Server protocol tests extras

[david-perez]

The client has suites like rest-json-extras.smithy that contains extra protocol tests, some of which are upstreamed in the awslabs/smithy repo and will be hosted there in the next Smithy release.

Ideally the server should also pass these suites, and we should put there additional tests we come up with.

Fixed tests should also go there, instead of hot-patching them at runtime like we currently do. Advantages:

• We can more easily upstream the fixed test to awslabs/smithy repo since we write Smithy and not Kotlin.
• When we upgrade to the next Smithy release, the broken ones in ExpectFailing will fail because they now pass, so we will get alerted and remove the fixed tests from the "extra" suite.

[david-perez]

A first test we should add to not regress on #1163 (but to the extras suite, not to simple.smithy like the diff below shows):

diff --git a/codegen-server-test/model/simple.smithy b/codegen-server-test/model/simple.smithy
index 70dee327..2feae1d2 100644
--- a/codegen-server-test/model/simple.smithy
+++ b/codegen-server-test/model/simple.smithy
@@ -63,7 +63,10 @@ resource Service {
         id: "RegisterServiceResponseTest",
         protocol: "aws.protocols#restJson1",
         params: { id: "1", name: "TestService" },
-        body: "{\"id\":\"1\",\"name\":\"TestService\"}",
+        headers: {
+            "Content-Type": "TestService",
+        },
+        body: "{\"id\":\"1\"}",
         code: 200,
     }
 ])
@@ -85,6 +88,9 @@ structure RegisterServiceInputRequest {
 structure RegisterServiceOutputResponse {
     @required
     id: ServiceId,
+
+    @required
+    @httpHeader("Content-Type")
     name: ServiceName,
 }

[david-perez]

Another one: httpQueryParams duplicate query keys behavior: https://github.com/awslabs/smithy/issues/1071

[drganjoo]

We can now remove the only remaining broken test as it has been fixed upstream

[david-perez]

I'm going to close this since I no longer stand by this:

Fixed tests should also go there, instead of hot-patching them at runtime like we currently do

Now that we have https://github.com/smithy-lang/smithy-rs/pull/3726/, there are no advantages to putting broken protocol tests in the <protocol>-extras.smithy models.