Add test vectors for Murmur3Hasher

Author: newAM

tests/murmur3.rs

@@ -0,0 +1,39 @@
+extern crate hash32;
+
+use hash32::Murmur3Hasher;
+use std::hash::Hasher;
+
+fn testcase(data: &[u8], expected_hash_value: u64) {
+    let mut hasher: Murmur3Hasher = Default::default();
+    hasher.write(data);
+    assert_eq!(hasher.finish(), expected_hash_value);
+}
+
+#[test]
+fn murmurhash3_vectors() {
+    // Test vectors are adapted from this gist
+    // https://gist.github.com/vladimirgamalyan/defb2482feefbf5c3ea25b14c557753b
+
+    // with zero data and zero seed, everything becomes zero
+    testcase(&[], 0);
+    // make sure 4-byte chunks use unsigned math
+    testcase(&[0xff, 0xff, 0xff, 0xff], 0x76293B50);
+    // Endian order. UInt32 should end up as 0x87654321
+    testcase(&[0x21, 0x43, 0x65, 0x87], 0xF55B516B);
+    // Only three bytes. Should end up as 0x654321
+    testcase(&[0x21, 0x43, 0x65], 0x7E4A8634);
+    // Only two bytes. Should end up as 0x4321
+    testcase(&[0x21, 0x43], 0xA0F7B07A);
+    // Only one byte. Should end up as 0x21
+    testcase(&[0x21], 0x72661CF4);
+    // Make sure compiler doesn't see zero and convert to null
+    testcase(&[0x00, 0x00, 0x00, 0x00], 0x2362F9DE);
+    testcase(&[0x00, 0x00, 0x00], 0x85F0B427);
+    testcase(&[0x00, 0x00], 0x30F4C306);
+    testcase(&[0x00], 0x514E28B7);
+
+    testcase(
+        "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq".as_bytes(),
+        0xEE925B90,
+    );
+}