feat(ask-sdk-core/util) Add new helper function to get user id

[hideokamoto]

We can get user id from the SDK.

Description

Add the getUserId function into the utils. We can get the user id more easier.

Motivation and Context

Now we can get the requested user's device id by the SDK. But we want to get the user id too.

Before

const userId = handlerInput.requestEnvelope.context.System.user.userId 

Our code will be too long line :(

After

const userId = getUserId(handlerInput.requestEnvelope)

It is the simplest way to get the user ID :)

Testing

To run unit test by gulp.

$ lerna bootstrap
$ lerna --scope ask-sdk-core run gulp -- test
  110 passing (76ms)

=============================== Coverage summary ===============================
Statements   : 100% ( 351/351 )
Branches     : 100% ( 88/88 )
Functions    : 96.26% ( 103/107 )
Lines        : 100% ( 330/330 )
================================================================================

[09:57:52] Finished 'test' after 1.76 s
lerna success run Ran npm script 'gulp' in 1 package in 2.9s:
lerna success - ask-sdk-core

Screenshots (if appropriate)

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] Docs(Add new document content)
• [ ] Translate Docs(Translate document content)

Checklist

• [x] My code follows the code style of this project
• [x] My change requires a change to the documentation
• [x] I have updated the documentation accordingly
• [x] I have read the README document
• [x] I have added tests to cover my changes
• [x] All new and existing tests passed
• [x] My commit message follows Conventional Commit Guideline

License

• [x] I confirm that this pull request can be released under the Apache 2 license

[kun432]

:+1:

[ShenChen93]

Hi @hideokamoto

The code looks good. Before I merge it in, could you please modify the commit name to "feat: add getUserId util function", In order to fit conventional commits structure.

Thanks, Shen

[hideokamoto]

I've rebased my commits.

[ShenChen93]

Hi, @hideokamoto

Thanks for the PR! Merging this in. It will be included in the next SDK release.

Regards, Shen