Replace chrono with time 0.3

.changelog/unreleased/breaking-changes/1030-remove-chrono.md

@@ -0,0 +1,9 @@
+- `[tendermint]` Reform `tendermint::Time`
+  ([#1030](https://github.com/informalsystems/tendermint-rs/issues/1030)):
+  * The struct content is made private.
+  * The range of acceptable values is restricted to years 1-9999
+    (as reckoned in UTC).
+  * Removed conversions from/to `chrono::DateTime<chrono::Utc>`.
+- `[rpc]` Use `OffsetDateTime` and `Date` types provided by the `time` crate
+  in query operands instead of their `chrono` counterparts.
+  ([#1030](https://github.com/informalsystems/tendermint-rs/issues/1030))

.changelog/unreleased/improvements/1030-new-time-api.md

@@ -0,0 +1,11 @@
+- Remove dependencies on the `chrono` crate.
+  ([#1030](https://github.com/informalsystems/tendermint-rs/issues/1030))
+- `[tendermint]` Improve `tendermint::Time`
+  ([#1030](https://github.com/informalsystems/tendermint-rs/issues/1030)):
+  * Restrict the validity range of `Time` to dates with years in the range
+    1-9999, to match the specification of protobuf message `Timestamp`.
+    Add an `ErrorDetail` variant `DateOutOfRange` to report when this
+    restriction is not met.
+  * Added a conversion to, and a fallible conversion from,
+    `OffsetDateTime` of the `time` crate.
+  * Added `Time` methods `checked_add` and `checked_sub`.

light-client/Cargo.toml

@@ -41,7 +41,6 @@ tendermint = { version = "0.23.0", path = "../tendermint", default-features = fa
 tendermint-rpc = { version = "0.23.0", path = "../rpc", default-features = false }
 
 contracts = { version = "0.4.0", default-features = false }
-chrono = { version = "0.4", default-features = false, features = ["clock"] }
 crossbeam-channel = { version = "0.4.2", default-features = false }
 derive_more = { version = "0.99.5", default-features = false, features = ["display"] }
 futures = { version = "0.3.4", default-features = false }
@@ -50,6 +49,7 @@ serde_cbor = { version = "0.11.1", default-features = false, features = ["alloc"
 serde_derive = { version = "1.0.106", default-features = false }
 sled = { version = "0.34.3", optional = true, default-features = false }
 static_assertions = { version = "1.1.0", default-features = false }
+time = { version = "0.3", default-features = false, features = ["std"] }
 tokio = { version = "1.0", default-features = false, features = ["rt"], optional = true }
 flex-error = { version = "0.4.4", default-features = false }
 

light-client/src/components/clock.rs

@@ -1,7 +1,8 @@
 //! Provides an interface and a default implementation of the `Clock` component
 
 use crate::types::Time;
-use chrono::Utc;
+use std::convert::TryInto;
+use time::OffsetDateTime;
 
 /// Abstracts over the current time.
 pub trait Clock: Send + Sync {
@@ -14,6 +15,8 @@ pub trait Clock: Send + Sync {
 pub struct SystemClock;
 impl Clock for SystemClock {
     fn now(&self) -> Time {
-        Time(Utc::now())
+        OffsetDateTime::now_utc()
+            .try_into()
+            .expect("system clock produces invalid time")
     }
 }

light-client/src/predicates.rs

@@ -205,10 +205,11 @@ pub trait VerificationPredicates: Send + Sync {
 
 #[cfg(test)]
 mod tests {
-    use chrono::Utc;
-    use std::ops::Sub;
+    use std::convert::TryInto;
     use std::time::Duration;
-    use tendermint::Time;
+    use tendermint::block::CommitSig;
+    use tendermint::validator::Set;
+    use time::OffsetDateTime;
 
     use tendermint_testgen::{
         light_block::{LightBlock as TestgenLightBlock, TmLightBlock},
@@ -224,8 +225,6 @@ mod tests {
         Hasher, ProdCommitValidator, ProdHasher, ProdVotingPowerCalculator, VotingPowerTally,
     };
     use crate::types::{LightBlock, TrustThreshold};
-    use tendermint::block::CommitSig;
-    use tendermint::validator::Set;
 
     impl From<TmLightBlock> for LightBlock {
         fn from(lb: TmLightBlock) -> Self {
@@ -294,7 +293,7 @@ mod tests {
 
         // 1. ensure valid header verifies
         let mut trusting_period = Duration::new(1000, 0);
-        let now = Time(Utc::now());
+        let now = OffsetDateTime::now_utc().try_into().unwrap();
 
         let result_ok = vp.is_within_trust_period(header.time, trusting_period, now);
         assert!(result_ok.is_ok());
@@ -322,13 +321,15 @@ mod tests {
         let vp = ProdPredicates::default();
         let one_second = Duration::new(1, 0);
 
+        let now = OffsetDateTime::now_utc().try_into().unwrap();
+
         // 1. ensure valid header verifies
-        let result_ok = vp.is_header_from_past(header.time, one_second, Time(Utc::now()));
+        let result_ok = vp.is_header_from_past(header.time, one_second, now);
 
         assert!(result_ok.is_ok());
 
         // 2. ensure it fails if header is from a future time
-        let now = Time(Utc::now()).sub(one_second * 15).unwrap();
+        let now = now.checked_sub(one_second * 15).unwrap();
         let result_err = vp.is_header_from_past(header.time, one_second, now);
 
         match result_err {

light-client/tests/model_based.rs

@@ -1,11 +1,10 @@
 #[cfg(feature = "mbt")]
 mod mbt {
-    use chrono::Utc;
     use rand::Rng;
     use serde::de::DeserializeOwned;
     use serde::{Deserialize, Serialize};
     use serde_json::Error;
-    use std::convert::TryFrom;
+    use std::convert::{TryFrom, TryInto};
     use std::str::FromStr;
     use std::time::Duration;
     use tendermint::validator::Set;
@@ -20,6 +19,7 @@ mod mbt {
         apalache::*, jsonatr::*, light_block::TmLightBlock, validator::generate_validators,
         Command, Generator, LightBlock as TestgenLightBlock, TestEnv, Tester, Validator, Vote,
     };
+    use time::OffsetDateTime;
 
     fn testgen_to_lb(tm_lb: TmLightBlock) -> LightBlock {
         LightBlock {
@@ -180,7 +180,8 @@ mod mbt {
     impl SingleStepTestFuzzer for HeaderTimeFuzzer {
         fn fuzz_input(input: &mut BlockVerdict) -> (String, LiteVerdict) {
             let mut rng = rand::thread_rng();
-            let secs = tendermint::Time(Utc::now())
+            let now: Time = OffsetDateTime::now_utc().try_into().unwrap();
+            let secs = now
                 .duration_since(tendermint::Time::unix_epoch())
                 .unwrap()
                 .as_secs();

pbt-gen/Cargo.toml

@@ -17,8 +17,10 @@ description = """
 
 [features]
 default = ["time"]
-time = ["chrono"]
 
 [dependencies]
-chrono = { version = "0.4", default-features = false, features = ["serde"], optional = true}
+time = { version = "0.3.5", default-features = false, optional = true }
 proptest = { version = "0.10.1", default-features = false, features = ["std"] }
+
+[dev-dependencies]
+time = { version = "0.3.5", features = ["macros"] }