Inconsistent debug Field Type in Error Details After connect-go v1.15.0 Update

[wangyuehong]

Describe the bug

After connectrpc/connect-go#688 was merged into connect-go, the debug field in error details is not consistently an object but can be any JSON type.

Error JSON produced by connect-go v1.14.0 and earlier:

{
    "code": "invalid_argument",
    "message": "bad sentence: xxx",
    "details": [
        {
            "type": "google.protobuf.StringValue",
            "value": "Cg5zZXJ2ZXIgZGV0YWlscw",
            "debug": {
                "@type": "type.googleapis.com/google.protobuf.StringValue",
                "value": "server details"
            }
        }
    ]
}

The same error JSON from connect-go v1.15.0:

{
    "code": "invalid_argument",
    "message": "bad sentence: xxx",
    "details": [
        {
            "type": "google.protobuf.StringValue",
            "value": "Cg5zZXJ2ZXIgZGV0YWlscw",
            "debug": "server details"
        }
    ]
}

The current code in connect-es expects the debug field to be an object, so the new error JSON format cannot be handled after connect-go v1.15.0.

connect-es/packages/connect/src/protocol-connect/error-json.ts

Line 65 in e580470

("debug" in detail && typeof detail.debug != "object")

To Reproduce
Return the following error in a connect-go server:

err := connect.NewError(connect.CodeInvalidArgument, fmt.Errorf("bad sentence: %s", "xxx"))
errDetail, _ := connect.NewErrorDetail(&wrapperspb.StringValue{Value: "server details"})
err.AddDetail(errDetail)

Expected error:

ConnectError: [invalid_argument] bad sentence: xxx

Actual error:

ConnectError: [invalid_argument] HTTP 400

Environment (please complete the following information):

• @connectrpc/connect-web version: 1.4.0
• connect-go version: v1.5.0 and later.

Additional context
This code might fix the issue, but I am not familiar with TypeScript, so I am just reporting it:

         typeof detail.type != "string" ||
-        typeof detail.value != "string" ||
-        ("debug" in detail && typeof detail.debug != "object")
+        typeof detail.value != "string"
       ) {

[srikrsna-buf]

Thank you for the detailed report. @jhump should this be added to conformance suite?

[jhump]

@jhump should this be added to conformance suite?

That's probably a good idea. The well-known types seem to always be causing problems :(