1 files changed, 1210 insertions, 0 deletions
diff --git a/third_party/rust/bytes/tests/test_bytes.rs b/third_party/rust/bytes/tests/test_bytes.rs
new file mode 100644
index 0000000000..5ec60a5b0e
--- /dev/null
+++ b/third_party/rust/bytes/tests/test_bytes.rs
@@ -0,0 +1,1210 @@
+#![warn(rust_2018_idioms)]
+
+use bytes::{Buf, BufMut, Bytes, BytesMut};
+
+use std::usize;
+
+const LONG: &[u8] = b"mary had a little lamb, little lamb, little lamb";
+const SHORT: &[u8] = b"hello world";
+
+fn is_sync<T: Sync>() {}
+fn is_send<T: Send>() {}
+
+#[test]
+fn test_bounds() {
+    is_sync::<Bytes>();
+    is_sync::<BytesMut>();
+    is_send::<Bytes>();
+    is_send::<BytesMut>();
+}
+
+#[test]
+fn test_layout() {
+    use std::mem;
+
+    assert_eq!(
+        mem::size_of::<Bytes>(),
+        mem::size_of::<usize>() * 4,
+        "Bytes size should be 4 words",
+    );
+    assert_eq!(
+        mem::size_of::<BytesMut>(),
+        mem::size_of::<usize>() * 4,
+        "BytesMut should be 4 words",
+    );
+
+    assert_eq!(
+        mem::size_of::<Bytes>(),
+        mem::size_of::<Option<Bytes>>(),
+        "Bytes should be same size as Option<Bytes>",
+    );
+
+    assert_eq!(
+        mem::size_of::<BytesMut>(),
+        mem::size_of::<Option<BytesMut>>(),
+        "BytesMut should be same size as Option<BytesMut>",
+    );
+}
+
+#[test]
+fn from_slice() {
+    let a = Bytes::from(&b"abcdefgh"[..]);
+    assert_eq!(a, b"abcdefgh"[..]);
+    assert_eq!(a, &b"abcdefgh"[..]);
+    assert_eq!(a, Vec::from(&b"abcdefgh"[..]));
+    assert_eq!(b"abcdefgh"[..], a);
+    assert_eq!(&b"abcdefgh"[..], a);
+    assert_eq!(Vec::from(&b"abcdefgh"[..]), a);
+
+    let a = BytesMut::from(&b"abcdefgh"[..]);
+    assert_eq!(a, b"abcdefgh"[..]);
+    assert_eq!(a, &b"abcdefgh"[..]);
+    assert_eq!(a, Vec::from(&b"abcdefgh"[..]));
+    assert_eq!(b"abcdefgh"[..], a);
+    assert_eq!(&b"abcdefgh"[..], a);
+    assert_eq!(Vec::from(&b"abcdefgh"[..]), a);
+}
+
+#[test]
+fn fmt() {
+    let a = format!("{:?}", Bytes::from(&b"abcdefg"[..]));
+    let b = "b\"abcdefg\"";
+
+    assert_eq!(a, b);
+
+    let a = format!("{:?}", BytesMut::from(&b"abcdefg"[..]));
+    assert_eq!(a, b);
+}
+
+#[test]
+fn fmt_write() {
+    use std::fmt::Write;
+    use std::iter::FromIterator;
+    let s = String::from_iter((0..10).map(|_| "abcdefg"));
+
+    let mut a = BytesMut::with_capacity(64);
+    write!(a, "{}", &s[..64]).unwrap();
+    assert_eq!(a, s[..64].as_bytes());
+
+    let mut b = BytesMut::with_capacity(64);
+    write!(b, "{}", &s[..32]).unwrap();
+    write!(b, "{}", &s[32..64]).unwrap();
+    assert_eq!(b, s[..64].as_bytes());
+
+    let mut c = BytesMut::with_capacity(64);
+    write!(c, "{}", s).unwrap();
+    assert_eq!(c, s[..].as_bytes());
+}
+
+#[test]
+fn len() {
+    let a = Bytes::from(&b"abcdefg"[..]);
+    assert_eq!(a.len(), 7);
+
+    let a = BytesMut::from(&b"abcdefg"[..]);
+    assert_eq!(a.len(), 7);
+
+    let a = Bytes::from(&b""[..]);
+    assert!(a.is_empty());
+
+    let a = BytesMut::from(&b""[..]);
+    assert!(a.is_empty());
+}
+
+#[test]
+fn index() {
+    let a = Bytes::from(&b"hello world"[..]);
+    assert_eq!(a[0..5], *b"hello");
+}
+
+#[test]
+fn slice() {
+    let a = Bytes::from(&b"hello world"[..]);
+
+    let b = a.slice(3..5);
+    assert_eq!(b, b"lo"[..]);
+
+    let b = a.slice(0..0);
+    assert_eq!(b, b""[..]);
+
+    let b = a.slice(3..3);
+    assert_eq!(b, b""[..]);
