Binary Agreement test updated to the proptest framework (#336)

* converted the BA test to net framework

* fixed lints and corrected docs

* seeded the Rng and removed logging

* allowed pass by value of binary_agreement argument

* handling of input via proptest and doc correction

tests/binary_agreement.rs

@@ -1,108 +1,140 @@
 #![deny(unused_must_use)]
-//! Tests of the Binary Agreement protocol. Only one proposer instance
-//! is tested. Each of the nodes in the simulated network run only one instance
-//! of Binary Agreement. This way we only test correctness of the protocol and not
-//! message dispatch between multiple proposers.
+//! Tests of the Binary Agreement protocol
+//!
+//! Each of the nodes in the simulated network runs one instance of Binary Agreement. This suffices
+//! to test correctness of the protocol.
 //!
 //! There are three properties that are tested:
 //!
-//! - Agreement: If any correct node outputs the bit b, then every correct node outputs b.
+//! - Agreement: If any correct node outputs the bit `b`, then every correct node outputs `b`.
 //!
 //! - Termination: If all correct nodes receive input, then every correct node outputs a bit.
 //!
-//! - Validity: If any correct node outputs b, then at least one correct node received b as input.
-//!
-//! TODO: Implement adversaries and send BVAL messages at different times.
+//! - Validity: If any correct node outputs `b`, then at least one correct node received `b` as
+//! input.
 
-extern crate env_logger;
+extern crate failure;
 extern crate hbbft;
-extern crate log;
+extern crate integer_sqrt;
+extern crate proptest;
 extern crate rand;
-extern crate rand_derive;
-extern crate serde_derive;
-extern crate threshold_crypto as crypto;
+extern crate threshold_crypto;
 
-mod network;
+pub mod net;
 
 use std::iter::once;
 use std::sync::Arc;
+use std::time;
 
-use log::info;
-use rand::Rng;
+use proptest::arbitrary::any;
+use proptest::{prelude::ProptestConfig, prop_compose, proptest, proptest_helper};
+use rand::{Rng, SeedableRng};
 
 use hbbft::binary_agreement::BinaryAgreement;
-use hbbft::NetworkInfo;
+use hbbft::DistAlgorithm;
 
-use network::{Adversary, MessageScheduler, NodeId, SilentAdversary, TestNetwork, TestNode};
+use net::adversary::ReorderingAdversary;
+use net::proptest::{gen_seed, NetworkDimension, TestRng, TestRngSeed};
+use net::{NetBuilder, NewNodeInfo, VirtualNet};
 
-fn test_binary_agreement<A: Adversary<BinaryAgreement<NodeId, u8>>>(
-    mut network: TestNetwork<A, BinaryAgreement<NodeId, u8>>,
+/// Test configuration for Binary Agreement tests.
+#[derive(Debug)]
+struct TestConfig {
+    /// The desired network dimension.
+    dimension: NetworkDimension,
+    /// Random number generator to be passed to subsystems.
+    seed: TestRngSeed,
+    /// Input to Binary Agreement instances that has the following meaning:
+    ///
+    /// - `Some(b)`: all instances receive `b` as input.
+    ///
+    /// - `None`: each instance receives a random `bool` as input.
     input: Option<bool>,
-) {
-    let ids: Vec<NodeId> = network.nodes.keys().cloned().collect();
-    for id in ids {
-        network.input(id, input.unwrap_or_else(rand::random));
-    }
+}
 
-    // Handle messages in random order until all nodes have output the proposed value.
-    while !network.nodes.values().all(TestNode::terminated) {
-        network.step();
+prop_compose! {
+    /// Strategy to generate a test configuration.
+    fn arb_config()
+        (
+            dimension in NetworkDimension::range(1, 50),
+            seed in gen_seed(),
+            input in any::<Option<bool>>(),
+        ) -> TestConfig
+    {
+        TestConfig { dimension, seed, input }
     }
-    // Verify that all instances output the same value.
-    let mut expected = input;
-    for node in network.nodes.values() {
-        if let Some(b) = expected {
-            assert!(once(&b).eq(node.outputs()));
-        } else {
-            assert_eq!(1, node.outputs().len());
-            expected = Some(node.outputs()[0]);
-        }
+}
+
+/// Proptest wrapper for `binary_agreement` that runs the test function on generated configurations.
+proptest!{
+    #![proptest_config(ProptestConfig {
+        cases: 1, .. ProptestConfig::default()
+    })]
+    #[test]
+    #[cfg_attr(feature = "cargo-clippy", allow(unnecessary_operation))]
+    fn run_binary_agreement(cfg in arb_config()) {
+        binary_agreement(cfg)
     }
-    assert!(expected.iter().eq(network.observer.outputs()));
 }
 
