Amplify Gen2 Schema Model Complexity Leads to TS2590 Error in TypeScript Client

[sevenkkk]

How did you install the Amplify CLI?

npm

If applicable, what version of Node.js are you using?

v18.20.1

Amplify CLI Version

"@aws-amplify/backend": "^1.0.3",
"@aws-amplify/backend-cli": "^1.0.4",
"@aws-amplify/data-schema": "1.2.8",
"aws-amplify": "^6.3.4",
"typescript": "^5.4.5"

What operating system are you using?

mac

Did you make any manual changes to the cloud resources managed by Amplify? Please describe the changes made.

NO

Describe the bug

I'm currently using Amplify Gen2 to manage my backend schema models. However, when the number of schema models exceeds a certain threshold and there are numerous dependencies between them, I encounter a TypeScript error in my client-side code: TS2590: Expression produces a union type that is too complex to represent. This results in the failure of all TypeScript type derivations.

Expected behavior

The generated TypeScript types should work correctly regardless of the number of schema models or their dependencies.

Reproduction steps

Here is the repository where my schema definitions are located: https://github.com/sevenkkk/amplify-next-template.git

Project Identifier

No response

Log output

# Put your logs below this line

Additional information

No response

Before submitting, please confirm:

• I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.
• I have removed any sensitive information from my code snippets and submission.

[chrisbonifacio]

Hi @sevenkkk 👋 thanks for raising this issue.

I was able to reproduce the TS error message

I'll mark this as a bug for the team to investigate but I don't see that the type suggestions are broken or missing, at least on the latest versions of the amplify backend packages.

Can you try running the following command to ugprade and let us know if your type suggestions performance improves?

npm upgrade @aws-amplify/backend @aws-amplify/backend-cli @aws-amplify/data-schema

[sevenkkk]

Hi @sevenkkk 👋 thanks for raising this issue.

I was able to reproduce the TS error message

I'll mark this as a bug for the team to investigate but I don't see that the type suggestions are broken or missing, at least on the latest versions of the amplify backend packages.

Can you try running the following command to ugprade and let us know if your type suggestions performance improves?

npm upgrade @aws-amplify/backend @aws-amplify/backend-cli @aws-amplify/data-schema

I have updated to the latest version, but it is still the same as before.

[chrisbonifacio]

@sevenkkk thank you for confirming. I've labeled this as a bug for the team to investigate further.

[iartemiev]

The root cause of this issue is the generated type for the selectionSet option (example). For schemas with highly interconnected models, this type comprises a massive union of literal strings representing valid selection set paths. This type gets eagerly constructed when invoking model-level methods (e.g. client.models.SomeModel.*) even if the selectionSet option is not specified. This is the "union type that is too complex to represent" referred to in the type error.

We've identified potential solutions to this problem and are validating them at the moment. I'll provide another update once we're closer to releasing a bug fix.

[LukaASoban]

Just wanted to pop in an say that I'm also unable to use Schema types in my code now due to this error. I have a lot of tables/relationships as well.

[ColtonGlasgow13]

Also coming in for an update - has there been any progress on this issue? The convenience of Amplify's schema typecasting is one of the main reasons to keep using it for a larger project, and this effectively takes that feature away.