+
+    let b = a.slice(a.len()..a.len());
+    assert_eq!(b, b""[..]);
+
+    let b = a.slice(..5);
+    assert_eq!(b, b"hello"[..]);
+
+    let b = a.slice(3..);
+    assert_eq!(b, b"lo world"[..]);
+}
+
+#[test]
+#[should_panic]
+fn slice_oob_1() {
+    let a = Bytes::from(&b"hello world"[..]);
+    a.slice(5..44);
+}
+
+#[test]
+#[should_panic]
+fn slice_oob_2() {
+    let a = Bytes::from(&b"hello world"[..]);
+    a.slice(44..49);
+}
+
+#[test]
+fn split_off() {
+    let mut hello = Bytes::from(&b"helloworld"[..]);
+    let world = hello.split_off(5);
+
+    assert_eq!(hello, &b"hello"[..]);
+    assert_eq!(world, &b"world"[..]);
+
+    let mut hello = BytesMut::from(&b"helloworld"[..]);
+    let world = hello.split_off(5);
+
+    assert_eq!(hello, &b"hello"[..]);
+    assert_eq!(world, &b"world"[..]);
+}
+
+#[test]
+#[should_panic]
+fn split_off_oob() {
+    let mut hello = Bytes::from(&b"helloworld"[..]);
+    let _ = hello.split_off(44);
+}
+
+#[test]
+fn split_off_uninitialized() {
+    let mut bytes = BytesMut::with_capacity(1024);
+    let other = bytes.split_off(128);
+
+    assert_eq!(bytes.len(), 0);
+    assert_eq!(bytes.capacity(), 128);
+
+    assert_eq!(other.len(), 0);
+    assert_eq!(other.capacity(), 896);
+}
+
+#[test]
+fn split_off_to_loop() {
+    let s = b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+    for i in 0..(s.len() + 1) {
+        {
+            let mut bytes = Bytes::from(&s[..]);
+            let off = bytes.split_off(i);
+            assert_eq!(i, bytes.len());
+            let mut sum = Vec::new();
+            sum.extend(bytes.iter());
+            sum.extend(off.iter());
+            assert_eq!(&s[..], &sum[..]);
+        }
+        {
+            let mut bytes = BytesMut::from(&s[..]);
+            let off = bytes.split_off(i);
+            assert_eq!(i, bytes.len());
+            let mut sum = Vec::new();
+            sum.extend(&bytes);
+            sum.extend(&off);
+            assert_eq!(&s[..], &sum[..]);
+        }
+        {
+            let mut bytes = Bytes::from(&s[..]);
+            let off = bytes.split_to(i);
+            assert_eq!(i, off.len());
+            let mut sum = Vec::new();
+            sum.extend(off.iter());
+            sum.extend(bytes.iter());
+            assert_eq!(&s[..], &sum[..]);
+        }
+        {
+            let mut bytes = BytesMut::from(&s[..]);
+            let off = bytes.split_to(i);
+            assert_eq!(i, off.len());
+            let mut sum = Vec::new();
+            sum.extend(&off);
+            sum.extend(&bytes);
+            assert_eq!(&s[..], &sum[..]);
+        }
+    }
+}
+
+#[test]
+fn split_to_1() {
+    // Static
+    let mut a = Bytes::from_static(SHORT);
+    let b = a.split_to(4);
+
+    assert_eq!(SHORT[4..], a);
+    assert_eq!(SHORT[..4], b);
+
+    // Allocated
+    let mut a = Bytes::copy_from_slice(LONG);
+    let b = a.split_to(4);
+
+    assert_eq!(LONG[4..], a);
+    assert_eq!(LONG[..4], b);
+
+    let mut a = Bytes::copy_from_slice(LONG);
+    let b = a.split_to(30);
+
+    assert_eq!(LONG[30..], a);
+    assert_eq!(LONG[..30], b);
+}
+
+#[test]
+fn split_to_2() {
+    let mut a = Bytes::from(LONG);
+    assert_eq!(LONG, a);
+
+    let b = a.split_to(1);
+
+    assert_eq!(LONG[1..], a);
+    drop(b);
+}
+
+#[test]
+#[should_panic]
+fn split_to_oob() {
+    let mut hello = Bytes::from(&b"helloworld"[..]);
+    let _ = hello.split_to(33);
+}
+
