Local Lambda debug (typescript): error: Cannot find module 'app'

[DavidCabaniuk]

System details (run the AWS: About Toolkit command)

• OS: Windows 10
• Visual Studio Code version: 1.82.2
• AWS Toolkit version: v1.89.0

Question

I'm trying to debug a node lambda through AWS Toolkit.

I've used sam init to generate the default hello-world typescript project.

I've gone to the lambdaHandler and selected AWS: Add Debug Configuration.

I then have run the debugger using the generated launch config.

I then get the error reported in the screen shots and my break point is never hit.

Any idea what I am doing wrong / missed?

Thanks

Debugger attached.
2023-09-14T23:02:07.592Z	undefined	ERROR	Uncaught Exception 	{"errorType":"Runtime.ImportModuleError","errorMessage":"Error: Cannot find module 'app'\nRequire stack:\n- /var/runtime/index.mjs","stack":["Runtime.ImportModuleError: Error: Cannot find module 'app'","Require stack:","- /var/runtime/index.mjs","    at _loadUserApp (file:///var/runtime/index.mjs:1061:17)","    at async Object.load (file:///var/runtime/index.mjs:1093:21)","    at async start (file:///var/runtime/index.mjs:1256:23)","    at async file:///var/runtime/index.mjs:1262:1"]}
Waiting for the debugger to disconnect...
14 Sep 2023 23:02:07,657 [ERROR] (rapid) Init failed error=Runtime exited with error: exit status 129 InvokeID=
Debugger listening on ws://0.0.0.0:5858/461ef53a-cace-487d-834f-eafc5243466f
For help, see: https://nodejs.org/en/docs/inspector

[justinmk3]

Can you provide the Toolkit logs (after removing any private info)?

1. In VSCode settings, ensure that "aws log level" is "debug".
2. Perform the steps to reproduce the issue.
3. Use the AWS: View Toolkit Logs command to get the logs.

AWS Toolkit attempts to support Typescript Lambdas but there are some cases where it has problems generating sourcemaps or sending the build files into the container. Haven't narrowed down the steps reproduce this issue, yet.

• lambda code not in root (CDK typescript project) #1487
• Related SAM CLI issue? Correct setup for multiple Lambda Functions using TypeScript/esbuild? aws-sam-cli#4357

[DavidCabaniuk]

Sure can logs attached
aws_toolkit_20230915T152357.log

To get the project im testing this on you can do sam init

Then Options) 1, 1, n, 11, 1, 2

With with aws toolkit plugin installed and codeslens on I just hit AWS: Add Debug Configuration

After then I just hit debug for that launch config

Also just to add, I tried a basic JS project and I am able to get the debugger working. Starting to feel like a typescript thing / something with the paths not right

[maximedemarey-wb]

Any news on this issue ? I'm facing same problem with AWS toolkit 1.95 / macOS Ventura

[bryceitoc9]

Just curious, does generating a debug handler from your template.yaml file work (use the codelens over the resource in the template.yaml file)? I'll look into the code-target handlers, but I'm having luck running a template-target one.

[maximedemarey-wb]

When I generate the debug launch config from template.yml, execution of the lambda is ok (but doesn't hit breakpoints)

{
    "configurations": [
        {
            "type": "aws-sam",
            "request": "direct-invoke",
            "name": "test-debug:HelloWorldFunction",
            "invokeTarget": {
                "target": "template",
                "templatePath": "${workspaceFolder}/template.yaml",
                "logicalId": "HelloWorldFunction"
            },
            "lambda": {
                "payload": {},
                "environmentVariables": {}
            }
        },
        {
            "type": "aws-sam",
            "request": "direct-invoke",
            "name": "nodejs:app.lambdaHandler (nodejs18.x)",
            "invokeTarget": {
                "target": "code",
                "projectRoot": "${workspaceFolder}/hello-world",
                "lambdaHandler": "app.lambdaHandler"
            },
            "lambda": {
                "runtime": "nodejs18.x",
                "payload": {},
                "environmentVariables": {}
            }
        }
    ]
}

[justinmk3]

execution of the lambda is ok (but doesn't hit breakpoints)

Is inlineSourceMap: true specified in your tsconfig.json ? Also try "noEmit": false, "sourceMap": true,.

Related:

• SAM: debug typescript lambda locally #3210 (comment)
• SAM: debug typescript lambda locally #3210 (comment)

[bryceitoc9]

#3952 for the code-target launch configs. Historically, the Typescript code-target launch configs were a best-guess (since we have to generate and tsc everything ourselves), but this seems like it fixes the base cases at the very least?