add tee module

1 files changed, 5 insertions, 0 deletions

diff --git a/pkg/server/env/env.go b/pkg/server/env/env.go
index 237c0c5..118f853 100644
--- a/pkg/server/env/env.go
+++ b/pkg/server/env/env.go
@@ -22,6 +22,7 @@ var isNamePattern = regexp.MustCompile("^" + namePattern + "$").MatchString
 var namePatternRe = regexp.MustCompile("@(" + namePattern + "|{" + namePattern + "})")
 
 var errBadVariable = errors.New("bad variable name")
+var errEmptyVariable = errors.New("empty variable")
 
 func New() Env {
 	return Env{new(env)}
@@ -66,6 +67,10 @@ func (e *env) Set(key string, value string) error {
 		return errBadVariable
 	}
 
+	if value == "" {
+		return errEmptyVariable
+	}
+
 	e.Lock()
 	defer e.Unlock()