+#[test]
+#[should_panic]
+fn split_to_oob_mut() {
+    let mut hello = BytesMut::from(&b"helloworld"[..]);
+    let _ = hello.split_to(33);
+}
+
+#[test]
+#[should_panic]
+fn split_to_uninitialized() {
+    let mut bytes = BytesMut::with_capacity(1024);
+    let _other = bytes.split_to(128);
+}
+
+#[test]
+fn split_off_to_at_gt_len() {
+    fn make_bytes() -> Bytes {
+        let mut bytes = BytesMut::with_capacity(100);
+        bytes.put_slice(&[10, 20, 30, 40]);
+        bytes.freeze()
+    }
+
+    use std::panic;
+
+    let _ = make_bytes().split_to(4);
+    let _ = make_bytes().split_off(4);
+
+    assert!(panic::catch_unwind(move || {
+        let _ = make_bytes().split_to(5);
+    })
+    .is_err());
+
+    assert!(panic::catch_unwind(move || {
+        let _ = make_bytes().split_off(5);
+    })
+    .is_err());
+}
+
+#[test]
+fn truncate() {
+    let s = &b"helloworld"[..];
+    let mut hello = Bytes::from(s);
+    hello.truncate(15);
+    assert_eq!(hello, s);
+    hello.truncate(10);
+    assert_eq!(hello, s);
+    hello.truncate(5);
+    assert_eq!(hello, "hello");
+}
+
+#[test]
+fn freeze_clone_shared() {
+    let s = &b"abcdefgh"[..];
+    let b = BytesMut::from(s).split().freeze();
+    assert_eq!(b, s);
+    let c = b.clone();
+    assert_eq!(c, s);
+}
+
+#[test]
+fn freeze_clone_unique() {
+    let s = &b"abcdefgh"[..];
+    let b = BytesMut::from(s).freeze();
+    assert_eq!(b, s);
+    let c = b.clone();
+    assert_eq!(c, s);
+}
+
+#[test]
+fn freeze_after_advance() {
+    let s = &b"abcdefgh"[..];
+    let mut b = BytesMut::from(s);
+    b.advance(1);
+    assert_eq!(b, s[1..]);
+    let b = b.freeze();
+    // Verify fix for #352. Previously, freeze would ignore the start offset
+    // for BytesMuts in Vec mode.
+    assert_eq!(b, s[1..]);
+}
+
+#[test]
+fn freeze_after_advance_arc() {
+    let s = &b"abcdefgh"[..];
+    let mut b = BytesMut::from(s);
+    // Make b Arc
+    let _ = b.split_to(0);
+    b.advance(1);
+    assert_eq!(b, s[1..]);
+    let b = b.freeze();
+    assert_eq!(b, s[1..]);
+}
+
+#[test]
+fn freeze_after_split_to() {
+    let s = &b"abcdefgh"[..];
+    let mut b = BytesMut::from(s);
+    let _ = b.split_to(1);
+    assert_eq!(b, s[1..]);
+    let b = b.freeze();
+    assert_eq!(b, s[1..]);
+}
+
+#[test]
+fn freeze_after_truncate() {
+    let s = &b"abcdefgh"[..];
+    let mut b = BytesMut::from(s);
+    b.truncate(7);
+    assert_eq!(b, s[..7]);
+    let b = b.freeze();
+    assert_eq!(b, s[..7]);
+}
+
+#[test]
+fn freeze_after_truncate_arc() {
+    let s = &b"abcdefgh"[..];
+    let mut b = BytesMut::from(s);
+    // Make b Arc
+    let _ = b.split_to(0);
+    b.truncate(7);
+    assert_eq!(b, s[..7]);
+    let b = b.freeze();
+    assert_eq!(b, s[..7]);
+}
+
+#[test]
+fn freeze_after_split_off() {
+    let s = &b"abcdefgh"[..];
+    let mut b = BytesMut::from(s);
+    let _ = b.split_off(7);
+    assert_eq!(b, s[..7]);
+    let b = b.freeze();
+    assert_eq!(b, s[..7]);
+}
+
+#[test]
+fn fns_defined_for_bytes_mut() {
+    let mut bytes = BytesMut::from(&b"hello world"[..]);
+
+    let _ = bytes.as_ptr();
+    let _ = bytes.as_mut_ptr();
+
+    // Iterator
+    let v: Vec<u8> = bytes.as_ref().iter().cloned().collect();
+    assert_eq!(&v[..], bytes);
+}
+
+#[test]
+fn reserve_convert() {
+    // Vec -> Vec
+    let mut bytes = BytesMut::from(LONG);
+    bytes.reserve(64);
+    assert_eq!(bytes.capacity(), LONG.len() + 64);
