TomTom::Matrix: Serialize `BigDecimal` as float

Rails serialises `BigDecimal`s as JSON strings to prevent loss of
precision. The `latitude` and `longitude` columns in `StopArea` are
stored as `BigDecimal`s. The trouble is that TomTom's API requires the
latitude & longitude values to be JSON floats, not strings.

Make a new JSON serialiser that converts the `BigDecimal` coordinates to
float to allow the values to be correctly interpreted by the API.

Refs #6222

1 files changed, 25 insertions, 0 deletions

diff --git a/lib/tom_tom/matrix/request_json_serializer.rb b/lib/tom_tom/matrix/request_json_serializer.rb
new file mode 100644
index 000000000..f4d12e482
--- /dev/null
+++ b/lib/tom_tom/matrix/request_json_serializer.rb
@@ -0,0 +1,25 @@
+module TomTom
+  class Matrix
+    class RequestJSONSerializer
+      def self.dump(hash)
+        hash[:origins].map! do |point|
+          point_to_f(point)
+        end
+        hash[:destinations].map! do |point|
+          point_to_f(point)
+        end
+
+        JSON.dump(hash)
+      end
+
+      private
+
+      def self.point_to_f(point)
+        point[:point][:latitude] = point[:point][:latitude].to_f
+        point[:point][:longitude] = point[:point][:longitude].to_f
+
+        point
+      end
+    end
+  end
+end