RSpec-匹配器 - 芒果文档

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📜 RSpec-匹配器

📅 最后修改于: 2020-12-06 10:55:33 🧑 作者: Mango

如果您还记得我们最初的Hello World示例，则其中包含以下内容：

expect(message).to eq "Hello World!"

关键字eql是RSpec “匹配器”。在这里，我们将介绍RSpec中的其他类型的匹配器。

平等/身份匹配者

匹配器以测试对象或值是否相等。

Matcher	Description	Example
eq	Passes when actual == expected	expect(actual).to eq expected
eql	Passes when actual.eql?(expected)	expect(actual).to eql expected
be	Passes when actual.equal?(expected)	expect(actual).to be expected
equal	Also passes when actual.equal?(expected)	expect(actual).to equal expected

例

describe "An example of the equality Matchers" do 

   it "should show how the equality Matchers work" do 
      a = "test string" 
      b = a 
      
      # The following Expectations will all pass 
      expect(a).to eq "test string" 
      expect(a).to eql "test string" 
      expect(a).to be b 
      expect(a).to equal b 
   end
   
end

执行以上代码后，将产生以下输出。秒数在您的计算机上可能略有不同-

.
Finished in 0.036 seconds (files took 0.11901 seconds to load)
1 example, 0 failures

比较匹配器

用于与值进行比较的匹配器。

Matcher	Description	Example
>	Passes when actual > expected	expect(actual).to be > expected
>=	Passes when actual >= expected	expect(actual).to be >= expected
<	Passes when actual < expected	expect(actual).to be < expected
<=	Passes when actual <= expected	expect(actual).to be <= expected
be_between inclusive	Passes when actual is <= min and >= max	expect(actual).to be_between(min, max).inclusive
be_between exclusive	Passes when actual is < min and > max	expect(actual).to be_between(min, max).exclusive
match	Passes when actual matches a regular expression	expect(actual).to match(/regex/)

例

describe "An example of the comparison Matchers" do

   it "should show how the comparison Matchers work" do
      a = 1
      b = 2
      c = 3        
      d = 'test string'
      
      # The following Expectations will all pass
      expect(b).to be > a
      expect(a).to be >= a 
      expect(a).to be < b 
      expect(b).to be <= b 
      expect(c).to be_between(1,3).inclusive 
      expect(b).to be_between(1,3).exclusive 
      expect(d).to match /TEST/i 
   end
   
end

执行以上代码后，将产生以下输出。秒数在您的计算机上可能略有不同-

. 
Finished in 0.013 seconds (files took 0.11801 seconds to load) 
1 example, 0 failures

类/类型匹配器

用于测试对象类型或类别的匹配器。

Matcher	Description	Example
be_instance_of	Passes when actual is an instance of the expected class.	expect(actual).to be_instance_of(Expected)
be_kind_of	Passes when actual is an instance of the expected class or any of its parent classes.	expect(actual).to be_kind_of(Expected)
respond_to	Passes when actual responds to the specified method.	expect(actual).to respond_to(expected)

例

describe "An example of the type/class Matchers" do
 
   it "should show how the type/class Matchers work" do
      x = 1 
      y = 3.14 
      z = 'test string' 
      
      # The following Expectations will all pass
      expect(x).to be_instance_of Fixnum 
      expect(y).to be_kind_of Numeric 
      expect(z).to respond_to(:length) 
   end
   
end

执行以上代码后，将产生以下输出。秒数在您的计算机上可能略有不同-

. 
Finished in 0.002 seconds (files took 0.12201 seconds to load) 
1 example, 0 failures

正确/错误/无匹配器

用于测试值是true，false还是nil的匹配器。

Matcher	Description	Example
be true	Passes when actual == true	expect(actual).to be true
be false	Passes when actual == false	expect(actual).to be false
be_truthy	Passes when actual is not false or nil	expect(actual).to be_truthy
be_falsey	Passes when actual is false or nil	expect(actual).to be_falsey
be_nil	Passes when actual is nil	expect(actual).to be_nil

例

describe "An example of the true/false/nil Matchers" do
   it "should show how the true/false/nil Matchers work" do
      x = true 
      y = false 
      z = nil 
      a = "test string" 
      
      # The following Expectations will all pass
      expect(x).to be true 
      expect(y).to be false 
      expect(a).to be_truthy 
      expect(z).to be_falsey 
      expect(z).to be_nil 
   end 
end

执行以上代码后，将产生以下输出。秒数在您的计算机上可能略有不同-

. 
Finished in 0.003 seconds (files took 0.12301 seconds to load) 
1 example, 0 failures

错误匹配器

当代码块引发错误时，用于测试的匹配器。

Matcher	Description	Example
raise_error(ErrorClass)	Passes when the block raises an error of type ErrorClass.	expect {block}.to raise_error(ErrorClass)
raise_error(“error message”)	Passes when the block raise an error with the message “error message”.	expect {block}.to raise_error(“error message”)
raise_error(ErrorClass, “error message”)	Passes when the block raises an error of type ErrorClass with the message “error message”	expect {block}.to raise_error(ErrorClass,“error message”)

例

将以下代码保存到名称为error_matcher_spec.rb的文件中，并使用以下命令运行它-rspec error_matcher_spec.rb 。

describe "An example of the error Matchers" do 
   it "should show how the error Matchers work" do 
      
      # The following Expectations will all pass 
      expect { 1/0 }.to raise_error(ZeroDivisionError)
      expect { 1/0 }.to raise_error("divided by 0") 
      expect { 1/0 }.to raise_error("divided by 0", ZeroDivisionError) 
   end 
end

执行以上代码后，将产生以下输出。秒数在您的计算机上可能略有不同-

. 
Finished in 0.002 seconds (files took 0.12101 seconds to load) 
1 example, 0 failures