Add a CSV blob view handler

app/models/blob.rb

@@ -20,6 +20,7 @@ class Blob < SimpleDelegator
   # type. LFS pointers to `.stl` files are assumed to always be the binary kind,
   # and use the `BinarySTL` viewer.
   RICH_VIEWERS = [
+    BlobViewer::CSV,
     BlobViewer::Markup,
     BlobViewer::Notebook,
     BlobViewer::SVG,

app/models/blob_viewer/csv.rb

+require 'csv'
+
+module BlobViewer
+  class CSV < Base
+    include ServerSide
+
+    self.binary = false
+    self.extensions = %w(csv)
+    self.partial_name = 'csv'
+    self.switcher_icon = 'file-excel-o'
+    self.type = :rich
+
+    def parse(&block)
+      begin
+        ::CSV.parse(blob.data).each_with_index(&block)
+      rescue ::CSV::MalformedCSVError => ex
+        # TODO (rspeicher): How do we want to handle this?
+      end
+    end
+  end
+end

app/views/projects/blob/viewers/_csv.html.haml

+%table.table-striped.table-bordered
+  - viewer.parse do |row, index|
+    %tr
+      - row.each do |column|
+        - if index == 0
+          %th= column
+        - else
+          %td= column