Use singular for directory names

example/hello/src/lib.rs

@@ -0,0 +1,35 @@
+/// # Example
+///
+/// ```
+/// # use hello::snuggle;
+/// let bunnies = snuggle(5);
+/// assert_eq!(bunnies, 40);
+/// ```
+pub fn snuggle(bunnies: u128) -> u128 {
+    bunnies << 3
+}
+
+#[cfg(test)]
+mod test {
+    use std::num::ParseIntError;
+
+    use super::*;
+
+    #[test]
+    fn snuggling_bunnies_multiply() {
+        assert_eq!(snuggle(2), 16);
+    }
+
+    #[should_panic]
+    #[test]
+    fn scared_bunny() {
+        panic!("Hop hoppity hop!");
+    }
+
+    #[test]
+    fn bunny_result() -> Result<(), ParseIntError> {
+        let num_bunnies: u64 = "4".parse()?;
+        assert_eq!(num_bunnies, 4);
+        Ok(())
+    }
+}

example/hello/src/main.rs

@@ -0,0 +1,10 @@
+fn main() {}
+
+#[cfg(test)]
+mod test {
+
+    #[test]
+    fn the_bin_test() {
+        assert_eq!(1 + 1, 2);
+    }
+}