Restructure project

internal/env/env.go

@@ -0,0 +1,70 @@
+package env
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/caarlos0/env/v8"
+	"github.com/containrrr/shoutrrr"
+	"github.com/go-playground/validator/v10"
+)
+
+type Config struct {
+	TimeZone    string `env:"TZ" envDefault:"Etc/UTC" validate:"timezone"`
+	Port        int    `env:"PORT" envDefault:"8080" validate:"min=1024,max=49151"`
+	LogLevel    string `env:"LOG_LEVEL" envDefault:"info" validate:"oneof=debug info warn error panic fatal"`
+	Version     string `env:"APP_VERSION" envDefault:"v0.0.0"`
+	SwaggerHost string `env:"SWAGGER_HOST" envDefault:"https://cafe.test"`
+	DB_Host     string `env:"DB_HOST"`
+	DB_User     string `env:"DB_USER"`
+	DB_Password string `env:"DB_PASSWORD"`
+	DB_Database string `env:"DB_DATABASE"`
+}
+
+var errParse = errors.New("error parsing environment variables")
+
+func Parse() (*Config, error) {
+	cfg := &Config{}
+	if err := env.Parse(cfg); err != nil {
+		return cfg, err
+	}
+	if err := validateContent(cfg); err != nil {
+		return cfg, err
+	}
+	setAllDefaultEnvs(cfg)
+	return cfg, nil
+}
+
+func newEnvValidator() *validator.Validate {
+	validate := validator.New()
+	validate.RegisterValidation(`shoutrrr`, func(fl validator.FieldLevel) bool {
+		value := fl.Field().Interface().(string)
+		_, err := shoutrrr.CreateSender(value)
+		return err == nil
+	})
+
+	return validate
+}
+
+func validateContent(cfg *Config) error {
+	validate := newEnvValidator()
+	err := validate.Struct(cfg)
+	if err != nil {
+		if _, ok := err.(*validator.InvalidValidationError); ok {
+			return err
+		} else {
+			for _, err := range err.(validator.ValidationErrors) {
+				return err
+			}
+		}
+		return errParse
+	}
+	return nil
+}
+
+func setAllDefaultEnvs(cfg *Config) {
+	os.Setenv("TZ", cfg.TimeZone)
+	os.Setenv("PORT", fmt.Sprintf("%d", cfg.Port))
+	os.Setenv("LOG_LEVEL", cfg.LogLevel)
+}

internal/env/env_test.go

@@ -0,0 +1,56 @@
+package env
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPortParser(t *testing.T) {
+	key := "PORT"
+	var err error
+	defer func() {
+		os.Unsetenv(key)
+	}()
+
+	os.Setenv(key, "1024")
+	_, err = Parse()
+	assert.Equal(t, err, nil, "Parsing should pass")
+
+	os.Setenv(key, "-12")
+	_, err = Parse()
+	assert.Equal(t, err.Error(), "Key: 'Config.Port' Error:Field validation for 'Port' failed on the 'min' tag", "Validation should fail")
+
+	os.Setenv(key, "60000")
+	_, err = Parse()
+	assert.Equal(t, err.Error(), "Key: 'Config.Port' Error:Field validation for 'Port' failed on the 'max' tag", "Validation should fail")
+
+	os.Setenv(key, "abc")
+	_, err = Parse()
+	assert.Equal(t, err.Error(), "env: parse error on field \"Port\" of type \"int\": strconv.ParseInt: parsing \"abc\": invalid syntax", "Parsing should fail")
+}
+
+func TestTimeZoneParser(t *testing.T) {
+	key := "TZ"
+	var err error
+	defer func() {
+		os.Unsetenv(key)
+	}()
+
+	os.Setenv(key, "Europe/Berlin")
+	_, err = Parse()
+	assert.Equal(t, err, nil, "Parsing should pass")
+
+	os.Setenv(key, "Etc/UTC")
+	_, err = Parse()
+	assert.Equal(t, err, nil, "Parsing should pass")
+
+	os.Setenv(key, "abc")
+	_, err = Parse()
+	assert.Equal(t, err.Error(), "Key: 'Config.TimeZone' Error:Field validation for 'TimeZone' failed on the 'timezone' tag", "Validation should fail")
+
+	os.Setenv(key, "-1")
+	_, err = Parse()
+	assert.Equal(t, err.Error(), "Key: 'Config.TimeZone' Error:Field validation for 'TimeZone' failed on the 'timezone' tag", "Validation should fail")
+}