feat: add golangci-lint for go linting

internal/utils/fs_utils_test.go

@@ -18,7 +18,7 @@ func TestReadFile(t *testing.T) {
 
 	err = file.Close()
 	require.NoError(t, err)
-	defer os.Remove("/tmp/tinyauth_test_file")
+	defer os.Remove("/tmp/tinyauth_test_file") //nolint:errcheck
 
 	// Normal case
 	content, err := ReadFile("/tmp/tinyauth_test_file")

internal/utils/security_utils.go

@@ -53,7 +53,7 @@ func FilterIP(filter string, ip string) (bool, error) {
 		return false, errors.New("invalid IP address")
 	}
 
-	filter = strings.Replace(filter, "-", "/", -1)
+	filter = strings.ReplaceAll(filter, "-", "/")
 
 	if strings.Contains(filter, "/") {
 		_, cidr, err := net.ParseCIDR(filter)

internal/utils/security_utils_test.go

@@ -19,7 +19,7 @@ func TestGetSecret(t *testing.T) {
 
 	err = file.Close()
 	require.NoError(t, err)
-	defer os.Remove("/tmp/tinyauth_test_secret")
+	defer os.Remove("/tmp/tinyauth_test_secret") //nolint:errcheck
 
 	// Get from config
 	assert.Equal(t, "mysecret", utils.GetSecret("mysecret", ""))

internal/utils/string_utils_test.go

@@ -73,7 +73,7 @@ func TestGetStringList(t *testing.T) {
 
 	err = file.Close()
 	assert.NoError(t, err)
-	defer os.Remove("/tmp/tinyauth_list_test_file")
+	defer os.Remove("/tmp/tinyauth_list_test_file") //nolint:errcheck
 
 	values, err := utils.GetStringList([]string{" first@example.com ", "", "second@example.com"}, "/tmp/tinyauth_list_test_file")
 	assert.NoError(t, err)

internal/utils/user_utils_test.go

@@ -24,7 +24,7 @@ func TestGetUsers(t *testing.T) {
 
 	err = file.Close()
 	require.NoError(t, err)
-	defer os.Remove(tmpDir + "/tinyauth_users_test.txt")
+	defer os.Remove(tmpDir + "/tinyauth_users_test.txt") //nolint:errcheck
 
 	noAttrs := map[string]model.UserAttributes{}