From ecd044c260f162e4a9f233aab11e8eefe7949826 Mon Sep 17 00:00:00 2001
From: Jerome Froelich <jeromefroelich@hotmail.com>
Date: Wed, 23 Oct 2019 17:22:57 -0400
Subject: [PATCH] Ensure replacement values are properly quoted

---
 expand.go      | 7 ++++++-
 option_test.go | 3 ++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/expand.go b/expand.go
index 2ad692d..f71a72c 100644
--- a/expand.go
+++ b/expand.go
@@ -27,6 +27,7 @@ import (
 	"strings"
 
 	"golang.org/x/text/transform"
+	yaml "gopkg.in/yaml.v2"
 )
 
 const (
@@ -68,7 +69,11 @@ func replace(lookUp LookupFunc) func(in string) (string, error) {
 		}
 
 		if envVal, ok := lookUp(key); ok {
-			return envVal, nil
+			buf, err := yaml.Marshal(envVal)
+			if err != nil {
+				return "", fmt.Errorf("unable to marshal value of %q to YAML: %v", key, err)
+			}
+			return string(buf), nil
 		}
 
 		if def == "" {
diff --git a/option_test.go b/option_test.go
index 6623a28..1bfd993 100644
--- a/option_test.go
+++ b/option_test.go
@@ -44,7 +44,7 @@ func TestStatic(t *testing.T) {
 }
 
 func TestExpand(t *testing.T) {
-	environment := map[string]string{"FOO": "bar"}
+	environment := map[string]string{"FOO": "bar", "BAR": "@bar"}
 	lookup := func(key string) (string, bool) {
 		s, ok := environment[key]
 		return s, ok
@@ -60,6 +60,7 @@ func TestExpand(t *testing.T) {
 		{"present bracketed", "${FOO:baz}", false, "bar"},
 		{"absent bracketed", "${NOT_THERE:baz}", false, "baz"},
 		{"absent bracketed no default", `${NOT_THERE:""}`, false, nil},
+		{"present bracketed quoted value", "${BAR}", false, "@bar"},
 	}
 	for _, tt := range tests {
 		t.Run(tt.desc, func(t *testing.T) {