fix(request): build request body by operation payload field

spec/02-requests/02-build_request_spec.lua

@@ -5,9 +5,9 @@ describe("operations protocol", function()
 
 
   local build_request
-  local operation
-  local config
-  local params
+  local operation, operation_with_payload_field
+  local config, config_with_payload
+  local params, params_with_payload
   local snapshot
   local binary_data
 
@@ -105,6 +105,37 @@ describe("operations protocol", function()
       }
     }
 
+    operation_with_payload_field = {
+      name = "PutObject",
+      http = {
+        method = "PUT",
+        requestUri = "/{Bucket}/{Key+}"
+      },
+      input = {
+        type = "structure",
+        required = {
+          "Bucket",
+          "Key"
+        },
+        members = {
+          Bucket = {
+            type = "string",
+            location = "uri",
+            locationName = "Bucket"
+          },
+          Key = {
+            type = "string",
+            location = "uri",
+            locationName = "Key"
+          },
+          Body = {
+            type = "blob",
+          },
+        },
+        payload = "Body"
+      },
+    }
+
     config = {
       apiVersion = "2011-06-15",
       --endpointPrefix = "sts",
@@ -119,6 +150,19 @@ describe("operations protocol", function()
       xmlNamespace = "https://sts.amazonaws.com/doc/2011-06-15/"
     }
 
+    config_with_payload = {
+      apiVersion = "2006-03-01",
+      signingName = "s3",
+      globalEndpoint = "s3.amazonaws.com",
+      --protocol = "query",
+      serviceAbbreviation = "AWS S3",
+      serviceFullName = "AWS Object Storage",
+      serviceId = "S3",
+      signatureVersion = "v4",
+      uid = "s3-2006-03-01",
+      xmlNamespace = "https://s3.amazonaws.com/doc/2006-03-01/"
+    }
+
     params = {
       RoleArn = "hello",
       RoleSessionName = "world",
@@ -134,6 +178,12 @@ describe("operations protocol", function()
       BinaryData = binary_data,
     }
 
+    params_with_payload = {
+      Bucket = "hello",
+      Key = "world",
+      Body = binary_data,
+    }
+
   end)
 
 
@@ -256,6 +306,27 @@ describe("operations protocol", function()
     }, request)
   end)
 
+  it("json: querystring, uri, header and body params, with payload field", function()
+
+    config_with_payload.protocol = "json"
+
+    local request = build_request(operation_with_payload_field, config_with_payload, params_with_payload)
+
+    assert.same({
+      headers = {
+        ["Content-Length"] = 4,
+        ["X-Amz-Target"] = "s3.PutObject",
+        ["Host"] = "s3.amazonaws.com",
+      },
+      method = 'PUT',
+      path = '/hello/world',
+      host = 's3.amazonaws.com',
+      port = 443,
+      body = binary_data,
+      query = {},
+    }, request)
+  end)
+
 
   it("rest-xml: querystring, uri, header and body params", function()
 

src/resty/aws/request/build.lua

@@ -205,6 +205,21 @@ local function build_request(operation, config, params)
     request.query[k] = v
   end
 
+  local payload_member = operation.input and operation.input.payload
+  if payload_member and body_tbl[payload_member] then
+    local member_config = operation.input.members[payload_member]
+    if member_config.type == "structure" then
+      body_tbl = type(body_tbl[payload_member]) == "table" and body_tbl[payload_member] or body_tbl
+
+    elseif body_tbl[payload_member] then
+      request.body = body_tbl[payload_member]
+      if member_config.type == "binary" and member_config.streaming == true then
+        request.headers["Content-Type"] = "binary/octet-stream"
+      end
+      body_tbl[payload_member] = nil
+    end
+  end
+
   local table_empty = not next(body_tbl)
   -- already has a raw body, or no body at all
   if request.body then