Golang测试资源如何清理 利用Cleanup和Teardown管理测试环境

func TestFileOperation(t *testing.T) {
    tempFile, err := os.CreateTemp("", "testfile-*.txt")
    if err != nil {
        t.Fatalf("failed to create temp file: %v", err)
    }
    // 注册清理函数，确保文件被关闭和删除
    t.Cleanup(func() {
        tempFile.Close()
        os.Remove(tempFile.Name())
        t.Logf("cleaned up temp file: %s", tempFile.Name())
    })

    // 写入一些内容
    _, err = tempFile.WriteString("hello world")
    if err != nil {
        t.Fatalf("failed to write to temp file: %v", err)
    }

    // 模拟读取或进一步操作
    // ...
}

package mypackage_test

import (
    "database/sql"
    "fmt"
    "log"
    "os"
    "testing"

    _ "github.com/go-sql-driver/mysql" // 假设使用MySQL
)

var testDB *sql.DB

func TestMain(m *testing.M) {
    // 设置环境变量或配置，连接测试数据库
    dbUser := os.Getenv("TEST_DB_USER")
    dbPass := os.Getenv("TEST_DB_PASS")
    dbHost := os.Getenv("TEST_DB_HOST")
    dbName := os.Getenv("TEST_DB_NAME")

    if dbUser == "" || dbPass == "" || dbHost == "" || dbName == "" {
        log.Fatal("TEST_DB_USER, TEST_DB_PASS, TEST_DB_HOST, TEST_DB_NAME environment variables must be set for database tests.")
    }

    dsn := fmt.Sprintf("%s:%s@tcp(%s)/%s?parseTime=true", dbUser, dbPass, dbHost, dbName)
    var err error
    testDB, err = sql.Open("mysql", dsn)
    if err != nil {
        log.Fatalf("could not connect to test database: %v", err)
    }
    if err = testDB.Ping(); err != nil {
        testDB.Close()
        log.Fatalf("could not ping test database: %v", err)
    }
    log.Println("Successfully connected to test database.")

    // 运行所有测试
    exitCode := m.Run()

    // 清理全局资源
    if testDB != nil {
        testDB.Close()
        log.Println("Closed test database connection.")
    }
    os.Exit(exitCode)
}

func TestDatabaseOperation(t *testing.T) {
    // 确保testDB可用
    if testDB == nil {
        t.Fatal("testDB is not initialized")
    }

    // 在这里进行数据库操作，并可以使用t.Cleanup()来清理特定测试的数据
    _, err := testDB.Exec("CREATE TABLE IF NOT EXISTS users (id INT PRIMARY KEY, name VARCHAR(255))")
    if err != nil {
        t.Fatalf("failed to create table: %v", err)
    }
    t.Cleanup(func() {
        _, err := testDB.Exec("DROP TABLE IF EXISTS users")
        if err != nil {
            t.Logf("failed to drop table in cleanup: %v", err) // Log instead of Fatal to not fail the cleanup itself
        }
    })

    // 插入数据
    _, err = testDB.Exec("INSERT INTO users (id, name) VALUES (?, ?)", 1, "Alice")
    if err != nil {
        t.Fatalf("failed to insert data: %v", err)
    }

    // 查询数据并断言
    var name string
    err = testDB.QueryRow("SELECT name FROM users WHERE id = ?", 1).Scan(&name)
    if err != nil {
        t.Fatalf("failed to query data: %v", err)
    }
    if name != "Alice" {
        t.Errorf("expected name Alice, got %s", name)
    }
}