Test_Writing_Exercise

flatten_array_spec.rb

require 'minitest/autorun'
require 'minitest/reporters'
require_relative 'flatten'

Minitest::Reporters.use!

describe "flatten_array" do
  it "can be called with integers" do

    #Arrange
    array = [1,2,[3,nil],nil,5]
    #Act up on that method
    new_array = flatten_array(array)
    #Assert that the output is
    # expect(new_array).must_include Integers
    expect(new_array).must_equal [1,2,3,5]

    # Testing is about calling upon the method that we are trying to tests
    # When we run the method 'the expect' is what we expect
    # the result of calling the method will output
    # Hence we call a specific value

  end

  it "can be called with string" do
    array = ['John', 'Paula',['Mary',['Joy']]]
    new_array = flatten_array(array)
    # expect(new_array).must_include Strings
    expect(new_array).must_equal ['John','Paula','Mary','Joy']
  end

  # Needs some work
  it " can be called with mixed values" do
    array = [1,3,nil,["Mary",["John"]]]
    new_array = flatten_array(array)
    # expect(new_array).must_include Strings and Integers
    # expect(new_array).must_inclue Mixed Elements
    expect(new_array).must_equal [1,3,'Mary','John']
  end

  it "will return a flattened array" do
    array = [1,3,["Mary",nil,["John"]]]
    new_array = flatten_array(array)
    expect(new_array).must_equal [1,3,'Mary','John']
  end

  it "will return a flattened array" do
    array = [[],[],[1]]
    new_array = flatten_array(array)
    expect(new_array).must_equal [1]
  end

  it "will not return nil as a value" do
    array = [1,3,['Mary',nil,['John']]]
    new_array = flatten_array(array)
    # expect(new_array).wont_include nil
    expect(new_array).must_equal [1,3,'Mary','John']
  end

  it "will return an empty array" do
    array = [nil,nil,[nil,nil,[nil]]]
    new_array = flatten_array(array)
    # expect(new_array).wont_include nil
    expect(new_array).must_equal [ ]
  end


  ## Do edge case need to be argument errors?
  ## For example - all nils input - edge or argument error

  ### Raising Arguments -> when the expected output is incorrect. The output that the method was expecting is different than the output provided.

  it "will raise an error when given an invalid argument" do
    ## no nested arrays
    expect {flatten_array[1,2,3,'John','Paul',nil]}.must_raise ArgumentError
    ## all nils
    expect {flatten_array[nil,nil,nil,[nil]]}.must_raise ArgumentError
    ## all empty arrays
    expect {flatten_array[[],[],[]]}.must_raise ArgumentError
    ## no nil
    expect {flatten_array[1,3,4,[5],"June","John"]}.must_raise ArgumentError
  end

end