Update @httpResponseCode to not be applicable to @input structures

- Changed the selector of `@httpResponseCode` to not select structures
  with the `@input` trait applied
- Updated the docs for `@httpResponseCode`
- Move `http-trait-conflicts` test to a `.smithy` file

Resolves #1105

docs/source-1.0/spec/core/http-traits.rst

@@ -1137,10 +1137,11 @@ Summary
 Trait selector
     .. code-block:: none
 
-        structure > member :test(> integer)
+        structure :not([trait|input]) > member :test(> integer)
 
     The ``httpResponseCode`` trait can be applied to ``structure`` members
-    that target an ``integer``.
+    that target an ``integer`` within any ``structure`` that has no ``input``
+    trait applied.
 Value type
     Annotation trait.
 Conflicts with
@@ -1157,12 +1158,12 @@ to the `code` set by the :ref:`http-trait`.
 
 .. rubric:: ``httpResponseCode`` is only used on output
 
-``httpResponseCode`` is ignored when resolving the HTTP bindings of an
-operation's input structure. This means that if a structure that contains
-members marked with the ``httpResponseCode`` trait is used as the top-level
-input structure of an operation, then those members are sent as part of the
-:ref:`protocol-specific document <http-protocol-document-payloads>` sent in
-the body of the request.
+``httpResponseCode`` is ignored when resolving the HTTP bindings of any
+structure except an operation's output structure. This means that if a
+structure that contains members marked with the ``httpResponseCode`` trait
+is not used as an output structure of an operation, then those members are
+sent as part of the :ref:`protocol-specific document <http-protocol-document-payloads>`
+sent in the body of the request.
 
 
 .. smithy-trait:: smithy.api#cors

docs/source-2.0/spec/http-bindings.rst

@@ -1139,10 +1139,11 @@ Summary
 Trait selector
     .. code-block:: none
 
-        structure > member :test(> integer)
+        structure :not([trait|input]) > member :test(> integer)
 
     The ``httpResponseCode`` trait can be applied to ``structure`` members
-    that target an ``integer``.
+    that target an ``integer`` within any ``structure`` that has no ``input``
+    trait applied.
 Value type
     Annotation trait.
 Conflicts with
@@ -1159,12 +1160,12 @@ to the `code` set by the :ref:`http-trait`.
 
 .. rubric:: ``httpResponseCode`` is only used on output
 
-``httpResponseCode`` is ignored when resolving the HTTP bindings of an
-operation's input structure. This means that if a structure that contains
-members marked with the ``httpResponseCode`` trait is used as the top-level
-input structure of an operation, then those members are sent as part of the
-:ref:`protocol-specific document <http-protocol-document-payloads>` sent in
-the body of the request.
+``httpResponseCode`` is ignored when resolving the HTTP bindings of any
+structure except an operation's output structure. This means that if a
+structure that contains members marked with the ``httpResponseCode`` trait
+is not used as an output structure of an operation, then those members are
+sent as part of the :ref:`protocol-specific document <http-protocol-document-payloads>`
+sent in the body of the request.
 
 
 .. smithy-trait:: smithy.api#cors

smithy-model/src/main/resources/software/amazon/smithy/model/loader/prelude.smithy

@@ -855,7 +855,7 @@ integer httpError
 /// status code. The value MAY differ from the HTTP status code provided
 /// on the response.
 @trait(
-    selector: "structure > member :test(> integer)",
+    selector: "structure :not([trait|input]) > member :test(> integer)",
     structurallyExclusive: "member",
     conflicts: [httpLabel, httpQuery, httpHeader, httpPrefixHeaders, httpPayload, httpQueryParams],
     breakingChanges: [{change: "any"}]

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/validators/http-response-code-input-conflicts.errors

@@ -0,0 +1 @@
+[ERROR] ns.foo#HttpOperationInput$Int: Trait `httpResponseCode` cannot be applied to `ns.foo#HttpOperationInput$Int`. This trait may only be applied to shapes that match the following selector: structure :not([trait|input]) > member :test(> integer) | TraitTarget

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/validators/http-response-code-input-conflicts.smithy

@@ -0,0 +1,11 @@
+$version: "2.0"
+
+namespace ns.foo
+
+@input
+structure HttpOperationInput {
+
+    @httpResponseCode
+    Int: Integer
+
+}

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/validators/http-trait-conflicts.errors

@@ -1 +1 @@
-[ERROR] ns.foo#HttpOperationInput$Int: Found conflicting traits on member shape: `httpHeader` conflicts with `httpLabel`, `httpHeader` conflicts with `httpQuery`, `httpHeader` conflicts with `httpResponseCode`, `httpLabel` conflicts with `httpHeader`, `httpLabel` conflicts with `httpQuery`, `httpLabel` conflicts with `httpResponseCode`, `httpQuery` conflicts with `httpHeader`, `httpQuery` conflicts with `httpLabel`, `httpQuery` conflicts with `httpResponseCode`, `httpResponseCode` conflicts with `httpHeader`, `httpResponseCode` conflicts with `httpLabel`, `httpResponseCode` conflicts with `httpQuery` | TraitConflict
+[ERROR] ns.foo#HttpOperationOutput$Int: Found conflicting traits on member shape: `httpHeader` conflicts with `httpLabel`, `httpHeader` conflicts with `httpQuery`, `httpHeader` conflicts with `httpResponseCode`, `httpLabel` conflicts with `httpHeader`, `httpLabel` conflicts with `httpQuery`, `httpLabel` conflicts with `httpResponseCode`, `httpQuery` conflicts with `httpHeader`, `httpQuery` conflicts with `httpLabel`, `httpQuery` conflicts with `httpResponseCode`, `httpResponseCode` conflicts with `httpHeader`, `httpResponseCode` conflicts with `httpLabel`, `httpResponseCode` conflicts with `httpQuery` | TraitConflict

smithy-model/src/test/resources/software/amazon/smithy/model/errorfiles/validators/http-trait-conflicts.smithy

@@ -0,0 +1,15 @@
+$version: "2.0"
+
+namespace ns.foo
+
+@output
+structure HttpOperationOutput {
+
+    @required
+    @httpResponseCode
+    @httpLabel
+    @httpQuery("foo")
+    @httpHeader("x-amz-foo")
+    Int: Integer
+
+}