chore: optimize rust program, add tests

leetcode/0929-unique-email-addresses/src/lib.rs

@@ -0,0 +1,57 @@
+use std::collections::HashSet;
+
+fn process_local_part(s: &str) -> String {
+    match s.find('+') {
+        Some(plus_index) => &s[0..plus_index],
+        None => s,
+    }
+    .replace('.', "")
+}
+
+#[cfg(test)]
+mod process_local_part_tests {
+    use super::process_local_part;
+
+    #[test]
+    fn processing_works() {
+        let result = process_local_part("a.b+c");
+        assert_eq!(result, "ab");
+    }
+
+    #[test]
+    fn processing_without_plus_works() {
+        let result = process_local_part("a.b");
+        assert_eq!(result, "ab");
+    }
+}
+
+pub fn num_unique_emails(emails: Vec<String>) -> i32 {
+    let mut unique_emails = HashSet::new();
+
+    for email in emails.iter() {
+        let parts: Vec<&str> = email.split('@').collect();
+        unique_emails.insert(format!("{}@{}", process_local_part(parts[0]), parts[1]));
+    }
+
+    unique_emails.len() as i32
+}
+
+#[cfg(test)]
+mod num_unique_emails_tests {
+    use super::num_unique_emails;
+
+    #[test]
+    fn num_unique_emails_is_correct() {
+        let result = num_unique_emails(
+            [
+                "test.email+alex@leetcode.com",
+                "test.e.mail+bob.cathy@leetcode.com",
+                "testemail+david@lee.tcode.com",
+            ]
+            .iter()
+            .map(|s| s.to_string())
+            .collect(),
+        );
+        assert_eq!(result, 2)
+    }
+}

leetcode/0929-unique-email-addresses/src/main.rs

@@ -1,29 +0,0 @@
-use std::collections::HashSet;
-
-pub fn num_unique_emails(emails: Vec<String>) -> i32 {
-    let mut unique_emails = HashSet::new();
-    
-    for email in emails.iter() {
-        let mut parts: Vec<String> = email
-            .split("@")
-            .map(|s| s.to_string())
-            .collect();
-        parts[0] = parts[0]
-            .replace(".", "")
-            .split("+")
-            .collect::<Vec<&str>>()[0]
-            .to_string();
-        unique_emails.insert(format!("{}@{}", parts[0], parts[1]));
-    }
-
-    unique_emails.len() as i32
-}
-
-fn main() {
-    let inp: Vec<String> = vec![
-        "test.email+alex@leetcode.com",
-        "test.e.mail+bob.cathy@leetcode.com",
-        "testemail+david@lee.tcode.com",
-    ].iter().map(|s| s.to_string()).collect();
-    println!("{}", num_unique_emails(inp));
-}