rust: Refactor protover tests with new methods; note altered behaviours.

Previously, the rust implementation of protover considered an empty string to be
a valid ProtoEntry, while the C version did not (it must have a "=" character).
Other differences include that unknown protocols must now be parsed as
`protover::UnknownProtocol`s, and hence their entries as
`protover::UnvalidatedProtoEntry`s, whereas before (nearly) all protoentries
could be parsed regardless of how erroneous they might be considered by the C
version.

My apologies for this somewhat messy and difficult to read commit, if any part
is frustrating to the reviewer, please feel free to ask me to split this into
smaller changes (possibly hard to do, since so much changed), or ask me to
comment on a specific line/change and clarify how/when the behaviours differ.

The tests here should more closely match the behaviours exhibited by the C
implementation, but I do not yet personally guarantee they match precisely.

 * REFACTOR unittests in protover::protover.
 * ADD new integration tests for previously untested behaviour.
 * FIXES part of #24031: https://bugs.torproject.org/24031.

1 files changed, 196 insertions, 159 deletions

diff --git a/src/rust/protover/tests/protover.rs b/src/rust/protover/tests/protover.rs
index f4e394b3e2..9f8b5a443a 100644
--- a/src/rust/protover/tests/protover.rs
+++ b/src/rust/protover/tests/protover.rs
@@ -3,289 +3,326 @@
 
 extern crate protover;
 
+use protover::ProtoEntry;
+use protover::ProtoverVote;
+use protover::UnvalidatedProtoEntry;
+
 #[test]
-fn parse_protocol_list_with_single_proto_and_single_version() {
-    let protocol = "Cons=1";
-    let (is_supported, unsupported) = protover::all_supported(protocol);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn parse_protocol_with_single_proto_and_single_version() {
+    let _: ProtoEntry = "Cons=1".parse().unwrap();
 }
 
 #[test]
-fn parse_protocol_list_with_single_protocol_and_multiple_versions() {
-    let protocol = "Cons=1-2";
-    let (is_supported, unsupported) = protover::all_supported(protocol);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn parse_protocol_with_single_protocol_and_multiple_versions() {
+    let _: ProtoEntry = "Cons=1-2".parse().unwrap();
 }
 
 #[test]
-fn parse_protocol_list_with_different_single_protocol_and_single_version() {
-    let protocol = "HSDir=1";
-    let (is_supported, unsupported) = protover::all_supported(protocol);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn parse_protocol_with_different_single_protocol_and_single_version() {
+    let _: ProtoEntry = "HSDir=1".parse().unwrap();
 }
 
 #[test]
-fn parse_protocol_list_with_single_protocol_and_supported_version() {
-    let protocol = "Desc=2";
-    let (is_supported, unsupported) = protover::all_supported(protocol);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn parse_protocol_with_single_protocol_and_supported_version() {
+    let _: ProtoEntry = "Desc=2".parse().unwrap();
 }
 
 #[test]
-fn parse_protocol_list_with_two_protocols_and_single_version() {
-    let protocols = "Cons=1 HSDir=1";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn parse_protocol_with_two_protocols_and_single_version() {
+    let _: ProtoEntry = "Cons=1 HSDir=1".parse().unwrap();
 }
 
-
 #[test]
-fn parse_protocol_list_with_single_protocol_and_two_nonsequential_versions() {
-    let protocol = "Desc=1,2";
-    let (is_supported, unsupported) = protover::all_supported(protocol);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn parse_protocol_with_single_protocol_and_two_sequential_versions() {
+    let _: ProtoEntry = "Desc=1-2".parse().unwrap();
 }
 
+#[test]
+fn parse_protocol_with_single_protocol_and_protocol_range() {
+    let _: ProtoEntry = "Link=1-4".parse().unwrap();
+}
 
 #[test]
-fn parse_protocol_list_with_single_protocol_and_two_sequential_versions() {
-    let protocol = "Desc=1-2";
-    let (is_supported, unsupported) = protover::all_supported(protocol);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn parse_protocol_with_single_protocol_and_protocol_set() {
+    let _: ProtoEntry = "Link=3-4 Desc=2".parse().unwrap();
 }
 
