Merge pull request #40 from lafriks-fork/feat/strategy_xml

Add XML strategy

README.md

@@ -173,8 +173,6 @@ Parsing [linguist/samples](https://github.com/github/linguist/tree/master/sample
 - Detection of [generated files](https://github.com/github/linguist/blob/bf95666fc15e49d556f2def4d0a85338423c25f3/lib/linguist/generated.rb#L53) is not supported yet.
   (Thus they are not excluded from CLI output). See [#213](https://github.com/src-d/enry/issues/213).
 
-- XML detection strategy is not implemented. See [#192](https://github.com/src-d/enry/issues/192).
-
 - Overriding languages and types though `.gitattributes` is not yet supported. See [#18](https://github.com/src-d/enry/issues/18).
 
 - `enry` CLI output does NOT exclude `.gitignore`ed files and git submodules, as Linguist does

common.go

@@ -22,6 +22,7 @@ var DefaultStrategies = []Strategy{
 	GetLanguagesByFilename,
 	GetLanguagesByShebang,
 	GetLanguagesByExtension,
+	GetLanguagesByXML,
 	GetLanguagesByManpage,
 	GetLanguagesByContent,
 	GetLanguagesByClassifier,
@@ -329,15 +330,23 @@ func getInterpreter(data []byte) (interpreter string) {
 	return
 }
 
-func getFirstLine(content []byte) []byte {
-	nlpos := bytes.IndexByte(content, '\n')
-	if nlpos < 0 {
-		return content
+func getFirstLines(content []byte, count int) []byte {
+	nlpos := -1
+	for ; count > 0; count-- {
+		pos := bytes.IndexByte(content[nlpos+1:], '\n')
+		if pos < 0 {
+			return content
+		}
+		nlpos += pos + 1
 	}
 
 	return content[:nlpos]
 }
 
+func getFirstLine(content []byte) []byte {
+	return getFirstLines(content, 1)
+}
+
 func hasShebang(line []byte) bool {
 	const shebang = `#!`
 	prefix := []byte(shebang)
@@ -404,6 +413,29 @@ func GetLanguagesByManpage(filename string, _ []byte, _ []string) []string {
 	return nil
 }
 
+var (
+	xmlHeader = regex.MustCompile(`<?xml version=`)
+)
+
+// GetLanguagesByXML returns a slice of possible XML language for the given filename.
+// It complies with the signature to be a Strategy type.
+func GetLanguagesByXML(_ string, content []byte, candidates []string) []string {
+	if len(candidates) > 0 {
+		return candidates
+	}
+
+	header := getFirstLines(content, 2)
+
+	// Check if contains XML header
+	if xmlHeader.Match(header) {
+		return []string{
+			"XML",
+		}
+	}
+
+	return nil
+}
+
 func getDotIndexes(filename string) []int {
 	dots := make([]int, 0, 2)
 	for i, letter := range filename {

common_test.go

@@ -23,6 +23,7 @@ type EnryTestSuite struct {
 	tmpLinguist string
 	needToClone bool
 	samplesDir  string
+	testFixturesDir string
 }
 
 func (s *EnryTestSuite) TestRegexpEdgeCases() {
@@ -72,6 +73,9 @@ func (s *EnryTestSuite) SetupSuite() {
 	s.samplesDir = filepath.Join(s.tmpLinguist, "samples")
 	s.T().Logf("using samples from %s", s.samplesDir)
 
+	s.testFixturesDir = filepath.Join(s.tmpLinguist, "test", "fixtures")
+	s.T().Logf("using test fixtures from %s", s.samplesDir)
+
 	cwd, err := os.Getwd()
 	assert.NoError(s.T(), err)
 
@@ -314,6 +318,31 @@ func (s *EnryTestSuite) TestGetLanguagesByManpage() {
 	}
 }
 
+
+func (s *EnryTestSuite) TestGetLanguagesByXML() {
+	tests := []struct {
+		name       string
+		filename   string
+		candidates []string
+		expected   []string
+
+	}{
+		{name: "TestGetLanguagesByXML_1", filename: filepath.Join(s.testFixturesDir, "XML/app.config"), expected: []string{"XML"}},
+		{name: "TestGetLanguagesByXML_2", filename: filepath.Join(s.testFixturesDir, "XML/AssertionIDRequestOptionalAttributes.xml.svn-base"), expected: []string{"XML"}},
+		// no XML header so should not be identified by this strategy
+		{name: "TestGetLanguagesByXML_3", filename: filepath.Join(s.samplesDir, "XML/libsomething.dll.config"), expected: nil},
+		{name: "TestGetLanguagesByXML_4", filename: filepath.Join(s.samplesDir, "Eagle/Eagle.sch"), candidates: []string{"Eagle"}, expected: []string{"Eagle"}},
+	}
+
+	for _, test := range tests {
+		content, err := ioutil.ReadFile(test.filename)
+		assert.NoError(s.T(), err)
+
+		languages := GetLanguagesByXML(test.filename, content, test.candidates)
+		assert.Equal(s.T(), test.expected, languages, fmt.Sprintf("%v: languages = %v, expected: %v", test.name, languages, test.expected))
+	}
+}
+
 func (s *EnryTestSuite) TestGetLanguagesByClassifier() {
 	test := []struct {
 		name       string