设置Cookie的最大使用期限； 失去最大年龄

Question

So.. I have this unit test:

func TestCookieVoodoo(t *testing.T) {
    req := httptest.NewRequest("GET", "/", nil)

    cookie := http.Cookie{Name: "potato", MaxAge: 1000}

    req.AddCookie(&cookie)

    cookieCopy, _ := req.Cookie("potato")

    println(fmt.Sprintf("Cookie orig: %v", cookie))
    println(fmt.Sprintf("Cookie Copy: %v", *cookieCopy))

    t.Fail()
}

When running it, the output is:

Cookie orig: {potato    0001-01-01 00:00:00 +0000 UTC  1000 false false 0  []}
Cookie copy: {potato    0001-01-01 00:00:00 +0000 UTC  0 false false 0  []}

Why does it loose the max age? (same thing happens when setting other cookie fields) Thanks

Answer 1

Because the Request.AddCookie only add key and value to the cookie string. the function is:

func (r *Request) AddCookie(c *Cookie) {
    s := fmt.Sprintf("%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value))
    if c := r.Header.Get("Cookie"); c != "" {
        r.Header.Set("Cookie", c+"; "+s)
    } else {
        r.Header.Set("Cookie", s)
    }
}

why?

1. this is the definition of cookie-string in RFC 6265
2. the Max-Age and other fields of cookie is used by client not server. they are config of client. for example: if the the cookie exprires, client doesn't send key=value to server. So the fields are ignored in request