1 files changed, 134 insertions, 0 deletions
diff --git a/third_party/rust/once_cell/tests/it/unsync_lazy.rs b/third_party/rust/once_cell/tests/it/unsync_lazy.rs
new file mode 100644
index 0000000000..0c308cab09
--- /dev/null
+++ b/third_party/rust/once_cell/tests/it/unsync_lazy.rs
@@ -0,0 +1,134 @@
+use core::{
+    cell::Cell,
+    sync::atomic::{AtomicUsize, Ordering::SeqCst},
+};
+
+use once_cell::unsync::Lazy;
+
+#[test]
+fn lazy_new() {
+    let called = Cell::new(0);
+    let x = Lazy::new(|| {
+        called.set(called.get() + 1);
+        92
+    });
+
+    assert_eq!(called.get(), 0);
+
+    let y = *x - 30;
+    assert_eq!(y, 62);
+    assert_eq!(called.get(), 1);
+
+    let y = *x - 30;
+    assert_eq!(y, 62);
+    assert_eq!(called.get(), 1);
+}
+
+#[test]
+fn lazy_deref_mut() {
+    let called = Cell::new(0);
+    let mut x = Lazy::new(|| {
+        called.set(called.get() + 1);
+        92
+    });
+
+    assert_eq!(called.get(), 0);
+
+    let y = *x - 30;
+    assert_eq!(y, 62);
+    assert_eq!(called.get(), 1);
+
+    *x /= 2;
+    assert_eq!(*x, 46);
+    assert_eq!(called.get(), 1);
+}
+
+#[test]
+fn lazy_force_mut() {
+    let called = Cell::new(0);
+    let mut x = Lazy::new(|| {
+        called.set(called.get() + 1);
+        92
+    });
+    assert_eq!(called.get(), 0);
+    let v = Lazy::force_mut(&mut x);
+    assert_eq!(called.get(), 1);
+
+    *v /= 2;
+    assert_eq!(*x, 46);
+    assert_eq!(called.get(), 1);
+}
+
+#[test]
+fn lazy_get_mut() {
+    let called = Cell::new(0);
+    let mut x: Lazy<u32, _> = Lazy::new(|| {
+        called.set(called.get() + 1);
+        92
+    });
+
+    assert_eq!(called.get(), 0);
+    assert_eq!(*x, 92);
+
+    let mut_ref: &mut u32 = Lazy::get_mut(&mut x).unwrap();
+    assert_eq!(called.get(), 1);
+
+    *mut_ref /= 2;
+    assert_eq!(*x, 46);
+    assert_eq!(called.get(), 1);
+}
+
+#[test]
+fn lazy_default() {
+    static CALLED: AtomicUsize = AtomicUsize::new(0);
+
+    struct Foo(u8);
+    impl Default for Foo {
+        fn default() -> Self {
+            CALLED.fetch_add(1, SeqCst);
+            Foo(42)
+        }
+    }
+
+    let lazy: Lazy<std::sync::Mutex<Foo>> = <_>::default();
+
+    assert_eq!(CALLED.load(SeqCst), 0);
+
+    assert_eq!(lazy.lock().unwrap().0, 42);
+    assert_eq!(CALLED.load(SeqCst), 1);
+
+    lazy.lock().unwrap().0 = 21;
+
+    assert_eq!(lazy.lock().unwrap().0, 21);
+    assert_eq!(CALLED.load(SeqCst), 1);
+}
+
+#[test]
+fn lazy_into_value() {
+    let l: Lazy<i32, _> = Lazy::new(|| panic!());
+    assert!(matches!(Lazy::into_value(l), Err(_)));
+    let l = Lazy::new(|| -> i32 { 92 });
+    Lazy::force(&l);
+    assert!(matches!(Lazy::into_value(l), Ok(92)));
+}
+
+#[test]
+#[cfg(feature = "std")]
+fn lazy_poisoning() {
+    let x: Lazy<String> = Lazy::new(|| panic!("kaboom"));
+    for _ in 0..2 {
+        let res = std::panic::catch_unwind(|| x.len());
+        assert!(res.is_err());
+    }
+}
+
+#[test]
+// https://github.com/rust-lang/rust/issues/34761#issuecomment-256320669
+fn arrrrrrrrrrrrrrrrrrrrrr() {
+    let lazy: Lazy<&String, _>;
+    {
+        let s = String::new();
+        lazy = Lazy::new(|| &s);
+        _ = *lazy;
+    }
+}