From 8f6dc2612a5834042410961584962c6aa1c8841e Mon Sep 17 00:00:00 2001
From: Ryan Hartlage <2488333+ryanplusplus@users.noreply.github.com>
Date: Sun, 3 May 2026 10:43:34 -0400
Subject: [PATCH 1/2] Add baffling-birthdays

---
 bin/generate-spec                             |  26 ++++
 config.json                                   |   8 ++
 .../practice/anagram/.meta/spec_generator.lua |  10 +-
 exercises/practice/baffling-birthdays/.busted |   5 +
 .../baffling-birthdays/.docs/instructions.md  |  23 ++++
 .../baffling-birthdays/.docs/introduction.md  |  25 ++++
 .../baffling-birthdays/.meta/config.json      |  19 +++
 .../baffling-birthdays/.meta/example.lua      |  41 ++++++
 .../.meta/spec_generator.lua                  |  64 +++++++++
 .../baffling-birthdays/.meta/tests.toml       |  61 +++++++++
 .../baffling-birthdays/baffling-birthdays.lua |  12 ++
 .../baffling-birthdays_spec.lua               | 122 ++++++++++++++++++
 .../practice/camicia/.meta/spec_generator.lua |  18 +--
 .../practice/connect/.meta/spec_generator.lua |  10 +-
 .../.meta/spec_generator.lua                  |  12 +-
 .../dominoes/.meta/spec_generator.lua         |  10 +-
 .../eliuds-eggs/.meta/spec_generator.lua      |  12 +-
 .../flower-field/.meta/spec_generator.lua     |  10 +-
 .../practice/forth/.meta/spec_generator.lua   |  22 ++--
 .../game-of-life/.meta/spec_generator.lua     |  10 +-
 .../grade-school/.meta/spec_generator.lua     |  21 +--
 .../.meta/spec_generator.lua                  |  10 +-
 .../.meta/spec_generator.lua                  |  10 +-
 .../list-ops/.meta/spec_generator.lua         |  12 +-
 .../practice/prism/.meta/spec_generator.lua   |  14 +-
 .../.meta/spec_generator.lua                  |  10 +-
 .../rectangles/.meta/spec_generator.lua       |  10 +-
 .../.meta/spec_generator.lua                  |  10 +-
 .../.meta/spec_generator.lua                  |  10 +-
 .../resistor-color/.meta/spec_generator.lua   |  10 +-
 .../saddle-points/.meta/spec_generator.lua    |  12 +-
 .../practice/series/.meta/spec_generator.lua  |  10 +-
 .../.meta/spec_generator.lua                  |  10 +-
 .../twelve-days/.meta/spec_generator.lua      |  10 +-
 .../.meta/spec_generator.lua                  |  10 +-
 .../word-search/.meta/spec_generator.lua      |  16 +--
 .../zebra-puzzle/.meta/spec_generator.lua     |  12 +-
 37 files changed, 474 insertions(+), 243 deletions(-)
 create mode 100644 exercises/practice/baffling-birthdays/.busted
 create mode 100644 exercises/practice/baffling-birthdays/.docs/instructions.md
 create mode 100644 exercises/practice/baffling-birthdays/.docs/introduction.md
 create mode 100644 exercises/practice/baffling-birthdays/.meta/config.json
 create mode 100644 exercises/practice/baffling-birthdays/.meta/example.lua
 create mode 100644 exercises/practice/baffling-birthdays/.meta/spec_generator.lua
 create mode 100644 exercises/practice/baffling-birthdays/.meta/tests.toml
 create mode 100644 exercises/practice/baffling-birthdays/baffling-birthdays.lua
 create mode 100644 exercises/practice/baffling-birthdays/baffling-birthdays_spec.lua

diff --git a/bin/generate-spec b/bin/generate-spec
index 909e5445..b23f6ba1 100755
--- a/bin/generate-spec
+++ b/bin/generate-spec
@@ -2,6 +2,32 @@
 
 local json = require 'dkjson'
 
