tests and iterators

exercises/iterators/iterators1.rs

@@ -9,18 +9,17 @@
 // Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 #[test]
 fn main() {
     let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
 
-    let mut my_iterable_fav_fruits = ???;   // TODO: Step 1
+    let mut my_iterable_fav_fruits = my_fav_fruits.iter();   // TODO: Step 1
 
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"custard apple"));     // TODO: Step 2
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach"));// TODO: Step 3
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 4
+    assert_eq!(my_iterable_fav_fruits.next(), None);     // TODO: Step 4
 }

exercises/iterators/iterators2.rs

@@ -6,8 +6,6 @@
 // Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 // Step 1.
 // Complete the `capitalize_first` function.
 // "hello" -> "Hello"
@@ -15,7 +13,7 @@ pub fn capitalize_first(input: &str) -> String {
     let mut c = input.chars();
     match c.next() {
         None => String::new(),
-        Some(first) => ???,
+        Some(first) => first.to_uppercase().to_string() + &input[1..],
     }
 }
 
@@ -24,7 +22,7 @@ pub fn capitalize_first(input: &str) -> String {
 // Return a vector of strings.
 // ["hello", "world"] -> ["Hello", "World"]
 pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
-    vec![]
+    words.iter().map(|w| capitalize_first(w)).collect()
 }
 
 // Step 3.
@@ -32,7 +30,7 @@ pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
 // Return a single string.
 // ["hello", " ", "world"] -> "Hello World"
 pub fn capitalize_words_string(words: &[&str]) -> String {
-    String::new()
+    capitalize_words_vector(words).join("")
 }
 
 #[cfg(test)]

exercises/iterators/iterators3.rs

@@ -9,8 +9,6 @@
 // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
     NotDivisible(NotDivisibleError),
@@ -26,23 +24,35 @@ pub struct NotDivisibleError {
 // Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
 // Otherwise, return a suitable error.
 pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
-    todo!();
+    if b == 0 {
+        Err(DivisionError::DivideByZero)
+    }
+    else if a % b == 0 {
+        Ok(a / b)
+    } else {
+        Err(DivisionError::NotDivisible(NotDivisibleError {
+           dividend: a,
+           divisor: b
+        }))
+    }
 }
 
 // Complete the function and return a value of the correct type so the test
 // passes.
 // Desired output: Ok([1, 11, 1426, 3])
-fn result_with_list() -> () {
+fn result_with_list() -> Result<Vec<i32>, DivisionError> {
     let numbers = vec![27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    let division_results: Result<Vec<_>, DivisionError> = numbers.into_iter().map(|n| divide(n, 27)).collect();
+    division_results
 }
 
 // Complete the function and return a value of the correct type so the test
 // passes.
 // Desired output: [Ok(1), Ok(11), Ok(1426), Ok(3)]
-fn list_of_results() -> () {
+fn list_of_results() -> Vec<Result<i32, DivisionError>> {
     let numbers = vec![27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    let division_results: Vec<Result<_, DivisionError>> = numbers.into_iter().map(|n| divide(n, 27)).collect();
+    division_results
 }
 
 #[cfg(test)]

exercises/iterators/iterators4.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 pub fn factorial(num: u64) -> u64 {
     // Complete this function to return the factorial of num
     // Do not use:
@@ -15,6 +13,7 @@ pub fn factorial(num: u64) -> u64 {
     // For an extra challenge, don't use:
     // - recursion
     // Execute `rustlings hint iterators4` for hints.
+    if num == 0 { 1 } else { (1..=num).fold(1, |acc, v| acc * v) }
 }
 
 #[cfg(test)]

exercises/tests/tests1.rs

@@ -10,12 +10,10 @@
 // Execute `rustlings hint tests1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert() {
-        assert!();
+        assert!(1 == 1);
     }
 }

exercises/tests/tests2.rs

@@ -6,12 +6,10 @@
 // Execute `rustlings hint tests2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert_eq() {
-        assert_eq!();
+        assert_eq!(1, 1);
     }
 }

exercises/tests/tests3.rs

@@ -7,8 +7,6 @@
 // Execute `rustlings hint tests3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 pub fn is_even(num: i32) -> bool {
     num % 2 == 0
 }
@@ -19,11 +17,11 @@ mod tests {
 
     #[test]
     fn is_true_when_even() {
-        assert!();
+        assert!(is_even(2));
     }
 
     #[test]
     fn is_false_when_odd() {
-        assert!();
+        assert!(!is_even(3));
     }
 }

exercises/tests/tests4.rs

@@ -5,8 +5,6 @@
 // Execute `rustlings hint tests4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 struct Rectangle {
     width: i32,
     height: i32
@@ -30,17 +28,19 @@ mod tests {
     fn correct_width_and_height() {
         // This test should check if the rectangle is the size that we pass into its constructor
         let rect = Rectangle::new(10, 20);
-        assert_eq!(???, 10); // check width
-        assert_eq!(???, 20); // check height
+        assert_eq!(rect.width, 10); // check width
+        assert_eq!(rect.height, 20); // check height
     }
 
     #[test]
+    #[should_panic]
     fn negative_width() {
         // This test should check if program panics when we try to create rectangle with negative width
         let _rect = Rectangle::new(-10, 10);
     }
 
     #[test]
+    #[should_panic]
     fn negative_height() {
         // This test should check if program panics when we try to create rectangle with negative height
         let _rect = Rectangle::new(10, -10);