feat: utility to generate random strings

src/utils/mod.rs

@@ -0,0 +1,5 @@
+// SPDX-FileCopyrightText: 2024 Aravinth Manivannan <realaravinth@batsense.net>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+pub mod random_string;

src/utils/random_string.rs

@@ -0,0 +1,68 @@
+// SPDX-FileCopyrightText: 2024 Aravinth Manivannan <realaravinth@batsense.net>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use std::sync::Arc;
+
+use actix_web::web;
+use mockall::predicate::*;
+use mockall::*;
+
+pub type WebGenerateRandomStringInterface = web::Data<Arc<dyn GenerateRandomStringInterface>>;
+
+#[automock]
+pub trait GenerateRandomStringInterface: Send + Sync {
+    fn get_random(&self, len: usize) -> String;
+}
+
+pub struct GenerateRandomString;
+impl GenerateRandomStringInterface for GenerateRandomString {
+    fn get_random(&self, len: usize) -> String {
+        use std::iter;
+
+        use rand::{distributions::Alphanumeric, rngs::ThreadRng, thread_rng, Rng};
+
+        let mut rng: ThreadRng = thread_rng();
+
+        iter::repeat(())
+            .map(|()| rng.sample(Alphanumeric))
+            .map(char::from)
+            .take(len)
+            .collect::<String>()
+    }
+}
+
+impl GenerateRandomString {
+    pub fn inject() -> impl FnOnce(&mut web::ServiceConfig) {
+        let g = WebGenerateRandomStringInterface::new(Arc::new(GenerateRandomString));
+        let f = move |cfg: &mut web::ServiceConfig| {
+            cfg.app_data(g);
+        };
+
+        Box::new(f)
+    }
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+
+    use std::sync::Arc;
+
+    pub fn mock_generate_random_string(
+        times: Option<usize>,
+        returning: String,
+    ) -> Arc<dyn GenerateRandomStringInterface> {
+        let mut m = MockGenerateRandomStringInterface::new();
+
+        if let Some(times) = times {
+            m.expect_get_random()
+                .times(times)
+                .return_const(returning.to_string());
+        } else {
+            m.expect_get_random().return_const(returning.to_string());
+        }
+
+        Arc::new(m)
+    }
+}