 #[test]
-fn parse_protocol_list_with_single_protocol_and_protocol_range_returns_set() {
-    let protocol = "Link=1-4";
-    let (is_supported, unsupported) = protover::all_supported(protocol);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn protocol_all_supported_with_single_protocol_and_protocol_set() {
+    let protocols: UnvalidatedProtoEntry = "Link=3-4 Desc=2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_none());
 }
 
 #[test]
-fn parse_protocol_list_with_single_protocol_and_protocol_set() {
-    let protocols = "Link=3-4 Desc=2";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+fn protocol_all_supported_with_two_values() {
+    let protocols: UnvalidatedProtoEntry = "Microdesc=1-2 Relay=2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_none());
 }
 
 #[test]
-fn protover_all_supported_with_two_values() {
-    let protocols = "Microdesc=1-2 Relay=2";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!("", &unsupported);
-    assert_eq!(true, is_supported);
+fn protocol_all_supported_with_one_value() {
+    let protocols: UnvalidatedProtoEntry = "Microdesc=1-2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_none());
 }
 
 #[test]
-fn protover_all_supported_with_one_value() {
-    let protocols = "Microdesc=1-2";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!("", &unsupported);
-    assert_eq!(true, is_supported);
+#[should_panic]
+fn parse_protocol_unvalidated_with_empty() {
+    let _: UnvalidatedProtoEntry = "".parse().unwrap();
 }
 
 #[test]
-fn protover_all_supported_with_empty() {
-    let protocols = "";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(true, is_supported);
-    assert_eq!("", &unsupported);
+#[should_panic]
+fn parse_protocol_validated_with_empty() {
+    let _: UnvalidatedProtoEntry = "".parse().unwrap();
 }
 
 #[test]
-fn protover_all_supported_with_three_values() {
-    let protocols = "LinkAuth=1 Microdesc=1-2 Relay=2";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!("", &unsupported);
-    assert_eq!(true, is_supported);
+fn protocol_all_supported_with_three_values() {
+    let protocols: UnvalidatedProtoEntry = "LinkAuth=1 Microdesc=1-2 Relay=2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_none());
 }
 
 #[test]
-fn protover_all_supported_with_unsupported_protocol() {
-    let protocols = "Wombat=9";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(false, is_supported);
-    assert_eq!("Wombat=9", &unsupported);
+fn protocol_all_supported_with_unsupported_protocol() {
+    let protocols: UnvalidatedProtoEntry = "Wombat=9".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_some());
+    assert_eq!("Wombat=9", &unsupported.unwrap().to_string());
 }
 
 #[test]
-fn protover_all_supported_with_unsupported_versions() {
-    let protocols = "Link=3-999";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(false, is_supported);
-    assert_eq!("Link=3-999", &unsupported);
+fn protocol_all_supported_with_unsupported_versions() {
+    let protocols: UnvalidatedProtoEntry = "Link=3-999".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_some());
+    assert_eq!("Link=6-999", &unsupported.unwrap().to_string());
 }
 
 #[test]
-fn protover_all_supported_with_unsupported_low_version() {
-    let protocols = "Cons=0-1";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(false, is_supported);
-    assert_eq!("Cons=0-1", &unsupported);
+fn protocol_all_supported_with_unsupported_low_version() {
+    let protocols: UnvalidatedProtoEntry = "Cons=0-1".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_some());
+    assert_eq!("Cons=0", &unsupported.unwrap().to_string());
 }
 
 #[test]
-fn protover_all_supported_with_unsupported_high_version() {
-    let protocols = "Cons=1-3";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(false, is_supported);
-    assert_eq!("Cons=1-3", &unsupported);
+fn protocol_all_supported_with_unsupported_high_version() {
+    let protocols: UnvalidatedProtoEntry = "Cons=1-2,999".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_some());
+    assert_eq!("Cons=999", &unsupported.unwrap().to_string());
 }
 
