, stringOrOptions);
    s3overrides = args[1];

    if (s3overrides.params) {
      options.bucket = s3overrides.params.Bucket;
    }
  } else if (args.length > 2) {
    throw new Error("Failed to configure S3Adapter. Arguments don't make sense");
  }

  options = fromOptionsDictionaryOrDefault(options, 's3overrides', s3overrides);
  options = requiredOrFromEnvironment(options, 'bucket', 'S3_BUCKET');
  options = fromEnvironmentOrDefault(options, 'accessKey', 'S3_ACCESS_KEY', null);
  options = fromEnvironmentOrDefault(options, 'secretKey', 'S3_SECRET_KEY', null);
  options = fromEnvironmentOrDefault(options, 'bucketPrefix', 'S3_BUCKET_PREFIX', '');
  options = fromEnvironmentOrDefault(options, 'region', 'S3_REGION', DEFAULT_S3_REGION);
  options = fromEnvironmentOrDefault(options, 'directAccess', 'S3_DIRECT_ACCESS', false);
  options = fromEnvironmentOrDefault(options, 'fileAcl', 'S3_FILE_ACL', null);
  options = fromEnvironmentOrDefault(options, 'baseUrl', 'S3_BASE_URL', null);
  options = fromEnvironmentOrDefault(options, 'baseUrlDirect', 'S3_BASE_URL_DIRECT', false);
  options = fromEnvironmentOrDefault(options, 'signatureVersion', 'S3_SIGNATURE_VERSION', 'v4');
  options = fromEnvironmentOrDefault(options, 'globalCacheControl', 'S3_GLOBAL_CACHE_CONTROL', null);
  options = fromEnvironmentOrDefault(options, 'presignedUrl', 'S3_PRESIGNED_URL', false);
  options = fromEnvironmentOrDefault(options, 'presignedUrlExpires', 'S3_PRESIGNED_URL_EXPIRES', null);
  options = fromOptionsDictionaryOrDefault(options, 'generateKey', null);
  options = fromOptionsDictionaryOrDefault(options, 'validateFilename', null);

  return options;
};

module.exports = optionsFromArguments;