# RSpec運作模式

### gem “rspec”

### gem “rspec-rails”

## 運作模式

RSpec.describe "calculation" do
  it "can add numbers" do
    expect(1 + 1).to eq(2)
  end
end

### describe

RSpec.describe "calculation" do
 ...
end

describe主要源自於example_group.rb

### it

  it "can add numbers" do
    ...
  end

it主要源自於example.rb

RSpec.describe "eg1" do
  it "e1"
  it "e2"
  context "eg1_1" do
   it "e3" 
  end
  context "eg2_1" do
    it "e3"
  end
end


### hook

before {}
after {}
around { |ex| ex.run}

hooks源自於hooks.rb

before(:suite) / after(:suite) #只會運行一次
before(:context) / after(:context) #每個example group會運行一次
before / after /arounf #每個example都會運行一次

### expect & to

expect(1 + 1).to eq(2)

Expectation來自rspec-expectations



### match

expect(...).to match([
 a_kind_of(String),
 a_hash_including(a: 4)
])

[
  “any string”,
  {a: 4, b: 6.0},
]

class Match < BaseMatcher
  def match(expected, actual)
    return true if values_match?(
      expected, actual)
    actual.match(expected)
  end
end

values_match?

def values_match?(expected, actual)
  expected =
    with_matchers_cloned(expected)
  Support::FuzzyMatcher.values_match?(
    expected, actual)
end

Support::FuzzyMatcher.values_match?

def self.values_match?(e, a)
  if Hash === a
    return hashes_match?(e, a) if Hash
                                  === e
  elsif Array === e
   && Enumerable === a
   && !(Struct === a)
  return arrays_match?(
    e, a)
end

hashes_match?

def self.hashes_match?(
    expected_hash, actual_hash)
  return false if
    expected_hash.size != actual_hash.size
  expected_hash.all? do |e_k, e_v|
    actual_value = actual_hash.fetch(e_k) {
      return false }
    values_match?(e_v, actual_value)
end end

#### Array === e
arrays_match?

def self.arrays_match?(
  expected_list, actual_list)
  return false if
    expected_list.size!=actual_list.size
  expected_list.zip(actual_list).all? do
    |expected, actual|
    values_match?(expected, actual)
  end
end

### 值與屬性

def self.values_match?(expected, actual) 
    ... 
    (the code we saw earlier) 
    return true if expected == actual 
  begin
    expected === actual
  rescue ArgumentError
    # Some objects, like 0-arg lambdas on
    # 1.9+, raise
    # ArgumentError for `expected === actual`.
    false
  end 
end

原比對內容

[
  “any string”,
  {a: 4, b: 6.0}
]

做了三件比對：arrays_match? / === / ===

### rspec-mocks

RSpec.describe "mocking" do
  it “adds a foo method" do
    allow(foo).to
      receive(:bees)
    expect(foo.bees).to eq(nil)
  end
end



call foo.bee

## RSpec運作流程