Add Load function to the facade

Signed-off-by: Ulysses Souza <[email protected]>

envlang.go

@@ -2,13 +2,16 @@ package envlang
 
 import (
 	"io"
+	"os"
 
 	"github.com/antlr4-go/antlr/v4"
 	"github.com/ulyssessouza/envlang/dao"
 	"github.com/ulyssessouza/envlang/gen/fileparser"
 	"github.com/ulyssessouza/envlang/handlers"
 )
 
+const defaultEnvFile = ".env"
+
 func GetVariablesFromInputStream(d dao.EnvLangDao, r io.Reader) map[string]*string {
 	return getVariablesFromInputStream(d, antlr.NewIoStream(r))
 }
@@ -17,6 +20,29 @@ func GetVariables(d dao.EnvLangDao, s string) map[string]*string {
 	return getVariablesFromInputStream(d, antlr.NewInputStream(s))
 }
 
+func Load(paths ...string) error {
+	if len(paths) == 0 {
+		paths = []string{defaultEnvFile}
+	}
+
+	for _, p := range paths {
+		f, err := os.Open(p)
+		if err != nil {
+			return err
+		}
+		m := GetVariablesFromInputStream(dao.NewDefaultDaoFromEnv(os.Environ()), f)
+		for k, v := range m {
+			if v == nil {
+				str := ""
+				v = &str
+			}
+			os.Setenv(k, *v)
+		}
+	}
+
+	return nil
+}
+
 func getVariablesFromInputStream(d dao.EnvLangDao, ais *antlr.InputStream) map[string]*string {
 	lexer := fileparser.NewEnvLangFileLexer(ais)
 	stream := antlr.NewCommonTokenStream(lexer, antlr.TokenDefaultChannel)

envlang_test.go

@@ -1,6 +1,7 @@
 package envlang
 
 import (
+	"os"
 	"strings"
 	"testing"
 
@@ -22,6 +23,15 @@ func TestGetFromReader(t *testing.T) {
 	assert.DeepEqual(t, expected, GetVariablesFromInputStream(d, strings.NewReader(`A=aaa`)))
 }
 
+func TestLoad(t *testing.T) {
+	const envlangOsLoadVariable = "ENVLANG_TEST_OSLOAD_VARIABLE"
+	err := Load("./fixtures/load.env")
+	assert.NilError(t, err)
+	osLoaded, ok := os.LookupEnv(envlangOsLoadVariable)
+	assert.Assert(t, ok)
+	assert.Equal(t, osLoaded, "ENVLANG_TEST_OSLOAD_VALUE")
+}
+
 //nolint:funlen
 func TestGetValue(t *testing.T) {
 	tests := []struct {

fixtures/load.env

@@ -0,0 +1 @@
+ENVLANG_TEST_OSLOAD_VARIABLE=ENVLANG_TEST_OSLOAD_VALUE