+local utils = {}
+
+utils.map = function(t, f)
+  local mapped = {}
+  for i, v in ipairs(t) do
+    mapped[i] = f(v)
+  end
+  return mapped
+end
+
+utils.stringify = function(x)
+  return ("'%s'"):format(x)
+end
+
+utils.snake_case = function(str)
+  local s = str:gsub('%u', function(c)
+    return '_' .. c:lower()
+  end)
+  if s:sub(1, 1) == '_' then
+    s = s:sub(2)
+  end
+  return s
+end
+
+package.loaded['utils'] = utils
+
 local function read_file(path)
   local f = assert(io.open(path, 'r'))
   local contents = f:read('*a')
diff --git a/config.json b/config.json
index 4a0afe0a..9f4329fc 100644
--- a/config.json
+++ b/config.json
@@ -1481,6 +1481,14 @@
           "exception_handling",
           "graphs"
         ]
+      },
+      {
+        "slug": "baffling-birthdays",
+        "name": "Baffling Birthdays",
+        "uuid": "54dd8d8f-b58c-47d0-8c77-22dd5fcdf14f",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
       }
     ]
   },
diff --git a/exercises/practice/anagram/.meta/spec_generator.lua b/exercises/practice/anagram/.meta/spec_generator.lua
index 33a13556..f815923f 100644
--- a/exercises/practice/anagram/.meta/spec_generator.lua
+++ b/exercises/practice/anagram/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local function map(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_list(list)
-  return '{ ' .. table.concat(map(list, function(v)
+  return '{ ' .. table.concat(utils.map(list, function(v)
     return "'" .. v .. "'"
   end), ', ') .. ' }'
 end
diff --git a/exercises/practice/baffling-birthdays/.busted b/exercises/practice/baffling-birthdays/.busted
new file mode 100644
index 00000000..86b84e7c
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.busted
@@ -0,0 +1,5 @@
+return {
+  default = {
+    ROOT = { '.' }
+  }
+}
diff --git a/exercises/practice/baffling-birthdays/.docs/instructions.md b/exercises/practice/baffling-birthdays/.docs/instructions.md
new file mode 100644
index 00000000..a01ec867
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.docs/instructions.md
@@ -0,0 +1,23 @@
+# Instructions
+
+Your task is to estimate the birthday paradox's probabilities.
+
+To do this, you need to:
+
+- Generate random birthdates.
+- Check if a collection of randomly generated birthdates contains at least two with the same birthday.
+- Estimate the probability that at least two people in a group share the same birthday for different group sizes.
+
+~~~~exercism/note
+A birthdate includes the full date of birth (year, month, and day), whereas a birthday refers only to the month and day, which repeat each year.
+Two birthdates with the same month and day correspond to the same birthday.
+~~~~
+
+~~~~exercism/caution
+The birthday paradox assumes that:
+
+- There are 365 possible birthdays (no leap years).
+- Each birthday is equally likely (uniform distribution).
+
+Your implementation must follow these assumptions.
+~~~~
diff --git a/exercises/practice/baffling-birthdays/.docs/introduction.md b/exercises/practice/baffling-birthdays/.docs/introduction.md
new file mode 100644
index 00000000..97dabd1e
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.docs/introduction.md
@@ -0,0 +1,25 @@
+# Introduction
+
+Fresh out of college, you're throwing a huge party to celebrate with friends and family.
+Over 70 people have shown up, including your mildly eccentric Uncle Ted.
+
+In one of his usual antics, he bets you £100 that at least two people in the room share the same birthday.
+That sounds ridiculous — there are many more possible birthdays than there are guests, so you confidently accept.
+
+To your astonishment, after collecting the birthdays of just 32 guests, you've already found two guests that share the same birthday.
+Accepting your loss, you hand Uncle Ted his £100, but something feels off.
+
+The next day, curiosity gets the better of you.
+A quick web search leads you to the [birthday paradox][birthday-problem], which reveals that with just 23 people, the probability of a shared birthday exceeds 50%.
+
+Ah. So _that's_ why Uncle Ted was so confident.
+
+Determined to turn the tables, you start looking up other paradoxes; next time, _you'll_ be the one making the bets.
+
+~~~~exercism/note
+The birthday paradox is a [veridical paradox][veridical-paradox]: even though it feels wrong, it is actually true.
+
+[veridical-paradox]: https://en.wikipedia.org/wiki/Paradox#Quine's_classification
+~~~~
+
+[birthday-problem]: https://en.wikipedia.org/wiki/Birthday_problem
diff --git a/exercises/practice/baffling-birthdays/.meta/config.json b/exercises/practice/baffling-birthdays/.meta/config.json
new file mode 100644
index 00000000..5cf1160c
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.meta/config.json
@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "ryanplusplus"
+  ],
+  "files": {
+    "solution": [
+      "baffling-birthdays.lua"
+    ],
+    "test": [
+      "baffling-birthdays_spec.lua"
+    ],
+    "example": [
+      ".meta/example.lua"
+    ]
+  },
+  "blurb": "Estimate the birthday paradox's probabilities.",
+  "source": "Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/pull/2539"
+}
diff --git a/exercises/practice/baffling-birthdays/.meta/example.lua b/exercises/practice/baffling-birthdays/.meta/example.lua
new file mode 100644
index 00000000..bab1ea98
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.meta/example.lua
@@ -0,0 +1,41 @@
+local baffling_birthdays = {}
+
+baffling_birthdays.shared_birthday = function(birthdates)
+  local seen = {}
+  for _, birthdate in ipairs(birthdates) do
+    local without_year = birthdate:sub(6)
+    if seen[without_year] then
+      return true
+    end
+    seen[without_year] = true
+  end
+  return false
+end
+
+baffling_birthdays.random_birthdates = function(count)
+  local birthdates = {}
+
+  local non_leap_year = 2026
+  local seconds_per_day = 24 * 60 * 60
+  local start = os.time { year = non_leap_year, month = 1, day = 1, hour = 12 }
+  for i = 1, count do
+    local offset = math.random(0, 364)
+    local t = start + offset * seconds_per_day
+    table.insert(birthdates, os.date('%Y-%m-%d', t))
+  end
+
+  return birthdates
+end
+
+baffling_birthdays.estimated_probability_of_shared_birthday = function(group_size)
+  local shared_count = 0
+  for i = 1, 10000 do
+    local birthdates = baffling_birthdays.random_birthdates(group_size)
+    if baffling_birthdays.shared_birthday(birthdates) then
+      shared_count = shared_count + 1
+    end
+  end
+  return shared_count / 100
+end
+
+return baffling_birthdays
diff --git a/exercises/practice/baffling-birthdays/.meta/spec_generator.lua b/exercises/practice/baffling-birthdays/.meta/spec_generator.lua
new file mode 100644
index 00000000..5ef22962
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.meta/spec_generator.lua
@@ -0,0 +1,64 @@
+local utils = require 'utils'
+
+return {
+  module_name = 'baffling_birthdays',
+
+  generate_test = function(case)
+    if type(case.expected) == 'table' then
+      if case.expected.years and case.expected.years.leapYear ~= nil then
+        return [[
+          local birthdates = baffling_birthdays.random_birthdates(1000)
+          for _, birthdate in ipairs(birthdates) do
+            local year = tonumber(birthdate:sub(1, 4))
+            assert.is_false(year % 4 == 0 and (year % 100 ~= 0 or year % 400 == 0))
+          end]]
+      elseif case.expected.months and case.expected.months.random ~= nil then
+        return [[
+          local birthdates = baffling_birthdays.random_birthdates(1000)
+          local seen = {}
+          local unique_count = 0
+          for _, birthdate in ipairs(birthdates) do
+            local month = tonumber(birthdate:sub(6, 7))
+            if not seen[month] then
+              seen[month] = true
+              unique_count = unique_count + 1
+            end
+          end
+          assert.are.equal(12, unique_count)]]
+      elseif case.expected.days and case.expected.days.random ~= nil then
+        return [[
+          local birthdates = baffling_birthdays.random_birthdates(1000)
+          local seen = {}
+          local unique_count = 0
+          for _, birthdate in ipairs(birthdates) do
+            local day = tonumber(birthdate:sub(9, 10))
+            if not seen[day] then
+              seen[day] = true
+              unique_count = unique_count + 1
+            end
+          end
+          assert.are.equal(31, unique_count)]]
+      else
+        error('Unhandled case')
+      end
+    elseif case.expected == 'length == groupsize' then
+      return [[
+        for i = 1, 10 do
+          assert.are.equal(i, #baffling_birthdays.random_birthdates(i))
+        end]]
