Handle nil

env/env.go

@@ -99,6 +99,30 @@ func ToShellWithPrefix(prefix string, kvl []KeyValue) string {
 	return sb.String()
 }
 
+func SerializeValue(value interface{}) string {
+	switch v := value.(type) {
+	case bool:
+		res := "false"
+		if v {
+			res = "true"
+		}
+		return res
+	case string:
+		return strconv.Quote(v)
+	default:
+		return strconv.Quote(fmt.Sprint(value))
+	}
+}
+
+func kindIsIn(k reflect.Kind, kinds ...reflect.Kind) bool {
+	for _, kind := range kinds {
+		if k == kind {
+			return true
+		}
+	}
+	return false
+}
+
 // StructToEnvVars converts a struct to a map of environment variables.
 // The struct can have a `env` tag on each field.
 // The tag should be in the format `env:"ENV_VAR_NAME"`.
@@ -119,16 +143,21 @@ func StructToEnvVars(s interface{}) []KeyValue {
 	}
 	t := v.Type()
 	for i := 0; i < t.NumField(); i++ {
-		field := t.Field(i)
-		tag := field.Tag.Get("env")
+		fieldType := t.Field(i)
+		tag := fieldType.Tag.Get("env")
 		if tag == "-" {
 			continue
 		}
 		if tag == "" {
-			tag = CamelCaseToUpperSnakeCase(field.Name)
+			tag = CamelCaseToUpperSnakeCase(fieldType.Name)
+		}
+		fieldValue := v.Field(i)
+		stringValue := ""
+		if !kindIsIn(fieldValue.Kind(), reflect.Ptr, reflect.Map, reflect.Array, reflect.Chan, reflect.Slice) {
+			value := fieldValue.Interface()
+			stringValue = SerializeValue(value)
 		}
-		value := v.Field(i).Interface()
-		envVars = append(envVars, KeyValue{Key: tag, Value: strconv.Quote(fmt.Sprint(value))})
+		envVars = append(envVars, KeyValue{Key: tag, Value: stringValue})
 	}
 	return envVars
 }

env/env_test.go

@@ -98,32 +98,38 @@ type FooConfig struct {
 	Foo        string
 	Bar        string
 	Blah       int `env:"A_SPECIAL_BLAH"`
+	ABool      bool
 	NotThere   int `env:"-"`
 	HTTPServer string
+	IntPointer *int
 }
 
 func TestStructToEnvVars(t *testing.T) {
 	foo := FooConfig{
 		Foo:        "a\nfoo with \" quotes and \\ and '",
 		Bar:        "42str",
 		Blah:       42,
+		ABool:      true,
 		NotThere:   13,
 		HTTPServer: "http://localhost:8080",
+		IntPointer: nil,
 	}
 	empty := env.StructToEnvVars(42) // error/empty
 	if len(empty) != 0 {
 		t.Errorf("expected empty, got %v", empty)
 	}
 	envVars := env.StructToEnvVars(&foo)
-	if len(envVars) != 4 {
-		t.Errorf("expected 4 env vars, got %+v", envVars)
+	if len(envVars) != 6 {
+		t.Errorf("expected 4 env vars, got %d: %+v", len(envVars), envVars)
 	}
 	str := env.ToShellWithPrefix("TST_", envVars)
 	expected := `TST_FOO="a\nfoo with \" quotes and \\ and '"
 TST_BAR="42str"
 TST_A_SPECIAL_BLAH="42"
+TST_A_BOOL=true
 TST_HTTP_SERVER="http://localhost:8080"
-export TST_FOO TST_BAR TST_A_SPECIAL_BLAH TST_HTTP_SERVER
+TST_INT_POINTER=
+export TST_FOO TST_BAR TST_A_SPECIAL_BLAH TST_A_BOOL TST_HTTP_SERVER TST_INT_POINTER
 `
 	if str != expected {
 		t.Errorf("\n---expected:---\n%s\n---got:---\n%s", expected, str)