麻煩通過RSpec測試。時間不能強制轉換爲Fixnum

Question

我在使用rspec測試時遇到了問題。我正在使用Ruby 1.93和RSPEC 2.14.8（我認爲）對不起，這篇文章將會持續多久。我可以得到我發現的其他代碼，但無法讓我的代碼正常工作，但我不知道爲什麼。

我的代碼：

def measure(number = 1) 
    counter = number 
    total = 0 
    while counter > 0 
    start = Time.now 
    counter-=1 

yield 

stop = Time.now 
total = total + stop - start 

end 

total/number 
end 

其他的代碼，我發現，工作原理：

def measure count=1 
    total_time = 0 
    count.times do 
    start_time = Time.now 

yield 

    end_time = Time.now 
    total_time += end_time - start_time 
end 
    total_time/count 
end 

測試：

require_relative "performance_monitor" 

require "time" # loads up the Time.parse method -- do NOT create time.rb! 

describe "Performance Monitor" do 
    before do 
    @eleven_am = Time.parse("2011-1-2 11:00:00") 
    end 

    it "takes about 0 seconds to run an empty block" do 
    elapsed_time = measure do 
    end 
    elapsed_time.should be_within(0.1).of(0) 
    end 

    it "takes exactly 0 seconds to run an empty block (with stubs)" do 
    Time.stub(:now) { @eleven_am } 
    elapsed_time = measure do 
    end 
    elapsed_time.should == 0 
    end 

    it "takes about 1 second to run a block that sleeps for 1 second" do 
    elapsed_time = measure do 
     sleep 1 
    end 
    elapsed_time.should be_within(0.1).of(1) 
    end 

    it "takes exactly 1 second to run a block that sleeps for 1 second (with stubs)" do 
    fake_time = @eleven_am 
    Time.stub(:now) { fake_time } 
    elapsed_time = measure do 
     fake_time += 60 # adds one minute to fake_time 
    end 
    elapsed_time.should == 60 
    end 

    it "runs a block N times" do 
    n = 0 
    measure(4) do 
     n += 1 
    end 
    n.should == 4 
    end 

    it "returns the average time, not the total time, when running multiple times" do 
    run_times = [8,6,5,7] 
    fake_time = @eleven_am 
    Time.stub(:now) { fake_time } 
    average_time = measure(4) do 
     fake_time += run_times.pop 
    end 
    average_time.should == 6.5 
    end 

    it "returns the average time when running a random number of times for random lengths of time" do 
    fake_time = @eleven_am 
    Time.stub(:now) { fake_time } 
    number_of_times = rand(10) + 2 
    average_time = measure(number_of_times) do 
     delay = rand(10) 
     fake_time += delay 
    end 
    average_time.should == (fake_time - @eleven_am).to_f/number_of_times 
    end 

end 

什麼它說當我運行它：

Performance Monitor takes about 0 seconds to run an empty block (FAILED - 1)

Failures:

1) Performance Monitor takes about 0 seconds to run an empty block
Failure/Error: elapsed_time = measure do
TypeError:
Time can't be coerced into Fixnum
# ./06_performance_monitor/performance_monitor.rb:11:in '+' #./06_performance_monitor/performance_monitor.rb:11:in 'measure' #./06_performance_monitor/performance_monitor_spec.rb:21:in `block (2 levels) in '

Finished in 0.008 seconds 1 example, 1 failure

Answer 1

total = total + stop - start是不一樣的total = total + (stop - start)

首先是實際評估爲total = (total + t) - n不工作，因爲你不能添加兩次到一起。

我想你的意思做的是：

total = total + (stop - start)或更簡潔total += stop - start