RUST-1960 Make large-dates time feature optional (#546)

Author: isabelatkinson

Cargo.toml

@@ -37,6 +37,8 @@ default = ["compat-3-0-0"]
 compat-3-0-0 = []
 # if enabled, include API for interfacing with chrono 0.4
 chrono-0_4 = ["dep:chrono"]
+# enable the large-dates feature for the time crate
+large_dates = ["time/large-dates"]
 # if enabled, include API for interfacing with uuid 1.x
 uuid-1 = []
 # if enabled, include API for interfacing with time 0.3
@@ -62,7 +64,7 @@ once_cell = "1.5.1"
 uuid = { version = "1.1.2", features = ["serde", "v4"] }
 serde_bytes = "0.11.5"
 serde_with = { version = "3.1.0", optional = true }
-time = { version = "0.3.9", features = ["formatting", "parsing", "macros", "large-dates"] }
+time = { version = "0.3.9", features = ["formatting", "parsing", "macros"] }
 bitvec = "1.0.1"
 serde_path_to_error = { version = "0.1.16", optional = true }
 simdutf8 = "0.1.5"

README.md

@@ -52,7 +52,8 @@ Note that if you are using `bson` through the `mongodb` crate, you do not need t
 | `time-0_3`   | Enable support for v0.3 of the [`time`](https://docs.rs/time/0.3) crate in the public API.                  | n/a                | no      |
 | `serde_with-3` | Enable [`serde_with`](https://docs.rs/serde_with/3.x) 3.x integrations for `bson::DateTime` and `bson::Uuid`.| serde_with         | no      |
 | `serde_path_to_error` | Enable support for error paths via integration with [`serde_path_to_error`](https://docs.rs/serde_path_to_err/latest).  This is an unstable feature and any breaking changes to `serde_path_to_error` may affect usage of it via this feature.  | serde_path_to_error  | no |
-| `compat-3-0-0` | Required for future compatibility if default features are disabled. | no |
+| `compat-3-0-0` | Required for future compatibility if default features are disabled. | n/a | no |
+| `large_dates` | Increase the supported year range for some `bson::DateTime` utilities from +/-9,999 (inclusive) to +/-999,999 (inclusive). Note that enabling this feature can impact performance and introduce parsing ambiguities. | n/a | no |
 
 ## Overview of the BSON Format
 

src/datetime.rs

@@ -174,6 +174,14 @@ use serde::{Deserialize, Deserializer, Serialize};
 /// # }
 /// # Ok::<(), Box<dyn std::error::Error>>(())
 /// ```
+///
+/// ## Large Dates
+/// The range of dates supported by `DateTime` is defined by [`DateTime::MIN`] and
+/// [`DateTime::MAX`]. However, some utilities for constructing and converting `DateTimes`, such as
+/// interop with the [`time::OffsetDateTime`] type and with RFC 3339 strings, are bounded by the
+/// [`time`] crate's supported date range. The `large_dates` feature can be enabled to expand this
+/// range, which enables the
+/// [`large-dates` feature for `time`](https://docs.rs/time/latest/time/#feature-flags).
 #[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Copy, Clone)]
 pub struct DateTime(i64);
 

src/lib.rs

@@ -67,6 +67,7 @@
 //! | `serde_with-3` | Enable [`serde_with`](https://docs.rs/serde_with/3.x) 3.x integrations for [`DateTime`] and [`Uuid`]. | no      |
 //! | `serde_path_to_error` | Enable support for error paths via integration with [`serde_path_to_error`](https://docs.rs/serde_path_to_err/latest).  This is an unstable feature and any breaking changes to `serde_path_to_error` may affect usage of it via this feature. | no |
 //! | `compat-3-0-0` | Required for future compatibility if default features are disabled. | no |
+//! | `large_dates` | Increase the supported year range for some `bson::DateTime` utilities from +/-9,999 (inclusive) to +/-999,999 (inclusive). Note that enabling this feature can impact performance and introduce parsing ambiguities. | no |
 //!
 //! ## BSON values
 //!

src/tests/datetime.rs

@@ -37,6 +37,7 @@ fn datetime_to_rfc3339() {
 }
 
 #[test]
+#[cfg(feature = "large_dates")]
 fn invalid_datetime_to_rfc3339() {
     assert!(crate::DateTime::MAX.try_to_rfc3339_string().is_err());
 }

src/tests/spec/corpus.rs

@@ -100,6 +100,11 @@ where
 fn run_test(test: TestFile) {
     let _guard = LOCK.run_concurrently();
     for valid in test.valid {
+        #[cfg(not(feature = "large_dates"))]
+        if valid.description == "Y10K" {
+            continue;
+        }
+
         let description = format!("{}: {}", test.description, valid.description);
 
         let canonical_bson = hex::decode(&valid.canonical_bson).expect(&description);