add iam getRole test

This test triggers the scenario that a required response element exists, which
forces our check for "we do not expect data for this call" to be comptime.
It previously was accidentally runtime, which was solved by making
expected_body_field_len a comptime var.

src/aws.zig

@@ -353,7 +353,7 @@ pub fn Request(comptime request_action: anytype) type {
             // First, we need to determine if we care about a response at all
             // If the expected result has no fields, there's no sense in
             // doing any more work. Let's bail early
-            var expected_body_field_len = std.meta.fields(action.Response).len;
+            comptime var expected_body_field_len = std.meta.fields(action.Response).len;
             if (@hasDecl(action.Response, "http_header"))
                 expected_body_field_len -= std.meta.fields(@TypeOf(action.Response.http_header)).len;
             if (@hasDecl(action.Response, "http_payload")) {
@@ -379,8 +379,6 @@ pub fn Request(comptime request_action: anytype) type {
 
             // We don't care about the body if there are no fields we expect there...
             if (std.meta.fields(action.Response).len == 0 or expected_body_field_len == 0) {
-                // ^^ This should be redundant, but is necessary. I suspect it's a compiler quirk
-                //
                 // Do we care if an unexpected body comes in?
                 return FullResponseType{
                     .response = .{},
@@ -1636,6 +1634,58 @@ test "query_no_input: sts getCallerIdentity comptime" {
     try std.testing.expectEqualStrings("123456789012", call.response.account.?);
     try std.testing.expectEqualStrings("8f0d54da-1230-40f7-b4ac-95015c4b84cd", call.response_metadata.request_id);
 }
+test "query_with_input: iam getRole runtime" {
+    // sqs switched from query to json in aws sdk for go v2 commit f5a08768ef820ff5efd62a49ba50c61c9ca5dbcb
+    const allocator = std.testing.allocator;
+    var test_harness = TestSetup.init(.{
+        .allocator = allocator,
+        .server_response =
+        \\<GetRoleResponse xmlns="https://iam.amazonaws.com/doc/2010-05-08/">
+        \\<GetRoleResult>
+        \\  <Role>
+        \\    <Path>/application_abc/component_xyz/</Path>
+        \\    <Arn>arn:aws:iam::123456789012:role/application_abc/component_xyz/S3Access</Arn>
+        \\    <RoleName>S3Access</RoleName>
+        \\    <AssumeRolePolicyDocument>
+        \\      {"Version":"2012-10-17","Statement":[{"Effect":"Allow",
+        \\      "Principal":{"Service":["ec2.amazonaws.com"]},"Action":["sts:AssumeRole"]}]}
+        \\    </AssumeRolePolicyDocument>
+        \\    <CreateDate>2012-05-08T23:34:01Z</CreateDate>
+        \\    <RoleId>AROADBQP57FF2AEXAMPLE</RoleId>
+        \\    <RoleLastUsed>
+        \\      <LastUsedDate>2019-11-20T17:09:20Z</LastUsedDate>
+        \\      <Region>us-east-1</Region>
+        \\    </RoleLastUsed>
+        \\  </Role>
+        \\</GetRoleResult>
+        \\<ResponseMetadata>
+        \\  <RequestId>df37e965-9967-11e1-a4c3-270EXAMPLE04</RequestId>
+        \\</ResponseMetadata>
+        \\</GetRoleResponse>
+        ,
+        .server_response_headers = &.{
+            .{ .name = "Content-Type", .value = "text/xml" },
+            .{ .name = "x-amzn-RequestId", .value = "df37e965-9967-11e1-a4c3-270EXAMPLE04" },
+        },
+    });
+    defer test_harness.deinit();
+    const options = try test_harness.start();
+    const iam = (Services(.{.iam}){}).iam;
+    const call = try test_harness.client.call(iam.get_role.Request{
+        .role_name = "S3Access",
+    }, options);
+    defer call.deinit();
+    test_harness.stop();
+    // Request expectations
+    try std.testing.expectEqual(std.http.Method.POST, test_harness.request_options.request_method);
+    try std.testing.expectEqualStrings("/", test_harness.request_options.request_target);
+    try std.testing.expectEqualStrings(
+        \\Action=GetRole&Version=2010-05-08&RoleName=S3Access
+    , test_harness.request_options.request_body);
+    // Response expectations
+    try std.testing.expectEqualStrings("arn:aws:iam::123456789012:role/application_abc/component_xyz/S3Access", call.response.role.arn);
+    try std.testing.expectEqualStrings("df37e965-9967-11e1-a4c3-270EXAMPLE04", call.response_metadata.request_id);
+}
 test "query_with_input: sts getAccessKeyInfo runtime" {
     // sqs switched from query to json in aws sdk for go v2 commit f5a08768ef820ff5efd62a49ba50c61c9ca5dbcb
     const allocator = std.testing.allocator;