libaray

manager.go

/**
@author CuiZhouwei
@date 2022/7/28
**/
package library
import (
    "errors"
    "fmt"
)
type Music struct {
    Id     string
    Name   string
    Artist string
    Source string
    Type   string
}
type MusicManager struct {
    musics []Music
}
func NewMusicManager() *MusicManager {
    return &MusicManager{
        musics: make([]Music, 0),
    }
}
func (m *MusicManager) Len() int {
    return len(m.musics)
}
func (m *MusicManager) Get(index int) (music *Music, err error) {
    if index < 0 || index >= len(m.musics) {
        return nil, errors.New("index out of range ")
    }
    return &m.musics[index], nil
}
func (m *MusicManager) Find(name string) (int, *Music) {
    if len(m.musics) == 0 {
        return 0, nil
    }
    for k, music := range m.musics {
        if music.Name == name {
            return k, &music
        }
    }
    return 0, nil
}
func (m *MusicManager) Add(music *Music) {
    m.musics = append(m.musics, *music)
}
func (m *MusicManager) Remove(index int) *Music {
    if index < 0 || index >= len(m.musics) {
        fmt.Println("请重新选择删除的序号..")
        return nil
    }
    removeMusic := &m.musics[index]
    fmt.Printf("remove %s music already\n", removeMusic.Name)
    if index < len(m.musics)-1 {
        m.musics = append(m.musics[:index], m.musics[index+1:]...)
    } else if index == 0 {
        m.musics = m.musics[0:0] //make([]music,0)
    } else {
        m.musics = m.musics[:index]
    }
    return removeMusic
}
func (m *MusicManager) RemoveByName(name string) *Music {
    if len(m.musics) == 0 {
        return nil
    }
    index, music := m.Find(name)
    if music == nil {
        fmt.Printf("ths music %s did`t find", name)
    }
    m.Remove(index)
    return nil
}

manager_test.go

/**
@author CuiZhouwei
@date 2022/7/29
**/
package library
import (
    "testing"
)
func TestOps(t *testing.T) {
    mm := NewMusicManager()
    if  mm == nil {
        t.Error("NewMusicManager failed")
    }
    if mm.Len() != 0{
        t.Error("NewMusicManager falied,not empty.")
    }
    m0 := &Music{
        Id: "1",
        Name: "Take me to you heart",
        Artist: "Mike",
        Source: "http://qbox.me/2450123",
        Type: "MP3",
    }
    m1 := &Music{
        Id: "1",
        Name: "Take me to you heart",
        Artist: "Mike",
        Source: "http://qbox.me/2450123",
        Type: "MP3",
    }
    mm.Add(m0)
    mm.Add(m1)
    if mm.Len() != 2{
        t.Error("MusicManager.Add() failed.")
    }
    _,m := mm.Find(m0.Name)
    if m== nil{
        t.Error("MusicManager.Find().")
    }
    if m.Id  != m0.Id||m.Artist != m0.Artist ||
        m.Type != m0.Type || m.Name != m0.Name ||m.Source != m0.Source{
        t.Error("MusicManager.Find() failed.Found item mismatch.")
    }
    m ,err:= mm.Get(0)
    if m== nil {
        t.Error("MusicManger.Get() failed.",err)
    }
    m = mm.Remove(0)
    if m == nil || mm.Len() != 1 {
        t.Error("musicmanager.Remove failed.",err)
    }
    m = mm.RemoveByName(m0.Name)
    if m == nil || mm.Len() != 0 {
        t.Error("musicmanager.Remove failed.",err)
    }
}