Go语言changeEmail函数测试触发空指针异常求助

问题描述 #

运行Go测试时，TestChangeEmail测试用例执行失败，changeEmail函数触发空指针解引用的运行时panic。

测试代码 #

func TestChangeEmail(t *testing.T) {
    ctx := context.Background()
    InitTestContext(ctx)

    buf := bytes.Buffer{}
    enc := json.NewEncoder(&buf)
    enc.Encode(testProfile)
    // Create the request object with JWT
    req, err := http.NewRequestWithContext(ctx, "PUT", "http://localhost:8080/v1/profile/", &buf)
    if err != nil {
        t.Fatal(err)
    }

    //  // 1) Create the initial profile

    const sqlSelectAll = `SELECT * FROM "profiles" WHERE email = $1 ORDER BY "profiles"."id" LIMIT 1`
    const sqlCreate = `INSERT INTO "profiles" ("created_at","updated_at","deleted_at","display_name","email","email_verified","id") VALUES ($1,$2,$3,$4,$5,$6,$7) RETURNING "id"`
    expected := sqlmock.NewRows([]string{"id", "display_name", "email"}).AddRow(testProfile.ID, testProfile.DisplayName, testProfile.Email)
    mock.ExpectQuery(regexp.QuoteMeta(sqlSelectAll)).WithArgs(testProfile.Email).WillReturnError(fmt.Errorf("not found"))
    mock.ExpectBegin()
    mock.ExpectQuery(regexp.QuoteMeta(sqlCreate)).WithArgs(anyTime{}, anyTime{}, nil, testProfile.DisplayName, testProfile.Email, testProfile.EmailVerified, sqlmock.AnyArg()).WillReturnRows(expected)
    mock.ExpectCommit()

    newEmail := "test-changed@gmail.com"
    //  // 2) Change the initial profile's email
    const sqlUpdate = `UPDATE "profiles" SET "email"=$1 WHERE "email"=$2`
    mock.ExpectBegin()
    mock.ExpectExec(regexp.QuoteMeta(sqlUpdate)).WithArgs(newEmail, testProfile.Email).WillReturnResult(sqlmock.NewResult(0, 1))
    mock.ExpectCommit()

    if err := executeAndValidateRequest(req, http.StatusCreated); err != nil {
        t.Error(err)
    }
}

错误信息 #

--- FAIL: TestChangeEmail (0.00s) panic: runtime error: invalid memory address or nil pointer dereference [recovered] panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x2 addr=0x18 pc=0x102d2fc94]

堆栈跟踪 #

goroutine 4 [running]:
testing.tRunner.func1.2({0x1050f65e0, 0x105512000})
    /usr/local/go/src/testing/testing.go:1396 +0x1c8
testing.tRunner.func1()
    /usr/local/go/src/testing/testing.go:1399 +0x378
panic({0x1050f65e0, 0x105512000})
    /usr/local/go/src/runtime/panic.go:884 +0x204
gitlab/developers/server/profile.changeEmail({0x105199db8, 0x14000341e80}, 0x14000374600)
    /Users/example/Documents/project/server/profile/handlers.go:75 +0x44
net/http.HandlerFunc.ServeHTTP(0x14000374500?, {0x105199db8?, 0x14000341e80?}, 0x0?)
    /usr/local/go/src/net/http/server.go:2109 +0x38
github.com/gorilla/mux.(*Router).ServeHTTP(0x1400015a480, {0x105199db8, 0x14000341e80}, 0x14000374400)
    /Users/example/go/pkg/mod/github.com/gorilla/mux@v1.8.0/mux.go:210 +0x19c
gitlab/developers/server/profile.executeAndValidateRequest(0x14000247ce0?, 0x12?)
    /Users/example/Documents/project/server/profile/handlers_test.go:134 +0xbc
gitlab/developers/server/profile.TestChangeEmail(0x14000156d00)
    /Users/example/Documents/project/server/profile/handlers_test.go:282 +0x89c
testing.tRunner(0x14000156d00, 0x105191b28)
    /usr/local/go/src/testing/testing.go:1446 +0x10c
created by testing.(*T).Run
    /usr/local/go/src/testing/testing.go:1493 +0x300
FAIL    gitlab/developers/server/profile    0.145s
FAIL

问题分析与修复方向 #

1. 核心定位：panic发生在handlers.go第75行的changeEmail函数中，说明该行代码尝试解引用一个nil指针。
2. 关键疑点：
   • 测试代码中注释了"Create the request object with JWT"但未实际添加JWT头，导致后端无法解析出用户身份信息，changeEmail函数中访问用户对象字段时触发nil解引用。
   • changeEmail函数中可能存在未做nil判断的变量，比如从请求上下文获取的用户对象、数据库操作返回的结果等。
   • SQL mock的预期是否与实际代码逻辑匹配，比如实际changeEmail是否依赖前置查询，而mock未覆盖该路径导致代码进入错误分支。
3. 修复步骤：
   • 给测试请求添加有效JWT头，示例：

     req.Header.Set("Authorization", "Bearer "+testJWTToken)
     

     其中testJWTToken是预先生成的测试用有效token。
   • 检查handlers.go第75行代码，确认nil指针来源，添加nil判断或确保变量初始化完成。
   • 验证SQL mock语句与实际执行的SQL完全一致，避免因不匹配导致代码执行未预期路径。

内容的提问来源于stack exchange，提问作者Buluc-Chabtan