Module: RSpecCommand

Extended by:
RSpec::SharedContext
Defined in:
lib/rspec_command.rb,
lib/rspec_command/rake.rb,
lib/rspec_command/match_fixture.rb

Overview

An RSpec helper module for testing command-line tools.

Examples:

Enable globally

RSpec.configure do |config|
  config.include RSpecCommand
end

Enable for a single example group

describe 'myapp' do
  command 'myapp --version'
  its(:stdout) { it_expected.to include('1.0.0') }
end

Since:

  • 1.0.0

Defined Under Namespace

Modules: Rake

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#fixture_root ⇒ String (readonly)

Base path for the fixtures directory. Default value is 'fixtures'.

Examples:

let(:fixture_root) { 'data' }

Returns:

  • (String) 


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# File 'lib/rspec_command.rb', line 63

let(:fixture_root) { 'fixtures' }

#temp_path ⇒ String (readonly)

Path to the temporary directory created for the current example.

Returns:

  • (String) 


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# File 'lib/rspec_command.rb', line 54

let(:temp_path) do |example|
  example.metadata[:rspec_command_temp_path]
end

Class Method Details

.command(cmd = nil, options = {}, &block) ⇒ Object

Run a command as the subject of this example. The command can be passed in as a string, array, or block. The subject will be a Mixlib::ShellOut object, all attributes from there will work with rspec-its.

Examples:

describe 'myapp' do
  command 'myapp show'
  its(:stdout) { is_expected.to match(/a thing/) }
end

Parameters:

  • cmd (String, Array) (defaults to: nil) —

    Command to run. If passed as an array, no shell expansion will be performed.

  • options (Hash<Symbol, Object>) (defaults to: {}) —

    Options to pass to Mixlib::ShellOut.new.

  • block (Proc) —

    Optional block to return a command to run.

Options Hash (options):

  • allow_error (Boolean) —

    If true, don't raise an error on failed commands.

See Also:

  • #command

Since:

  • 1.0.0



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# File 'lib/rspec_command.rb', line 276

def command(cmd=nil, options={}, &block)
  metadata[:command] = true
  subject do |example|
    # If a block is given, use it to get the command.
    cmd = instance_eval(&block) if block
    command(cmd, options)
  end
end

.environment(variables) ⇒ Object

Set an environment variable for this example.

Examples:

describe 'myapp' do
  command 'myapp show'
  environment DEBUG: true
  its(:stderr) { is_expected.to include('[debug]') }
end

Parameters:

  • variables (Hash) —

    Key/value pairs to set.

Since:

  • 1.0.0



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# File 'lib/rspec_command.rb', line 347

def environment(variables)
  before do
    variables.each do |key, value|
      if value.nil?
        _environment.delete(key.to_s)
      else
        _environment[key.to_s] = value.to_s
      end
    end
  end
end

.file(path, content = nil, &block) ⇒ Object

Create a file in the temporary directory for this example.

Examples:

describe 'myapp' do
  command 'myapp read data.txt'
  file 'data.txt', <<-EOH
a thing
EOH
  its(:exitstatus) { is_expected.to eq 0 }
end

Parameters:

  • path (String) —

    Path within the temporary directory to write to.

  • content (String) (defaults to: nil) —

    File data to write.

  • block (Proc) —

    Optional block to return file data to write.

Since:

  • 1.0.0



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# File 'lib/rspec_command.rb', line 298

def file(path, content=nil, &block)
  raise "file path should be relative the the temporary directory." if path == File.expand_path(path)
  before do
    content = instance_eval(&block) if block
    dest_path = File.join(temp_path, path)
    FileUtils.mkdir_p(File.dirname(dest_path))
    IO.write(dest_path, content)
  end
end

.fixture_file(path, dest = nil) ⇒ Object

Copy fixture data from the spec folder to the temporary directory for this example.

Examples:

describe 'myapp' do
  command 'myapp run test/'
  fixture_file 'test'
  its(:exitstatus) { is_expected.to eq 0 }
end

Parameters:

  • path (String) —

    Path of the fixture to copy.

  • dest (String) (defaults to: nil) —

    Optional destination path. By default the destination is the same as path.

Since:

  • 1.0.0



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# File 'lib/rspec_command.rb', line 320

def fixture_file(path, dest=nil)
  raise "file path should be relative the the temporary directory." if path == File.expand_path(path)
  before do |example|
    fixture_path = find_fixture(example.file_path, path)
    dest_path = dest ? File.join(temp_path, dest) : temp_path
    FileUtils.mkdir_p(dest_path)
    file_list = MatchFixture::FileList.new(fixture_path)
    file_list.files.each do |file|
      abs = file_list.absolute(file)
      if File.directory?(abs)
        FileUtils.mkdir_p(File.join(dest_path, file))
      else
        FileUtils.copy(abs , File.join(dest_path, file), preserve: true)
      end
    end
  end
end

Instance Method Details

#capture_output(&block) ⇒ String

Run a local block with $stdout and $stderr redirected to a strings. Useful for running CLI code in unit tests. The returned string has #stdout, #stderr and #exitstatus attributes to emulate the output from command.

Examples:

describe 'my rake task' do
  subject do
    capture_output do
      Rake::Task['mytask'].invoke
    end
  end
end

Parameters:

  • block (Proc) —

    Code to run.

Returns:

  • (String)

Since:

  • 1.0.0



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# File 'lib/rspec_command.rb', line 141

def capture_output(&block)
  old_stdout = $stdout.dup
  old_stderr = $stderr.dup
  # Potential future improvement is to use IO.pipe instead of temp files, but
  # that would require threads or something to read contiuously since the
  # buffer is only 64k on the kernel side.
  Tempfile.open('capture_stdout') do |tmp_stdout|
    Tempfile.open('capture_stderr') do |tmp_stderr|
      $stdout.reopen(tmp_stdout)
      $stdout.sync = true
      $stderr.reopen(tmp_stderr)
      $stderr.sync = true
      output = nil
      begin
        # Inner block to make sure the ensure happens first.
        begin
          block.call
        ensure
          # Rewind.
          tmp_stdout.seek(0, 0)
          tmp_stderr.seek(0, 0)
          # Read in the output.
          output = OutputString.new(tmp_stdout.read, tmp_stderr.read)
        end
      rescue Exception => e
        if output
          # Try to add the output so far as an attribute on the exception via
          # a closure.
          e.define_singleton_method(:output_so_far) do
            output
          end
        end
        raise
      else
        output
      end
    end
  end
ensure
  $stdout.reopen(old_stdout)
  $stderr.reopen(old_stderr)
end

#match_fixture(fixture_path, local_path = nil) ⇒ Object

Matcher to compare files or folders from the temporary directory to a fixture.

Examples:

describe 'myapp' do
  command 'myapp write'
  it { is_expected.to match_fixture('write_data') }
end

Since:

  • 1.0.0



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# File 'lib/rspec_command.rb', line 123

def match_fixture(fixture_path, local_path=nil)
  MatchFixture.new(find_fixture(self.class.file_path), temp_path, fixture_path, local_path)
end