[typescript] Non-null default fields are incorrectly optional

[jun-sheaf]

Describe the bug

Default values are handled incorrectly.

To Reproduce
Steps to reproduce the behavior:
Suppose we have the schema

input SomeInput {
  test: String! = "test"
}

Then graphql-codegen will optionalize the argument test.

Expected behavior

The above should not be optional as String! is never null.

Environment:

• OS: Mac OS Catalina
• @graphql-codegen/...: Latest as of issue date
• NodeJS: Latest as of issue date

[ardatan]

If you provide a default value for an input field, it means that input field is optional for the client side.
If test = null, test will be evaluated as "test" so this means test is nullable then optional for the client side.

[jun-sheaf]

Your reasoning is a little off. Test cannot be set to null on client side since test is a non-nullable type. In particular, it will error out, and not default to "test".

However, I understand what you mean. This issue is more about server implementations where the resolver should know the arguments are provided.

I've added a "defaultValue" option to the AvoidOptionalsConfig. Perhaps this will be a good compromise?

[ardatan]

I was talking about this behavior so in this case bar is optional there even if it is String!.
https://codesandbox.io/s/late-cache-npyqj?file=/src/index.js

[jun-sheaf]

Yes, I am aware, but as I stated, bar is not actually null for the resolver. See here

Thus it would be better to have an avoidOptionals option for defaultValue for those who generate server types.

[dotansimha]

Merged and published. Thanks @jun-sheaf!