Serverless-offline: In `alpha-13`, the code executed is not the one transpiled by Webpack / Babel

[verekia]

On alpha-13, the code executed doesn't seem to be the one transpiled by Babel via Webpack (serverless-webpack plugin). The .webpack folder contains the correct compiled sources, and serverless offline does compile them, but it seems like what's being executed is the original file :

$ yarn sls offline
Serverless: Bundling with Webpack...
Time: 5219ms
Built at: 08/19/2019 1:37:15 AM
                   Asset      Size                 Chunks             Chunk Names
          example/app.js  2.49 MiB            example/app  [emitted]  example/app
src/functions/graphql.js     4 MiB  src/functions/graphql  [emitted]  src/functions/graphql
Entrypoint src/functions/graphql = src/functions/graphql.js
Entrypoint example/app = example/app.js
[./example/app.js] 5.39 KiB {example/app} [built]

# webpack stuff

[./src/functions/graphql.js] 3.74 KiB {src/functions/graphql} [built]
    + 1150 hidden modules
Serverless: Watching for changes...
offline: Starting Offline: prod/us-east-1.
offline: 
offline: [HTTP] server ready: http://localhost:3000 🚀
offline: 
offline: OpenAPI/Swagger documentation:
offline: [GET] http://localhost:3000/documentation
offline: 
offline: Enter "rp" to replay the last request
offline: 
offline: [ANY] http://localhost:3000/graphql
offline: [ANY] http://localhost:3000/
offline: [ANY] http://localhost:3000/{any*}

offline: ANY / (λ: example)
/Users/verekia/Local/Code/sharyn-boilerplate-serverless/example/app.js:117
export const main = async (event: Object, context: Object) => {
^^^^^^

SyntaxError: Unexpected token export

The exact same code works with 5.10.1.

[dnalborczyk]

thank you @verekia for filing the issue! that's interesting.

The .webpack folder contains the correct compiled sources, and serverless offline does compile them,

I think serverless-webpack + Babel is compiling your code, not serverless-offline.

I'm guessing serverless-webpack "overwrites" the path to the handler, which has a different location for the compiled files.

could you create a small repository so I can debug this issue?

[verekia]

Here it is @dnalborczyk , in its most minimal form!

https://github.com/verekia/serverless-offline-alpha-webpack-bug

[verekia]

I think serverless-webpack + Babel is compiling your code, not serverless-offline.

True, what I meant is that serverless-offline correctly triggers the Webpack compilation, but it seems to use the wrong file after that.

[ozsay]

similar issue is happening to me as well with serverless-webpack.

configuration that works on latest 5.x.x, doesn't work on 6 latest alpha.

running sls offline does generate bundled code in .webpack folder, but i'm getting this error while accessing the function: "Error: Cannot find module 'path/to/original/handler/path'"

seems like serverless-offline is trying to require the original module

[dnalborczyk]

Here it is @dnalborczyk , in its most minimal form!

https://github.com/verekia/serverless-offline-alpha-webpack-bug

thank you @verekia Looking into the issue.

[verekia]

Thank you for the quick fix! Looking forward to the release.
Keep up the great work 👍

[verekia]

Confirming that the fix works in both the demo repository and in my own project. Thank you.

[hsz]

This one fixes not only the webpack+babel integration, but typescript as well. However when I tried to run the project that has custom authorizers configured (so one function refers to another using the second as an authorizer), second is still loaded from the /src/.. directory because HttpServer also uses servicePath from options. Then createAuthScheme uses this path in:

https://github.com/hsz/serverless-offline/blob/4956230912f26d40f0fea78ab5fe0dbdbfe4085f/src/events/http/createAuthScheme.js#L48

Reusing the solution from https://github.com/dherault/serverless-offline/commit/e301a2d00315fb1a7eaa876faa6287a8169ce6e6 fixes this custom authorizer problem as well.

I've created a PR for that:

https://github.com/dherault/serverless-offline/pull/835

[thebarefootdev]

Stilll an issue with "serverless-offline": "^6.8.0",

It would be nice to see any configuration changes that could sollve this, the documentation simply refers to using serverless-webpack