feat(config): Added env var helper

config/README.md

@@ -145,10 +145,11 @@ func main() {
 	cfg, _ := config.NewDefaultConfigFactory().Create()
 
 	// helpers
-	fmt.Printf("name: %s", cfg.AppName())       // name: app
-	fmt.Printf("env: %s", cfg.AppEnv())         // env: test
-	fmt.Printf("version: %s", cfg.AppVersion()) // version: 0.1.0
-	fmt.Printf("debug: %v", cfg.AppDebug())     // debug: true
+	fmt.Printf("var: %s", cfg.GetEnvVar("APP_ENV")) // var: test
+	fmt.Printf("name: %s", cfg.AppName())           // name: app
+	fmt.Printf("env: %s", cfg.AppEnv())             // env: test
+	fmt.Printf("version: %s", cfg.AppVersion())     // version: 0.1.0
+	fmt.Printf("debug: %v", cfg.AppDebug())         // debug: true
 
 	// others
 	fmt.Printf("string_value: %s", cfg.GetString("config.values.string_value")) // string_value: test

config/config.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"github.com/spf13/viper"
+	"os"
 )
 
 const (
@@ -20,6 +21,11 @@ type Config struct {
 	*viper.Viper
 }
 
+// GetEnvVar returns the value of an env var.
+func (c *Config) GetEnvVar(envVar string) string {
+	return os.Getenv(envVar)
+}
+
 // AppName returns the configured application name (from config field app.name or env var APP_NAME).
 func (c *Config) AppName() string {
 	return c.GetString("app.name")

config/config_test.go

@@ -7,6 +7,15 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestGetEnvVar(t *testing.T) {
+	cfg, err := createTestConfig()
+	assert.NoError(t, err)
+
+	t.Setenv("foo", "bar")
+
+	assert.Equal(t, "bar", cfg.GetEnvVar("foo"))
+}
+
 func TestAppNameFromDefaultConfig(t *testing.T) {
 	cfg, err := createTestConfig()
 
@@ -19,7 +28,7 @@ func TestAppNameOverrideFromTestEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "test-app", cfg.AppName())
 }
 
@@ -28,7 +37,7 @@ func TestAppNameOverrideFromCustomEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "custom-app", cfg.AppName())
 }
 
@@ -53,7 +62,7 @@ func TestAppNameOverrideFromEnvVar(t *testing.T) {
 func TestAppEnvFromConfig(t *testing.T) {
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, config.AppEnvDev, cfg.AppEnv())
 	assert.False(t, cfg.IsProdEnv())
 	assert.True(t, cfg.IsDevEnv())
@@ -65,7 +74,7 @@ func TestAppEnvOverrideFromTestEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, config.AppEnvTest, cfg.AppEnv())
 	assert.False(t, cfg.IsProdEnv())
 	assert.False(t, cfg.IsDevEnv())
@@ -77,7 +86,7 @@ func TestAppEnvOverrideFromCustomEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "custom", cfg.AppEnv())
 	assert.False(t, cfg.IsProdEnv())
 	assert.False(t, cfg.IsDevEnv())
@@ -87,7 +96,7 @@ func TestAppEnvOverrideFromCustomEnvConfig(t *testing.T) {
 func TestAppDebugFromConfig(t *testing.T) {
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.False(t, cfg.AppDebug())
 }
 
@@ -96,7 +105,7 @@ func TestAppDebugOverrideFromTestEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.True(t, cfg.AppDebug())
 }
 
@@ -105,14 +114,14 @@ func TestAppDebugOverrideFromEnvVar(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.True(t, cfg.AppDebug())
 }
 
 func TestAppVersionFromConfig(t *testing.T) {
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "0.1.0", cfg.AppVersion())
 }
 
@@ -121,7 +130,7 @@ func TestAppVersionOverrideFromTestEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "0.1.0", cfg.AppVersion())
 }
 
@@ -130,14 +139,14 @@ func TestAppVersionOverrideFromEnvVar(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "0.1.2", cfg.AppVersion())
 }
 
 func TestValuesFromConfig(t *testing.T) {
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "default", cfg.GetString("config.values.string_value"))
 	assert.Equal(t, 0, cfg.GetInt("config.values.int_value"))
 }
@@ -147,7 +156,7 @@ func TestValuesOverrideFromTestEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "test", cfg.GetString("config.values.string_value"))
 	assert.Equal(t, 0, cfg.GetInt("config.values.int_value"))
 }
@@ -157,36 +166,36 @@ func TestValuesOverrideFromCustomEnvConfig(t *testing.T) {
 
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "custom", cfg.GetString("config.values.string_value"))
 	assert.Equal(t, 0, cfg.GetInt("config.values.int_value"))
 }
 
 func TestValuesWithEnvVarsPlaceholder(t *testing.T) {
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "foo--baz", cfg.GetString("config.placeholder"))
 
 	t.Setenv("BAR", "bar")
 
 	cfg, err = createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "foo-bar-baz", cfg.GetString("config.placeholder"))
 }
 
 func TestValuesWithEnvVarsSubstitution(t *testing.T) {
 	cfg, err := createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "foo", cfg.GetString("config.substitution"))
 
 	t.Setenv("CONFIG_SUBSTITUTION", "bar")
 
 	cfg, err = createTestConfig()
 
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 	assert.Equal(t, "bar", cfg.GetString("config.substitution"))
 }