diff options
Diffstat (limited to 'rand/rand_xorshift/tests')
-rw-r--r-- | rand/rand_xorshift/tests/mod.rs | 92 |
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()); + } +} |