ruby - grade-school

ruby/grade-school/README.md

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+# Grade School
+
+Given students' names along with the grade that they are in, create a roster
+for the school.
+
+In the end, you should be able to:
+
+- Add a student's name to the roster for a grade
+  - "Add Jim to grade 2."
+  - "OK."
+- Get a list of all students enrolled in a grade
+  - "Which students are in grade 2?"
+  - "We've only got Jim just now."
+- Get a sorted list of all students in all grades.  Grades should sort
+  as 1, 2, 3, etc., and students within a grade should be sorted
+  alphabetically by name.
+  - "Who all is enrolled in school right now?"
+  - "Grade 1: Anna, Barb, and Charlie. Grade 2: Alex, Peter, and Zoe.
+    Grade 3…"
+
+Note that all our students only have one name.  (It's a small town, what
+do you want?)
+
+## For bonus points
+
+Did you get the tests passing and the code clean? If you want to, these
+are some additional things you could try:
+
+- If you're working in a language with mutable data structures and your
+  implementation allows outside code to mutate the school's internal DB
+  directly, see if you can prevent this. Feel free to introduce additional
+  tests.
+
+Then please share your thoughts in a comment on the submission. Did this
+experiment make the code better? Worse? Did you learn anything from it?
+
+* * * *
+
+For installation and learning resources, refer to the
+[exercism help page](http://exercism.io/languages/ruby).
+
+For running the tests provided, you will need the Minitest gem. Open a
+terminal window and run the following command to install minitest:
+
+    gem install minitest
+
+If you would like color output, you can `require 'minitest/pride'` in
+the test file, or note the alternative instruction, below, for running
+the test file.
+
+Run the tests from the exercise directory using the following command:
+
+    ruby grade_school_test.rb
+
+To include color from the command line:
+
+    ruby -r minitest/pride grade_school_test.rb
+
+
+## Source
+
+A pairing session with Phil Battos at gSchool [http://gschool.it](http://gschool.it)
+
+## Submitting Incomplete Solutions
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

ruby/grade-school/grade_school.rb

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+class School
+  def initialize
+    @roster = {}
+  end
+
+  def students(grade)
+    @roster[grade] || []
+  end
+
+  def add(name, grade)
+    if @roster[grade].nil?
+      @roster[grade] = []
+    end
+    @roster[grade].push(name).sort!
+  end
+
+  def students_by_grade
+    @roster.sort.map {|key, value| {grade: key, students: value}}
+  end
+end

ruby/grade-school/grade_school_test.rb

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+require 'minitest/autorun'
+require_relative 'grade_school'
+
+class SchoolTest < Minitest::Test
+  def test_empty_grade
+    school = School.new
+    expected = []
+    assert_equal expected, school.students(1)
+  end
+
+  def test_add_student
+    # skip
+    school = School.new
+    assert school.add('Aimee', 2)
+    expected = ['Aimee']
+    assert_equal expected, school.students(2)
+  end
+
+  def test_add_students_to_different_grades
+    # skip
+    school = School.new
+    school.add('Aimee', 3)
+    school.add('Beemee', 7)
+    assert_equal ['Aimee'], school.students(3)
+    assert_equal ['Beemee'], school.students(7)
+  end
+
+  def test_grade_with_multiple_students
+    # skip
+    school = School.new
+    grade    = 6
+    students = %w(Aimee Beemee Ceemee)
+    students.each { |student| school.add(student, grade) }
+    assert_equal students, school.students(grade)
+  end
+
+  def test_grade_with_multiple_students_sorts_correctly
+    # skip
+    school = School.new
+    grade    = 6
+    students = %w(Beemee Aimee Ceemee)
+    students.each { |student| school.add(student, grade) }
+    expected = students.sort
+    assert_equal expected, school.students(grade)
+  end
+
+  def test_empty_students_by_grade
+    # skip
+    school = School.new
+    expected = []
+    assert_equal expected, school.students_by_grade
+  end
+
+  def test_students_by_grade
+    # skip
+    school = School.new
+    grade    = 6
+    students = %w(Beemee Aimee Ceemee)
+    students.each { |student| school.add(student, grade) }
+    expected = [{ grade: grade, students: students.sort }]
+    assert_equal expected, school.students_by_grade
+  end
+
+  def test_students_by_grade_sorted
+    # skip
+    school = School.new
+    everyone.each do |grade|
+      grade[:students].each { |student| school.add(student, grade[:grade]) }
+    end
+    expected = everyone_sorted
+    assert_equal expected, school.students_by_grade
+  end
+
+  def everyone
+    [
+      { grade: 3, students: %w(Deemee Eeemee) },
+      { grade: 1, students: %w(Effmee Geemee) },
+      { grade: 2, students: %w(Aimee Beemee Ceemee) }
+    ]
+  end
+
+  def everyone_sorted
+    [
+      { grade: 1, students: %w(Effmee Geemee) },
+      { grade: 2, students: %w(Aimee Beemee Ceemee) },
+      { grade: 3, students: %w(Deemee Eeemee) }
+    ]
+  end
+end