Fix ParseAPTConfigFolder when sources.list is missing

go.mod

@@ -0,0 +1,11 @@
+module github.com/sigmonsays/go-apt-client
+
+go 1.20
+
+require github.com/stretchr/testify v1.8.4
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,10 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

repos.go

@@ -150,7 +150,13 @@ func parseAPTConfigFile(configPath string) (RepositoryList, error) {
 // get information about all configured repositories, it scans also
 // "source.list.d" subfolder to find all the "*.list" files.
 func ParseAPTConfigFolder(folderPath string) (RepositoryList, error) {
-	sources := []string{filepath.Join(folderPath, "sources.list")}
+	sources := make([]string, 0)
+
+
+	sourcesFile := filepath.Join(folderPath, "sources.list")
+	if FileExists(sourcesFile) {
+		sources = append(sources, sourcesFile)
+	}
 
 	sourcesFolder := filepath.Join(folderPath, "sources.list.d")
 	list, err := ioutil.ReadDir(sourcesFolder)

util.go

@@ -0,0 +1,14 @@
+package apt
+
+import "os"
+
+func FileExists(path string) bool {
+	st, err := os.Stat(path)
+	if err != nil && os.IsNotExist(err) {
+		return false
+	}
+	if st.IsDir() == true {
+		return false
+	}
+	return true
+}