+    elseif case.property == 'estimatedProbabilityOfSharedBirthday' then
+      local template = [[
+        local actual = baffling_birthdays.%s(%s)
+        assert.are.near(%s, actual, 1)]]
+
+      return template:format(utils.snake_case(case.property), case.input.groupSize, case.expected)
+    else
+      local template = [[
+        local actual = baffling_birthdays.%s(%s)
+        assert.are.equal(%s, actual)]]
+
+      local input = '{ ' .. table.concat(utils.map(case.input.birthdates, utils.stringify), ', ') .. ' }'
+      return template:format(utils.snake_case(case.property), input, case.expected)
+    end
+  end
+}
diff --git a/exercises/practice/baffling-birthdays/.meta/tests.toml b/exercises/practice/baffling-birthdays/.meta/tests.toml
new file mode 100644
index 00000000..c76afb46
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.meta/tests.toml
@@ -0,0 +1,61 @@
+# 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.
+
+[716dcc2b-8fe4-4fc9-8c48-cbe70d8e6b67]
+description = "shared birthday -> one birthdate"
+
+[f7b3eb26-bcfc-4c1e-a2de-af07afc33f45]
+description = "shared birthday -> two birthdates with same year, month, and day"
+
+[7193409a-6e16-4bcb-b4cc-9ffe55f79b25]
+description = "shared birthday -> two birthdates with same year and month, but different day"
+
+[d04db648-121b-4b72-93e8-d7d2dced4495]
+description = "shared birthday -> two birthdates with same month and day, but different year"
+
+[3c8bd0f0-14c6-4d4c-975a-4c636bfdc233]
+description = "shared birthday -> two birthdates with same year, but different month and day"
+
+[df5daba6-0879-4480-883c-e855c99cdaa3]
+description = "shared birthday -> two birthdates with different year, month, and day"
+
+[0c17b220-cbb9-4bd7-872f-373044c7b406]
+description = "shared birthday -> multiple birthdates without shared birthday"
+
+[966d6b0b-5c0a-4b8c-bc2d-64939ada49f8]
+description = "shared birthday -> multiple birthdates with one shared birthday"
+
+[b7937d28-403b-4500-acce-4d9fe3a9620d]
+description = "shared birthday -> multiple birthdates with more than one shared birthday"
+
+[70b38cea-d234-4697-b146-7d130cd4ee12]
+description = "random birthdates -> generate requested number of birthdates"
+
+[d9d5b7d3-5fea-4752-b9c1-3fcd176d1b03]
+description = "random birthdates -> years are not leap years"
+
+[d1074327-f68c-4c8a-b0ff-e3730d0f0521]
+description = "random birthdates -> months are random"
+
+[7df706b3-c3f5-471d-9563-23a4d0577940]
+description = "random birthdates -> days are random"
+
+[89a462a4-4265-4912-9506-fb027913f221]
+description = "estimated probability of at least one shared birthday -> for one person"
+
+[ec31c787-0ebb-4548-970c-5dcb4eadfb5f]
+description = "estimated probability of at least one shared birthday -> among ten people"
+
+[b548afac-a451-46a3-9bb0-cb1f60c48e2f]
+description = "estimated probability of at least one shared birthday -> among twenty-three people"
+
+[e43e6b9d-d77b-4f6c-a960-0fc0129a0bc5]
+description = "estimated probability of at least one shared birthday -> among seventy people"
diff --git a/exercises/practice/baffling-birthdays/baffling-birthdays.lua b/exercises/practice/baffling-birthdays/baffling-birthdays.lua
new file mode 100644
index 00000000..050599c0
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/baffling-birthdays.lua
@@ -0,0 +1,12 @@
+local baffling_birthdays = {}
+
+baffling_birthdays.shared_birthday = function(birthdates)
+end
+
+baffling_birthdays.random_birthdates = function(count)
+end
+
+baffling_birthdays.estimated_probability_of_shared_birthday = function(group_size)
+end
+
+return baffling_birthdays
diff --git a/exercises/practice/baffling-birthdays/baffling-birthdays_spec.lua b/exercises/practice/baffling-birthdays/baffling-birthdays_spec.lua
new file mode 100644
index 00000000..5247912d
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/baffling-birthdays_spec.lua
@@ -0,0 +1,122 @@
+local baffling_birthdays = require('baffling-birthdays')
+
+describe('baffling-birthdays', function()
+  describe('shared birthday', function()
+    it('one birthdate', function()
+      local actual = baffling_birthdays.shared_birthday({ '2000-01-01' })
+      assert.are.equal(false, actual)
+    end)
+
+    it('two birthdates with same year, month, and day', function()
+      local actual = baffling_birthdays.shared_birthday({ '2000-01-01', '2000-01-01' })
+      assert.are.equal(true, actual)
+    end)
+
+    it('two birthdates with same year and month, but different day', function()
+      local actual = baffling_birthdays.shared_birthday({ '2012-05-09', '2012-05-17' })
+      assert.are.equal(false, actual)
+    end)
+
+    it('two birthdates with same month and day, but different year', function()
+      local actual = baffling_birthdays.shared_birthday({ '1999-10-23', '1988-10-23' })
+      assert.are.equal(true, actual)
+    end)
+
+    it('two birthdates with same year, but different month and day', function()
+      local actual = baffling_birthdays.shared_birthday({ '2007-12-19', '2007-04-27' })
+      assert.are.equal(false, actual)
+    end)
+
+    it('two birthdates with different year, month, and day', function()
+      local actual = baffling_birthdays.shared_birthday({ '1997-08-04', '1963-11-23' })
+      assert.are.equal(false, actual)
+    end)
+
+    it('multiple birthdates without shared birthday', function()
+      local actual = baffling_birthdays.shared_birthday({ '1966-07-29', '1977-02-12', '2001-12-25', '1980-11-10' })
+      assert.are.equal(false, actual)
+    end)
+
+    it('multiple birthdates with one shared birthday', function()
+      local actual = baffling_birthdays.shared_birthday({ '1966-07-29', '1977-02-12', '2001-07-29', '1980-11-10' })
+      assert.are.equal(true, actual)
+    end)
+
+    it('multiple birthdates with more than one shared birthday', function()
+      local actual = baffling_birthdays.shared_birthday({
+        '1966-07-29',
+        '1977-02-12',
+        '2001-12-25',
+        '1980-07-29',
+        '2019-02-12'
+      })
+      assert.are.equal(true, actual)
+    end)
+  end)
+
+  describe('random birthdates', function()
+    it('generate requested number of birthdates', function()
+      for i = 1, 10 do
+        assert.are.equal(i, #baffling_birthdays.random_birthdates(i))
+      end
+    end)
+
+    it('years are not leap years', function()
+      local birthdates = baffling_birthdays.random_birthdates(1000)
+      for _, birthdate in ipairs(birthdates) do
+        local year = tonumber(birthdate:sub(1, 4))
+        assert.is_false(year % 4 == 0 and (year % 100 ~= 0 or year % 400 == 0))
+      end
+    end)
+
+    it('months are random', function()
+      local birthdates = baffling_birthdays.random_birthdates(1000)
+      local seen = {}
+      local unique_count = 0
+      for _, birthdate in ipairs(birthdates) do
+        local month = tonumber(birthdate:sub(6, 7))
+        if not seen[month] then
+          seen[month] = true
+          unique_count = unique_count + 1
+        end
+      end
+      assert.are.equal(12, unique_count)
+    end)
+
+    it('days are random', function()
+      local birthdates = baffling_birthdays.random_birthdates(1000)
+      local seen = {}
+      local unique_count = 0
+      for _, birthdate in ipairs(birthdates) do
+        local day = tonumber(birthdate:sub(9, 10))
+        if not seen[day] then
+          seen[day] = true
+          unique_count = unique_count + 1
+        end
+      end
+      assert.are.equal(31, unique_count)
+    end)
+  end)
+
+  describe('estimated probability of at least one shared birthday', function()
+    it('for one person', function()
+      local actual = baffling_birthdays.estimated_probability_of_shared_birthday(1)
+      assert.are.near(0.0, actual, 1)
+    end)
+
+    it('among ten people', function()
+      local actual = baffling_birthdays.estimated_probability_of_shared_birthday(10)
+      assert.are.near(11.694818, actual, 1)
+    end)
+
+    it('among twenty-three people', function()
+      local actual = baffling_birthdays.estimated_probability_of_shared_birthday(23)
+      assert.are.near(50.729723, actual, 1)
+    end)
+
+    it('among seventy people', function()
+      local actual = baffling_birthdays.estimated_probability_of_shared_birthday(70)
+      assert.are.near(99.915958, actual, 1)
+    end)
+  end)
+end)
diff --git a/exercises/practice/camicia/.meta/spec_generator.lua b/exercises/practice/camicia/.meta/spec_generator.lua
index 7328187a..b26440b3 100644
--- a/exercises/practice/camicia/.meta/spec_generator.lua
+++ b/exercises/practice/camicia/.meta/spec_generator.lua
@@ -1,25 +1,15 @@
+local utils = require 'utils'
+
 return {
   module_name = 'camicia',
 
