I want output line, which was failed during rspec comparasion inside example, but I don't know how to do it best.
For example I have test like this:
require 'rspec'
describe 'My behaviour' do
it 'should do something' do
test_string = 'test'
expect(test_string).to eq('failed_test')
end
after :each do |example|
puts example.metadata[:expect_line]
end
end
And I want to outputed line in after :each be
"expect(test_string).to eq('failed_test')"
I know, I have acces to example.metadata[:location] which return something like "./spec/test_spec.rb:4" and I can parse it and extract line, but is there already something like I need hided in whole example structure?
Update:
I just understand. that example.metadata[:location] return not failed line, but actually line in whitch it started, so it have no use for me :(
So question still exist - how to get failed line?
This information isn't hidden anywhere in the example structure that I'm aware of. RSpec's default output shows the line that failed:
Failures:
1) My Description should fail
Failure/Error: expect(1).to eq(2)
expected: 2
got: 1
If we look at how rspec itself gets this in rspec/core/formatters/exception_presenter.rb and rspec/core/formatters/snippet_extractor.rb, it appears that they go through the backtrace of the example exception to find the spec file and extract the line (similar to what you mentioned). If there was an easier way to pull that out of the example, I would think RSpec itself would use that :)
Related
I have a Ruby project with a UNIX executable file called parse located in a bin subfolder in my project root directory.
At the moment it's just this:
#!/usr/bin/env ruby
# frozen_string_literal: true
puts 'hello world'
The file can be executed on the command line when this command is run from the project root directory: bin/parse
It works fine, but I also want to write a passing Rspec test for it.
I have this spec file:
RSpec.describe "end-to-end application behaviour" do
subject { system('bin/parse') }
it 'prints the expected messsage to stdout' do
expect { subject }.to output(
'hello world'
).to_stdout
end
end
When I run it I get the test failure:
expected block to output "hello world" to stdout, but output nothing
This is the location of my spec file relative to my project root: spec/integration/parse_spec.rb
I tried placing require and require_relative statements in that spec file with the paths to the parse executable, in case that would help, but I just kept getting:
LoadError: cannot load such file
Does anyone know how I can write a test in that file that will pass and prove the parse executable behaviour works?
Don't Use the RSpec Output Matcher
RSpec has a built-in output matcher than can test both where output goes, as well as its contents. However, it's testing where your Ruby output goes, not whether some external application is using standard input or standard error. You're going to have to make some different assumptions about your code.
You can avoid driving yourself nuts by comparing strings rather than testing the underlying shell or your output streams. For example, consider:
RSpec.describe "parse utility output" do
it "prints the right string on standard output" do
expect(`echo hello world`).to start_with("hello world")
end
it "shows nothing on standard output when it prints to stderr" do
expect(`echo foo >&2 > /dev/null`).to be_empty
end
end
Just replace the echo statements with the correct invocation of parse for your system, perhaps by setting PATH directly in your shell, using a utility like direnv, or by modifying ENV["PATH"] in your spec or spec_helper.
As a rule of thumb, RSpec isn't really meant for testing command-line applications. If you want to do that, consider using the Aruba framework to exercise your command-line applications. It's best to use RSpec to test the results of methods or the output of commands, rather than trying to test basic functionality. Of course, your mileage may vary.
Use to_stdout_from_any_process instead of to_stdout:
expect { subject }.to output('hello world').to_stdout_from_any_process
I have an rspec test defined like below. I know that I can run rspec -e "guessing" to run the full block of tests, but I want to run only specific contexts at a time. This way I can code the "correctly" tests first, and then later the "incorrectly" portion. Is there a command line way run the specified tests without naming them individually?
describe 'guessing' do
context 'correctly' do
it 'changes correct guess list' do
end
it 'returns true' do
end
end
context 'incorrectly' do
it 'changes wrong guess list' do
end
it 'returns true' do
end
end
end
You can use -e to match any part of the description, so rspec -e incorrectly will run those two tests. (I don't know of a way to only match "correctly", as it's also a substring of "incorrectly".)
You can also use a line number reference to match a context block: rspec your_spec.rb:2 (given the above content exactly, with context 'correctly' do on line 2) will run that set of specs.
I've got a Thor based ruby CLI project to which I'm trying to add unit testing. It started as a pet project and is now rather large and important internally. Anyway, I have never really started unit testing, only grafted onto existing examples, and so I'm very much a noob when it comes to rspec.
