fix: add missing docstring

src/index.ts

@@ -7,6 +7,84 @@ import * as types from './types/core';
 require('winston');
 const winstonVersion = require('winston/package.json').version;
 
+/**
+ * This module provides support for streaming your winston logs to
+ * [Stackdriver Logging](https://cloud.google.com/logging).
+ *
+ * @class
+ *
+ * @param {object} [options]
+ * @param {object} [options.level] The default log level. Winston will filter
+ *     messages with a severity lower than this.
+ * @param {object} [options.levels] Custom logging levels as supported by
+ *     winston. This list is used to translate your log level to the Stackdriver
+ *     Logging level. Each property should have an integer value between 0 (most
+ *     severe) and 7 (least severe). If you are passing a list of levels to your
+ *     winston logger, you should provide the same list here.
+ * @param {boolean} [options.inspectMetadata=false] Serialize winston-provided log
+ *     metadata using `util.inspect`.
+ * @param {string} [options.logName=winston_log] The name of the log that will receive
+ *     messages written to this transport.
+ * @param {object} [options.resource] The monitored resource that the transport
+ *     corresponds to. On Google Cloud Platform, this is detected automatically,
+ *     but you may optionally specify a specific monitored resource. For more
+ *     information see the
+ *     [official documentation]{@link
+ * https://cloud.google.com/logging/docs/api/reference/rest/v2/MonitoredResource}.
+ * @param {object} [options.serviceContext] For logged errors, we provide this
+ *     as the service context. For more information see
+ *     [this guide]{@link
+ * https://cloud.google.com/error-reporting/docs/formatting-error-messages} and
+ * the [official documentation]{@link
+ * https://cloud.google.com/error-reporting/reference/rest/v1beta1/ServiceContext}.
+ * @param {string} [options.serviceContext.service] An identifier of the
+ *     service, such as the name of the executable, job, or Google App Engine
+ *     service name.
+ * @param {string} [options.serviceContext.version] Represents the version of
+ *     the service.
+ * @param {string} [options.projectId] The project ID from the Google Cloud
+ *     Console, e.g. 'grape-spaceship-123'. We will also check the environment
+ *     variable `GCLOUD_PROJECT` for your project ID. If your app is running in
+ *     an environment which supports {@link
+ * https://cloud.google.com/docs/authentication/production#providing_credentials_to_your_application
+ * Application Default Credentials}, your project ID will be detected
+ * automatically.
+ * @param {string} [options.keyFilename] Full path to the a .json, .pem, or .p12
+ *     key downloaded from the Google Cloud Console. If you provide a path
+ *     to a JSON file, the `projectId` option above is not necessary. NOTE: .pem
+ *     and .p12 require you to specify the `email` option as well.
+ * @param {string} [options.email] Account email address. Required when using a
+ *     .pem or .p12 keyFilename.
+ * @param {object} [options.credentials] Credentials object.
+ * @param {string} [options.credentials.client_email]
+ * @param {string} [options.credentials.private_key]
+ * @param {boolean} [options.autoRetry=true] Automatically retry requests if the
+ *     response is related to rate limits or certain intermittent server errors.
+ *     We will exponentially backoff subsequent requests by default.
+ * @param {number} [options.maxRetries=3] Maximum number of automatic retries
+ *     attempted before returning the error.
+ * @param {constructor} [options.promise] Custom promise module to use instead
+ *     of native Promises.
+ *
+ * @example <caption>Import the client library</caption>
+ * const {LoggingWinston} = require('@google-cloud/logging-winston');
+ *
+ * @example <caption>Create a client that uses <a
+ * href="https://cloud.google.com/docs/authentication/production#providing_credentials_to_your_application">Application
+ * Default Credentials (ADC)</a>:</caption> const loggingWinston = new
+ * LoggingWinston();
+ *
+ * @example <caption>Create a client with <a
+ * href="https://cloud.google.com/docs/authentication/production#obtaining_and_providing_service_account_credentials_manually">explicit
+ * credentials</a>:</caption> const loggingWinston = new LoggingWinston({
+ *   projectId: 'your-project-id',
+ *   keyFilename: '/path/to/keyfile.json'
+ * });
+ *
+ * @example <caption>include:samples/quickstart.js</caption>
+ * region_tag:logging_winston_quickstart
+ * Full quickstart example:
+ */
 // This is a class.
 // tslint:disable-next-line:variable-name
 export const LoggingWinston: types.Logger = semver.lt(winstonVersion, '3.0.0') ?