internal/function: language should return nil for unknown languages

Signed-off-by: Miguel Molina <[email protected]>

Author: erizocosmico

internal/function/language.go

@@ -110,7 +110,11 @@ func (f *Language) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 		blob = right.([]byte)
 	}
 
-	return enry.GetLanguage(path, blob), nil
+	if lang := enry.GetLanguage(path, blob); lang != "" {
+		return lang, nil
+	}
+
+	return nil, nil
 }
 
 // Children implements the Expression interface.

internal/function/language_test.go

@@ -20,6 +20,7 @@ func TestLanguage(t *testing.T) {
 		{"right is null", sql.NewRow("foo", nil), nil, nil},
 		{"both are null", sql.NewRow(nil, nil), nil, nil},
 		{"only path is given", sql.NewRow("foo.rb"), "Ruby", nil},
+		{"only path is given", sql.NewRow("foo.foobar"), nil, nil},
 		{"too many args given", sql.NewRow("foo.rb", "bar", "baz"), nil, sql.ErrInvalidArgumentNumber},
 		{"path and blob are given", sql.NewRow("foo", "#!/usr/bin/env python\n\nprint 'foo'"), "Python", nil},
 		{"invalid blob type given", sql.NewRow("foo", 5), nil, sql.ErrInvalidType},