+
+    // Arc -> Vec
+    let mut bytes = BytesMut::from(LONG);
+    let a = bytes.split_to(30);
+
+    bytes.reserve(128);
+    assert!(bytes.capacity() >= bytes.len() + 128);
+
+    drop(a);
+}
+
+#[test]
+fn reserve_growth() {
+    let mut bytes = BytesMut::with_capacity(64);
+    bytes.put("hello world".as_bytes());
+    let _ = bytes.split();
+
+    bytes.reserve(65);
+    assert_eq!(bytes.capacity(), 117);
+}
+
+#[test]
+fn reserve_allocates_at_least_original_capacity() {
+    let mut bytes = BytesMut::with_capacity(1024);
+
+    for i in 0..1020 {
+        bytes.put_u8(i as u8);
+    }
+
+    let _other = bytes.split();
+
+    bytes.reserve(16);
+    assert_eq!(bytes.capacity(), 1024);
+}
+
+#[test]
+#[cfg_attr(miri, ignore)] // Miri is too slow
+fn reserve_max_original_capacity_value() {
+    const SIZE: usize = 128 * 1024;
+
+    let mut bytes = BytesMut::with_capacity(SIZE);
+
+    for _ in 0..SIZE {
+        bytes.put_u8(0u8);
+    }
+
+    let _other = bytes.split();
+
+    bytes.reserve(16);
+    assert_eq!(bytes.capacity(), 64 * 1024);
+}
+
+#[test]
+fn reserve_vec_recycling() {
+    let mut bytes = BytesMut::with_capacity(16);
+    assert_eq!(bytes.capacity(), 16);
+    let addr = bytes.as_ptr() as usize;
+    bytes.put("0123456789012345".as_bytes());
+    assert_eq!(bytes.as_ptr() as usize, addr);
+    bytes.advance(10);
+    assert_eq!(bytes.capacity(), 6);
+    bytes.reserve(8);
+    assert_eq!(bytes.capacity(), 16);
+    assert_eq!(bytes.as_ptr() as usize, addr);
+}
+
+#[test]
+fn reserve_in_arc_unique_does_not_overallocate() {
+    let mut bytes = BytesMut::with_capacity(1000);
+    let _ = bytes.split();
+
+    // now bytes is Arc and refcount == 1
+
+    assert_eq!(1000, bytes.capacity());
+    bytes.reserve(2001);
+    assert_eq!(2001, bytes.capacity());
+}
+
+#[test]
+fn reserve_in_arc_unique_doubles() {
+    let mut bytes = BytesMut::with_capacity(1000);
+    let _ = bytes.split();
+
+    // now bytes is Arc and refcount == 1
+
+    assert_eq!(1000, bytes.capacity());
+    bytes.reserve(1001);
+    assert_eq!(2000, bytes.capacity());
+}
+
+#[test]
+fn reserve_in_arc_unique_does_not_overallocate_after_split() {
+    let mut bytes = BytesMut::from(LONG);
+    let orig_capacity = bytes.capacity();
+    drop(bytes.split_off(LONG.len() / 2));
+
+    // now bytes is Arc and refcount == 1
+
+    let new_capacity = bytes.capacity();
+    bytes.reserve(orig_capacity - new_capacity);
+    assert_eq!(bytes.capacity(), orig_capacity);
+}
+
+#[test]
+fn reserve_in_arc_unique_does_not_overallocate_after_multiple_splits() {
+    let mut bytes = BytesMut::from(LONG);
+    let orig_capacity = bytes.capacity();
+    for _ in 0..10 {
+        drop(bytes.split_off(LONG.len() / 2));
+
+        // now bytes is Arc and refcount == 1
+
+        let new_capacity = bytes.capacity();
+        bytes.reserve(orig_capacity - new_capacity);
+    }
+    assert_eq!(bytes.capacity(), orig_capacity);
+}
+
+#[test]
+fn reserve_in_arc_nonunique_does_not_overallocate() {
+    let mut bytes = BytesMut::with_capacity(1000);
+    let _copy = bytes.split();
+
+    // now bytes is Arc and refcount == 2
+
+    assert_eq!(1000, bytes.capacity());
+    bytes.reserve(2001);
+    assert_eq!(2001, bytes.capacity());
+}
+
+/// This function tests `BytesMut::reserve_inner`, where `BytesMut` holds
+/// a unique reference to the shared vector and decide to reuse it
+/// by reallocating the `Vec`.
