Add robot-name exercise (#144)

config.json

@@ -585,6 +585,17 @@
         ],
         "difficulty": 2
       },
+      {
+        "slug": "robot-name",
+        "name": "Robot Name",
+        "uuid": "33c4d67c-8365-41d2-9a3e-c41bbf0dd131",
+        "practices": [],
+        "prerequisites": [
+          "numbers",
+          "strings"
+        ],
+        "difficulty": 2
+      },
       {
         "slug": "say",
         "name": "Say",

exercises/practice/robot-name/.docs/instructions.md

@@ -0,0 +1,14 @@
+# Instructions
+
+Manage robot factory settings.
+
+When a robot comes off the factory floor, it has no name.
+
+The first time you turn on a robot, a random name is generated in the format of two uppercase letters followed by three digits, such as RX837 or BC811.
+
+Every once in a while we need to reset a robot to its factory settings, which means that its name gets wiped.
+The next time you ask, that robot will respond with a new random name.
+
+The names must be random: they should not follow a predictable sequence.
+Using random names means a risk of collisions.
+Your solution must ensure that every existing robot has a unique name.

exercises/practice/robot-name/.meta/config.json

@@ -0,0 +1,18 @@
+{
+  "authors": [
+    "ErikSchierboom"
+  ],
+  "files": {
+    "solution": [
+      "src/robot_name.cljs"
+    ],
+    "test": [
+      "test/robot_name_test.cljs"
+    ],
+    "example": [
+      ".meta/src/example.cljs"
+    ]
+  },
+  "blurb": "Manage robot factory settings.",
+  "source": "A debugging session with Paul Blackwell at gSchool."
+}

exercises/practice/robot-name/.meta/src/example.cljs

@@ -0,0 +1,16 @@
+(ns robot-name)
+
+(def ^:private letters (map char (range 65 91)))
+(defn- generate-name []
+  (apply str 
+    (concat (repeatedly 2 #(rand-nth letters))
+            (repeatedly 3 #(rand-int 10)))))
+
+(defn robot []
+  (atom {:name (generate-name)}))
+
+(defn robot-name [robot]
+  (:name @robot))
+
+(defn reset-name [robot]
+  (swap! robot assoc :name (generate-name)))

exercises/practice/robot-name/deps.edn

@@ -0,0 +1,10 @@
+{:deps
+ {org.clojure/clojure {:mvn/version "1.10.1"}
+  org.clojure/clojurescript {:mvn/version "1.10.773"}}
+
+ :aliases
+ {:test
+  {:extra-paths ["test"]
+   :extra-deps
+   {olical/cljs-test-runner {:mvn/version "3.8.0"}}
+   :main-opts ["-m" "cljs-test-runner.main"]}}}

exercises/practice/robot-name/src/robot_name.cljs

@@ -0,0 +1,13 @@
+(ns robot-name)
+
+(defn robot [] ;; <- arglist goes here
+  ;; your code goes here
+)
+
+(defn robot-name [robot] ;; <- arglist goes here
+      ;; your code goes here
+)
+
+(defn reset-name [robot] ;; <- arglist goes here
+  ;; your code goes here
+)

exercises/practice/robot-name/test/robot_name_test.cljs

@@ -0,0 +1,47 @@
+(ns robot-name-test
+  (:require [clojure.test :refer [deftest is testing]]
+            robot-name))
+
+(deftest robot-name
+  (let [a-robot (robot-name/robot)
+        its-name (robot-name/robot-name a-robot)]
+      (is (re-seq #"[A-Z]{2}\d{3}" its-name))))
+
+(deftest name-matches-pattern
+   (let [a-robot (robot-name/robot)
+         its-name (robot-name/robot-name a-robot)]
+     (is (= its-name (robot-name/robot-name a-robot)))))
+
+(deftest different-robots-different-names
+ (let [a-robot (robot-name/robot)
+        its-name (robot-name/robot-name a-robot)]
+      (is (not= its-name (-> (robot-name/robot) robot-name/robot-name)))))
+
+(deftest new-name-matches
+  (let [a-robot (robot-name/robot)
+        its-original-name (robot-name/robot-name a-robot)
+        its-new-name (do (robot-name/reset-name a-robot)
+                         (robot-name/robot-name a-robot))]
+      (is (re-seq #"[A-Z]{2}\d{3}" its-new-name))))
+
+(deftest new-name-different
+  (let [a-robot (robot-name/robot)
+        its-original-name (robot-name/robot-name a-robot)
+        its-new-name (do (robot-name/reset-name a-robot)
+                         (robot-name/robot-name a-robot))]
+      (is (not= its-original-name its-new-name))))
+
+(deftest new-name-does-not-change-until-reset
+  (let [a-robot (robot-name/robot)
+        its-original-name (robot-name/robot-name a-robot)
+        its-new-name (do (robot-name/reset-name a-robot)
+                         (robot-name/robot-name a-robot))]
+      (is (= its-new-name (robot-name/robot-name a-robot)))))
+
+(deftest new-names-different-each-time
+  (let [a-robot (robot-name/robot)
+        its-original-name (robot-name/robot-name a-robot)
+        its-new-name (do (robot-name/reset-name a-robot)
+                         (robot-name/robot-name a-robot))]
+  (is (not= its-new-name (do (robot-name/reset-name a-robot)
+                             (robot-name/robot-name a-robot))))))