Expose serial number certificate getter.

packages/hurl/src/http/certificate.rs

@@ -31,7 +31,7 @@ pub struct Certificate {
     issuer: Option<String>,
     start_date: Option<DateTime<Utc>>,
     expire_date: Option<DateTime<Utc>>,
-    pub serial_number: Option<String>,
+    serial_number: Option<String>,
     pub subject_alt_name: Option<String>,
 }
 
@@ -70,6 +70,10 @@ impl Certificate {
     pub fn expire_date(&self) -> Option<DateTime<Utc>> {
         self.expire_date
     }
+
+    pub fn serial_number(&self) -> Option<&String> {
+        self.serial_number.as_ref()
+    }
 }
 
 impl TryFrom<CertInfo> for Certificate {

packages/hurl/src/json/result.rs

@@ -454,7 +454,7 @@ impl CertificateJson {
             issuer: c.issuer().cloned(),
             start_date: c.start_date().map(|d| d.to_string()),
             expire_date: c.expire_date().map(|d| d.to_string()),
-            serial_number: c.serial_number.clone(),
+            serial_number: c.serial_number().cloned(),
             subject_alt_name: c.subject_alt_name.clone(),
         }
     }

packages/hurl/src/report/html/run.rs

@@ -147,7 +147,7 @@ fn get_call_html(
         if let Some(expire_date) = expire_date.as_ref() {
             values.push(("Expire Date", expire_date.as_str()));
         }
-        if let Some(serial_number) = certificate.serial_number.as_ref() {
+        if let Some(serial_number) = certificate.serial_number() {
             values.push(("Serial Number", serial_number.as_str()));
         }
         if let Some(subject_alt_name) = certificate.subject_alt_name.as_ref() {

packages/hurl/src/runner/query.rs

@@ -393,8 +393,7 @@ fn eval_query_certificate(
             CertificateAttributeName::StartDate => certificate.start_date().map(Value::Date),
             CertificateAttributeName::ExpireDate => certificate.expire_date().map(Value::Date),
             CertificateAttributeName::SerialNumber => certificate
-                .serial_number
-                .as_ref()
+                .serial_number()
                 .map(|it| Value::String(it.clone())),
             CertificateAttributeName::SubjectAltName => certificate
                 .subject_alt_name