 #[test]
-fn protover_all_supported_with_mix_of_supported_and_unsupproted() {
-    let protocols = "Link=3-4 Wombat=9";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(false, is_supported);
-    assert_eq!("Wombat=9", &unsupported);
+fn protocol_all_supported_with_mix_of_supported_and_unsupproted() {
+    let protocols: UnvalidatedProtoEntry = "Link=3-4 Wombat=9".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_some());
+    assert_eq!("Wombat=9", &unsupported.unwrap().to_string());
 }
 
 #[test]
 fn protover_string_supports_protocol_returns_true_for_single_supported() {
-    let protocols = "Link=3-4 Cons=1";
-    let is_supported = protover::protover_string_supports_protocol(
-        protocols,
-        protover::Proto::Cons,
-        1,
-    );
+    let protocols: UnvalidatedProtoEntry = "Link=3-4 Cons=1".parse().unwrap();
+    let is_supported = protocols.supports_protocol(&protover::Protocol::Cons.into(), &1);
     assert_eq!(true, is_supported);
 }
 
 #[test]
 fn protover_string_supports_protocol_returns_false_for_single_unsupported() {
-    let protocols = "Link=3-4 Cons=1";
-    let is_supported = protover::protover_string_supports_protocol(
-        protocols,
-        protover::Proto::Cons,
-        2,
-    );
+    let protocols: UnvalidatedProtoEntry = "Link=3-4 Cons=1".parse().unwrap();
+    let is_supported = protocols.supports_protocol(&protover::Protocol::Cons.into(), &2);
     assert_eq!(false, is_supported);
 }
 
 #[test]
 fn protover_string_supports_protocol_returns_false_for_unsupported() {
-    let protocols = "Link=3-4";
-    let is_supported = protover::protover_string_supports_protocol(
-        protocols,
-        protover::Proto::Cons,
-        2,
-    );
+    let protocols: UnvalidatedProtoEntry = "Link=3-4".parse().unwrap();
+    let is_supported = protocols.supports_protocol(&protover::Protocol::Cons.into(), &2);
     assert_eq!(false, is_supported);
 }
 
 #[test]
-fn protover_all_supported_with_unexpected_characters() {
-    let protocols = "Cons=*-%";
-    let (is_supported, unsupported) = protover::all_supported(protocols);
-    assert_eq!(false, is_supported);
-    assert_eq!("Cons=*-%", &unsupported);
+#[should_panic]
+fn parse_protocol_with_unexpected_characters() {
+    let _: UnvalidatedProtoEntry = "Cons=*-%".parse().unwrap();
 }
 
