feat: add clock

Cargo.toml

@@ -10,7 +10,10 @@ keywords = ["mock", "mockable", "mocking", "test"]
 categories = ["development-tools::testing"]
 
 [features]
+clock = ["dep:chrono"]
+full = ["clock"]
 mock = ["dep:mockall"]
 
 [dependencies]
+chrono = { version = "0.4", optional = true }
 mockall = { version = "0.11", optional = true }

src/clock.rs

@@ -0,0 +1,70 @@
+use chrono::{DateTime, Local, Utc};
+use mockall::mock;
+
+// Clock
+
+/// A trait for getting the current time.
+///
+/// **This is supported on `feature=clock` only.**
+/// # Examples
+///
+/// ```
+/// use chrono::{DateTime, Utc, Duration};
+/// use mockable::{Clock, DefaultClock, MockClock};
+///
+/// fn now(clock: &dyn Clock) -> DateTime<Utc> {
+/// clock.utc()
+/// }
+///
+/// // Default
+/// let time = now(&DefaultClock);
+/// assert!(time < Utc::now() + Duration::seconds(1));
+///
+/// // Mock
+/// let expected = Utc::now();
+/// let mut clock = MockClock::new();
+/// clock
+/// .expect_utc()
+/// .returning(move || expected);
+/// let time = now(&clock);
+/// assert_eq!(time, expected);
+/// ```
+pub trait Clock: Send + Sync {
+ /// Returns the current time in the local timezone.
+ fn local(&self) -> DateTime<Local>;
+
+ /// Returns the current time in UTC.
+ fn utc(&self) -> DateTime<Utc>;
+}
+
+// DefaultClock
+
+/// Default implementation of `Clock`.
+///
+/// **This is supported on `feature=clock` only.**
+pub struct DefaultClock;
+
+impl Clock for DefaultClock {
+ fn local(&self) -> DateTime<Local> {
+ Local::now()
+ }
+
+ fn utc(&self) -> DateTime<Utc> {
+ Utc::now()
+ }
+}
+
+// MockClock
+
+#[cfg(feature = "mock")]
+mock! {
+ /// `mockall` implementation of `Clock`.
+ ///
+ /// **This is supported on `feature=clock,mock` only.**
+ pub Clock {}
+
+ impl super::Clock for Clock {
+ fn local(&self) -> DateTime<Local>;
+ fn utc(&self) -> DateTime<Utc>;
+ }
+}

src/lib.rs

@@ -1 +1,9 @@
+// Re-use
 
+#[cfg(feature = "clock")]
+pub use self::clock::*;
+
+// Mods
+
+#[cfg(feature = "clock")]
+mod clock;