   generate_test = function(case)
     local lines = {}
-    local function snake_case(str)
-      local s = str:gsub('%u', function(c)
-        return '_' .. c:lower()
-      end)
-      if s:sub(1, 1) == '_' then
-        s = s:sub(2)
-      end
-      return s
-    end
     local function string_array(arr)
       if #arr == 0 then
         return "{}"
       end
-      local formatted = {}
-      for _, v in ipairs(arr) do
-        table.insert(formatted, string.format("'%s'", v))
-      end
+      local formatted = utils.map(arr, utils.stringify)
       return string.format("{ %s }", table.concat(formatted, ", "))
     end
 
@@ -31,7 +21,7 @@ return {
 
     table.insert(lines, string.format("local expected = %s", expected))
 
-    table.insert(lines, string.format("local result = camicia.%s(playerA, playerB)", snake_case(case.property)))
+    table.insert(lines, string.format("local result = camicia.%s(playerA, playerB)", utils.snake_case(case.property)))
     table.insert(lines, "assert.are.same(expected, result)")
 
     return table.concat(lines, "\n")
diff --git a/exercises/practice/connect/.meta/spec_generator.lua b/exercises/practice/connect/.meta/spec_generator.lua
index ca7f0e22..9d194595 100644
--- a/exercises/practice/connect/.meta/spec_generator.lua
+++ b/exercises/practice/connect/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_board(board)
-  return table.concat(map(board, function(row)
+  return table.concat(utils.map(board, function(row)
     return "'" .. row .. "', --"
   end), '\n      ')
 end
diff --git a/exercises/practice/difference-of-squares/.meta/spec_generator.lua b/exercises/practice/difference-of-squares/.meta/spec_generator.lua
index fd08d262..910b8732 100644
--- a/exercises/practice/difference-of-squares/.meta/spec_generator.lua
+++ b/exercises/practice/difference-of-squares/.meta/spec_generator.lua
@@ -1,12 +1,4 @@
-local function snake_case(str)
-  local s = str:gsub('%u', function(c)
-    return '_' .. c:lower()
-  end)
-  if s:sub(1, 1) == '_' then
-    s = s:sub(2)
-  end
-  return s
-end
+local utils = require 'utils'
 