+#[test]
+fn reserve_shared_reuse() {
+    let mut bytes = BytesMut::with_capacity(1000);
+    bytes.put_slice(b"Hello, World!");
+    drop(bytes.split());
+
+    bytes.put_slice(b"!123ex123,sadchELLO,_wORLD!");
+    // Use split_off so that v.capacity() - self.cap != off
+    drop(bytes.split_off(9));
+    assert_eq!(&*bytes, b"!123ex123");
+
+    bytes.reserve(2000);
+    assert_eq!(&*bytes, b"!123ex123");
+    assert_eq!(bytes.capacity(), 2009);
+}
+
+#[test]
+fn extend_mut() {
+    let mut bytes = BytesMut::with_capacity(0);
+    bytes.extend(LONG);
+    assert_eq!(*bytes, LONG[..]);
+}
+
+#[test]
+fn extend_from_slice_mut() {
+    for &i in &[3, 34] {
+        let mut bytes = BytesMut::new();
+        bytes.extend_from_slice(&LONG[..i]);
+        bytes.extend_from_slice(&LONG[i..]);
+        assert_eq!(LONG[..], *bytes);
+    }
+}
+
+#[test]
+fn extend_mut_from_bytes() {
+    let mut bytes = BytesMut::with_capacity(0);
+    bytes.extend([Bytes::from(LONG)]);
+    assert_eq!(*bytes, LONG[..]);
+}
+
+#[test]
+fn extend_mut_without_size_hint() {
+    let mut bytes = BytesMut::with_capacity(0);
+    let mut long_iter = LONG.iter();
+
+    // Use iter::from_fn since it doesn't know a size_hint
+    bytes.extend(std::iter::from_fn(|| long_iter.next()));
+    assert_eq!(*bytes, LONG[..]);
+}
+
+#[test]
+fn from_static() {
+    let mut a = Bytes::from_static(b"ab");
+    let b = a.split_off(1);
+
+    assert_eq!(a, b"a"[..]);
+    assert_eq!(b, b"b"[..]);
+}
+
+#[test]
+fn advance_static() {
+    let mut a = Bytes::from_static(b"hello world");
+    a.advance(6);
+    assert_eq!(a, &b"world"[..]);
+}
+
+#[test]
+fn advance_vec() {
+    let mut a = Bytes::from(b"hello world boooo yah world zomg wat wat".to_vec());
+    a.advance(16);
+    assert_eq!(a, b"o yah world zomg wat wat"[..]);
+
+    a.advance(4);
+    assert_eq!(a, b"h world zomg wat wat"[..]);
+
+    a.advance(6);
+    assert_eq!(a, b"d zomg wat wat"[..]);
+}
+
+#[test]
+fn advance_bytes_mut() {
+    let mut a = BytesMut::from("hello world boooo yah world zomg wat wat");
+    a.advance(16);
+    assert_eq!(a, b"o yah world zomg wat wat"[..]);
+
+    a.advance(4);
+    assert_eq!(a, b"h world zomg wat wat"[..]);
+
+    // Reserve some space.
+    a.reserve(1024);
+    assert_eq!(a, b"h world zomg wat wat"[..]);
+
+    a.advance(6);
+    assert_eq!(a, b"d zomg wat wat"[..]);
+}
+
+#[test]
+#[should_panic]
+fn advance_past_len() {
+    let mut a = BytesMut::from("hello world");
+    a.advance(20);
+}
+
+#[test]
+// Only run these tests on little endian systems. CI uses qemu for testing
+// big endian... and qemu doesn't really support threading all that well.
+#[cfg(any(miri, target_endian = "little"))]
+fn stress() {
+    // Tests promoting a buffer from a vec -> shared in a concurrent situation
+    use std::sync::{Arc, Barrier};
+    use std::thread;
+
+    const THREADS: usize = 8;
+    const ITERS: usize = if cfg!(miri) { 100 } else { 1_000 };
+
+    for i in 0..ITERS {
+        let data = [i as u8; 256];
+        let buf = Arc::new(Bytes::copy_from_slice(&data[..]));
+
+        let barrier = Arc::new(Barrier::new(THREADS));
+        let mut joins = Vec::with_capacity(THREADS);
+
+        for _ in 0..THREADS {
+            let c = barrier.clone();
+            let buf = buf.clone();
+
+            joins.push(thread::spawn(move || {
+                c.wait();
+                let buf: Bytes = (*buf).clone();
+                drop(buf);
+            }));
+        }
+
+        for th in joins {
+            th.join().unwrap();
+        }
+
+        assert_eq!(*buf, data[..]);
+    }
+}
+
+#[test]
+fn partial_eq_bytesmut() {
+    let bytes = Bytes::from(&b"The quick red fox"[..]);
+    let bytesmut = BytesMut::from(&b"The quick red fox"[..]);
+    assert!(bytes == bytesmut);
+    assert!(bytesmut == bytes);
+    let bytes2 = Bytes::from(&b"Jumped over the lazy brown dog"[..]);
+    assert!(bytes2 != bytesmut);
+    assert!(bytesmut != bytes2);
+}
+
+/*
+#[test]
+fn bytes_unsplit_basic() {
+    let buf = Bytes::from(&b"aaabbbcccddd"[..]);
+
+    let splitted = buf.split_off(6);
+    assert_eq!(b"aaabbb", &buf[..]);
+    assert_eq!(b"cccddd", &splitted[..]);
+
+    buf.unsplit(splitted);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_empty_other() {
+    let buf = Bytes::from(&b"aaabbbcccddd"[..]);
+
+    // empty other
+    let other = Bytes::new();
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_empty_self() {
+    // empty self
+    let mut buf = Bytes::new();
+
+    let mut other = Bytes::with_capacity(64);
+    other.extend_from_slice(b"aaabbbcccddd");
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_arc_different() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeee");
+
