[rust] Binary Search

1 files changed, 93 insertions, 0 deletions

diff --git a/rust/binary-search/tests/binary-search.rs b/rust/binary-search/tests/binary-search.rs
new file mode 100644
index 0000000..aa5cc8b
--- /dev/null
+++ b/rust/binary-search/tests/binary-search.rs
@@ -0,0 +1,93 @@
+use binary_search::find;
+
+#[test]
+fn finds_a_value_in_an_array_with_one_element() {
+    assert_eq!(find(&[6], 6), Some(0));
+}
+
+#[test]
+fn finds_first_value_in_an_array_with_two_element() {
+    assert_eq!(find(&[1, 2], 1), Some(0));
+}
+
+#[test]
+fn finds_second_value_in_an_array_with_two_element() {
+    assert_eq!(find(&[1, 2], 2), Some(1));
+}
+
+#[test]
+fn finds_a_value_in_the_middle_of_an_array() {
+    assert_eq!(find(&[1, 3, 4, 6, 8, 9, 11], 6), Some(3));
+}
+
+#[test]
+fn finds_a_value_at_the_beginning_of_an_array() {
+    assert_eq!(find(&[1, 3, 4, 6, 8, 9, 11], 1), Some(0));
+}
+
+#[test]
+fn finds_a_value_at_the_end_of_an_array() {
+    assert_eq!(find(&[1, 3, 4, 6, 8, 9, 11], 11), Some(6));
+}
+
+#[test]
+fn finds_a_value_in_an_array_of_odd_length() {
+    assert_eq!(
+        find(&[1, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 634], 144),
+        Some(9)
+    );
+}
+
+#[test]
+fn finds_a_value_in_an_array_of_even_length() {
+    assert_eq!(
+        find(&[1, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377], 21),
+        Some(5)
+    );
+}
+
+#[test]
+fn identifies_that_a_value_is_not_included_in_the_array() {
+    assert_eq!(find(&[1, 3, 4, 6, 8, 9, 11], 7), None);
+}
+
+#[test]
+fn a_value_smaller_than_the_arrays_smallest_value_is_not_included() {
+    assert_eq!(find(&[1, 3, 4, 6, 8, 9, 11], 0), None);
+}
+
+#[test]
+fn a_value_larger_than_the_arrays_largest_value_is_not_included() {
+    assert_eq!(find(&[1, 3, 4, 6, 8, 9, 11], 13), None);
+}
+
+#[test]
+fn nothing_is_included_in_an_empty_array() {
+    assert_eq!(find(&[], 1), None);
+}
+
+#[test]
+fn nothing_is_found_when_the_left_and_right_bounds_cross() {
+    assert_eq!(find(&[1, 2], 0), None);
+}
+
+#[test]
+#[cfg(feature = "generic")]
+fn works_for_arrays() {
+    assert_eq!(find([6], 6), Some(0));
+}
+
+#[test]
+#[cfg(feature = "generic")]
+fn works_for_vec() {
+    let vector = vec![6];
+    assert_eq!(find(&vector, 6), Some(0));
+    assert_eq!(find(vector, 6), Some(0));
+}
+
+#[test]
+#[cfg(feature = "generic")]
+fn works_for_str_elements() {
+    assert_eq!(find(["a"], "a"), Some(0));
+    assert_eq!(find(["a", "b"], "b"), Some(1));
+}