added language detection by filename strategy

cli/slinguist/main.go

@@ -48,7 +48,7 @@ func main() {
 			return nil
 		}
 
-		l := slinguist.GetLanguage(path, content)
+		l := slinguist.GetLanguage(filepath.Base(path), content)
 
 		r, err := filepath.Rel(root, path)
 		if err != nil {

common.go

@@ -36,6 +36,10 @@ func GetLanguageExtensions(language string) []string {
 
 // GetLanguage return the Language for a given filename and file content.
 func GetLanguage(filename string, content []byte) string {
+	if lang, safe := GetLanguageByFilename(filename); safe {
+		return lang
+	}
+
 	if lang, safe := GetLanguageByShebang(content); safe {
 		return lang
 	}

filename_test.go

@@ -0,0 +1,37 @@
+package slinguist
+
+import . "gopkg.in/check.v1"
+
+func (s *TSuite) TestGetLanguageByFilename(c *C) {
+	lang, safe := GetLanguageByFilename(`unknown.interpreter`)
+	c.Assert(lang, Equals, OtherLanguage)
+	c.Assert(safe, Equals, false)
+
+	lang, safe = GetLanguageByFilename(`.bashrc`)
+	c.Assert(lang, Equals, "Shell")
+	c.Assert(safe, Equals, true)
+
+	lang, safe = GetLanguageByFilename(`Dockerfile`)
+	c.Assert(lang, Equals, "Dockerfile")
+	c.Assert(safe, Equals, true)
+
+	lang, safe = GetLanguageByFilename(`Makefile.frag`)
+	c.Assert(lang, Equals, "Makefile")
+	c.Assert(safe, Equals, true)
+
+	lang, safe = GetLanguageByFilename(`makefile`)
+	c.Assert(lang, Equals, "Makefile")
+	c.Assert(safe, Equals, true)
+
+	lang, safe = GetLanguageByFilename(`Vagrantfile`)
+	c.Assert(lang, Equals, "Ruby")
+	c.Assert(safe, Equals, true)
+
+	lang, safe = GetLanguageByFilename(`_vimrc`)
+	c.Assert(lang, Equals, "Vim script")
+	c.Assert(safe, Equals, true)
+
+	lang, safe = GetLanguageByFilename(`pom.xml`)
+	c.Assert(lang, Equals, "Maven POM")
+	c.Assert(safe, Equals, true)
+}