 return {
   module_name = 'diff',
@@ -14,6 +6,6 @@ return {
   generate_test = function(case)
     local template = [[
       assert.equal(%s, diff.%s(%s))]]
-    return template:format(case.expected, snake_case(case.property), case.input.number)
+    return template:format(case.expected, utils.snake_case(case.property), case.input.number)
   end
 }
diff --git a/exercises/practice/dominoes/.meta/spec_generator.lua b/exercises/practice/dominoes/.meta/spec_generator.lua
index f9e0360f..b242c443 100644
--- a/exercises/practice/dominoes/.meta/spec_generator.lua
+++ b/exercises/practice/dominoes/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_dominoes(dominoes)
-  return table.concat(map(dominoes, function(domino)
+  return table.concat(utils.map(dominoes, function(domino)
     return ('{ %s }'):format(table.concat(domino, ', '))
   end), ', ')
 end
diff --git a/exercises/practice/eliuds-eggs/.meta/spec_generator.lua b/exercises/practice/eliuds-eggs/.meta/spec_generator.lua
index 698909cd..e22a4eef 100644
--- a/exercises/practice/eliuds-eggs/.meta/spec_generator.lua
+++ b/exercises/practice/eliuds-eggs/.meta/spec_generator.lua
@@ -1,12 +1,4 @@
-local function snake_case(str)
-  local s = str:gsub('%u', function(c)
-    return '_' .. c:lower()
-  end)
-  if s:sub(1, 1) == '_' then
-    s = s:sub(2)
-  end
-  return s
-end
+local utils = require 'utils'
 
 return {
   module_name = 'EliudsEggs',
@@ -14,6 +6,6 @@ return {
   generate_test = function(case)
     local template = [[
       assert.equal(%s, EliudsEggs.%s(%s))]]
-    return template:format(case.expected, snake_case(case.property), case.input.number)
+    return template:format(case.expected, utils.snake_case(case.property), case.input.number)
   end
 }
diff --git a/exercises/practice/flower-field/.meta/spec_generator.lua b/exercises/practice/flower-field/.meta/spec_generator.lua
index ba087f75..b43cd678 100644
--- a/exercises/practice/flower-field/.meta/spec_generator.lua
+++ b/exercises/practice/flower-field/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_garden(garden)
-  return table.concat(map(garden, function(row)
+  return table.concat(utils.map(garden, function(row)
     return "'" .. row .. "', --"
   end), '\n      ')
 end
diff --git a/exercises/practice/forth/.meta/spec_generator.lua b/exercises/practice/forth/.meta/spec_generator.lua
index 3169e52b..dc827d87 100644
--- a/exercises/practice/forth/.meta/spec_generator.lua
+++ b/exercises/practice/forth/.meta/spec_generator.lua
@@ -1,10 +1,4 @@
-local function map(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function stringify(x)
   return ("'%s'"):format(x)
@@ -20,22 +14,22 @@ return {
           forth.evaluate({ %s })
         end)]]
 
-      return template:format(table.concat(map(case.input.instructions, stringify), ' '), case.expected.error)
+      return template:format(table.concat(utils.map(case.input.instructions, stringify), ' '), case.expected.error)
     elseif case.input.instructions then
       local template = [[
         assert.are.same({ %s }, forth.evaluate({ %s }))]]
 
-      return template:format(table.concat(map(case.expected, tostring), ', '),
-                             table.concat(map(case.input.instructions, stringify), ', '))
+      return template:format(table.concat(utils.map(case.expected, tostring), ', '),
+                             table.concat(utils.map(case.input.instructions, stringify), ', '))
     else
       local template = [[
         assert.are.same({ %s }, forth.evaluate({ %s }))
         assert.are.same({ %s }, forth.evaluate({ %s }))]]
 
-      return template:format(table.concat(map(case.expected[1], tostring), ', '),
-                             table.concat(map(case.input.instructionsFirst, stringify), ', '),
-                             table.concat(map(case.expected[2], tostring), ', '),
-                             table.concat(map(case.input.instructionsSecond, stringify), ', '))
+      return template:format(table.concat(utils.map(case.expected[1], tostring), ', '),
+                             table.concat(utils.map(case.input.instructionsFirst, stringify), ', '),
+                             table.concat(utils.map(case.expected[2], tostring), ', '),
+                             table.concat(utils.map(case.input.instructionsSecond, stringify), ', '))
     end
   end
 }
diff --git a/exercises/practice/game-of-life/.meta/spec_generator.lua b/exercises/practice/game-of-life/.meta/spec_generator.lua
index 6ca9126a..b26cfad5 100644
--- a/exercises/practice/game-of-life/.meta/spec_generator.lua
+++ b/exercises/practice/game-of-life/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_matrix(matrix)
-  return table.concat(map(matrix, function(row)
+  return table.concat(utils.map(matrix, function(row)
     return '{' .. table.concat(row, ', ') .. '}, --'
   end), '\n')
 end
diff --git a/exercises/practice/grade-school/.meta/spec_generator.lua b/exercises/practice/grade-school/.meta/spec_generator.lua
index ed1e930b..a2ac2c28 100644
--- a/exercises/practice/grade-school/.meta/spec_generator.lua
+++ b/exercises/practice/grade-school/.meta/spec_generator.lua
@@ -1,14 +1,4 @@
-local function map(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
-
-local function stringify(x)
-  return ("'%s'"):format(x)
-end
+local utils = require 'utils'
 
