1 files changed, 70 insertions, 0 deletions

diff --git a/rust/proverb/tests/proverb.rs b/rust/proverb/tests/proverb.rs
new file mode 100644
index 0000000..220de45
--- /dev/null
+++ b/rust/proverb/tests/proverb.rs
@@ -0,0 +1,70 @@
+use proverb::build_proverb;
+
+#[test]
+fn test_two_pieces() {
+    let input = vec!["nail", "shoe"];
+    let expected = vec![
+        "For want of a nail the shoe was lost.",
+        "And all for the want of a nail.",
+    ]
+    .join("\n");
+    assert_eq!(build_proverb(&input), expected);
+}
+
+// Notice the change in the last line at three pieces.
+#[test]
+fn test_three_pieces() {
+    let input = vec!["nail", "shoe", "horse"];
+    let expected = vec![
+        "For want of a nail the shoe was lost.",
+        "For want of a shoe the horse was lost.",
+        "And all for the want of a nail.",
+    ]
+    .join("\n");
+    assert_eq!(build_proverb(&input), expected);
+}
+
+#[test]
+fn test_one_piece() {
+    let input = vec!["nail"];
+    let expected = String::from("And all for the want of a nail.");
+    assert_eq!(build_proverb(&input), expected);
+}
+
+#[test]
+fn test_zero_pieces() {
+    let input: Vec<&str> = vec![];
+    let expected = String::new();
+    assert_eq!(build_proverb(&input), expected);
+}
+
+#[test]
+fn test_full() {
+    let input = vec![
+        "nail", "shoe", "horse", "rider", "message", "battle", "kingdom",
+    ];
+    let expected = vec![
+        "For want of a nail the shoe was lost.",
+        "For want of a shoe the horse was lost.",
+        "For want of a horse the rider was lost.",
+        "For want of a rider the message was lost.",
+        "For want of a message the battle was lost.",
+        "For want of a battle the kingdom was lost.",
+        "And all for the want of a nail.",
+    ]
+    .join("\n");
+    assert_eq!(build_proverb(&input), expected);
+}
+
+#[test]
+fn test_three_pieces_modernized() {
+    let input = vec!["pin", "gun", "soldier", "battle"];
+    let expected = vec![
+        "For want of a pin the gun was lost.",
+        "For want of a gun the soldier was lost.",
+        "For want of a soldier the battle was lost.",
+        "And all for the want of a pin.",
+    ]
+    .join("\n");
+    assert_eq!(build_proverb(&input), expected);
+}