From 0ed51a711ad0dcaf3eef5b1a5b20279c7f73300b Mon Sep 17 00:00:00 2001
From: Silentroar <tujiayu@tujiayudeMacBook-Pro.local>
Date: Tue, 31 May 2022 09:54:09 +0800
Subject: [PATCH] fix(#38): add a guard for slices with length 0

When the slice's length is 0, should directly return to prevent false
result or slice out of bounds runtime error
---
 ex4.5/unique.go      |  4 ++++
 ex4.5/unique_test.go | 21 ++++++++++++++++-----
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/ex4.5/unique.go b/ex4.5/unique.go
index d1ad75b..68eb6a5 100644
--- a/ex4.5/unique.go
+++ b/ex4.5/unique.go
@@ -2,6 +2,10 @@
 package unique
 
 func unique(strs []string) []string {
+	if len(strs) == 0 {
+		return strs
+	}
+
 	w := 0 // index of last written string
 	for _, s := range strs {
 		if strs[w] == s {
diff --git a/ex4.5/unique_test.go b/ex4.5/unique_test.go
index f00064a..0c473bd 100644
--- a/ex4.5/unique_test.go
+++ b/ex4.5/unique_test.go
@@ -6,10 +6,21 @@ import (
 )
 
 func TestUnique(t *testing.T) {
-	s := []string{"a", "a", "b", "c", "c", "c", "d", "d", "e"}
-	got := unique(s)
-	want := []string{"a", "b", "c", "d", "e"}
-	if !reflect.DeepEqual(got, want) {
-		t.Errorf("got %v, want %v", got, want)
+	ss := [][]string{
+		{"a", "a", "b", "c", "c", "c", "d", "d", "e"},
+		{},
 	}
+
+	want := [][]string{
+		{"a", "b", "c", "d", "e"},
+		{},
+	}
+
+	for i, s := range ss {
+		got := unique(s)
+		if !reflect.DeepEqual(got, want[i]) {
+			t.Errorf("got %v, want %v", got, want[i])
+		}
+	}
+
 }