Improve splice docs and tests

Author: mattico

src/libcollections/string.rs

@@ -1386,8 +1386,8 @@ impl String {
     /// replaces with the given string, and yields the removed chars.
     /// The given string doesn’t need to be the same length as the range.
     ///
-    /// Note: The element range is removed even if the iterator is not
-    /// consumed until the end.
+    /// Note: The element range is removed when the `Splice` is dropped,
+    /// even if the iterator is not consumed until the end.
     ///
     /// # Panics
     ///

src/libcollections/tests/string.rs

@@ -427,6 +427,54 @@ fn test_splice() {
     assert_eq!(t, "world");
 }
 
+#[test]
+#[should_panic]
+fn test_splice_char_boundary() {
+    let mut s = "Hello, 世界!".to_owned();
+    s.splice(..8, "");
+}
+
+#[test]
+fn test_splice_inclusive_range() {
+    let mut v = String::from("12345");
+    let t: String = v.splice(2...3, "789").collect();
+    assert_eq!(v, "127895");
+    assert_eq!(t, "34");
+    let t2: String = v.splice(1...2, "A").collect();
+    assert_eq!(v, "1A895");
+    assert_eq!(t2, "27");
+}
+
+#[test]
+#[should_panic]
+fn test_splice_out_of_bounds() {
+    let mut s = String::from("12345");
+    s.splice(5..6, "789");
+}
+
+#[test]
+#[should_panic]
+fn test_splice_inclusive_out_of_bounds() {
+    let mut s = String::from("12345");
+    s.splice(5...5, "789");
+}
+
+#[test]
+fn test_splice_empty() {
+    let mut s = String::from("12345");
+    let t: String = s.splice(1..2, "").collect();
+    assert_eq!(s, "1345");
+    assert_eq!(t, "2");
+}
+
+#[test]
+fn test_splice_unbounded() {
+    let mut s = String::from("12345");
+    let t: String = s.splice(.., "").collect();
+    assert_eq!(s, "");
+    assert_eq!(t, "12345");
+}
+
 #[test]
 fn test_extend_ref() {
     let mut a = "foo".to_string();

src/libcollections/tests/vec.rs

@@ -580,7 +580,7 @@ fn test_drain_inclusive_out_of_bounds() {
 }
 
 #[test]
-fn splice() {
+fn test_splice() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
     v.splice(2..4, a.iter().cloned());
@@ -589,6 +589,51 @@ fn splice() {
     assert_eq!(v, &[1, 20, 11, 12, 5]);
 }
 
+#[test]
+fn test_splice_inclusive_range() {
+    let mut v = vec![1, 2, 3, 4, 5];
+    let a = [10, 11, 12];
+    let t1: Vec<_> = v.splice(2...3, a.iter().cloned()).collect();
+    assert_eq!(v, &[1, 2, 10, 11, 12, 5]);
+    assert_eq!(t1, &[3, 4]);
+    let t2: Vec<_> = v.splice(1...2, Some(20)).collect();
+    assert_eq!(v, &[1, 20, 11, 12, 5]);
+    assert_eq!(t2, &[2, 10]);
+}
+
+#[test]
+#[should_panic]
+fn test_splice_out_of_bounds() {
+    let mut v = vec![1, 2, 3, 4, 5];
+    let a = [10, 11, 12];
+    v.splice(5..6, a.iter().cloned());
+}
+
+#[test]
+#[should_panic]
+fn test_splice_inclusive_out_of_bounds() {
+    let mut v = vec![1, 2, 3, 4, 5];
+    let a = [10, 11, 12];
+    v.splice(5...5, a.iter().cloned());
+}
+
+#[test]
+fn test_splice_items_zero_sized() {
+    let mut vec = vec![(), (), ()];
+    let vec2 = vec![];
+    let t: Vec<_> = vec.splice(1..2, vec2.iter().cloned()).collect();
+    assert_eq!(vec, &[(), ()]);
+    assert_eq!(t, &[()]);
+}
+
+#[test]
+fn test_splice_unbounded() {
+    let mut vec = vec![1, 2, 3, 4, 5];
+    let t: Vec<_> = vec.splice(.., None).collect();
+    assert_eq!(vec, &[]);
+    assert_eq!(t, &[1, 2, 3, 4, 5]);
+}
+
 #[test]
 fn test_into_boxed_slice() {
     let xs = vec![1, 2, 3];

src/libcollections/vec.rs

@@ -1063,7 +1063,7 @@ impl<T> Vec<T> {
     /// Note 1: The element range is removed even if the iterator is only
     /// partially consumed or not consumed at all.
     ///
-    /// Note 2: It is unspecified how many elements are removed from the vector,
+    /// Note 2: It is unspecified how many elements are removed from the vector
     /// if the `Drain` value is leaked.
     ///
     /// # Panics