weather data kata.

2 files changed, 95 insertions, 0 deletions

diff --git a/spec/fixtures/weather.dat b/spec/fixtures/weather.dat
new file mode 100644
index 0000000..53789aa
--- /dev/null
+++ b/spec/fixtures/weather.dat
@@ -0,0 +1,33 @@
+  Dy MxT   MnT   AvT   HDDay  AvDP 1HrP TPcpn WxType PDir AvSp Dir MxS SkyC MxR MnR AvSLP
+
+   1  88    59    74          53.8       0.00 F       280  9.6 270  17  1.6  93 23 1004.5
+   2  79    63    71          46.5       0.00         330  8.7 340  23  3.3  70 28 1004.5
+   3  77    55    66          39.6       0.00         350  5.0 350   9  2.8  59 24 1016.8
+   4  77    59    68          51.1       0.00         110  9.1 130  12  8.6  62 40 1021.1
+   5  90    66    78          68.3       0.00 TFH     220  8.3 260  12  6.9  84 55 1014.4
+   6  81    61    71          63.7       0.00 RFH     030  6.2 030  13  9.7  93 60 1012.7
+   7  73    57    65          53.0       0.00 RF      050  9.5 050  17  5.3  90 48 1021.8
+   8  75    54    65          50.0       0.00 FH      160  4.2 150  10  2.6  93 41 1026.3
+   9  86    32*   59       6  61.5       0.00         240  7.6 220  12  6.0  78 46 1018.6
+  10  84    64    74          57.5       0.00 F       210  6.6 050   9  3.4  84 40 1019.0
+  11  91    59    75          66.3       0.00 H       250  7.1 230  12  2.5  93 45 1012.6
+  12  88    73    81          68.7       0.00 RTH     250  8.1 270  21  7.9  94 51 1007.0
+  13  70    59    65          55.0       0.00 H       150  3.0 150   8 10.0  83 59 1012.6
+  14  61    59    60       5  55.9       0.00 RF      060  6.7 080   9 10.0  93 87 1008.6
+  15  64    55    60       5  54.9       0.00 F       040  4.3 200   7  9.6  96 70 1006.1
+  16  79    59    69          56.7       0.00 F       250  7.6 240  21  7.8  87 44 1007.0
+  17  81    57    69          51.7       0.00 T       260  9.1 270  29* 5.2  90 34 1012.5
+  18  82    52    67          52.6       0.00         230  4.0 190  12  5.0  93 34 1021.3
+  19  81    61    71          58.9       0.00 H       250  5.2 230  12  5.3  87 44 1028.5
+  20  84    57    71          58.9       0.00 FH      150  6.3 160  13  3.6  90 43 1032.5
+  21  86    59    73          57.7       0.00 F       240  6.1 250  12  1.0  87 35 1030.7
+  22  90    64    77          61.1       0.00 H       250  6.4 230   9  0.2  78 38 1026.4
+  23  90    68    79          63.1       0.00 H       240  8.3 230  12  0.2  68 42 1021.3
+  24  90    77    84          67.5       0.00 H       350  8.5 010  14  6.9  74 48 1018.2
+  25  90    72    81          61.3       0.00         190  4.9 230   9  5.6  81 29 1019.6
+  26  97*   64    81          70.4       0.00 H       050  5.1 200  12  4.0 107 45 1014.9
+  27  91    72    82          69.7       0.00 RTH     250 12.1 230  17  7.1  90 47 1009.0
+  28  84    68    76          65.6       0.00 RTFH    280  7.6 340  16  7.0 100 51 1011.0
+  29  88    66    77          59.7       0.00         040  5.4 020   9  5.3  84 33 1020.6
+  30  90    45    68          63.6       0.00 H       240  6.0 220  17  4.8 200 41 1022.7
+  mo  82.9  60.5  71.7    16  58.8       0.00              6.9          5.3
diff --git a/spec/kata/weather_data_spec.rb b/spec/kata/weather_data_spec.rb
new file mode 100644
index 0000000..fdfccf3
--- /dev/null
+++ b/spec/kata/weather_data_spec.rb
@@ -0,0 +1,62 @@
+require 'spec_helper'
+require 'csv'
+require 'ostruct'
+#In weather.dat you’ll find daily weather data for Morristown, NJ for June 2002. 
+#Download this text file, then write a program to output the day number (column one) 
+#with the smallest temperature spread (the maximum temperature is the second column, the minimum the third column).
+
+class Day
+  include Comparable
+  attr_reader :day, :spread
+
+  def initialize(day:, max:, min:)
+    @day = day
+    @spread = max - min
+  end
+
+  def <=>(other)
+    @spread <=> other.spread
+  end
+
+  def self.map_from(row)
+    Day.new(day: row[0], max: row[1].to_f, min: row[2].to_f)
+  end
+end
+
+class Spread
+  include Enumerable
+
+  def initialize(filename, mapper)
+    @file_path = File.join(File.dirname(__FILE__), "../fixtures", filename)
+    @mapper = mapper
+  end
+
+  def each
+    open_file do |file|
+      file.each_line.with_index do |line, index|
+        next if index == 0
+        next if line.chomp.empty?
+        yield mapper.map_from(line.split)
+      end
+    end
+  end
+
+  private
+
+  def open_file
+    file = File.new(file_path)
+    yield file
+  ensure
+    file.close
+  end
+
+  attr_reader :file_path, :mapper
+end
+
+describe "spread" do
+  subject { Spread.new('weather.dat', Day) }
+
+  it 'returns the day with the smallest temperature spread' do
+    expect(subject.min.day).to eql('14')
+  end
+end