Initial commit.

Author: sjohnsonaz

claim_map.go

@@ -0,0 +1,79 @@
+package config
+
+import (
+	"reflect"
+)
+
+type ClaimMap map[string]interface{}
+
+func GetClaimMap[T any](claims T, claimMap ClaimMap) ClaimMap {
+	if claimMap == nil {
+		claimMap = ClaimMap{}
+	}
+
+	t := reflect.TypeOf(claims)
+	v := reflect.ValueOf(claims)
+	length := t.NumField()
+	for index := 0; index < length; index++ {
+		typeField := t.Field(index)
+		valueField := v.Field(index)
+		tag := typeField.Tag
+		if isNonZero(valueField) {
+			value := valueField.Interface()
+			claim := tag.Get("claim")
+			if claim != "" {
+				claimMap[claim] = value
+			}
+		}
+	}
+
+	return claimMap
+}
+
+func GetConfigMap[T any](claims T) T {
+	t := reflect.TypeOf(claims)
+	v := reflect.ValueOf(&claims).Elem()
+	length := t.NumField()
+	for index := 0; index < length; index++ {
+		typeField := t.Field(index)
+		valueField := v.Field(index)
+		tag := typeField.Tag
+		if isNonZero(valueField) {
+			value := valueField.Interface()
+			claim := tag.Get("config")
+			if claim == "" {
+				continue
+			}
+			switch val := value.(type) {
+			case string:
+				valueField.SetString(GetEnvString(claim, val))
+			case int:
+				valueField.SetInt(int64(GetEnvInt(claim, &val)))
+			}
+		}
+	}
+	return claims
+}
+
+func isNonZero(value reflect.Value) bool {
+	if value.IsZero() {
+		return false
+	}
+
+	switch value.Kind() {
+	case reflect.Chan:
+		fallthrough
+	case reflect.Func:
+		fallthrough
+	case reflect.Interface:
+		fallthrough
+	case reflect.Map:
+		fallthrough
+	case reflect.Pointer:
+		fallthrough
+	case reflect.Slice:
+		return !value.IsNil()
+	default:
+		return true
+	}
+}

claim_map_test.go

@@ -0,0 +1,22 @@
+package config
+
+import "testing"
+
+func TestGetClaimsTags(t *testing.T) {
+	type Claims struct {
+		TestField string `claim:"test_field"`
+	}
+
+	want := "Test Field Value"
+	claims := GetClaimMap(Claims{
+		TestField: want,
+	}, nil)
+
+	if len(claims) == 0 {
+		t.Fatalf("Claims map is empty")
+	}
+	result := claims["test_field"]
+	if result != want {
+		t.Fatalf("Received incorrect value for key.  Received: %v, Expected: %v", result, want)
+	}
+}

config_file.go

@@ -0,0 +1,129 @@
+package config
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"io/fs"
+	"log"
+	"os"
+	"strconv"
+
+	"github.com/joho/godotenv"
+	"gopkg.in/yaml.v3"
+)
+
+// Read a ConfigFile by name from an [fs.FS].
+func ReadConfigFile[T any](fsys fs.FS, name string) (T, error) {
+	buffer, err := getBuffer(fsys, name)
+	if err != nil {
+		var t T
+		return t, err
+	}
+
+	conf, err := getConfigFile[T](buffer)
+	if err != nil {
+		return conf, err
+	}
+
+	conf = GetConfigMap(conf)
+
+	return conf, nil
+}
+
+func getBuffer(fsys fs.FS, name string) (*bytes.Buffer, error) {
+	b, err := fs.ReadFile(fsys, name)
+	if err != nil {
+		return nil, err
+	}
+
+	buf := bytes.NewBuffer(b)
+	if buf == nil {
+		return nil, ErrNilReader
+	}
+
+	return buf, nil
+}
+
+var ErrNilReader = errors.New("nil Reader")
+
+func getConfigFile[T any](r io.Reader) (T, error) {
+	var configFile T
+
+	decoder := yaml.NewDecoder(r)
+	err := decoder.Decode(&configFile)
+
+	return configFile, err
+}
+
+func LoadEnv(filenames ...string) error {
+	err := godotenv.Load(filenames...)
+	if err != nil {
+		log.Fatal("Error loading .env file")
+	}
+	return nil
+}
+
+func GetEnvString(name string, defaultValues ...string) string {
+	value := os.Getenv(name)
+	if value != "" {
+		return value
+	}
+
+	for _, newValue := range defaultValues {
+		value = newValue
+		if value != "" {
+			break
+		}
+	}
+
+	return value
+}
+
+func GetEnvInt[U ~int](name string, defaultValues ...*U) U {
+	if i, ok := getOsInt(name); ok {
+		return U(i)
+	}
+
+	for _, value := range defaultValues {
+		if value != nil {
+			return U(*value)
+		}
+	}
+
+	return 0
+}
+
+func GetEnvInt64[U ~int64](name string, defaultValues ...*U) U {
+	if i, ok := getOsInt(name); ok {
+		return U(i)
+	}
+
+	for _, value := range defaultValues {
+		if value != nil {
+			return U(*value)
+		}
+	}
+
+	return 0
+}
+
+func Nullable[U any](value U) *U {
+	return &value
+}
+
+func getOsInt(name string) (int, bool) {
+	var i int
+
+	s := os.Getenv(name)
+	if s == "" {
+		return 0, false
+	}
+
+	i, err := strconv.Atoi(s)
+	if err != nil {
+		return 0, false
+	}
+
+	return i, true
+}