+    buf.split_off(8); //arc
+
+    let mut buf2 = Bytes::with_capacity(64);
+    buf2.extend_from_slice(b"ccccddddeeee");
+
+    buf2.split_off(8); //arc
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_arc_non_contiguous() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeeeccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+
+    let buf3 = buf2.split_off(4); //arc
+
+    buf.unsplit(buf3);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_two_split_offs() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+    let buf3 = buf2.split_off(4); //arc
+
+    buf2.unsplit(buf3);
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_unsplit_overlapping_references() {
+    let mut buf = Bytes::with_capacity(64);
+    buf.extend_from_slice(b"abcdefghijklmnopqrstuvwxyz");
+    let mut buf0010 = buf.slice(0..10);
+    let buf1020 = buf.slice(10..20);
+    let buf0515 = buf.slice(5..15);
+    buf0010.unsplit(buf1020);
+    assert_eq!(b"abcdefghijklmnopqrst", &buf0010[..]);
+    assert_eq!(b"fghijklmno", &buf0515[..]);
+}
+*/
+
+#[test]
+fn bytes_mut_unsplit_basic() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaabbbcccddd");
+
+    let splitted = buf.split_off(6);
+    assert_eq!(b"aaabbb", &buf[..]);
+    assert_eq!(b"cccddd", &splitted[..]);
+
+    buf.unsplit(splitted);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_mut_unsplit_empty_other() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaabbbcccddd");
+
+    // empty other
+    let other = BytesMut::new();
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_mut_unsplit_empty_self() {
+    // empty self
+    let mut buf = BytesMut::new();
+
+    let mut other = BytesMut::with_capacity(64);
+    other.extend_from_slice(b"aaabbbcccddd");
+
+    buf.unsplit(other);
+    assert_eq!(b"aaabbbcccddd", &buf[..]);
+}
+
+#[test]
+fn bytes_mut_unsplit_other_keeps_capacity() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aabb");
+
+    // non empty other created "from" buf
+    let mut other = buf.split_off(buf.len());
+    other.extend_from_slice(b"ccddee");
+    buf.unsplit(other);
+
+    assert_eq!(buf.capacity(), 64);
+}
+
+#[test]
+fn bytes_mut_unsplit_empty_other_keeps_capacity() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aabbccddee");
+
+    // empty other created "from" buf
+    let other = buf.split_off(buf.len());
+    buf.unsplit(other);
+
+    assert_eq!(buf.capacity(), 64);
+}
+
+#[test]
+fn bytes_mut_unsplit_arc_different() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeee");
+
+    let _ = buf.split_off(8); //arc
+
+    let mut buf2 = BytesMut::with_capacity(64);
+    buf2.extend_from_slice(b"ccccddddeeee");
+
+    let _ = buf2.split_off(8); //arc
+
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_mut_unsplit_arc_non_contiguous() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbeeeeccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+
+    let buf3 = buf2.split_off(4); //arc
+
+    buf.unsplit(buf3);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn bytes_mut_unsplit_two_split_offs() {
+    let mut buf = BytesMut::with_capacity(64);
+    buf.extend_from_slice(b"aaaabbbbccccdddd");
+
+    let mut buf2 = buf.split_off(8); //arc
+    let buf3 = buf2.split_off(4); //arc
+
+    buf2.unsplit(buf3);
+    buf.unsplit(buf2);
+    assert_eq!(b"aaaabbbbccccdddd", &buf[..]);
+}
+
+#[test]
+fn from_iter_no_size_hint() {
+    use std::iter;
+
+    let mut expect = vec![];
+
+    let actual: Bytes = iter::repeat(b'x')
+        .scan(100, |cnt, item| {
+            if *cnt >= 1 {
+                *cnt -= 1;
+                expect.push(item);
+                Some(item)
+            } else {
+                None
+            }
+        })
+        .collect();
+
+    assert_eq!(&actual[..], &expect[..]);
+}
+
+fn test_slice_ref(bytes: &Bytes, start: usize, end: usize, expected: &[u8]) {
+    let slice = &(bytes.as_ref()[start..end]);
+    let sub = bytes.slice_ref(slice);
+    assert_eq!(&sub[..], expected);
+}
+
+#[test]
+fn slice_ref_works() {
+    let bytes = Bytes::from(&b"012345678"[..]);
+
+    test_slice_ref(&bytes, 0, 0, b"");
+    test_slice_ref(&bytes, 0, 3, b"012");
+    test_slice_ref(&bytes, 2, 6, b"2345");
+    test_slice_ref(&bytes, 7, 9, b"78");
+    test_slice_ref(&bytes, 9, 9, b"");
+}
+
+#[test]
+fn slice_ref_empty() {
+    let bytes = Bytes::from(&b""[..]);
+    let slice = &(bytes.as_ref()[0..0]);
+
+    let sub = bytes.slice_ref(slice);
+    assert_eq!(&sub[..], b"");
+}
+
+#[test]
+fn slice_ref_empty_subslice() {
+    let bytes = Bytes::from(&b"abcde"[..]);
+    let subbytes = bytes.slice(0..0);
+    let slice = &subbytes[..];
+    // The `slice` object is derived from the original `bytes` object
+    // so `slice_ref` should work.
