1 files changed, 80 insertions, 0 deletions
diff --git a/rand/rand_os/tests/mod.rs b/rand/rand_os/tests/mod.rs
new file mode 100644
index 0000000..2130e16
--- /dev/null
+++ b/rand/rand_os/tests/mod.rs
@@ -0,0 +1,80 @@
+extern crate rand_os;
+
+use rand_os::rand_core::RngCore;
+use rand_os::OsRng;
+
+#[test]
+fn test_os_rng() {
+    let mut r = OsRng::new().unwrap();
+
+    r.next_u32();
+    r.next_u64();
+
+    let mut v1 = [0u8; 1000];
+    r.fill_bytes(&mut v1);
+
+    let mut v2 = [0u8; 1000];
+    r.fill_bytes(&mut v2);
+
+    let mut n_diff_bits = 0;
+    for i in 0..v1.len() {
+        n_diff_bits += (v1[i] ^ v2[i]).count_ones();
+    }
+
+    // Check at least 1 bit per byte differs. p(failure) < 1e-1000 with random input.
+    assert!(n_diff_bits >= v1.len() as u32);
+}
+
+#[test]
+fn test_os_rng_empty() {
+    let mut r = OsRng::new().unwrap();
+
+    let mut empty = [0u8; 0];
+    r.fill_bytes(&mut empty);
+}
+
+#[test]
+fn test_os_rng_huge() {
+    let mut r = OsRng::new().unwrap();
+
+    let mut huge = [0u8; 100_000];
+    r.fill_bytes(&mut huge);
+}
+
+#[cfg(not(any(target_arch = "wasm32", target_arch = "asmjs")))]
+#[test]
+fn test_os_rng_tasks() {
+    use std::sync::mpsc::channel;
+    use std::thread;
+
+    let mut txs = vec!();
+    for _ in 0..20 {
+        let (tx, rx) = channel();
+        txs.push(tx);
+
+        thread::spawn(move|| {
+            // wait until all the tasks are ready to go.
+            rx.recv().unwrap();
+
+            // deschedule to attempt to interleave things as much
+            // as possible (XXX: is this a good test?)
+            let mut r = OsRng::new().unwrap();
+            thread::yield_now();
+            let mut v = [0u8; 1000];
+
+            for _ in 0..100 {
+                r.next_u32();
+                thread::yield_now();
+                r.next_u64();
+                thread::yield_now();
+                r.fill_bytes(&mut v);
+                thread::yield_now();
+            }
+        });
+    }
+
+    // start all the tasks
+    for tx in txs.iter() {
+        tx.send(()).unwrap();
+    }
+}