I’m running into an issue with Golang’s coverage report where case statements within a switch block are marked as not covered, even though I have written tests that execute these cases. Is this a known issue with Go’s coverage tool, or am I missing something in my tests? How can I ensure that each case statement is accurately tracked in the coverage report?

Code:

func SanitizeMobile(mobile string) (string, serror.SError) {
    // Remove all non-digit characters
    var cleanedMobile strings.Builder

    for _, char := range mobile {
        if unicode.IsDigit(char) {
            cleanedMobile.WriteRune(char)
        }
    }

    mobile = cleanedMobile.String()

    switch {
    case len(mobile) < 10 || len(mobile) > 12:
        // After cleaning up all non-digits, mobile number cannot be greater than 12 digits in length
        return "", serror.New(serror.BadRequestError, InvalidMobile, nil)

    case len(mobile) == 10 && mobile[0] == '0':
        // In case mobile number is 10 digits long, we don't allow it to start with 0
        // As of now, first digit of the mobile number can only be 5,6,7,8,9 but we relax
        // this criteria a bit, to allow 1,2,3,4 as well.
        return "", serror.New(serror.BadRequestError, InvalidMobile, nil)

    case len(mobile) == 11 && mobile[0] != '0':
        return "", serror.New(serror.BadRequestError, InvalidMobile, nil)

    case len(mobile) == 12 && mobile[0:2] != "91":
        return "", serror.New(serror.BadRequestError, InvalidMobile, nil)

    default:
        break
    }

    return mobile[len(mobile)-constant.IndianMobileLen:], nil
}

Coverage report: