Add a simple version of the function for basic usage. (#49)

* Add simple version of call to add segment

* Update readme

Author: terodox

README.md

@@ -3,19 +3,34 @@
 [![NPM](https://nodei.co/npm/aws-xray-lambda-promise-subsegment.png?compact=true)](https://npmjs.org/package/aws-xray-lambda-promise-subsegment)
 
 # aws-xray-lambda-promise-subsegment
+
 This will wrap an existing promise in a new promise that also creates a new subsegment in aws x-ray. It takes advantage of lambda already having an open trace to add a sub-segment to.
 
 ## Running locally
 
 If you are running locally an not inside lambda, you will get a warning:
 
-**WARNING: Skipping adding subsegment because we are not executing inside of aws lambda**
+```text
+WARNING: Skipping adding subsegment because we are not executing inside of aws lambda
+```
 
-This is because there is no open trace to add a segment to.  However, this will allow you to test locally without errors occuring.
+This is because there is no open trace to add a segment to.  However, this will allow you to test locally without errors occurring.
 
 ## Usage
 
 ## Without a parent segment
+
+You have two options available. For the simplest possible addition use:
+
+```javascript
+// javascript
+const addSegment = require("aws-xray-lambda-promise-subsegment").addSegment;
+
+const promiseWrappedInSubsegment = addSegment('subSegmentName', promiseOfThingsFactory());
+```
+
+However, if you want to add metadata or annotations, then you'll need the more complex version:
+
 ```javascript
 // javascript
 const addPromiseSegment = require("aws-xray-lambda-promise-subsegment").addPromiseSegment;
@@ -34,6 +49,15 @@ const promiseWrappedInSubsegment = addPromiseSegment({
 });
 ```
 
+### Es6 Syntax
+
+```javascript
+// es6
+const { addSegment } = require("aws-xray-lambda-promise-subsegment");
+
+const promiseWrappedInSubsegment = addSegment('subSegmentName', promiseOfThingsFactory());
+```
+
 ```javascript
 // es6
 import { addPromiseSegment } from "aws-xray-lambda-promise-subsegment";

demo/index.js

@@ -6,7 +6,7 @@ console.log('----------------------------------------');
 console.log('----------------------------------------');
 
 const AWSXRay = require('aws-xray-sdk-core');
-const addPromiseSegment = require('../index.js').addPromiseSegment;
+const { addPromiseSegment, addSegment } = require('../index.js');
 const Enquirer = require('enquirer');
 
 process.env.LAMBDA_TASK_ROOT = 'The taskiest root of them all';
@@ -76,6 +76,7 @@ async function basicTracing() {
 (async function() {
     const BASIC_EXAMPLE = 'Basic';
     const NESTED_EXAMPLE = 'Nested';
+    const ADD_SEGMENT = 'addSegment';
 
     enquirer = new Enquirer();
     const response = await enquirer.prompt({
@@ -84,14 +85,17 @@ async function basicTracing() {
         message: 'Which example?',
         choices: [
             BASIC_EXAMPLE,
-            NESTED_EXAMPLE
+            NESTED_EXAMPLE,
+            ADD_SEGMENT
         ]
     });
 
     if(response.example === BASIC_EXAMPLE) {
         return basicTracing();
     } else if(response.example === NESTED_EXAMPLE) {
         return nestedTracing();
+    } else if(response.example === ADD_SEGMENT) {
+        return runWithTracing(() => addSegment('add-segment-example', Promise.resolve({ all: 'of it works' })));
     }
 })()
     .then(console.log)

index.d.ts

@@ -17,4 +17,6 @@ export declare function addPromiseSegment<T>({
     parentSegment?: object,
     promiseFactory: (subsegment) => Promise<T>,
     segmentName: string
-}): Promise<T>;
+}): Promise<T>;
+
+export declare function addSegment<T>(segmentName: string, promise: Promise): Promise<T>;

index.js

@@ -22,7 +22,7 @@ function addAnnotations(subSegment, annotations) {
     }
 }
 
-module.exports.addPromiseSegment = async function ({
+async function addPromiseSegment ({
     annotations,
     parentSegment,
     promiseFactory,
@@ -64,4 +64,16 @@ module.exports.addPromiseSegment = async function ({
             reject(err);
         }
     });
+};
+
+async function addSegment (segmentName, promise) {
+    return addPromiseSegment({
+        segmentName,
+        promiseFactory: () => promise
+    })
+}
+
+module.exports = {
+    addPromiseSegment,
+    addSegment
 };