remove remaining probabilistic tests

Author: senekor

exercises/practice/robot-name/tests/robot_name.rs

@@ -1,5 +1,3 @@
-use std::collections::HashSet;
-
 use rand::SeedableRng as _;
 use rand::rngs::SmallRng;
 use robot_name::*;
@@ -28,15 +26,6 @@ fn name_should_match_expected_pattern() {
     assert_name_matches_pattern(robot.name());
 }
 
-#[test]
-#[ignore]
-fn factory_prevents_name_collisions() {
-    let mut factory = RobotFactory::new();
-    let robot_1 = factory.new_robot(&mut deterministic_rng());
-    let robot_2 = factory.new_robot(&mut deterministic_rng());
-    assert_ne!(robot_1.name(), robot_2.name());
-}
-
 #[test]
 #[ignore]
 fn robot_name_depends_on_rng() {
@@ -56,13 +45,11 @@ fn robot_name_only_depends_on_rng() {
 
 #[test]
 #[ignore]
-fn many_different_robots_have_different_names() {
-    // In 3,529 random robot names, there is ~99.99% chance of a name collision
-    let mut rng = deterministic_rng();
+fn factory_prevents_name_collisions() {
     let mut factory = RobotFactory::new();
-    let robots: Vec<_> = (0..3529).map(|_| factory.new_robot(&mut rng)).collect();
-    let mut set = HashSet::new();
-    assert!(robots.iter().all(|robot| set.insert(robot.name())));
+    let robot_1 = factory.new_robot(&mut deterministic_rng());
+    let robot_2 = factory.new_robot(&mut deterministic_rng());
+    assert_ne!(robot_1.name(), robot_2.name());
 }
 
 #[test]
@@ -91,19 +78,17 @@ fn new_name_is_different_from_old_name() {
 #[test]
 #[ignore]
 fn factory_prevents_name_collision_despite_reset() {
-    // To keep the same probablity as the first test with many robots, we
-    // generate 3,529 robots and reset their names, then generate another 3,529
-    // robots and check if there are collisions across these two groups.
-    let mut rng = deterministic_rng();
     let mut factory = RobotFactory::new();
-    let mut reset_robots: Vec<_> = (0..3529).map(|_| factory.new_robot(&mut rng)).collect();
-    for robot in &mut reset_robots {
-        robot.reset(&mut rng);
-    }
-    let mut set = HashSet::new();
-    assert!(reset_robots.iter().all(|robot| set.insert(robot.name())));
 
-    assert!((0..3529).all(|_| !set.contains(factory.new_robot(&mut rng).name())));
+    let mut rng = deterministic_rng();
+    let mut robot_1 = factory.new_robot(&mut rng);
+    robot_1.reset(&mut rng);
+
+    let mut rng = deterministic_rng();
+    let mut robot_2 = factory.new_robot(&mut rng);
+    robot_2.reset(&mut rng);
+
+    assert_ne!(robot_1.name(), robot_2.name());
 }
 
 #[test]