diff --git a/spec/formatter_spec.cr b/spec/formatter_spec.cr
new file mode 100644
index 0000000..679ebf5
--- /dev/null
+++ b/spec/formatter_spec.cr
@@ -0,0 +1,26 @@
+require "./spec_helper"
+require "../src/entry"
+require "../src/options"
+
+def new_formatter(path, options = Lister::Options.new)
+  Lister::Formatter.new(path, options)
+end
+
+describe Lister::Formatter do
+  klass = Lister::Formatter
+
+  describe "#line" do
+    pending "should not attempt to insert color codes past the end of the line" do
+      long_filename = "asdfghjklqwertyuiopzxcvbnm"
+      opts = Lister::Options.new
+      # stub out terminal width somehow
+      opts.terminal.width
+      # make entry
+      entry = Entry.new long_filename, opts
+      formatter = new_formatter(long_filename, opts)
+      formatter.line(entry, entry.name.size, 0)
+      # should generate a filename much lonager than the line, which before the fix would error out
+      # like "index out of range" for String#insert
+    end
+  end
+end