feat: Email syntax validation

Cargo.toml

@@ -18,7 +18,15 @@ tokio = { version = "1", features = ["macros", "rt-multi-thread"] }
 serde = "1.0.115"
 config = { version = "0.13", default-features = false, features = ["yaml"] }
 uuid = { version = "1", features = ["v4"] }
-sqlx = { version = "0.6", default-features = false, features = ["runtime-actix-rustls", "macros", "postgres", "uuid", "chrono", "migrate", "offline"] }
+sqlx = { version = "0.6", default-features = false, features = [
+    "runtime-actix-rustls",
+    "macros",
+    "postgres",
+    "uuid",
+    "chrono",
+    "migrate",
+    "offline",
+] }
 chrono = { version = "0.4.22", default-features = false, features = ["clock"] }
 tracing = { version = "0.1", features = ["log"] }
 tracing-subscriber = { version = "0.3", features = ["registry", "env-filter"] }
@@ -30,8 +38,10 @@ tracing-actix-web = "0.7"
 serde-aux = "4"
 unicode-segmentation = "1"
 claim = "0.5.0"
+validator = "0.16.1"
 
 [dev-dependencies]
 reqwest = { version = "0.11", features = ["json"] }
-
-
+fake = "~2.3"
+quickcheck = "0.9.2"
+quickcheck_macros = "0.9.1"

src/domain/mod.rs

@@ -0,0 +1,7 @@
+pub mod new_subscriber;
+pub mod subscriber_email;
+pub mod subscriber_name;
+
+pub use new_subscriber::NewSubscriber;
+pub use subscriber_email::SubscriberEmail;
+pub use subscriber_name::SubscriberName;

src/domain/new_subscriber.rs

@@ -0,0 +1,8 @@
+use crate::domain::subscriber_name::SubscriberName;
+
+use super::SubscriberEmail;
+
+pub struct NewSubscriber {
+    pub email: SubscriberEmail,
+    pub name: SubscriberName,
+}

src/domain/subscriber_email.rs

@@ -0,0 +1,60 @@
+use validator::validate_email;
+
+#[derive(Debug)]
+pub struct SubscriberEmail(String);
+
+impl SubscriberEmail {
+    pub fn parse(s: String) -> Result<SubscriberEmail, String> {
+        if validate_email(&s) {
+            Ok(Self(s))
+        } else {
+            Err(format!("{} is not a valid subscriber email", s))
+        }
+    }
+}
+
+impl AsRef<str> for SubscriberEmail {
+    fn as_ref(&self) -> &str {
+        &self.0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::SubscriberEmail;
+    use claim::assert_err;
+    use fake::{faker::internet::en::SafeEmail, Fake};
+
+    #[test]
+    fn empty_string_is_rejected() {
+        let email = "".to_string();
+        assert_err!(SubscriberEmail::parse(email));
+    }
+
+    #[test]
+    fn email_missing_at_symbol_is_rejected() {
+        let email = "ursuladomain.com".to_string();
+        assert_err!(SubscriberEmail::parse(email));
+    }
+
+    #[test]
+    fn email_missing_subject_is_rejected() {
+        let email = "@domain.com".to_string();
+        assert_err!(SubscriberEmail::parse(email));
+    }
+
+    #[derive(Debug, Clone)]
+    struct ValidEmailFixture(pub String);
+
+    impl quickcheck::Arbitrary for ValidEmailFixture {
+        fn arbitrary<G: quickcheck::Gen>(g: &mut G) -> Self {
+            let email = SafeEmail().fake_with_rng(g);
+            Self(email)
+        }
+    }
+
+    #[quickcheck_macros::quickcheck]
+    fn valid_emails_are_parsed_successfully(valid_email: ValidEmailFixture) -> bool {
+        SubscriberEmail::parse(valid_email.0).is_ok()
+    }
+}