[WIP] Read env variables from file

env.go

@@ -0,0 +1,95 @@
+package envconf
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"io"
+	"os"
+	"strings"
+)
+
+var (
+	ErrInvalidPair = errors.New("invalid pair for env variable")
+)
+
+const (
+	commentSymbol = '#'
+)
+
+type EnvConfig struct {
+	envs map[string]string
+}
+
+func NewEnvConf() *EnvConfig {
+	return &EnvConfig{envs: map[string]string{}}
+}
+
+func (e *EnvConfig) Parse(data io.Reader) error {
+	b := bufio.NewReader(data)
+	for {
+		n, err := b.ReadBytes('\n')
+		if err != nil {
+			if err != io.EOF {
+				return err
+			}
+			if len(n) == 0 {
+				return nil
+			}
+		}
+		n = bytes.Trim(n, " ")
+		n = bytes.Trim(n, "\n")
+		n = bytes.Trim(n, "\t")
+		if n[0] == commentSymbol {
+			continue
+		}
+		i := bytes.Index(n, []byte("="))
+		if i == -1 {
+			return ErrInvalidPair
+		}
+		key := string(n[:i])
+		value := string(n[i+1 : len(n)])
+		if isEmptyLine(value) {
+			e.envs[key] = ""
+			continue
+		}
+		if isQuotes(value, 0, len(value)-1) {
+			value = cutQuotes(value)
+		}
+		e.envs[key] = value
+	}
+}
+
+func (e *EnvConfig) Set() error {
+	for k, v := range e.envs {
+		err := os.Setenv(k, v)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func isEmptyLine(s string) bool {
+	return isQuotes(s, 0, 1)
+}
+
+func cutQuotes(s string) string {
+	if isQuotes(s, 0, len(s)-1) {
+		if string(s[0]) == `"` {
+			s = strings.Trim(s, `"`)
+		} else {
+			s = strings.Trim(s, `'`)
+		}
+	}
+	return s
+}
+
+func isQuotes(s string, first, second int) bool {
+	open := string(s[first])
+	close := string(s[second])
+	if (open == `"` || open == `'`) && open == close {
+		return true
+	}
+	return false
+}

