我正在学习 TestFirst.org 的 Ruby 教程。我目前正在上“字典”课。我被困在关键字示例上。这是 Ruby 文档以及 RSpec 文件。
我感到困惑的原因是我不确定这个例子是否正确。如果按照 RSpec 文件,“可以检查给定关键字是否存在”之前的示例使用 add 方法将“鱼”添加到字典中。然后,在给我一个错误的例子中,包括?方法(我需要实现)应该返回 false。
它应该返回false吗?我们不是在上面的例子中添加了“鱼”吗?还是我错过了什么?
这是我的 Ruby 程序:
class Dictionary
def initialize
@entries = {}
end
def entries
@entries
end
def keywords
@entries.keys
end
def add(pairings)
if pairings.is_a?(String)
@entries[pairings] = nil
else
pairings.each do |word, definition|
@entries[word] = definition
end
end
end
def include?(keyword)
@entries.keys.include?(keyword)
end
end
以下是 RSpec 文件: # # 主题 # # * 哈希 # * 数组 # * 实例变量 # * 正则表达式 #
require 'dictionary'
describe Dictionary do
before do
@d = Dictionary.new
end
it 'is empty when created' do
@d.entries.should == {}
end
it 'can add whole entries with keyword and definition' do
@d.add('fish' => 'aquatic animal')
@d.entries.should == {'fish' => 'aquatic animal'}
@d.keywords.should == ['fish']
end
it 'add keywords (without definition)' do
@d.add('fish')
@d.entries.should == {'fish' => nil}
@d.keywords.should == ['fish']
end
it 'can check whether a given keyword exists' do
@d.include?('fish').should be_false
end
it "doesn't cheat when checking whether a given keyword exists" do
@d.include?('fish').should be_false # if the method is empty, this test passes with nil returned
@d.add('fish')
@d.include?('fish').should be_true # confirms that it actually checks
@d.include?('bird').should be_false # confirms not always returning true after add
end
it "doesn't include a prefix that wasn't added as a word in and of itself" do
@d.add('fish')
@d.include?('fi').should be_false
end
it "doesn't find a word in empty dictionary" do
@d.find('fi').should be_empty # {}
end
it 'finds nothing if the prefix matches nothing' do
@d.add('fiend')
@d.add('great')
@d.find('nothing').should be_empty
end
it "finds an entry" do
@d.add('fish' => 'aquatic animal')
@d.find('fish').should == {'fish' => 'aquatic animal'}
end
it 'finds multiple matches from a prefix and returns the entire entry (keyword + definition)' do
@d.add('fish' => 'aquatic animal')
@d.add('fiend' => 'wicked person')
@d.add('great' => 'remarkable')
@d.find('fi').should == {'fish' => 'aquatic animal', 'fiend' => 'wicked person'}
end
it 'lists keywords alphabetically' do
@d.add('zebra' => 'African land animal with stripes')
@d.add('fish' => 'aquatic animal')
@d.add('apple' => 'fruit')
@d.keywords.should == %w(apple fish zebra)
end
it 'can produce printable output like so: [keyword] "definition"' do
@d.add('zebra' => 'African land animal with stripes')
@d.add('fish' => 'aquatic animal')
@d.add('apple' => 'fruit')
@d.printable.should == %Q{[apple] "fruit"\n[fish] "aquatic animal"\n[zebra] "African land animal with stripes"}
end
end