add doc and test

README.md

@@ -70,6 +70,7 @@ end
     - [[mix coveralls.detail] Show coverage with detail](#mix-coverallsdetail-show-coverage-with-detail)
     - [[mix coveralls.html] Show coverage as HTML report](#mix-coverallshtml-show-coverage-as-html-report)
     - [[mix coveralls.json] Show coverage as JSON report](#mix-coverallsjson-show-coverage-as-json-report)
+    - [[mix coveralls.xml] Show coverage as XML report](#mix-coverallsjson-show-coverage-as-xml-report)
   - [coveralls.json](#coverallsjson)
       - [Stop Words](#stop-words)
       - [Exclude Files](#exclude-files)
@@ -321,6 +322,13 @@ or to Code Climate using their [test-reporter](https://docs.codeclimate.com/docs
 
 Output reports are written to `cover/excoveralls.json` by default, however, the path can be specified by overwriting the `"output_dir"` coverage option.
 
+### [mix coveralls.xml] Show coverage as XML report
+This task displays coverage information at the source-code level formatted as a XML document.
+The report follows a format supported by several code coverage services like SonarQube.
+Output to the shell is the same as running the command `mix coveralls` (to suppress this output, add `"print_summary": false` to your project's `coveralls.json` file). In a similar manner to `mix coveralls.detail`, reported source code can be filtered by specifying arguments using the `--filter` flag.
+
+Output reports are written to `cover/excoveralls.xml` by default, however, the path can be specified by overwriting the `"output_dir"` coverage option.
+
 ## coveralls.json
 `coveralls.json` provides settings for excoveralls.
 
@@ -394,7 +402,8 @@ to `false`:
     "treat_no_relevant_lines_as_covered": true,
     "output_dir": "cover/",
     "template_path": "custom/path/to/template/",
-    "minimum_coverage": 90
+    "minimum_coverage": 90,
+    "xml_base_dir": "custom/path/for/xml/reports/"
   }
 }
 ```

lib/excoveralls/xml.ex

@@ -19,7 +19,7 @@ defmodule ExCoveralls.Xml do
   end
 
   def generate_xml(stats, _options) do
-    base_dir = IO.inspect(Settings.get_xml_base_dir())
+    base_dir = Settings.get_xml_base_dir()
     "<coverage version=\"1\">" <> Enum.map_join(stats, fn %{name: name, coverage: coverage} ->
       "<file path=\"#{base_dir}/#{name}\">" <>
         Enum.map_join(Enum.with_index(coverage), fn 
@@ -36,7 +36,7 @@ defmodule ExCoveralls.Xml do
       output_dir ->
         output_dir
       true ->
-        options = ExCoveralls.Settings.get_coverage_options
+        options = Settings.get_coverage_options
         case Map.fetch(options, "output_dir") do
           {:ok, val} -> val
           _ -> "cover/"

test/xml_test.exs

@@ -0,0 +1,65 @@
+defmodule ExCoveralls.XmlTest do
+  use ExUnit.Case
+  import Mock
+  import ExUnit.CaptureIO
+  alias ExCoveralls.Xml
+
+  @file_name "excoveralls.xml"
+  @test_output_dir "cover_test/"
+
+  @content     "defmodule Test do\n  def test do\n  end\nend\n"
+  @counts      [0, 1, nil, nil]
+  @source_info [%{name: "test/fixtures/test.ex",
+                  source: @content,
+                  coverage: @counts
+               }]
+
+  @stats_result "" <>
+    "----------------\n" <>
+    "COV    FILE                                        LINES RELEVANT   MISSED\n" <>
+    " 50.0% test/fixtures/test.ex                           4        2        1\n"  <>
+    "[TOTAL]  50.0%\n" <>
+    "----------------\n"
+
+  setup do
+    path = Path.expand(@file_name, @test_output_dir)
+
+    # Assert does not exist prior to write
+    assert(File.exists?(path) == false)
+    on_exit fn ->
+      if File.exists?(path) do
+        # Ensure removed after test
+        File.rm!(path)
+        File.rmdir!(@test_output_dir)
+      end
+    end
+
+    {:ok, report: path}
+  end
+
+  test_with_mock "generate xml file", %{report: report}, ExCoveralls.Settings, [],
+      [
+        get_coverage_options: fn -> %{"output_dir" => @test_output_dir} end,
+        get_file_col_width: fn -> 40 end,
+        get_print_summary: fn -> true end,
+        get_print_files: fn -> true end,
+        get_xml_base_dir: fn -> "base_dir" end
+      ] do
+
+    assert capture_io(fn ->
+      Xml.execute(@source_info)
+    end) =~ @stats_result
+
+    assert File.read!(report) =~ ~s(<coverage version="1"><file path="base_dir/test/fixtures/test.ex"><lineToCover lineNumber="1" covered="false"/><lineToCover lineNumber="2" covered="true"/></file></coverage>)
+    assert %{size: 173} = File.stat! report
+  end
+
+  test "generate json file with output_dir parameter", %{report: report} do
+    assert capture_io(fn ->
+      Xml.execute(@source_info, [output_dir: @test_output_dir])
+    end) =~ @stats_result
+
+    assert File.read!(report) =~ ~s(<coverage version="1"><file path="/test/fixtures/test.ex"><lineToCover lineNumber="1" covered="false"/><lineToCover lineNumber="2" covered="true"/></file></coverage>)
+    assert %{size: 165} = File.stat! report
+  end
+end