+    assert_eq!(Bytes::new(), bytes.slice_ref(slice));
+}
+
+#[test]
+#[should_panic]
+fn slice_ref_catches_not_a_subset() {
+    let bytes = Bytes::from(&b"012345678"[..]);
+    let slice = &b"012345"[0..4];
+
+    bytes.slice_ref(slice);
+}
+
+#[test]
+fn slice_ref_not_an_empty_subset() {
+    let bytes = Bytes::from(&b"012345678"[..]);
+    let slice = &b""[0..0];
+
+    assert_eq!(Bytes::new(), bytes.slice_ref(slice));
+}
+
+#[test]
+fn empty_slice_ref_not_an_empty_subset() {
+    let bytes = Bytes::new();
+    let slice = &b"some other slice"[0..0];
+
+    assert_eq!(Bytes::new(), bytes.slice_ref(slice));
+}
+
+#[test]
+fn bytes_buf_mut_advance() {
+    let mut bytes = BytesMut::with_capacity(1024);
+
+    unsafe {
+        let ptr = bytes.chunk_mut().as_mut_ptr();
+        assert_eq!(1024, bytes.chunk_mut().len());
+
+        bytes.advance_mut(10);
+
+        let next = bytes.chunk_mut().as_mut_ptr();
+        assert_eq!(1024 - 10, bytes.chunk_mut().len());
+        assert_eq!(ptr.offset(10), next);
+
+        // advance to the end
+        bytes.advance_mut(1024 - 10);
+
+        // The buffer size is doubled
+        assert_eq!(1024, bytes.chunk_mut().len());
+    }
+}
+
+#[test]
+fn bytes_buf_mut_reuse_when_fully_consumed() {
+    use bytes::{Buf, BytesMut};
+    let mut buf = BytesMut::new();
+    buf.reserve(8192);
+    buf.extend_from_slice(&[0u8; 100][..]);
+
+    let p = &buf[0] as *const u8;
+    buf.advance(100);
+
+    buf.reserve(8192);
+    buf.extend_from_slice(b" ");
+
+    assert_eq!(&buf[0] as *const u8, p);
+}
+
+#[test]
+#[should_panic]
+fn bytes_reserve_overflow() {
+    let mut bytes = BytesMut::with_capacity(1024);
+    bytes.put_slice(b"hello world");
+
+    bytes.reserve(usize::MAX);
+}
+
+#[test]
+fn bytes_with_capacity_but_empty() {
+    // See https://github.com/tokio-rs/bytes/issues/340
+    let vec = Vec::with_capacity(1);
+    let _ = Bytes::from(vec);
+}
+
+#[test]
+fn bytes_put_bytes() {
+    let mut bytes = BytesMut::new();
+    bytes.put_u8(17);
+    bytes.put_bytes(19, 2);
+    assert_eq!([17, 19, 19], bytes.as_ref());
+}
+
+#[test]
+fn box_slice_empty() {
+    // See https://github.com/tokio-rs/bytes/issues/340
+    let empty: Box<[u8]> = Default::default();
+    let b = Bytes::from(empty);
+    assert!(b.is_empty());
+}
+
+#[test]
+fn bytes_into_vec() {
+    // Test kind == KIND_VEC
+    let content = b"helloworld";
+
+    let mut bytes = BytesMut::new();
+    bytes.put_slice(content);
+
+    let vec: Vec<u8> = bytes.into();
+    assert_eq!(&vec, content);
+
+    // Test kind == KIND_ARC, shared.is_unique() == True
+    let mut bytes = BytesMut::new();
+    bytes.put_slice(b"abcdewe23");
+    bytes.put_slice(content);
+
+    // Overwrite the bytes to make sure only one reference to the underlying
+    // Vec exists.
