moved constants, size_utils, string_utils to shared

shared/src/utils/string_utils.rs

@@ -0,0 +1,74 @@
+use rand::Rng;
+
+pub trait Capitalize {
+    fn capitalize(&self) -> String;
+}
+
+// Implement the Capitalize trait for &str
+impl<T: AsRef<str>> Capitalize for T {
+    fn capitalize(&self) -> String {
+        let s = self.as_ref();
+        let mut chars = s.chars();
+        let first = chars
+            .next()
+            .map(|c| c.to_uppercase().collect::<String>())
+            .unwrap_or_default();
+        let rest = chars.as_str().to_lowercase();
+        first + &rest
+    }
+}
+
+pub fn get_trimmed_string(value: &Option<String>) -> Option<String> {
+    if let Some(v) = value {
+        let trimmed = v.trim();
+        if !trimmed.is_empty() {
+            return Some(trimmed.to_string());
+        }
+    }
+    None
+}
+
+pub fn generate_random_string(length: usize) -> String {
+    let charset = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+    let mut rng = rand::rng();
+
+    let random_string: String = (0..length)
+        .map(|_| {
+            let idx = rng.random_range(0..charset.len());
+            charset[idx] as char
+        })
+        .collect();
+
+    random_string
+}
+
+pub fn get_non_empty_str<'a>(first: &'a str, second: &'a str, third: &'a str) -> &'a str {
+    if !first.is_empty() {
+        first
+    } else if !second.is_empty() {
+        second
+    } else {
+        third
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use std::collections::HashSet;
+    use super::generate_random_string;
+
+    #[test]
+    fn test_generate_random_string() {
+        let mut strings = HashSet::new();
+        for _i in 0..100 {
+            strings.insert(generate_random_string(5));
+        }
+        assert_eq!(strings.len(), 100);
+    }
+
+    #[test]
+    fn test_capitalize() {
+        assert_eq!("hELLO".capitalize(), "Hello");
+    }
+
+}