config_file_test.go

@@ -0,0 +1,57 @@
+package config
+
+import (
+	"bytes"
+	"testing"
+	"testing/fstest"
+)
+
+type configFile struct {
+	DbString string `yaml:"dbString"`
+}
+
+func TestConfigFile(t *testing.T) {
+	var data = `
+dbString: mongodb://mongodb:27017
+`
+
+	var fileName = "file.yml"
+
+	var fileSystem = fstest.MapFS{
+		fileName: {Data: []byte(data)},
+	}
+
+	t.Run("should return error on nil data", func(t *testing.T) {
+		t.Skip()
+		_, err := getConfigFile[configFile](nil)
+		if err == nil {
+			t.Errorf("err should not be nil. err: %v", err)
+		}
+	})
+
+	t.Run("should read from a reader", func(t *testing.T) {
+		r := bytes.NewBufferString(data)
+		_, err := getConfigFile[configFile](r)
+		if err != nil {
+			t.Errorf("%v", err)
+		}
+	})
+
+	t.Run("should read data", func(t *testing.T) {
+		r := bytes.NewBufferString(data)
+		c, err := getConfigFile[configFile](r)
+		if err != nil {
+			t.Errorf("%v", err)
+		}
+		if c.DbString == "" {
+			t.Errorf("DB_STRING is empty")
+		}
+	})
+
+	t.Run("should read from a file", func(t *testing.T) {
+		_, err := ReadConfigFile[configFile](fileSystem, fileName)
+		if err != nil {
+			t.Errorf("%v", err)
+		}
+	})
+}

config_test.go

@@ -0,0 +1,38 @@
+package config
+
+import "testing"
+
+func TestGetString(t *testing.T) {
+	table := []struct {
+		Name          string
+		EnvValue      string
+		DefaultValues []string
+		Result        string
+	}{{
+		Name:          "Name0",
+		EnvValue:      "Env",
+		DefaultValues: []string{"A", "B"},
+		Result:        "Env",
+	}, {
+		Name:          "Name1",
+		DefaultValues: []string{"A", "B"},
+		Result:        "A",
+	}, {
+		Name:          "Name2",
+		DefaultValues: []string{"", "B"},
+		Result:        "B",
+	}, {
+		Name:          "Name3",
+		DefaultValues: []string{},
+		Result:        "",
+	}}
+	for _, item := range table {
+		if item.EnvValue != "" {
+			t.Setenv(item.Name, item.EnvValue)
+		}
+		result := GetEnvString(item.Name, item.DefaultValues...)
+		if result != item.Result {
+			t.Errorf("Received: %v, Expected %v", result, item.Result)
+		}
+	}
+}

go.mod

@@ -0,0 +1,8 @@
+module github.com/cardboardrobots/config
+
+go 1.23.1
+
+require (
+	github.com/joho/godotenv v1.5.1
+	gopkg.in/yaml.v3 v3.0.1
+)

go.sum

@@ -0,0 +1,6 @@
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+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=