+    bytes = bytes.split_off(9);
+
+    let vec: Vec<u8> = bytes.into();
+    assert_eq!(&vec, content);
+
+    // Test kind == KIND_ARC, shared.is_unique() == False
+    let prefix = b"abcdewe23";
+
+    let mut bytes = BytesMut::new();
+    bytes.put_slice(prefix);
+    bytes.put_slice(content);
+
+    let vec: Vec<u8> = bytes.split_off(prefix.len()).into();
+    assert_eq!(&vec, content);
+
+    let vec: Vec<u8> = bytes.into();
+    assert_eq!(&vec, prefix);
+}
+
+#[test]
+fn test_bytes_into_vec() {
+    // Test STATIC_VTABLE.to_vec
+    let bs = b"1b23exfcz3r";
+    let vec: Vec<u8> = Bytes::from_static(bs).into();
+    assert_eq!(&*vec, bs);
+
+    // Test bytes_mut.SHARED_VTABLE.to_vec impl
+    eprintln!("1");
+    let mut bytes_mut: BytesMut = bs[..].into();
+
+    // Set kind to KIND_ARC so that after freeze, Bytes will use bytes_mut.SHARED_VTABLE
+    eprintln!("2");
+    drop(bytes_mut.split_off(bs.len()));
+
+    eprintln!("3");
+    let b1 = bytes_mut.freeze();
+    eprintln!("4");
+    let b2 = b1.clone();
+
+    eprintln!("{:#?}", (&*b1).as_ptr());
+
+    // shared.is_unique() = False
+    eprintln!("5");
+    assert_eq!(&*Vec::from(b2), bs);
+
+    // shared.is_unique() = True
+    eprintln!("6");
+    assert_eq!(&*Vec::from(b1), bs);
+
+    // Test bytes_mut.SHARED_VTABLE.to_vec impl where offset != 0
+    let mut bytes_mut1: BytesMut = bs[..].into();
+    let bytes_mut2 = bytes_mut1.split_off(9);
+
+    let b1 = bytes_mut1.freeze();
+    let b2 = bytes_mut2.freeze();
+
+    assert_eq!(Vec::from(b2), bs[9..]);
+    assert_eq!(Vec::from(b1), bs[..9]);
+}
+
+#[test]
+fn test_bytes_into_vec_promotable_even() {
+    let vec = vec![33u8; 1024];
+
+    // Test cases where kind == KIND_VEC
+    let b1 = Bytes::from(vec.clone());
+    assert_eq!(Vec::from(b1), vec);
+
+    // Test cases where kind == KIND_ARC, ref_cnt == 1
+    let b1 = Bytes::from(vec.clone());
+    drop(b1.clone());
+    assert_eq!(Vec::from(b1), vec);
+
+    // Test cases where kind == KIND_ARC, ref_cnt == 2
+    let b1 = Bytes::from(vec.clone());
+    let b2 = b1.clone();
+    assert_eq!(Vec::from(b1), vec);
+
+    // Test cases where vtable = SHARED_VTABLE, kind == KIND_ARC, ref_cnt == 1
+    assert_eq!(Vec::from(b2), vec);
+
+    // Test cases where offset != 0
+    let mut b1 = Bytes::from(vec.clone());
+    let b2 = b1.split_off(20);
+
+    assert_eq!(Vec::from(b2), vec[20..]);
+    assert_eq!(Vec::from(b1), vec[..20]);
+}
+
+#[test]
+fn test_bytes_vec_conversion() {
+    let mut vec = Vec::with_capacity(10);
+    vec.extend(b"abcdefg");
+    let b = Bytes::from(vec);
+    let v = Vec::from(b);
+    assert_eq!(v.len(), 7);
+    assert_eq!(v.capacity(), 10);
+
+    let mut b = Bytes::from(v);
+    b.advance(1);
+    let v = Vec::from(b);
+    assert_eq!(v.len(), 6);
+    assert_eq!(v.capacity(), 10);
+    assert_eq!(v.as_slice(), b"bcdefg");
+}
+
+#[test]
+fn test_bytes_mut_conversion() {
+    let mut b1 = BytesMut::with_capacity(10);
+    b1.extend(b"abcdefg");
+    let b2 = Bytes::from(b1);
+    let v = Vec::from(b2);
+    assert_eq!(v.len(), 7);
+    assert_eq!(v.capacity(), 10);
+
+    let mut b = Bytes::from(v);
+    b.advance(1);
+    let v = Vec::from(b);
+    assert_eq!(v.len(), 6);
+    assert_eq!(v.capacity(), 10);
+    assert_eq!(v.as_slice(), b"bcdefg");
+}
+
+#[test]
+fn test_bytes_capacity_len() {
+    for cap in 0..100 {
+        for len in 0..=cap {
+            let mut v = Vec::with_capacity(cap);
+            v.resize(len, 0);
+            let _ = Bytes::from(v);
+        }
+    }
+}