tests: add tests for go/list (#14962)

Signed-off-by: ChaitanyaD48 <[email protected]>

go/list/list_test.go

@@ -0,0 +1,135 @@
+/*
+Copyright 2024 The Vitess Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package list
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestInitEmptyList(t *testing.T) {
+	l := New[int]()
+	assert.Equal(t, 0, l.Len())
+	assert.Nil(t, l.Front())
+	assert.Nil(t, l.Back())
+}
+
+func TestInsertFront(t *testing.T) {
+	l := New[int]()
+	e := l.PushFront(1)
+	assert.Equal(t, 1, l.Len())
+	assert.Equal(t, e, l.Front())
+	assert.Equal(t, e, l.Back())
+}
+
+func TestInsertBack(t *testing.T) {
+	l := New[int]()
+	e := l.PushBack(1)
+	assert.Equal(t, 1, l.Len())
+	assert.Equal(t, e, l.Front())
+	assert.Equal(t, e, l.Back())
+}
+
+func TestInsertFrontEmptyList(t *testing.T) {
+	l := New[int]()
+	e := l.PushFront(1)
+	assert.Equal(t, 1, l.Len())
+	assert.Equal(t, e, l.Front())
+	assert.Equal(t, e, l.Back())
+}
+
+func TestInsertBackEmptyList(t *testing.T) {
+	l := New[int]()
+	e := l.PushBack(1)
+	assert.Equal(t, 1, l.Len())
+	assert.Equal(t, e, l.Front())
+	assert.Equal(t, e, l.Back())
+}
+
+func TestRemoveOnlyElement(t *testing.T) {
+	l := New[int]()
+	e := l.PushFront(1)
+	l.Remove(e)
+	assert.Equal(t, 0, l.Len())
+	assert.Nil(t, l.Front())
+	assert.Nil(t, l.Back())
+}
+
+func TestRemoveFromWrongList(t *testing.T) {
+	l1 := New[int]()
+	l2 := New[int]()
+	e := l1.PushFront(1)
+	assert.Panics(t, func() { l2.Remove(e) })
+}
+
+func TestGetFirstElement(t *testing.T) {
+	l := New[int]()
+	e := l.PushFront(1)
+	assert.Equal(t, e, l.Front())
+}
+
+func TestGetLastElement(t *testing.T) {
+	l := New[int]()
+	e := l.PushBack(1)
+	assert.Equal(t, e, l.Back())
+}
+
+func TestGetNextElement(t *testing.T) {
+	l := New[int]()
+	e := l.PushBack(1)
+	assert.Nil(t, e.Next())
+	f := l.PushBack(2)
+	assert.Equal(t, f, e.Next())
+}
+
+func TestGetPrevElement(t *testing.T) {
+	l := New[int]()
+	e := l.PushBack(1)
+	assert.Nil(t, e.Prev())
+	f := l.PushBack(2)
+	assert.Equal(t, e, f.Prev())
+}
+
+func TestMoveElement(t *testing.T) {
+	l := New[int]()
+	e := l.PushBack(1)
+	l.move(e, e)
+	assert.Equal(t, e, l.Front())
+	f := l.PushBack(2)
+	l.move(e, f)
+	assert.Equal(t, f, l.Front())
+	assert.Equal(t, e, l.Back())
+	assert.Equal(t, e, f.next)
+}
+
+func TestPushBackValue(t *testing.T) {
+	l := New[int]()
+	m := New[int]()
+	a := m.PushBack(5)
+	e := l.PushBack(1)
+	l.PushBackValue(a)
+	assert.Equal(t, a, l.Back())
+	assert.Equal(t, a, e.next)
+}
+
+func TestPushFrontValue(t *testing.T) {
+	l := New[int]()
+	m := New[int]()
+	a := m.PushBack(5)
+	e := l.PushBack(1)
+	l.PushFrontValue(a)
+	assert.Equal(t, a, l.Front())
+	assert.Equal(t, a, e.prev)
+}