 return {
   module_name = 'School',
@@ -19,11 +9,12 @@ return {
     if case.property == 'grade' or case.property == 'roster' then
       for _, input in ipairs(case.input.students) do
         local student, grade = table.unpack(input)
-        table.insert(lines, ('school:add(%s, %d)'):format(stringify(student), grade))
+        table.insert(lines, ('school:add(%s, %d)'):format(utils.stringify(student), grade))
       end
       table.insert(lines,
-                   ('assert.are.same({ %s }, school:%s(%s))'):format(table.concat(map(case.expected, stringify), ', '),
-                                                                     case.property, case.input.desiredGrade or ''))
+                   ('assert.are.same({ %s }, school:%s(%s))'):format(
+                     table.concat(utils.map(case.expected, utils.stringify), ', '), case.property,
+                     case.input.desiredGrade or ''))
     elseif case.property == 'add' then
       for i, input in ipairs(case.input.students) do
         local student, grade = table.unpack(input)
@@ -35,7 +26,7 @@ return {
             expected = case.expected
           end
         end
-        table.insert(lines, ('assert.is_%s(school:add(%s, %d))'):format(expected, stringify(student), grade))
+        table.insert(lines, ('assert.is_%s(school:add(%s, %d))'):format(expected, utils.stringify(student), grade))
       end
     else
       error("Unknown property: " .. case.property)
diff --git a/exercises/practice/killer-sudoku-helper/.meta/spec_generator.lua b/exercises/practice/killer-sudoku-helper/.meta/spec_generator.lua
index 26973e9e..efe196a9 100644
--- a/exercises/practice/killer-sudoku-helper/.meta/spec_generator.lua
+++ b/exercises/practice/killer-sudoku-helper/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_solutions(solutions)
-  return table.concat(map(solutions, function(solution)
+  return table.concat(utils.map(solutions, function(solution)
     return '{' .. table.concat(solution, ', ') .. '}, --'
   end), '\n')
 end
diff --git a/exercises/practice/kindergarten-garden/.meta/spec_generator.lua b/exercises/practice/kindergarten-garden/.meta/spec_generator.lua
index 874d230d..70cd19f5 100644
--- a/exercises/practice/kindergarten-garden/.meta/spec_generator.lua
+++ b/exercises/practice/kindergarten-garden/.meta/spec_generator.lua
@@ -1,17 +1,11 @@
-local function map(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 return {
   module_name = 'Garden',
 
   generate_test = function(case)
     local diagram = case.input.diagram:gsub('\n', '\\n')
-    local expected = table.concat(map(case.expected, function(x)
+    local expected = table.concat(utils.map(case.expected, function(x)
       return ("'%s'"):format(x)
     end), ', ')
 
diff --git a/exercises/practice/list-ops/.meta/spec_generator.lua b/exercises/practice/list-ops/.meta/spec_generator.lua
index ac469847..e927ed0c 100644
--- a/exercises/practice/list-ops/.meta/spec_generator.lua
+++ b/exercises/practice/list-ops/.meta/spec_generator.lua
@@ -1,17 +1,11 @@
-local function map(t, f)
-  local result = {}
-  for i, v in ipairs(t) do
-    result[i] = f(v)
-  end
-  return result
-end
+local utils = require 'utils'
 
 local function render_list(list)
   if type(list) ~= 'table' then
     return list
   end
 
-  return '{' .. table.concat(map(list, render_list), ', ') .. '}'
+  return '{' .. table.concat(utils.map(list, render_list), ', ') .. '}'
 end
 
 local function render_function(s)
@@ -31,7 +25,7 @@ return {
         assert.are.same(expected, actual)]]
 
       return template:format(render_list(case.expected), case.property,
-                             render_list(table.concat(map(case.input.lists, render_list), ', ')))
+                             render_list(table.concat(utils.map(case.input.lists, render_list), ', ')))
     elseif case.input.list1 and case.input.list2 then
       local template = [[
         local expected = %s
diff --git a/exercises/practice/prism/.meta/spec_generator.lua b/exercises/practice/prism/.meta/spec_generator.lua
index 7aec3499..c2354827 100644
--- a/exercises/practice/prism/.meta/spec_generator.lua
+++ b/exercises/practice/prism/.meta/spec_generator.lua
@@ -1,19 +1,11 @@
+local utils = require 'utils'
+
 return {
   module_name = 'prism',
 
   generate_test = function(case)
     local lines = {}
 
-    local function snake_case(str)
-      local s = str:gsub('%u', function(c)
-        return '_' .. c:lower()
-      end)
-      if s:sub(1, 1) == '_' then
-        s = s:sub(2)
-      end
-      return s
-    end
-
     table.insert(lines,
                  string.format("local start = { x = %s, y = %s, angle = %s }", case.input.start.x, case.input.start.y,
                                case.input.start.angle))
@@ -37,7 +29,7 @@ return {
     end
 
     table.insert(lines, string.format("local expected = %s", expected))
-    table.insert(lines, string.format("local result = prism.%s(start, prisms)", snake_case(case.property)))
+    table.insert(lines, string.format("local result = prism.%s(start, prisms)", utils.snake_case(case.property)))
     table.insert(lines, "assert.are.same(expected, result)")
 
     return table.concat(lines, "\n")
diff --git a/exercises/practice/protein-translation/.meta/spec_generator.lua b/exercises/practice/protein-translation/.meta/spec_generator.lua
index e06e3865..4150f582 100644
--- a/exercises/practice/protein-translation/.meta/spec_generator.lua
+++ b/exercises/practice/protein-translation/.meta/spec_generator.lua
@@ -1,10 +1,4 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function stringify(v)
   return ("'%s'"):format(tostring(v))
@@ -25,7 +19,7 @@ return {
       local template = [[
         assert.are.same({ %s }, protein_translation.%s('%s'))]]
 
