fix: Handle empty body

rust/pact_ffi/src/mock_server/handles.rs

@@ -1680,6 +1680,11 @@ fn process_body(
         matching_rules,
         generators
     );
+
+    if body.is_empty() {
+      return OptionalBody::Empty;
+    }
+
     let detected_type = detect_content_type_from_string(body);
     let content_type = content_type
         .clone()
@@ -1752,11 +1757,7 @@ fn process_body(
         _ => {
             // We either have no content type, or an unsupported content type.
             trace!("Raw body");
-            if body.is_empty() {
-                OptionalBody::Empty
-            } else {
-                OptionalBody::Present(Bytes::from(body.to_owned()), content_type, None)
-            }
+            OptionalBody::Present(Bytes::from(body.to_owned()), content_type, None)
         }
     }
 }
@@ -4374,4 +4375,35 @@ mod tests {
             Some(Bytes::from(raw))
         )
   }
+
+  #[test]
+  fn pactffi_with_empty_body_test() {
+      let pact_handle = PactHandle::new("Consumer", "Provider");
+      let description = CString::new("Generator Test").unwrap();
+      let i_handle = pactffi_new_interaction(pact_handle, description.as_ptr());
+
+      let body = CString::new("").unwrap();
+      let content_type = CString::new("text/plain").unwrap();
+      let result = pactffi_with_body(
+          i_handle,
+          InteractionPart::Request,
+          content_type.as_ptr(),
+          body.as_ptr(),
+      );
+      assert!(result);
+
+      let interaction = i_handle
+          .with_interaction(&|_, _, inner| inner.as_v4_http().unwrap())
+          .unwrap();
+
+      expect!(
+          interaction
+              .request
+              .headers
+      ).to(be_none());
+      assert_eq!(
+          interaction.request.body.value(),
+          None
+      )
+  }
 }