Handle nil response from Lambda when invocation_type = "Event"

[ryota765]

This is a 🐞 bug fix.

• I've added tests (if it's a bug, feature or enhancement)
• I've adjusted the documentation (if it's a feature or enhancement)
• The test suite passes (run bundle exec rspec to verify this)

Summary

In v5.0.X, when Lambda function is invoked with invocation_type = "Event", the response from Lambda will only include status code and the payload becomes null.
This will cause NoMethodError (undefined method read for nil:NilClass).
Therefore, I added handling for nil value.

• Invoked location

  • jets/lib/jets/commands/call/caller.rb

    Line 66 in e682c5d

    resp = lambda_client.invoke(options)

• Null error location

  • jets/lib/jets/commands/call/caller.rb

    Line 78 in e682c5d

    result = resp.payload.read # already been normalized/JSON.dump by AWS

• Lambda document
  • https://docs.aws.amazon.com/lambda/latest/api/API_Invoke.html#API_Invoke_RequestParameters

Context

No specific context.

How to Test

Call Lambda functions with invocation_type = "Event" option in v5.0.X

Version Changes

v5.0.15 (Please merge to v5 branch, instead of latest master branch 🙏 )