-      return template:format(table.concat(map(case.expected, stringify), ', '), case.property, case.input.strand)
+      return template:format(table.concat(utils.map(case.expected, stringify), ', '), case.property, case.input.strand)
     end
   end
 }
diff --git a/exercises/practice/rectangles/.meta/spec_generator.lua b/exercises/practice/rectangles/.meta/spec_generator.lua
index dea9b98a..00d7a128 100644
--- a/exercises/practice/rectangles/.meta/spec_generator.lua
+++ b/exercises/practice/rectangles/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_strings(strings)
-  return table.concat(map(strings, function(row)
+  return table.concat(utils.map(strings, function(row)
     return "'" .. row .. "', --"
   end), '\n      ')
 end
diff --git a/exercises/practice/resistor-color-duo/.meta/spec_generator.lua b/exercises/practice/resistor-color-duo/.meta/spec_generator.lua
index 6d0de7d3..eed6cb3d 100644
--- a/exercises/practice/resistor-color-duo/.meta/spec_generator.lua
+++ b/exercises/practice/resistor-color-duo/.meta/spec_generator.lua
@@ -1,10 +1,4 @@
-local function map(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function stringify(s)
   return "'" .. s .. "'"
@@ -16,6 +10,6 @@ return {
   generate_test = function(case)
     local template = [[
         assert.equal(%d, rcd.value({ %s }))]]
-    return template:format(case.expected, table.concat(map(case.input.colors, stringify), ', '))
+    return template:format(case.expected, table.concat(utils.map(case.input.colors, stringify), ', '))
   end
 }
diff --git a/exercises/practice/resistor-color-trio/.meta/spec_generator.lua b/exercises/practice/resistor-color-trio/.meta/spec_generator.lua
index b75bf626..54c3c79b 100644
--- a/exercises/practice/resistor-color-trio/.meta/spec_generator.lua
+++ b/exercises/practice/resistor-color-trio/.meta/spec_generator.lua
@@ -1,10 +1,4 @@
-local function map(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function stringify(s)
   return "'" .. s .. "'"
@@ -20,7 +14,7 @@ return {
         assert.are.equal('%s', unit)]]
     return template:format(table.unpack({
       case.property,
-      table.concat(map(case.input.colors, stringify), ', '),
+      table.concat(utils.map(case.input.colors, stringify), ', '),
       case.expected.value,
       case.expected.unit
     }))
diff --git a/exercises/practice/resistor-color/.meta/spec_generator.lua b/exercises/practice/resistor-color/.meta/spec_generator.lua
index 01b2d96e..5f08565e 100644
--- a/exercises/practice/resistor-color/.meta/spec_generator.lua
+++ b/exercises/practice/resistor-color/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_table(t)
-  return table.concat(map(t, function(element)
+  return table.concat(utils.map(t, function(element)
     return "'" .. element .. "'"
   end), ', --\n')
 end
diff --git a/exercises/practice/saddle-points/.meta/spec_generator.lua b/exercises/practice/saddle-points/.meta/spec_generator.lua
index 3e3e7336..6eab07e4 100644
--- a/exercises/practice/saddle-points/.meta/spec_generator.lua
+++ b/exercises/practice/saddle-points/.meta/spec_generator.lua
@@ -1,19 +1,13 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_matrix(matrix)
-  return table.concat(map(matrix, function(row)
+  return table.concat(utils.map(matrix, function(row)
     return '{' .. table.concat(row, ', ') .. '}, --'
   end), '\n')
 end
 
 local function render_result(result)
-  return table.concat(map(result, function(point)
+  return table.concat(utils.map(result, function(point)
     return ('{ row = %s, column = %s }, --'):format(point.row, point.column)
   end), '\n')
 end
diff --git a/exercises/practice/series/.meta/spec_generator.lua b/exercises/practice/series/.meta/spec_generator.lua
index ca173ba7..66391c01 100644
--- a/exercises/practice/series/.meta/spec_generator.lua
+++ b/exercises/practice/series/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_substrings(substrings)
-  return table.concat(map(substrings, function(substring)
+  return table.concat(utils.map(substrings, function(substring)
     return string.format('"%s"', substring)
   end), ', ')
 end
diff --git a/exercises/practice/state-of-tic-tac-toe/.meta/spec_generator.lua b/exercises/practice/state-of-tic-tac-toe/.meta/spec_generator.lua
index 0a4e0720..1496b3fd 100644
--- a/exercises/practice/state-of-tic-tac-toe/.meta/spec_generator.lua
+++ b/exercises/practice/state-of-tic-tac-toe/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_board(board)
-  return table.concat(map(board, function(row)
+  return table.concat(utils.map(board, function(row)
     return '\'' .. row .. '\', --'
   end), '\n')
 end
diff --git a/exercises/practice/twelve-days/.meta/spec_generator.lua b/exercises/practice/twelve-days/.meta/spec_generator.lua
index 8088c862..3cf227e0 100644
--- a/exercises/practice/twelve-days/.meta/spec_generator.lua
+++ b/exercises/practice/twelve-days/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_song(lines)
-  return table.concat(map(lines, function(line)
+  return table.concat(utils.map(lines, function(line)
     return '\'' .. line .. '\''
   end), ',\n')
 end
diff --git a/exercises/practice/variable-length-quantity/.meta/spec_generator.lua b/exercises/practice/variable-length-quantity/.meta/spec_generator.lua
index 6595c50f..6258d121 100644
--- a/exercises/practice/variable-length-quantity/.meta/spec_generator.lua
+++ b/exercises/practice/variable-length-quantity/.meta/spec_generator.lua
@@ -1,13 +1,7 @@
-local map = function(t, f)
-  local mapped = {}
-  for i, v in ipairs(t) do
-    mapped[i] = f(v)
-  end
-  return mapped
-end
+local utils = require 'utils'
 
 local function render_integers(integers)
-  return table.concat(map(integers, function(integer)
+  return table.concat(utils.map(integers, function(integer)
     return string.format("0x%x", integer)
   end), ', ')
 end
diff --git a/exercises/practice/word-search/.meta/spec_generator.lua b/exercises/practice/word-search/.meta/spec_generator.lua
index 81959ffc..eddc26c2 100644
--- a/exercises/practice/word-search/.meta/spec_generator.lua
+++ b/exercises/practice/word-search/.meta/spec_generator.lua
@@ -1,14 +1,4 @@
-local function map(t, f)
-  local result = {}
-  for i, v in ipairs(t) do
-    result[i] = f(v)
-  end
-  return result
-end
-
-local function stringify(x)
-  return ("'%s'"):format(x)
-end
+local utils = require 'utils'
 
 local function render_expected(expected)
   local key_value_pairs = {}
@@ -40,8 +30,8 @@ return {
       local expected = %s
       assert.are.same(expected, WordSearch(grid).search(words))]]
 
