feat(Changex.Formatter.Markdown): pass version in opts instead arguments

Previously there was an inconsistency between
`Changex.Formatter.Markdown` and `Changex.Formatter.Elixir` where in
`Elixir` it would take the version as part of the opts list and in
`Markdown` it was a separate argument. In commit
c3919d4 it is made clear that the
intention was to pass an opts instead of the version, however this
change was node made for `Markdown` at the same time. The format
function between the two modules is now consistent.

The `update` and `diff` tasks have been updated to use the new function
with an arity of 2.

BREAKING CHANGE: Calling `Changex.Formatter.Markdown.format` with an
arity of 3 is no longer valid. The `version` should be specified as a
keyword in the second argument which is a keyword list.

lib/changex/formatter/markdown.ex

@@ -42,8 +42,8 @@ defmodule Changex.Formatter.Markdown do
         * commit 8 - hash
 
   """
-  def format(commits, version \\ nil, opts \\ []) do
-    heading(version) <> types(commits, opts)
+  def format(commits, opts \\ []) do
+    heading(Keyword.get(opts, :version)) <> types(commits, opts)
   end
 
   defp heading(version) do

lib/mix/tasks/changex/diff.ex

@@ -81,7 +81,7 @@ defmodule Mix.Tasks.Changex.Diff do
     Changex.Formatter.Terminal.output(commits, version)
   end
   defp output(commits, "markdown", version, opts) do
-    Changex.Formatter.Markdown.format(commits, version, opts) |> IO.puts
+    Changex.Formatter.Markdown.format(commits, Keyword.put(opts, :version, version)) |> IO.puts
   end
   defp output(commits, "elixir", version, opts) do
     Changex.Formatter.Elixir.format(commits, version: version) |> IO.puts

lib/mix/tasks/changex/update.ex

@@ -48,12 +48,12 @@ defmodule Mix.Tasks.Changex.Update do
   end
 
   defp build(commits, previous, "markdown", opts) do
-    head = commits |> Changex.Formatter.Markdown.format(nil, opts)
+    head = commits |> Changex.Formatter.Markdown.format(opts)
     head <> "\n\n" <> previous
   end
 
   defp build(commits, previous, "elixir", opts) do
-    head = commits |> Changex.Formatter.Elixir.format(nil, opts)
+    head = commits |> Changex.Formatter.Elixir.format(opts)
     head <> "\n\n" <> previous
   end
 

test/changex/formatter/markdown_test.exs

@@ -19,7 +19,7 @@ defmodule Changex.Formatter.MarkdownTest do
   end
 
   test "Formatting with an explicit version", %{commits: commits} do
-    assert Changex.Formatter.Markdown.format(commits, "v10") == expected_markdown("v10")
+    assert Changex.Formatter.Markdown.format(commits, version: "v10") == expected_markdown("v10")
   end
 
   test "Formatting with an implicit version", %{commits: commits} do
@@ -28,7 +28,7 @@ defmodule Changex.Formatter.MarkdownTest do
   end
 
   test "Formatting with a github url", %{commits: commits} do
-    assert Changex.Formatter.Markdown.format(commits, "v10", [github: "gazler/changex"]) == expected_markdown_with_github
+    assert Changex.Formatter.Markdown.format(commits, [version: "v10", github: "gazler/changex"]) == expected_markdown_with_github
   end
 
   test "Formatting with a missing section" do
@@ -43,7 +43,7 @@ defmodule Changex.Formatter.MarkdownTest do
      * **dashboard**
       * show number of bots on the dashboard (5c764b2957d1c6e7ed73e1691a55399c85b62c34)
     """ |> String.rstrip
-    assert Changex.Formatter.Markdown.format(commits, "v10") == expected
+    assert Changex.Formatter.Markdown.format(commits, version: "v10") == expected
   end
 
   defp expected_markdown(version) do