From 5adfee5761204c9c65d29dd9a418fc0519ad46ad Mon Sep 17 00:00:00 2001
From: kuba-- <kuba@sourced.tech>
Date: Thu, 14 Mar 2019 13:26:00 +0100
Subject: [PATCH] Do not return empty lang. It's better to return any potential
 candidate than nothing.

Signed-off-by: kuba-- <kuba@sourced.tech>
---
 .gitignore     |  1 +
 classifier.go  | 25 +++++++++++++++----------
 common.go      |  9 +++++----
 common_test.go |  8 +++++---
 4 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/.gitignore b/.gitignore
index c2cb0a9..b76c892 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,4 +6,5 @@ Makefile.main
 .idea
 .docsrv-resources
 build/
+vendor/
 java/lib/
diff --git a/classifier.go b/classifier.go
index 8f72296..fed1d0e 100644
--- a/classifier.go
+++ b/classifier.go
@@ -26,9 +26,6 @@ type scoredLanguage struct {
 
 // Classify returns a sorted slice of possible languages sorted by decreasing language's probability
 func (c *classifier) Classify(content []byte, candidates map[string]float64) []string {
-	if len(content) == 0 {
-		return nil
-	}
 
 	var languages map[string]float64
 	if len(candidates) == 0 {
@@ -44,15 +41,23 @@ func (c *classifier) Classify(content []byte, candidates map[string]float64) []s
 		}
 	}
 
-	tokens := tokenizer.Tokenize(content)
+	empty := len(content) == 0
 	scoredLangs := make([]*scoredLanguage, 0, len(languages))
-	for language := range languages {
-		scoredLang := &scoredLanguage{
-			language: language,
-			score:    c.tokensLogProbability(tokens, language) + c.languagesLogProbabilities[language],
-		}
 
-		scoredLangs = append(scoredLangs, scoredLang)
+	var tokens []string
+	if !empty {
+		tokens = tokenizer.Tokenize(content)
+	}
+
+	for language := range languages {
+		score := c.languagesLogProbabilities[language]
+		if !empty {
+			score += c.tokensLogProbability(tokens, language)
+		}
+		scoredLangs = append(scoredLangs, &scoredLanguage{
+			language: language,
+			score:    score,
+		})
 	}
 
 	return sortLanguagesByScore(scoredLangs)
diff --git a/common.go b/common.go
index 9bc968a..3486274 100644
--- a/common.go
+++ b/common.go
@@ -41,11 +41,12 @@ func GetLanguage(filename string, content []byte) (language string) {
 }
 
 func firstLanguage(languages []string) string {
-	if len(languages) == 0 {
-		return OtherLanguage
+	for _, l := range languages {
+		if l != "" {
+			return l
+		}
 	}
-
-	return languages[0]
+	return OtherLanguage
 }
 
 // GetLanguageByModeline returns detected language. If there are more than one possibles languages
diff --git a/common_test.go b/common_test.go
index edaed4c..4a5f8a0 100644
--- a/common_test.go
+++ b/common_test.go
@@ -101,9 +101,10 @@ func (s *EnryTestSuite) TestGetLanguage() {
 		expected string
 		safe     bool
 	}{
+		{name: "TestGetLanguage_0", filename: "foo.h", content: []byte{}, expected: "C"},
 		{name: "TestGetLanguage_1", filename: "foo.py", content: []byte{}, expected: "Python"},
 		{name: "TestGetLanguage_2", filename: "foo.m", content: []byte(":- module"), expected: "Mercury"},
-		{name: "TestGetLanguage_3", filename: "foo.m", content: nil, expected: OtherLanguage},
+		{name: "TestGetLanguage_3", filename: "foo.m", content: nil, expected: "MATLAB"},
 		{name: "TestGetLanguage_4", filename: "foo.mo", content: []byte{0xDE, 0x12, 0x04, 0x95, 0x00, 0x00, 0x00, 0x00}, expected: OtherLanguage},
 		{name: "TestGetLanguage_5", filename: "", content: nil, expected: OtherLanguage},
 	}
@@ -276,6 +277,7 @@ func (s *EnryTestSuite) TestGetLanguagesByExtension() {
 		candidates []string
 		expected   []string
 	}{
+		{name: "TestGetLanguagesByExtension_0", filename: "foo.h", expected: []string{"C", "C++", "Objective-C"}},
 		{name: "TestGetLanguagesByExtension_1", filename: "foo.foo", expected: nil},
 		{name: "TestGetLanguagesByExtension_2", filename: "foo.go", expected: []string{"Go"}},
 		{name: "TestGetLanguagesByExtension_3", filename: "foo.go.php", expected: []string{"Hack", "PHP"}},
@@ -301,7 +303,7 @@ func (s *EnryTestSuite) TestGetLanguagesByClassifier() {
 		{name: "TestGetLanguagesByClassifier_4", filename: filepath.Join(s.samplesDir, "C/blob.c"), candidates: []string{"python", "ruby", "c++"}, expected: "C++"},
 		{name: "TestGetLanguagesByClassifier_5", filename: filepath.Join(s.samplesDir, "C/blob.c"), candidates: []string{"ruby"}, expected: "Ruby"},
 		{name: "TestGetLanguagesByClassifier_6", filename: filepath.Join(s.samplesDir, "Python/django-models-base.py"), candidates: []string{"python", "ruby", "c", "c++"}, expected: "Python"},
-		{name: "TestGetLanguagesByClassifier_7", filename: "", candidates: []string{"python"}, expected: OtherLanguage},
+		{name: "TestGetLanguagesByClassifier_7", filename: "", candidates: []string{"python"}, expected: "Python"},
 	}
 
 	for _, test := range test {
@@ -339,7 +341,7 @@ func (s *EnryTestSuite) TestGetLanguagesBySpecificClassifier() {
 		{name: "TestGetLanguagesByClassifier_4", filename: filepath.Join(s.samplesDir, "C/blob.c"), candidates: []string{"python", "ruby", "c++"}, classifier: DefaultClassifier, expected: "C++"},
 		{name: "TestGetLanguagesByClassifier_5", filename: filepath.Join(s.samplesDir, "C/blob.c"), candidates: []string{"ruby"}, classifier: DefaultClassifier, expected: "Ruby"},
 		{name: "TestGetLanguagesByClassifier_6", filename: filepath.Join(s.samplesDir, "Python/django-models-base.py"), candidates: []string{"python", "ruby", "c", "c++"}, classifier: DefaultClassifier, expected: "Python"},
-		{name: "TestGetLanguagesByClassifier_7", filename: os.DevNull, candidates: nil, classifier: DefaultClassifier, expected: OtherLanguage},
+		{name: "TestGetLanguagesByClassifier_7", filename: os.DevNull, candidates: nil, classifier: DefaultClassifier, expected: "XML"},
 	}
 
 	for _, test := range test {