-    local grid = table.concat(map(case.input.grid, stringify), ', --\n')
-    local words = table.concat(map(case.input.wordsToSearchFor, stringify), ', --\n')
+    local grid = table.concat(utils.map(case.input.grid, utils.stringify), ', --\n')
+    local words = table.concat(utils.map(case.input.wordsToSearchFor, utils.stringify), ', --\n')
     local expected = render_expected(case.expected)
 
     return template:format(grid, words, expected)
diff --git a/exercises/practice/zebra-puzzle/.meta/spec_generator.lua b/exercises/practice/zebra-puzzle/.meta/spec_generator.lua
index e3e3997a..a5e3fd54 100644
--- a/exercises/practice/zebra-puzzle/.meta/spec_generator.lua
+++ b/exercises/practice/zebra-puzzle/.meta/spec_generator.lua
@@ -1,12 +1,4 @@
-local function snake_case(str)
-  local s = str:gsub('%u', function(c)
-    return '_' .. c:lower()
-  end)
-  if s:sub(1, 1) == '_' then
-    s = s:sub(2)
-  end
-  return s
-end
+local utils = require 'utils'
 
 return {
   module_name = 'zebra_puzzle',
@@ -14,6 +6,6 @@ return {
   generate_test = function(case)
     local template = [[
       assert.equal('%s', zebra_puzzle.%s())]]
-    return template:format(case.expected, snake_case(case.property))
+    return template:format(case.expected, utils.snake_case(case.property))
   end
 }

From 6e7a03f8cd383da883f16059d0bc1c4d23d5fc3b Mon Sep 17 00:00:00 2001
From: Ryan Hartlage <2488333+ryanplusplus@users.noreply.github.com>
Date: Sun, 3 May 2026 19:01:48 -0400
Subject: [PATCH 2/2] Use a more capable stringify

---
 bin/generate-spec                                   | 13 +++++++++----
 .../practice/baffling-birthdays/.meta/example.lua   |  2 +-
 .../practice/word-count/.meta/spec_generator.lua    | 13 +++----------
 3 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/bin/generate-spec b/bin/generate-spec
index b23f6ba1..ad8f13c9 100755
--- a/bin/generate-spec
+++ b/bin/generate-spec
@@ -12,8 +12,13 @@ utils.map = function(t, f)
   return mapped
 end
 
-utils.stringify = function(x)
-  return ("'%s'"):format(x)
+utils.stringify = function(s)
+  s = s:gsub('\n', '\\n')
+  if s:match("'") and not s:match('"') then
+    return '"' .. s .. '"'
+  else
+    return "'" .. s:gsub("'", "\\'") .. "'"
+  end
 end
 
 utils.snake_case = function(str)
@@ -107,12 +112,12 @@ local function process(node)
     return table.concat(output, '\n')
   else
     local template = [[
-      it('%s', function()
+      it(%s, function()
         %s
       end)]]
 
     return template:format(
-      node.description:lower():gsub('\'', '\\\''),
+      utils.stringify(node.description:lower()),
       spec_generator.generate_test(node)
     )
   end
diff --git a/exercises/practice/baffling-birthdays/.meta/example.lua b/exercises/practice/baffling-birthdays/.meta/example.lua
index bab1ea98..b5d8df7a 100644
--- a/exercises/practice/baffling-birthdays/.meta/example.lua
+++ b/exercises/practice/baffling-birthdays/.meta/example.lua
@@ -17,7 +17,7 @@ baffling_birthdays.random_birthdates = function(count)
 
   local non_leap_year = 2026
   local seconds_per_day = 24 * 60 * 60
-  local start = os.time { year = non_leap_year, month = 1, day = 1, hour = 12 }
+  local start = os.time({ year = non_leap_year, month = 1, day = 1, hour = 12 })
   for i = 1, count do
     local offset = math.random(0, 364)
     local t = start + offset * seconds_per_day
diff --git a/exercises/practice/word-count/.meta/spec_generator.lua b/exercises/practice/word-count/.meta/spec_generator.lua
index 89a6e8f7..70074656 100644
--- a/exercises/practice/word-count/.meta/spec_generator.lua
+++ b/exercises/practice/word-count/.meta/spec_generator.lua
@@ -1,16 +1,9 @@
-local function stringify(s)
-  s = s:gsub('\n', '\\n')
-  if s:match("'") and not s:match('"') then
-    return '"' .. s .. '"'
-  else
-    return "'" .. s:gsub("'", "\\'") .. "'"
-  end
-end
+local utils = require 'utils'
 
 local function format_hash(t)
   local key_value_pairs = {}
   for key in pairs(t) do
-    table.insert(key_value_pairs, "[" .. stringify(key) .. "] = " .. t[key])
+    table.insert(key_value_pairs, "[" .. utils.stringify(key) .. "] = " .. t[key])
   end
 
   table.sort(key_value_pairs)
@@ -27,6 +20,6 @@ return {
       local expected = %s
       assert.are.same(expected, result)]]
 
-    return template:format(stringify(case.input.sentence), format_hash(case.expected))
+    return template:format(utils.stringify(case.input.sentence), format_hash(case.expected))
   end
 }