1 files changed, 50 insertions, 0 deletions
diff --git a/third_party/rust/itertools/tests/peeking_take_while.rs b/third_party/rust/itertools/tests/peeking_take_while.rs
new file mode 100644
index 0000000000..a1147027e8
--- /dev/null
+++ b/third_party/rust/itertools/tests/peeking_take_while.rs
@@ -0,0 +1,50 @@
+use itertools::Itertools;
+use itertools::{put_back, put_back_n};
+
+#[test]
+fn peeking_take_while_peekable() {
+    let mut r = (0..10).peekable();
+    r.peeking_take_while(|x| *x <= 3).count();
+    assert_eq!(r.next(), Some(4));
+}
+
+#[test]
+fn peeking_take_while_put_back() {
+    let mut r = put_back(0..10);
+    r.peeking_take_while(|x| *x <= 3).count();
+    assert_eq!(r.next(), Some(4));
+    r.peeking_take_while(|_| true).count();
+    assert_eq!(r.next(), None);
+}
+
+#[test]
+fn peeking_take_while_put_back_n() {
+    let mut r = put_back_n(6..10);
+    for elt in (0..6).rev() {
+        r.put_back(elt);
+    }
+    r.peeking_take_while(|x| *x <= 3).count();
+    assert_eq!(r.next(), Some(4));
+    r.peeking_take_while(|_| true).count();
+    assert_eq!(r.next(), None);
+}
+
+#[test]
+fn peeking_take_while_slice_iter() {
+    let v = [1, 2, 3, 4, 5, 6];
+    let mut r = v.iter();
+    r.peeking_take_while(|x| **x <= 3).count();
+    assert_eq!(r.next(), Some(&4));
+    r.peeking_take_while(|_| true).count();
+    assert_eq!(r.next(), None);
+}
+
+#[test]
+fn peeking_take_while_slice_iter_rev() {
+    let v = [1, 2, 3, 4, 5, 6];
+    let mut r = v.iter().rev();
+    r.peeking_take_while(|x| **x >= 3).count();
+    assert_eq!(r.next(), Some(&2));
+    r.peeking_take_while(|_| true).count();
+    assert_eq!(r.next(), None);
+}