From 332d978bd0c8593cc0bcabbd05ec94d6d76db10b Mon Sep 17 00:00:00 2001
From: nasa9084 <nasa.9084.bassclarinet@gmail.com>
Date: Wed, 12 Feb 2020 19:39:33 +0900
Subject: [PATCH 1/2] add test for Stack

---
 stack_test.go | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 stack_test.go

diff --git a/stack_test.go b/stack_test.go
new file mode 100644
index 0000000..9a8a677
--- /dev/null
+++ b/stack_test.go
@@ -0,0 +1,54 @@
+package stack
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestPush(t *testing.T) {
+	s := Stack{}
+	s.Push("foo")
+	s.Push("bar")
+
+	want := Stack([]string{"foo", "bar"})
+	if !reflect.DeepEqual(s, want) {
+		// TODO: more detail message
+		t.Error("error")
+		return
+	}
+}
+
+func TestPop(t *testing.T) {
+	s := Stack([]string{"foo", "bar"})
+	t.Run("pop 1", func(t *testing.T) {
+		got := s.Pop()
+		wantVal := "bar"
+		if got != wantVal {
+			// TODO: more detail message
+			t.Error("error on 1 val")
+			return
+		}
+		want := Stack([]string{"foo"})
+		if !reflect.DeepEqual(s, want) {
+			// TODO: more detail message
+			t.Error("error on 1")
+			return
+		}
+	})
+
+	t.Run("pop 2", func(t *testing.T) {
+		got := s.Pop()
+		wantVal := "foo"
+		if got != wantVal {
+			// TODO: more detail message
+			t.Error("error on 2 val")
+			return
+		}
+		want := Stack{}
+		if !reflect.DeepEqual(s, want) {
+			// TODO: more detail message
+			t.Error("error on 2")
+			return
+		}
+	})
+}

From f15869ca9e0b14459dd7205b67a3507b0180cdb8 Mon Sep 17 00:00:00 2001
From: nasa9084 <nasa.9084.bassclarinet@gmail.com>
Date: Wed, 12 Feb 2020 19:50:16 +0900
Subject: [PATCH 2/2] add testcase and fix panic when there's no elements

---
 stack.go      |  3 +++
 stack_test.go | 16 ++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/stack.go b/stack.go
index 0598fd8..185f3d9 100644
--- a/stack.go
+++ b/stack.go
@@ -10,6 +10,9 @@ func (stack *Stack) Push(s string) {
 
 // Pop do pop from the top of stack and remove it.
 func (stack *Stack) Pop() string {
+	if len(*stack) == 0 {
+		return ""
+	}
 	ret := (*stack)[len(*stack)-1]
 	*stack = (*stack)[:len(*stack)-1]
 	return ret
diff --git a/stack_test.go b/stack_test.go
index 9a8a677..bc9f3b5 100644
--- a/stack_test.go
+++ b/stack_test.go
@@ -51,4 +51,20 @@ func TestPop(t *testing.T) {
 			return
 		}
 	})
+
+	t.Run("pop 3", func(t *testing.T) {
+		got := s.Pop()
+		wantVal := ""
+		if got != wantVal {
+			// TODO: more detail message
+			t.Error("error on 3 val")
+			return
+		}
+		want := Stack{}
+		if !reflect.DeepEqual(s, want) {
+			// TODO: more detail message
+			t.Error("error on 3")
+			return
+		}
+	})
 }