tests/lib: Only use Arbitrary trait for randomness

Pre quickcheck v1.0 rand and quickcheck had to be updated in lock-step,
given that the latter makes use of traits of the former.

This commit decouples the two, only depending on quickcheck directly for
randomness. This will ease the transisition to quickcheck 1.0, see
BurntSushi/quickcheck#241.

tests/lib.rs

@@ -2,11 +2,10 @@ use data_encoding::HEXUPPER;
 use multihash::Multihash;
 use multiaddr::*;
 use quickcheck::{Arbitrary, Gen, QuickCheck};
-use rand::Rng;
 use std::{
     borrow::Cow,
-    convert::TryFrom,
-    iter::FromIterator,
+    convert::{TryFrom, TryInto},
+    iter::{FromIterator, self},
     net::{Ipv4Addr, Ipv6Addr},
     str::FromStr
 };
@@ -87,8 +86,8 @@ struct Proto(Protocol<'static>);
 impl Arbitrary for Proto {
     fn arbitrary<G: Gen>(g: &mut G) -> Self {
         use Protocol::*;
-        match g.gen_range(0, 25) { // TODO: Add Protocol::Quic
-             0 => Proto(Dccp(g.gen())),
+        match u8::arbitrary(g) % 25  { // TODO: Add Protocol::Quic
+             0 => Proto(Dccp(Arbitrary::arbitrary(g))),
              1 => Proto(Dns(Cow::Owned(SubString::arbitrary(g).0))),
              2 => Proto(Dns4(Cow::Owned(SubString::arbitrary(g).0))),
              3 => Proto(Dns6(Cow::Owned(SubString::arbitrary(g).0))),
@@ -99,28 +98,35 @@ impl Arbitrary for Proto {
              8 => Proto(P2pWebRtcDirect),
              9 => Proto(P2pWebRtcStar),
             10 => Proto(P2pWebSocketStar),
-            11 => Proto(Memory(g.gen())),
+            11 => Proto(Memory(Arbitrary::arbitrary(g))),
             // TODO: impl Arbitrary for Multihash:
             12 => Proto(P2p(multihash("QmcgpsyWgH8Y8ajJz1Cu72KnS5uo2Aa2LpzU7kinSupNKC"))),
             13 => Proto(P2pCircuit),
             14 => Proto(Quic),
-            15 => Proto(Sctp(g.gen())),
-            16 => Proto(Tcp(g.gen())),
-            17 => Proto(Udp(g.gen())),
+            15 => Proto(Sctp(Arbitrary::arbitrary(g))),
+            16 => Proto(Tcp(Arbitrary::arbitrary(g))),
+            17 => Proto(Udp(Arbitrary::arbitrary(g))),
             18 => Proto(Udt),
             19 => Proto(Unix(Cow::Owned(SubString::arbitrary(g).0))),
             20 => Proto(Utp),
             21 => Proto(Ws("/".into())),
             22 => Proto(Wss("/".into())),
             23 => {
-                let mut a = [0; 10];
-                g.fill(&mut a);
-                Proto(Onion(Cow::Owned(a), g.gen_range(1, std::u16::MAX)))
+
+                let a = iter::repeat_with(|| u8::arbitrary(g))
+                    .take(10)
+                    .collect::<Vec<_>>()
+                    .try_into()
+                    .unwrap();
+                Proto(Onion(Cow::Owned(a), std::cmp::max(1, u16::arbitrary(g))))
             },
             24 => {
-                let mut a = [0; 35];
-                g.fill_bytes(&mut a);
-                Proto(Onion3((a, g.gen_range(1, std::u16::MAX)).into()))
+                let a: [u8;35] = iter::repeat_with(|| u8::arbitrary(g))
+                    .take(35)
+                    .collect::<Vec<_>>()
+                    .try_into()
+                    .unwrap();
+                Proto(Onion3((a, std::cmp::max(1, u16::arbitrary(g))).into()))
             },
              _ => panic!("outside range")
         }