env_test.go

@@ -0,0 +1,182 @@
+package envconf
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"testing"
+)
+
+func TestSimpleExternalEnvConfigOK(t *testing.T) {
+	env := bytes.NewBuffer([]byte("Foo=Bar"))
+	tc := struct {
+		Foo string `env:"Foo"`
+	}{}
+	envf := NewEnvConf()
+	if err := envf.Parse(env); err != nil {
+		t.Error("invalid parse env data:", err)
+	}
+	if err := envf.Set(); err != nil {
+		t.Error("invalid set env variables:", err)
+	}
+	err := Parse(&tc)
+	if err != nil {
+		t.Error(err)
+	}
+	if tc.Foo != "Bar" {
+		t.Errorf("incorrect values was set. %#v", tc.Foo)
+	}
+	fmt.Println(os.Getenv("Name"))
+}
+
+func TestSimpleExternalEnvConfigFieldWithUnderscoreOK(t *testing.T) {
+	env := bytes.NewBuffer([]byte("FOO_BAR=FOO_BAR"))
+	tc := struct {
+		FooBar string `env:"FOO_BAR"`
+	}{}
+	envf := NewEnvConf()
+	if err := envf.Parse(env); err != nil {
+		t.Error("invalid parse env data:", err)
+	}
+	if err := envf.Set(); err != nil {
+		t.Error("invalid set env variables:", err)
+	}
+	err := Parse(&tc)
+	if err != nil {
+		t.Errorf("failed to external parse. err=%s", err)
+	}
+	if tc.FooBar != "FOO_BAR" {
+		t.Errorf("incorrect values was set. %#v", tc.FooBar)
+	}
+}
+
+func TestSimpleExternaEnvConfigTwoVariablesOK(t *testing.T) {
+	env := bytes.NewBuffer([]byte("FOO_FIRST=FOO_FIRST\nFOO_SECOND=FOO_SECOND\n"))
+	tc := struct {
+		FooFirst  string `env:"FOO_FIRST"`
+		FooSecond string `env:"FOO_SECOND"`
+	}{}
+	envf := NewEnvConf()
+	envf.Parse(env)
+	envf.Set()
+	err := Parse(&tc)
+	if err != nil {
+		t.Errorf("failed to external parse. err=%s", err)
+	}
+	if tc.FooFirst != "FOO_FIRST" {
+		t.Errorf("incorrect first values was set. %#v", tc.FooFirst)
+	}
+	if tc.FooSecond != "FOO_SECOND" {
+		t.Errorf("incorrect value was set. %#v", tc.FooSecond)
+	}
+}
+
+func TestSimpleExternaEnvConfigTwoVariablesWithCommentOK(t *testing.T) {
+	env := bytes.NewBuffer([]byte("# COMMENT=COMMENT\nFOO_FIRST=FOO_FIRST\nFOO_SECOND=FOO_SECOND\n"))
+	tc := struct {
+		Comment   string `env:"COMMENT"`
+		FooFirst  string `env:"FOO_FIRST"`
+		FooSecond string `env:"FOO_SECOND"`
+	}{}
+	envf := NewEnvConf()
+	if err := envf.Parse(env); err != nil {
+		t.Error("invalid parse env data:", err)
+	}
+	if err := envf.Set(); err != nil {
+		t.Error("invalid set env variables:", err)
+	}
+	err := Parse(&tc)
+	if err != nil {
+		t.Errorf("failed to external parse. err=%s", err)
+	}
+	if tc.FooFirst != "FOO_FIRST" {
+		t.Errorf("incorrect first values was set. %#v", tc.FooFirst)
+	}
+	if tc.FooSecond != "FOO_SECOND" {
+		t.Errorf("incorrect value was set. %#v", tc.FooSecond)
+	}
+	if tc.Comment != "" {
+		t.Errorf("incorrect values was set. %#v", tc.Comment)
+	}
+}
+
+func TestSimpleExternaEnvConfigTwoVariablesWithQueteOK(t *testing.T) {
+	env := bytes.NewBuffer([]byte(`FOO_FIRST="FOO_FIRST"
+	FOO_SECOND='FOO_SECOND'`))
+	tc := struct {
+		FooFirst  string `env:"FOO_FIRST"`
+		FooSecond string `env:"FOO_SECOND"`
+	}{}
+	envf := NewEnvConf()
+	if err := envf.Parse(env); err != nil {
+		t.Error("invalid parse env data:", err)
+	}
+	if err := envf.Set(); err != nil {
+		t.Error("invalid set env variables:", err)
+	}
+	err := Parse(&tc)
+	if err != nil {
+		t.Errorf("failed to external parse. err=%s", err)
+	}
+	if tc.FooFirst != "FOO_FIRST" {
+		t.Errorf("incorrect first values was set. %#v", tc.FooFirst)
+	}
+	if tc.FooSecond != "FOO_SECOND" {
+		t.Errorf("incorrect value was set. %#v", tc.FooSecond)
+	}
+}
+
+func TestSimpleExternaEnvConfigTwoVariablesEmptyStringOK(t *testing.T) {
+	env := bytes.NewBuffer([]byte(`FOO_FIRST=""
+	FOO_SECOND=''`))
+	tc := struct {
+		FooFirst  string `env:"FOO_FIRST"`
+		FooSecond string `env:"FOO_SECOND"`
+	}{
+		FooFirst:  "foo_first",
+		FooSecond: "foo_second",
+	}
+	envf := NewEnvConf()
+	if err := envf.Parse(env); err != nil {
+		t.Error("invalid parse env data:", err)
+	}
+	if err := envf.Set(); err != nil {
+		t.Error("invalid set env variables:", err)
+	}
+	err := Parse(&tc)
+	if err != nil {
+		t.Errorf("failed to external parse. err=%s", err)
+	}
+	if tc.FooFirst != "" {
+		t.Errorf("incorrect first values was set. %#v", tc.FooFirst)
+	}
+	if tc.FooSecond != "" {
+		t.Errorf("incorrect value was set. %#v", tc.FooSecond)
+	}
+}
+
+func TestSimpleExternaEnvConfigTwoVariablesEmptySpaceStringOK(t *testing.T) {
+	env := bytes.NewBuffer([]byte(`FOO_FIRST=" "
+	FOO_SECOND=' '`))
+	tc := struct {
+		FooFirst  string `env:"FOO_FIRST"`
+		FooSecond string `env:"FOO_SECOND"`
+	}{}
+	envf := NewEnvConf()
+	if err := envf.Parse(env); err != nil {
+		t.Error("invalid parse env data:", err)
+	}
+	if err := envf.Set(); err != nil {
+		t.Error("invalid set env variables:", err)
+	}
+	err := Parse(&tc)
+	if err != nil {
+		t.Errorf("failed to external parse. err=%s", err)
+	}
+	if tc.FooFirst != " " {
+		t.Errorf("incorrect first values was set. %#v", tc.FooFirst)
+	}
+	if tc.FooSecond != " " {
+		t.Errorf("incorrect value was set. %#v", tc.FooSecond)
+	}
+}

value.go

@@ -186,15 +186,16 @@ func (v *value) define() error {
 				owner = owner.parent
 			}
 			value, exists = v.owner.external.Get(values...)
+			if exists {
+				return nil
+			} else if value != nil {
+				exists = true
+			}
 		case DefaultPriority:
 			value, exists = v.defaultV.value()
 		}
 		if exists {
 			debugLogger.Printf("envconf: set variable name=%s value=%v source=%s", v.fullname(), value, p)
-			if p == ExternalPriority {
-				// value setted in external source
-				return nil
-			}
 			break
 		}
 	}