Add split stopwatch (#757)

* Fixes to concept tree

* Add Split-Second Stopwatch exercise with initial implementation and tests

* Format files

* Apply suggestion from @ryanplusplus

---------

Co-authored-by: Ryan Hartlage <2488333+ryanplusplus@users.noreply.github.com>

Author: meatball133

config.json

@@ -1044,6 +1044,16 @@
         "prerequisites": [],
         "difficulty": 3
       },
+      {
+        "slug": "split-second-stopwatch",
+        "name": "Split-Second Stopwatch",
+        "uuid": "2bf80456-020c-4adc-8e81-8dfe75da7083",
+        "practices": [
+          "classes"
+        ],
+        "prerequisites": [],
+        "difficulty": 3
+      },
       {
         "slug": "baffling-birthdays",
         "name": "Baffling Birthdays",

exercises/practice/split-second-stopwatch/.docs/instructions.md

@@ -0,0 +1,22 @@
+# Instructions
+
+Your task is to build a stopwatch to keep precise track of lap times.
+
+The stopwatch uses four commands (start, stop, lap, and reset) to keep track of:
+
+1. The current lap's tracked time
+2. Previously recorded lap times
+
+What commands can be used depends on which state the stopwatch is in:
+
+1. Ready: initial state
+2. Running: tracking time
+3. Stopped: not tracking time
+
+| Command | Begin state | End state | Effect                                                   |
+| ------- | ----------- | --------- | -------------------------------------------------------- |
+| Start   | Ready       | Running   | Start tracking time                                      |
+| Start   | Stopped     | Running   | Resume tracking time                                     |
+| Stop    | Running     | Stopped   | Stop tracking time                                       |
+| Lap     | Running     | Running   | Add current lap to previous laps, then reset current lap |
+| Reset   | Stopped     | Ready     | Reset current lap and clear previous laps                |

exercises/practice/split-second-stopwatch/.docs/introduction.md

@@ -0,0 +1,6 @@
+# Introduction
+
+You've always run for the thrill of it — no schedules, no timers, just the sound of your feet on the pavement.
+But now that you've joined a competitive running crew, things are getting serious.
+Training sessions are timed to the second, and every split second counts.
+To keep pace, you've picked up the _Split-Second Stopwatch_ — a sleek, high-tech gadget that's about to become your new best friend.

exercises/practice/split-second-stopwatch/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "meatball133"
+  ],
+  "files": {
+    "solution": [
+      "src/split_second_stopwatch.cr"
+    ],
+    "test": [
+      "spec/split_second_stopwatch_spec.cr"
+    ],
+    "example": [
+      ".meta/src/example.cr"
+    ]
+  },
+  "blurb": "Keep track of time through a digital stopwatch.",
+  "source": "Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/pull/2547"
+}

exercises/practice/split-second-stopwatch/.meta/src/example.cr

@@ -0,0 +1,73 @@
+class SplitSecondStopwatch
+  def initialize
+    @time = 0
+    @split_times = [] of Int32
+    @state = "ready"
+  end
+
+  def start
+    if @state == "running"
+      raise ArgumentError.new("Stopwatch is already running")
+    end
+
+    @state = "running"
+  end
+
+  def stop
+    if @state != "running"
+      raise ArgumentError.new("Stopwatch is not running")
+    end
+
+    @state = "stopped"
+  end
+
+  def total : String
+    convert_time(@time + @split_times.sum)
+  end
+
+  def current_lap : String
+    convert_time(@time)
+  end
+
+  def previous_laps : Array(String)
+    @split_times.map { |t| convert_time(t) }
+  end
+
+  def state : String
+    @state
+  end
+
+  def advance_time(time : String)
+    parts = time.split(":").map(&.to_i)
+    total_seconds = parts[0] * 3600 + parts[1] * 60 + parts[2]
+    if @state == "running"
+      @time += total_seconds
+    end
+  end
+
+  def lap
+    if @state != "running"
+      raise ArgumentError.new("Stopwatch is not running")
+    end
+
+    @split_times << @time
+    @time = 0
+  end
+
+  def reset
+    if @state != "stopped"
+      raise ArgumentError.new("Stopwatch needs to be stopped before it can be reset")
+    end
+    @time = 0
+    @split_times.clear
+    @state = "ready"
+  end
+
+  private def convert_time(time : Int32) : String
+    hours = time / 3600
+    minutes = (time % 3600) / 60
+    seconds = time % 60
+
+    "%02d:%02d:%02d" % [hours, minutes, seconds]
+  end
+end

