From 14948fab0014b51f997e10a48690274f385b0d05 Mon Sep 17 00:00:00 2001
From: Kailash Nadh <kailash@nadh.in>
Date: Sat, 9 Mar 2024 12:39:59 +0530
Subject: [PATCH] Fix incorrect map unflatten behaviour on no delim. Closes
 #275.

---
 maps/maps.go       |  8 +++++++-
 tests/maps_test.go | 12 ++++++------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/maps/maps.go b/maps/maps.go
index 0a409f9a..bdb9d62b 100644
--- a/maps/maps.go
+++ b/maps/maps.go
@@ -74,10 +74,16 @@ func Unflatten(m map[string]interface{}, delim string) map[string]interface{} {
 	// Iterate through the flat conf map.
 	for k, v := range m {
 		var (
-			keys = strings.Split(k, delim)
+			keys []string
 			next = out
 		)
 
+		if delim != "" {
+			keys = strings.Split(k, delim)
+		} else {
+			keys = []string{k}
+		}
+
 		// Iterate through key parts, for eg:, parent.child.key
 		// will be ["parent", "child", "key"]
 		for _, k := range keys[:len(keys)-1] {
diff --git a/tests/maps_test.go b/tests/maps_test.go
index c3acd0db..9b52b3c2 100644
--- a/tests/maps_test.go
+++ b/tests/maps_test.go
@@ -101,7 +101,7 @@ var testMap3 = map[string]interface{}{
 }
 
 func TestFlatten(t *testing.T) {
-	f, k := maps.Flatten(testMap, nil, ".")
+	f, k := maps.Flatten(testMap, nil, delim)
 	assert.Equal(t, map[string]interface{}{
 		"parent.child.key":          123,
 		"parent.child.key.with.dot": 456,
@@ -118,17 +118,17 @@ func TestFlatten(t *testing.T) {
 
 func BenchmarkFlatten(b *testing.B) {
 	for n := 0; n < b.N; n++ {
-		maps.Flatten(testMap3, nil, ".")
+		maps.Flatten(testMap3, nil, delim)
 	}
 }
 
 func TestUnflatten(t *testing.T) {
-	m, _ := maps.Flatten(testMap, nil, ".")
-	um := maps.Unflatten(m, ".")
+	m, _ := maps.Flatten(testMap, nil, delim)
+	um := maps.Unflatten(m, delim)
 	assert.NotEqual(t, um, testMap)
 
-	m, _ = maps.Flatten(testMap2, nil, ".")
-	um = maps.Unflatten(m, ".")
+	m, _ = maps.Flatten(testMap2, nil, delim)
+	um = maps.Unflatten(m, delim)
 	assert.Equal(t, um, testMap2)
 }