 #[test]
+#[should_panic]
 fn protover_compute_vote_returns_empty_for_empty_string() {
-    let protocols = vec![String::from("")];
-    let listed = protover::compute_vote(protocols, 1);
-    assert_eq!("", listed);
+    let protocols: &[UnvalidatedProtoEntry] = &["".parse().unwrap()];
+    let listed = ProtoverVote::compute(protocols, &1);
+    assert_eq!("", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_returns_single_protocol_for_matching() {
-    let protocols = vec![String::from("Cons=1")];
-    let listed = protover::compute_vote(protocols, 1);
-    assert_eq!("Cons=1", listed);
+    let protocols: &[UnvalidatedProtoEntry] = &["Cons=1".parse().unwrap()];
+    let listed = ProtoverVote::compute(protocols, &1);
+    assert_eq!("Cons=1", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_returns_two_protocols_for_two_matching() {
-    let protocols = vec![String::from("Link=1 Cons=1")];
-    let listed = protover::compute_vote(protocols, 1);
-    assert_eq!("Cons=1 Link=1", listed);
+    let protocols: &[UnvalidatedProtoEntry] = &["Link=1 Cons=1".parse().unwrap()];
+    let listed = ProtoverVote::compute(protocols, &1);
+    assert_eq!("Cons=1 Link=1", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_returns_one_protocol_when_one_out_of_two_matches() {
-    let protocols = vec![String::from("Cons=1 Link=2"), String::from("Cons=1")];
-    let listed = protover::compute_vote(protocols, 2);
-    assert_eq!("Cons=1", listed);
+    let protocols: &[UnvalidatedProtoEntry] = &["Cons=1 Link=2".parse().unwrap(), "Cons=1".parse().unwrap()];
+    let listed = ProtoverVote::compute(protocols, &2);
+    assert_eq!("Cons=1", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_returns_protocols_that_it_doesnt_currently_support() {
-    let protocols = vec![String::from("Foo=1 Cons=2"), String::from("Bar=1")];
-    let listed = protover::compute_vote(protocols, 1);
-    assert_eq!("Bar=1 Cons=2 Foo=1", listed);
+    let protocols: &[UnvalidatedProtoEntry] = &["Foo=1 Cons=2".parse().unwrap(), "Bar=1".parse().unwrap()];
+    let listed = ProtoverVote::compute(protocols, &1);
+    assert_eq!("Bar=1 Cons=2 Foo=1", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_returns_matching_for_mix() {
-    let protocols = vec![String::from("Link=1-10,500 Cons=1,3-7,8")];
-    let listed = protover::compute_vote(protocols, 1);
-    assert_eq!("Cons=1,3-8 Link=1-10,500", listed);
+    let protocols: &[UnvalidatedProtoEntry] = &["Link=1-10,500 Cons=1,3-7,8".parse().unwrap()];
+    let listed = ProtoverVote::compute(protocols, &1);
+    assert_eq!("Cons=1,3-8 Link=1-10,500", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_returns_matching_for_longer_mix() {
-    let protocols = vec![
-        String::from("Desc=1-10,500 Cons=1,3-7,8"),
-        String::from("Link=123-456,78 Cons=2-6,8 Desc=9"),
+    let protocols: &[UnvalidatedProtoEntry] = &[
+        "Desc=1-10,500 Cons=1,3-7,8".parse().unwrap(),
+        "Link=123-456,78 Cons=2-6,8 Desc=9".parse().unwrap(),
     ];
 
-    let listed = protover::compute_vote(protocols, 1);
-    assert_eq!("Cons=1-8 Desc=1-10,500 Link=78,123-456", listed);
+    let listed = ProtoverVote::compute(protocols, &1);
+    assert_eq!("Cons=1-8 Desc=1-10,500 Link=78,123-456", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_returns_matching_for_longer_mix_with_threshold_two() {
-    let protocols = vec![
-        String::from("Desc=1-10,500 Cons=1,3-7,8"),
-        String::from("Link=123-456,78 Cons=2-6,8 Desc=9"),
+    let protocols: &[UnvalidatedProtoEntry] = &[
+        "Desc=1-10,500 Cons=1,3-7,8".parse().unwrap(),
+        "Link=123-456,78 Cons=2-6,8 Desc=9".parse().unwrap(),
     ];
 
-    let listed = protover::compute_vote(protocols, 2);
-    assert_eq!("Cons=3-6,8 Desc=9", listed);
+    let listed = ProtoverVote::compute(protocols, &2);
+    assert_eq!("Cons=3-6,8 Desc=9", listed.to_string());
 }
 
 #[test]
 fn protover_compute_vote_handles_duplicated_versions() {
-    let protocols = vec![String::from("Cons=1"), String::from("Cons=1")];
-    assert_eq!("Cons=1", protover::compute_vote(protocols, 2));
+    let protocols: &[UnvalidatedProtoEntry] = &["Cons=1".parse().unwrap(), "Cons=1".parse().unwrap()];
+    assert_eq!("Cons=1", ProtoverVote::compute(protocols, &2).to_string());
 
-    let protocols = vec![String::from("Cons=1-2"), String::from("Cons=1-2")];
-    assert_eq!("Cons=1-2", protover::compute_vote(protocols, 2));
+    let protocols: &[UnvalidatedProtoEntry] = &["Cons=1-2".parse().unwrap(), "Cons=1-2".parse().unwrap()];
+    assert_eq!("Cons=1-2", ProtoverVote::compute(protocols, &2).to_string());
 }
 
