Support properties with no type as an object

[pauly4it]

I tried using the codegen tool on our OpenAPI v3 spec with just one resource to test it out, and I got the following error:

time=2023-10-19T17:00:55.405-06:00 level=WARN msg="skipping resource schema mapping" resource=user oas_line_number=8174 err="no 'type' array or supported allOf, oneOf, anyOf constraint - attribute cannot be created"

When I dug into our schema, it looks like our spec doesn't include the type field for most schema objects, though they are specified in the various properties values. For example:

"users.v1.UsersPutRequest": {
    "properties": {
        "enabled": {
            "type": "boolean"
        },
        "roles": {
            "items": {
                "type": "string"
            },
            "type": "array"
        }
    },
    "required": [
        "enabled"
    ]
},

I spoke with our engineering team, and they said that in JSON Schema the type defaults to “object” and OpenAPI inherits that. For context, we're using getkin/kin-openapi to create the OpenAPI v3 spec.

Just to checkt, I added type manually to the schema objects needed for the user resource, and then the tool worked without errors.

Is this a requirement of the codegen tool? Or can the behavior be adjusted to assume an object type if type is not explicitly defined?

Really appreciate the work put into this tool!

[austinvalle]

Hey there @pauly4it 👋🏻 , thanks for opening the issue. Very interesting! We hadn't really considered the use-case of an empty type being considered an object 🤔.

... can the behavior be adjusted to assume an object type if type is not explicitly defined?

At first glance this sounds reasonable to me: if type is undefined, and properties exist, default to object. Our goal with this tool is to not stray far from the OpenAPI 3.0, 3.1, and JSON schema specifications, but there are going to be cases where that either doesn't make sense, or causes conflicts with existing tooling like getkin/kin-openapi.

I spoke with our engineering team, and they said that in JSON Schema the type defaults to “object” and OpenAPI inherits that.

I looked into the JSON schema spec, and while I can't find an explicit statement of type: object being the default... It seems to imply that properties will only be used to describe objects, which is good enough for me 👍🏻

[austinvalle]

@pauly4it
If you'd like to test out a fix for this issue from the linked PR and you're using the Go toolchain for installing:

go install github.com/hashicorp/terraform-plugin-codegen-openapi/cmd/tfplugingen-openapi@8002d1668f3d0a95679f2bdb0089348a85d3120d

[pauly4it]

That solved the issue. Thanks for the quick response!

[austinvalle]

This has been merged into main and can be installed via the Go toolchain for now. This will eventually be released with v0.2.0 (we're trying to batch the fixes and enhancements together 🙂)

go install github.com/hashicorp/terraform-plugin-codegen-openapi/cmd/tfplugingen-openapi@28389a734a7050940e5541d95baca3c5ba833a4d

[github-actions]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.
If you have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.