exercises/practice/split-second-stopwatch/.meta/test_template.ecr

@@ -0,0 +1,28 @@
+require "spec"
+require "../src/*"
+
+describe "<%-= to_capitalized(@json["exercise"].to_s) %>" do
+<%- @json["cases"].as_a.each do |cases| %>
+    <%= status()%> "<%-= cases["description"] %>" do
+    <%- cases["input"]["commands"].as_a.each do |command| %>
+        <%- if command["command"] == "new" %>
+            stopwatch = SplitSecondStopwatch.new
+        <%- elsif command["command"] == "state" || command["command"] == "currentLap" %>
+            stopwatch.<%= command["command"].to_s.underscore %>.should eq("<%= command["expected"] %>")
+        <%- elsif command["command"] == "previousLaps" %>
+            stopwatch.previous_laps.should eq(<%= command["expected"].to_s == "[]" ? "[] of String": to_s_deep(command["expected"]) %>)
+        <%- elsif command["command"] == "start" || command["command"] == "stop" || command["command"] == "lap" || command["command"] == "reset" %>
+            <%- if command["expected"]? %>
+                expect_raises(ArgumentError) do
+                    stopwatch.<%= command["command"] %>
+                end
+            <%- else -%>
+            stopwatch.<%= command["command"] %>
+            <%- end %>
+        <%- elsif command["command"] == "advanceTime" %>
+            stopwatch.advance_time("<%= command["by"] %>")
+        <%- end %>
+    <%- end %>
+    end
+<% end %>
+end

exercises/practice/split-second-stopwatch/.meta/tests.toml

@@ -0,0 +1,97 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[ddb238ea-99d4-4eaa-a81d-3c917a525a23]
+description = "new stopwatch starts in ready state"
+
+[b19635d4-08ad-4ac3-b87f-aca10e844071]
+description = "new stopwatch's current lap has no elapsed time"
+
+[492eb532-268d-43ea-8a19-2a032067d335]
+description = "new stopwatch's total has no elapsed time"
+
+[8a892c1e-9ef7-4690-894e-e155a1fe4484]
+description = "new stopwatch does not have previous laps"
+
+[5b2705b6-a584-4042-ba3a-4ab8d0ab0281]
+description = "start from ready state changes state to running"
+
+[748235ce-1109-440b-9898-0a431ea179b6]
+description = "start does not change previous laps"
+
+[491487b1-593d-423e-a075-aa78d449ff1f]
+description = "start initiates time tracking for current lap"
+
+[a0a7ba2c-8db6-412c-b1b6-cb890e9b72ed]
+description = "start initiates time tracking for total"
+
+[7f558a17-ef6d-4a5b-803a-f313af7c41d3]
+description = "start cannot be called from running state"
+
+[32466eef-b2be-4d60-a927-e24fce52dab9]
+description = "stop from running state changes state to stopped"
+
+[621eac4c-8f43-4d99-919c-4cad776d93df]
+description = "stop pauses time tracking for current lap"
+
+[465bcc82-7643-41f2-97ff-5e817cef8db4]
+description = "stop pauses time tracking for total"
+
+[b1ba7454-d627-41ee-a078-891b2ed266fc]
+description = "stop cannot be called from ready state"
+
+[5c041078-0898-44dc-9d5b-8ebb5352626c]
+description = "stop cannot be called from stopped state"
+
+[3f32171d-8fbf-46b6-bc2b-0810e1ec53b7]
+description = "start from stopped state changes state to running"
+
+[626997cb-78d5-4fe8-b501-29fdef804799]
+description = "start from stopped state resumes time tracking for current lap"
+
+[58487c53-ab26-471c-a171-807ef6363319]
+description = "start from stopped state resumes time tracking for total"
+
+[091966e3-ed25-4397-908b-8bb0330118f8]
+description = "lap adds current lap to previous laps"
+
+[1aa4c5ee-a7d5-4d59-9679-419deef3c88f]
+description = "lap resets current lap and resumes time tracking"
+
+[4b46b92e-1b3f-46f6-97d2-0082caf56e80]
+description = "lap continues time tracking for total"
+
+[ea75d36e-63eb-4f34-97ce-8c70e620bdba]
+description = "lap cannot be called from ready state"
+
+[63731154-a23a-412d-a13f-c562f208eb1e]
+description = "lap cannot be called from stopped state"
+
+[e585ee15-3b3f-4785-976b-dd96e7cc978b]
+description = "stop does not change previous laps"
+
+[fc3645e2-86cf-4d11-97c6-489f031103f6]
+description = "reset from stopped state changes state to ready"
+
+[20fbfbf7-68ad-4310-975a-f5f132886c4e]
+description = "reset resets current lap"
+
+[00a8f7bb-dd5c-43e5-8705-3ef124007662]
+description = "reset clears previous laps"
+
+[76cea936-6214-4e95-b6d1-4d4edcf90499]
+description = "reset cannot be called from ready state"
+
+[ba4d8e69-f200-4721-b59e-90d8cf615153]
+description = "reset cannot be called from running state"
+
+[0b01751a-cb57-493f-bb86-409de6e84306]
+description = "supports very long laps"