 #[test]
 fn protover_compute_vote_handles_invalid_proto_entries() {
-    let protocols = vec![
-        String::from("Cons=1"),
-        String::from("Cons=1"),
-        String::from("Link=a"),
+    let protocols: &[UnvalidatedProtoEntry] = &[
+        "Cons=1".parse().unwrap(),
+        "Cons=1".parse().unwrap(),
+        "Dinosaur=1".parse().unwrap(),
     ];
-    assert_eq!("Cons=1", protover::compute_vote(protocols, 2));
+    assert_eq!("Cons=1", ProtoverVote::compute(protocols, &2).to_string());
+}
 
-    let protocols = vec![
-        String::from("Cons=1"),
-        String::from("Cons=1"),
-        String::from("Link=1-%"),
-    ];
-    assert_eq!("Cons=1", protover::compute_vote(protocols, 2));
+#[test]
+fn parse_protocol_with_single_protocol_and_two_nonsequential_versions() {
+    let _: ProtoEntry = "Desc=1,2".parse().unwrap();
 }
 
 #[test]
 fn protover_is_supported_here_returns_true_for_supported_protocol() {
-    assert_eq!(true, protover::is_supported_here(protover::Proto::Cons, 1));
+    assert_eq!(true, protover::is_supported_here(&protover::Protocol::Cons, &1));
 }
 
 #[test]
 fn protover_is_supported_here_returns_false_for_unsupported_protocol() {
-    assert_eq!(false, protover::is_supported_here(protover::Proto::Cons, 5));
+    assert_eq!(false, protover::is_supported_here(&protover::Protocol::Cons, &5));
+}
+
+#[test]
+fn protocol_all_supported_with_single_proto_and_single_version() {
+    let protocol: UnvalidatedProtoEntry = "Cons=1".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocol.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+#[test]
+fn protocol_all_supported_with_single_protocol_and_multiple_versions() {
+    let protocol: UnvalidatedProtoEntry = "Cons=1-2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocol.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+#[test]
+fn protocol_all_supported_with_different_single_protocol_and_single_version() {
+    let protocol: UnvalidatedProtoEntry = "HSDir=1".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocol.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+#[test]
+fn protocol_all_supported_with_single_protocol_and_supported_version() {
+    let protocol: UnvalidatedProtoEntry = "Desc=2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocol.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+#[test]
+fn protocol_all_supported_with_two_protocols_and_single_version() {
+    let protocols: UnvalidatedProtoEntry = "Cons=1 HSDir=1".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+#[test]
+fn protocol_all_supported_with_single_protocol_and_two_nonsequential_versions() {
+    let protocol: UnvalidatedProtoEntry = "Desc=1,2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocol.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+#[test]
+fn protocol_all_supported_with_single_protocol_and_two_sequential_versions() {
+    let protocol: UnvalidatedProtoEntry = "Desc=1-2".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocol.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+#[test]
+fn protocol_all_supported_with_single_protocol_and_protocol_range() {
+    let protocol: UnvalidatedProtoEntry = "Link=1-4".parse().unwrap();
+    let unsupported: Option<UnvalidatedProtoEntry> = protocol.all_supported();
+    assert_eq!(true, unsupported.is_none());
+}
+
+// By allowing us to add to votes, the C implementation allows us to
+// exceed the limit.
+#[test]
+fn protover_compute_vote_may_exceed_limit() {
+    let proto1: UnvalidatedProtoEntry = "Sleen=1-65535".parse().unwrap();
+    let proto2: UnvalidatedProtoEntry = "Sleen=100000".parse().unwrap();
+
+    let _result: UnvalidatedProtoEntry = ProtoverVote::compute(&[proto1, proto2], &1);
+}
+
+#[test]
+fn protover_all_supported_should_include_version_we_actually_do_support() {
+    let proto: UnvalidatedProtoEntry = "Link=3-999".parse().unwrap();
+    let _result: String = proto.all_supported().unwrap().to_string();
+
+    assert_eq!(_result, "Link=3-999".to_string());
 }