Fix "undefined method `[]' for #<Nori::StringIOFile>" when adding File

When calling `File#add`, the response XML sets a `type="file"` attribute
on the `baseRef` element, where "file" corresponds to the NetSuite
record. This then causes Nori (the XML parser used by Savon, the SOAP
client) to interpret that element as representing a base64 encoded file,
so it tries to get fancy about how it parses that element into a hash by
returning an instance of it's `StringIOFile` class:
https://github.com/savonrb/nori/blob/f59f8e18b0e53285c87d75a635058745e66b0bfb/lib/nori/xml_utility_node.rb#L131-L136

Either NetSuite's doing something non-standard with it's use of the
`type` attribute that Nori is trying to enforce, or Nori is
over-aggressive in trying to typecast to aid the developer.

The end result was that when we tried to extract the `internal_id` from
the response, the `body` was actually an instance of `StringIOFile`, not
a hash:
https://github.com/NetSweet/netsuite/blob/f0e46a076d0e7cb2abd5e9001ccbfd4bbb3d35c3/lib/netsuite/actions/add.rb#L80

To work around this, as I don't see a way to disable such behavior in
Savon/Nori, if we detect the `baseRef` element was parsed to
`StringIOFile`, we'll then take the raw XML and parse out the `baseRef`
ourselves, returning a hash with the `internal_id` as we'd exect from
non-`File` responses.

I'm not thrilled with this solution. If we ever needed something else
from the `baseRef` element, this effectively drops all other attributes
for file records. It also introduces explicit references to `Nori` and
`Nokogiri`, both of which are dependencies of Savon, but I'm not sure if
that means this gem should list them as explicit dependencies to guard
against Savon replacing them in a future update. Listing them as
dependencies would then require keeping their version constraints in
sync with Savon most likely.

I believe this answers a question from NetSweet#481:
NetSweet#481 (comment)

However the fix in NetSweet#481 solves it by not trying to extract the
`internal_id`, which would create a problem if someone wanted to add a
file then save the ID in their own database for future use.

lib/netsuite/actions/add.rb

@@ -49,7 +49,11 @@ def success?
       end
 
       def response_body
-        @response_body ||= response_hash[:base_ref]
+        @response_body ||= if response_hash[:base_ref].is_a?(Nori::StringIOFile)
+          { :@internal_id => Nokogiri::XML(@response.to_s).remove_namespaces!.at_xpath('//baseRef')[:internalId] }
+        else
+          response_hash[:base_ref]
+        end
       end
 
       def response_errors

spec/netsuite/actions/add_spec.rb

@@ -114,4 +114,40 @@
     end
   end
 
+  context 'File' do
+    let(:file) do
+      NetSuite::Records::File.new(name: 'foo.pdf', content: 'abc123')
+    end
+
+    context 'when successful' do
+      before do
+        savon.expects(:add).with(:message => {
+          'platformMsgs:record' => {
+            :content! => {
+              'fileCabinet:name' => 'foo.pdf',
+              'fileCabinet:content' => 'abc123',
+            },
+            '@xsi:type' => 'fileCabinet:File'
+          },
+        }).returns(File.read('spec/support/fixtures/add/add_file.xml'))
+      end
+
+      it 'makes a valid request to the NetSuite API' do
+        NetSuite::Actions::Add.call([file])
+      end
+
+      it 'returns a valid Response object' do
+        response = NetSuite::Actions::Add.call([file])
+        expect(response).to be_kind_of(NetSuite::Response)
+        expect(response).to be_success
+      end
+
+      it 'properly extracts internal ID from response' do
+        file.add
+
+        expect(file.internal_id).to eq('23556')
+      end
+    end
+  end
+
 end

spec/support/fixtures/add/add_file.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <soapenv:Header>
+    <platformMsgs:documentInfo xmlns:platformMsgs="urn:messages_2020_2.platform.webservices.netsuite.com">
+      <platformMsgs:nsId>REDACTED</platformMsgs:nsId>
+    </platformMsgs:documentInfo>
+  </soapenv:Header>
+  <soapenv:Body>
+    <addResponse xmlns="urn:messages_2020_2.platform.webservices.netsuite.com">
+      <writeResponse>
+        <platformCore:status xmlns:platformCore="urn:core_2020_2.platform.webservices.netsuite.com" isSuccess="true">
+          <platformCore:statusDetail>
+            <platformCore:afterSubmitFailed>false</platformCore:afterSubmitFailed>
+          </platformCore:statusDetail>
+        </platformCore:status>
+        <baseRef xmlns:platformCore="urn:core_2020_2.platform.webservices.netsuite.com" internalId="23556" type="file" xsi:type="platformCore:RecordRef"/>
+      </writeResponse>
+    </addResponse>
+  </soapenv:Body>
+</soapenv:Envelope>