aboutsummaryrefslogtreecommitdiff
path: root/rand/rand_xorshift/tests
diff options
context:
space:
mode:
Diffstat (limited to 'rand/rand_xorshift/tests')
-rw-r--r--rand/rand_xorshift/tests/mod.rs92
1 files changed, 92 insertions, 0 deletions
diff --git a/rand/rand_xorshift/tests/mod.rs b/rand/rand_xorshift/tests/mod.rs
new file mode 100644
index 0000000..8374b64
--- /dev/null
+++ b/rand/rand_xorshift/tests/mod.rs
@@ -0,0 +1,92 @@
+extern crate rand_core;
+extern crate rand_xorshift;
+#[cfg(all(feature="serde1", test))] extern crate bincode;
+
+use rand_core::{RngCore, SeedableRng};
+use rand_xorshift::XorShiftRng;
+
+#[test]
+fn test_xorshift_construction() {
+ // Test that various construction techniques produce a working RNG.
+ let seed = [1,2,3,4, 5,6,7,8, 9,10,11,12, 13,14,15,16];
+ let mut rng1 = XorShiftRng::from_seed(seed);
+ assert_eq!(rng1.next_u64(), 4325440999699518727);
+
+ let _rng2 = XorShiftRng::from_rng(rng1).unwrap();
+ // Note: we cannot test the state of _rng2 because from_rng does not
+ // fix Endianness. This is allowed in the trait specification.
+}
+
+#[test]
+fn test_xorshift_true_values() {
+ let seed = [16,15,14,13, 12,11,10,9, 8,7,6,5, 4,3,2,1];
+ let mut rng = XorShiftRng::from_seed(seed);
+
+ let mut results = [0u32; 9];
+ for i in results.iter_mut() { *i = rng.next_u32(); }
+ let expected: [u32; 9] = [
+ 2081028795, 620940381, 269070770, 16943764, 854422573, 29242889,
+ 1550291885, 1227154591, 271695242];
+ assert_eq!(results, expected);
+
+ let mut results = [0u64; 9];
+ for i in results.iter_mut() { *i = rng.next_u64(); }
+ let expected: [u64; 9] = [
+ 9247529084182843387, 8321512596129439293, 14104136531997710878,
+ 6848554330849612046, 343577296533772213, 17828467390962600268,
+ 9847333257685787782, 7717352744383350108, 1133407547287910111];
+ assert_eq!(results, expected);
+
+ let mut results = [0u8; 32];
+ rng.fill_bytes(&mut results);
+ let expected = [102, 57, 212, 16, 233, 130, 49, 183,
+ 158, 187, 44, 203, 63, 149, 45, 17,
+ 117, 129, 131, 160, 70, 121, 158, 155,
+ 224, 209, 192, 53, 10, 62, 57, 72];
+ assert_eq!(results, expected);
+}
+
+#[test]
+fn test_xorshift_zero_seed() {
+ // Xorshift does not work with an all zero seed.
+ // Assert it does not panic.
+ let seed = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0];
+ let mut rng = XorShiftRng::from_seed(seed);
+ let a = rng.next_u64();
+ let b = rng.next_u64();
+ assert!(a != 0);
+ assert!(b != a);
+}
+
+#[test]
+fn test_xorshift_clone() {
+ let seed = [1,2,3,4, 5,5,7,8, 8,7,6,5, 4,3,2,1];
+ let mut rng1 = XorShiftRng::from_seed(seed);
+ let mut rng2 = rng1.clone();
+ for _ in 0..16 {
+ assert_eq!(rng1.next_u64(), rng2.next_u64());
+ }
+}
+
+#[cfg(feature="serde1")]
+#[test]
+fn test_xorshift_serde() {
+ use bincode;
+ use std::io::{BufWriter, BufReader};
+
+ let seed = [1,2,3,4, 5,6,7,8, 9,10,11,12, 13,14,15,16];
+ let mut rng = XorShiftRng::from_seed(seed);
+
+ let buf: Vec<u8> = Vec::new();
+ let mut buf = BufWriter::new(buf);
+ bincode::serialize_into(&mut buf, &rng).expect("Could not serialize");
+
+ let buf = buf.into_inner().unwrap();
+ let mut read = BufReader::new(&buf[..]);
+ let mut deserialized: XorShiftRng = bincode::deserialize_from(&mut read)
+ .expect("Could not deserialize");
+
+ for _ in 0..16 {
+ assert_eq!(rng.next_u64(), deserialized.next_u64());
+ }
+}