I'm starting with a rather basic example, making sure that if I give it a file that doesn't exist, that it replies with an explanatory error and exits.
Here's the ways I have tried to compound them:
context 'with incorrect filename' do
it 'should fail cleanly' do
expect do
subject.format('bad_file_name')
end.to output(' ERROR Unable to load file bad_file_name, exiting...').to_stdout.and raise_error(SystemExit)
end
end
which works but doesn't capture the stdout properly output here.. also tried:
context 'with incorrect filename' do
it 'should fail cleanly' do
expect do
expect do
subject.format('fixtures/invalid.yaml')
end.to output(' ERROR Unable to load file bad_file_name, exiting...').to_stdout
end.to raise_error(SystemExit)
end
end
Which looks like it works, except (as this example shows) it's not actually testing the output because that output wouldn't match.
So what's the right way to check both an error that was raised and the output to stdout at the same time?
this works for me
expect { whatever }.to output('stderr message').to_stderr
.and output(Regexp.new('stdout message')).to_stdout
.and raise_error('Error message')
New to rubby and rspec i am trying to test a class that opens and write to a file.
The class name is SimpleLogger
Here is the spec that generates an error:
describe SimpleLogger do
...
context 'when using a file' do
require 'fakefs/spec_helpers'
before(:all) do
#path = 'my_file'
logger = SimpleLogger.new #path
logger.write "Hello, world!"
logger.close
end
...
it 'we expect the file to have a valid content' do
expect(File.read(#path)).to eq "Hello, world!\n"
end
end
end
The error generated is:
Failure/Error: expect(File.read(#path)).to eq "Hello, world!\n"
expected: "Hello, world!\n"
got: ""
(compared using ==)
Diff:
## -1,2 +1 ##
-Hello, world!
The file exists on my file system, and when I'm testing a simple puts Find.read("my_file") on an independant ruby file i've got the expected result.
I've tested and have the same issue without the fakefs gem
Why is it when run in a spec it doesn't work?
And beside that i fail to understand the advantage of fakefs, as it creates the file juste the same. So why fakefs is used?
And as it creates the file should i erase it within the spec?
Thanks in advance ;)
From the documentation - it seems that you need to include the helpers to activate the FakeFS:
FakeFS::SpecHelpers provides a simple macro for RSpec example groups to turn FakeFS on and off.
To use it simply require 'fakefs/spec_helpers', then include FakeFS::SpecHelpers into any
example groups that you wish to use FakeFS in. For example:
require 'fakefs/spec_helpers'
describe "Some specs that deal with files" do
include FakeFS::SpecHelpers
...
end
By default, including FakeFS::SpecHelpers will run for each example inside a describe block.
If you want to turn on FakeFS one time only for all your examples, you will need to
include FakeFS::SpecHelpers::All.
Alternatively, you can include FakeFS::SpecHelpers in all your example groups using RSpec's
configuration block in your spec helper:
require 'fakefs/spec_helpers'
Spec::Runner.configure do |config|
config.include FakeFS::SpecHelpers
end
If you do the above then use_fakefs will be available in all of your example groups.
You will also need to use before(:each) instead of before(:all) - like many unit test helpers, FakeFS adheres to unit-test isolation principles, in which side-effects of one test should not affect another's. That is why after every test, the gem 'resets' the state of its container, and clears all files from it.
I am using rspec for my test in a ruby project, and I want to spec that my program should not output anything when the -q option is used. I tried:
Kernel.should_not_receive :puts
That did not result in a failed test when there was output to the console.
How do I verify the absents of text output?
puts uses $stdout internally. Due to the way it works, the easiest way to check is to simply use: $stdout.should_not_receive(:write)
Which checks nothing is written to stdout as expected.
Kernel.puts (as above) would only result in a failed test when it
is explictely called as such (e.g. Kernel.puts "Some text"), where
as most cases it's call in the scope of the current object.
The accepted answer above is incorrect. It "works" because it doesn't receive a :write message but it might have received a :puts message.
The correct line should read:
$stdout.should_not_receive(:puts)
Also you need to make sure you put the line before the code that will write to STDIO. For instance:
it "should print a copyright message" do
$stdout.should_receive(:puts).with(/copyright/i)
app = ApplicationController.new(%w[project_name])
end
it "should not print an error message" do
$stdout.should_not_receive(:puts).with(/error/i)
app = ApplicationController.new(%w[project_name])
end
That's an actual working RSpec from a project