-fn test_binary_agreement_different_sizes<A, F>(new_adversary: F)
-where
-    A: Adversary<BinaryAgreement<NodeId, u8>>,
-    F: Fn(usize, usize) -> A,
-{
-    // This returns an error in all but the first test.
-    let _ = env_logger::try_init();
+type NodeId = u16;
+type Algo = BinaryAgreement<NodeId, u8>;
 
-    let mut rng = rand::thread_rng();
-    let sizes = (1..6)
-        .chain(once(rng.gen_range(6, 20)))
-        .chain(once(rng.gen_range(30, 50)));
-    for size in sizes {
-        let num_faulty_nodes = (size - 1) / 3;
-        let num_good_nodes = size - num_faulty_nodes;
-        for &input in &[None, Some(false), Some(true)] {
-            info!(
-                "Test start: {} good nodes and {} faulty nodes, input: {:?}",
-                num_good_nodes, num_faulty_nodes, input
-            );
-            let adversary = |_| new_adversary(num_good_nodes, num_faulty_nodes);
-            let new_ba = |netinfo: Arc<NetworkInfo<NodeId>>| {
-                BinaryAgreement::new(netinfo, 0).expect("Binary Agreement instance")
-            };
-            let network = TestNetwork::new(num_good_nodes, num_faulty_nodes, adversary, new_ba);
-            test_binary_agreement(network, input);
-            info!(
-                "Test success: {} good nodes and {} faulty nodes, input: {:?}",
-                num_good_nodes, num_faulty_nodes, input
-            );
+impl VirtualNet<Algo> {
+    fn test_binary_agreement<R>(&mut self, input: Option<bool>, mut rng: R)
+    where
+        R: Rng + 'static,
+    {
+        let ids: Vec<NodeId> = self.nodes().map(|n| *n.id()).collect();
+        for id in ids {
+            let _ = self.send_input(id, input.unwrap_or_else(|| rng.gen::<bool>()));
         }
-    }
-}
 
-#[test]
-fn test_binary_agreement_random_silent() {
-    let new_adversary = |_: usize, _: usize| SilentAdversary::new(MessageScheduler::Random);
-    test_binary_agreement_different_sizes(new_adversary);
+        // Handle messages in random order until all nodes have output the proposed value.
+        while !self.nodes().all(|node| node.algorithm().terminated()) {
+            let _ = self.crank_expect();
+        }
+        // Verify that all instances output the same value.
+        let mut expected = input;
+        for node in self.nodes() {
+            if let Some(b) = expected {
+                assert!(once(&b).eq(node.outputs()));
+            } else {
+                assert_eq!(1, node.outputs().len());
+                expected = Some(node.outputs()[0]);
+            }
+        }
+        // TODO: As soon as observers are added to the test framework, compare the expected output
+        // against the output of observers.
+    }
 }
 
-#[test]
-fn test_binary_agreement_first_silent() {
-    let new_adversary = |_: usize, _: usize| SilentAdversary::new(MessageScheduler::First);
-    test_binary_agreement_different_sizes(new_adversary);
+/// Tests Binary Agreement on a given configuration.
+#[cfg_attr(feature = "cargo-clippy", allow(needless_pass_by_value))]
+fn binary_agreement(cfg: TestConfig) {
+    let mut rng: TestRng = TestRng::from_seed(cfg.seed);
+    let size = cfg.dimension.size();
+    let num_faulty_nodes = cfg.dimension.faulty();
+    let num_good_nodes = size - num_faulty_nodes;
+    println!(
+        "Test start: {} good nodes and {} faulty nodes, input: {:?}",
+        num_good_nodes, num_faulty_nodes, cfg.input
+    );
+    // Create a network with `size` validators and one observer.
+    let mut net: VirtualNet<Algo> = NetBuilder::new(0..size as u16)
+        .num_faulty(num_faulty_nodes as usize)
+        .message_limit(10_000 * size as usize)
+        .time_limit(time::Duration::from_secs(30 * size as u64))
+        .rng(rng.gen::<TestRng>())
+        .adversary(ReorderingAdversary::new(rng.gen::<TestRng>()))
+        .using(move |node_info: NewNodeInfo<_>| {
+            BinaryAgreement::new(Arc::new(node_info.netinfo), 0)
+                .expect("Failed to create a BinaryAgreement instance.")
+        }).build()
+        .expect("Could not construct test network.");
+    net.test_binary_agreement(cfg.input, rng.gen::<TestRng>());
+    println!(
+        "Test success: {} good nodes and {} faulty nodes, input: {:?}",
+        num_good_nodes, num_faulty_nodes, cfg.input
+    );
 }