fix(adapter/aws-lambda): add alb event requestContext undefined check for testing convenience

[ospatil]

Issue Summary

While testing a lambda using aws lambda invoke or from the AWS Console, the current aws-lambda adapter isProxyEventALB implementation results in following error:

{
    "errorType": "TypeError",
    "errorMessage": "Cannot convert undefined or null to object",
    "stack": [
        "TypeError: Cannot convert undefined or null to object",
        "    at Function.hasOwn (<anonymous>)",
        "    at isProxyEventALB (/var/task/index.js:1816:17)",
        "    at getProcessor (/var/task/index.js:1807:7)",
        "    at Runtime.handler (/var/task/index.js:1620:23)",
        "    at Runtime.handleOnceNonStreaming (file:///var/runtime/index.mjs:1173:29)"
    ]
}

This can be reproduced by scaffolding a lambda project using npm create hono@latest and deploying it in an AWS account without any changes to the code.

Benefits of the fix

A fix by adding an undefined check for event.requestContext will significantly ease the testing of lambda using simple tools like aws lambda invoke and AWS Console.

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.70%. Comparing base (163657a) to head (d3376e9).
Report is 6 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3691   +/-   ##
=======================================
  Coverage   91.70%   91.70%           
=======================================
  Files         159      159           
  Lines       10145    10162   +17     
  Branches     2910     2883   -27     
=======================================
+ Hits         9303     9319   +16     
- Misses        840      842    +2     
+ Partials        2        1    -1     

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[yusukebe]

Hi @ospatil

Thank you for the PR. Looks good, but one thing. Can you write a test for this change? There may not be enough tests for this AWS Lambda adapter currently, but we have to add a test for the patch.

[ospatil]

@yusukebe I have added tests for getProcessor function. Since the Processor class types are not exported, I had to limit the assertions to the processor being defined after calling the function.

A big shout-out to you and the team for this amazing project 🙌🏼 .

[exoego]

This line is not covered

[ospatil]

That's from the report before I updated the PR with the tests. After adding the tests, the coverage report has not run as it's awaiting maintainer approval.

I ran the coverage locally (bun coverage) after adding the tests and it's all green.

[exoego]

I see.
New tests are not executed since approval needed

[yusukebe]

LGTM!

[yusukebe]

@ospatil

Nice job! I'll merge this and release a new version. Thank you for your contribution!