go: delete pertinent ENVs after loading settings

app/settings/settings.go

@@ -1,6 +1,8 @@
 package settings
 
 import (
+	"os"
+
 	"git.dotya.ml/mirre-mt/pcmt/config"
 	"git.dotya.ml/mirre-mt/pcmt/slogging"
 	"golang.org/x/exp/slog"
@@ -22,6 +24,14 @@ type Settings struct {
 	dbIsSetUp           bool
 }
 
+// cleantgt is a list of ENV vars pertaining to pcmt.
+var cleantgt = []string{
+	"PCMT_LIVE",
+	"PCMT_DEVEL",
+	"PCMT_CONNSTRING",
+	"PCMT_DBTYPE",
+}
+
 // New returns a new instance of the settings struct.
 func New() *Settings {
 	return &Settings{}
@@ -205,3 +215,15 @@ func (s *Settings) SetDbType(dbType string) {
 func (s *Settings) SetDbIsSetUp(is bool) {
 	s.dbIsSetUp = is
 }
+
+// EraseENVs attempts to clear environment vars pertaining to pcmt.
+func (s *Settings) EraseENVs() error {
+	for _, v := range cleantgt {
+		err := os.Unsetenv(v)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}