Categories
Category results are hidden when using a custom project result order
3.08
Sorbet's runtime type checking component
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.0
Lookout
Lookout is a unit testing framework for Ruby┬╣ that puts your results in
focus. Tests (expectations) are written as follows
expect 2 do
1 + 1
end
expect ArgumentError do
Integer('1 + 1')
end
expect Array do
[1, 2, 3].select{ |i| i % 2 == 0 }
end
expect [2, 4, 6] do
[1, 2, 3].map{ |i| i * 2 }
end
Lookout is designed to encourage ΓÇô force, even ΓÇô unit testing best practices
such as
ΓÇó Setting up only one expectation per test
ΓÇó Not setting expectations on non-public APIs
ΓÇó Test isolation
This is done by
ΓÇó Only allowing one expectation to be set per test
ΓÇó Providing no (additional) way of accessing private state
ΓÇó Providing no setup and tear-down methods, nor a method of providing test
helpers
Other important points are
ΓÇó Putting the expected outcome of a test in focus with the steps of the
calculation of the actual result only as a secondary concern
ΓÇó A focus on code readability by providing no mechanism for describing an
expectation other than the code in the expectation itself
ΓÇó A unified syntax for setting up both state-based and behavior-based
expectations
The way Lookout works has been heavily influenced by expectations┬▓, by
{Jay Fields}┬│. The code base was once also heavily based on expectations,
based at Subversion {revision 76}⁴. A lot has happened since then and all of
the work past that revision are due to {Nikolai Weibull}⁵.
┬╣ Ruby: http://ruby-lang.org/
┬▓ Expectations: http://expectations.rubyforge.org/
┬│ Jay FieldsΓÇÖs blog: http://blog.jayfields.com/
⁴ Lookout revision 76:
https://github.com/now/lookout/commit/537bedf3e5b3eb4b31c066b3266f42964ac35ebe
⁵ Nikolai Weibull’s home page: http://disu.se/
§ Installation
Install Lookout with
% gem install lookout
§ Usage
Lookout allows you to set expectations on an objectΓÇÖs state or behavior.
WeΓÇÖll begin by looking at state expectations and then take a look at
expectations on behavior.
§ Expectations on State: Literals
An expectation can be made on the result of a computation:
expect 2 do
1 + 1
end
Most objects, in fact, have their state expectations checked by invoking
‹#==› on the expected value with the result as its argument.
Checking that a result is within a given range is also simple:
expect 0.099..0.101 do
0.4 - 0.3
end
Here, the more general ‹#===› is being used on the ‹Range›.
§ Regexps
‹Strings› of course match against ‹Strings›:
expect 'ab' do
'abc'[0..1]
end
but we can also match a ‹String› against a ‹Regexp›:
expect %r{a substring} do
'a string with a substring'
end
(Note the use of ‹%r{…}› to avoid warnings that will be generated when
Ruby parses ‹expect /…/›.)
§ Modules
Checking that the result includes a certain module is done by expecting the
‹Module›.
expect Enumerable do
[]
end
This, due to the nature of Ruby, of course also works for classes (as
they are also modules):
expect String do
'a string'
end
This doesn’t hinder us from expecting the actual ‹Module› itself:
expect Enumerable do
Enumerable
end
or the ‹Class›:
expect String do
String
end
for obvious reasons.
As you may have figured out yourself, this is accomplished by first
trying ‹#==› and, if it returns ‹false›, then trying ‹#===› on the
expected ‹Module›. This is also true of ‹Ranges› and ‹Regexps›.
§ Booleans
Truthfulness is expected with ‹true› and ‹false›:
expect true do
1
end
expect false do
nil
end
Results equaling ‹true› or ‹false› are slightly different:
expect TrueClass do
true
end
expect FalseClass do
false
end
The rationale for this is that you should only care if the result of a
computation evaluates to a value that Ruby considers to be either true or
false, not the exact literals ‹true› or ‹false›.
§ IO
Expecting output on an IO object is also common:
expect output("abc\ndef\n") do |io|
io.puts 'abc', 'def'
end
This can be used to capture the output of a formatter that takes an
output object as a parameter.
§ Warnings
Expecting warnings from code isnΓÇÖt very common, but should be done:
expect warning('this is your final one!') do
warn 'this is your final one!'
end
expect warning('this is your final one!') do
warn '%s:%d: warning: this is your final one!' % [__FILE__, __LINE__]
end
‹$VERBOSE› is set to ‹true› during the execution of the block, so you
donΓÇÖt need to do so yourself. If you have other code that depends on the
value of $VERBOSE, that can be done with ‹#with_verbose›
expect nil do
with_verbose nil do
$VERBOSE
end
end
§ Errors
You should always be expecting errors from ΓÇô and in, but thatΓÇÖs a
different story ΓÇô your code:
expect ArgumentError do
Integer('1 + 1')
end
Often, not only the type of the error, but its description, is important
to check:
expect StandardError.new('message') do
raise StandardError.new('message')
end
As with ‹Strings›, ‹Regexps› can be used to check the error description:
expect StandardError.new(/mess/) do
raise StandardError.new('message')
end
§ Queries Through Symbols
Symbols are generally matched against symbols, but as a special case,
symbols ending with ‹?› are seen as expectations on the result of query
methods on the result of the block, given that the method is of zero
arity and that the result isnΓÇÖt a Symbol itself. Simply expect a symbol
ending with ‹?›:
expect :empty? do
[]
end
To expect it’s negation, expect the same symbol beginning with ‹not_›:
expect :not_nil? do
[1, 2, 3]
end
This is the same as
expect true do
[].empty?
end
and
expect false do
[1, 2, 3].empty?
end
but provides much clearer failure messages. It also makes the
expectationΓÇÖs intent a lot clearer.
§ Queries By Proxy
ThereΓÇÖs also a way to make the expectations of query methods explicit by
invoking methods on the result of the block. For example, to check that
the even elements of the Array ‹[1, 2, 3]› include ‹1› you could write
expect result.to.include? 1 do
[1, 2, 3].reject{ |e| e.even? }
end
You could likewise check that the result doesnΓÇÖt include 2:
expect result.not.to.include? 2 do
[1, 2, 3].reject{ |e| e.even? }
end
This is the same as (and executes a little bit slower than) writing
expect false do
[1, 2, 3].reject{ |e| e.even? }.include? 2
end
but provides much clearer failure messages. Given that these two last
examples would fail, youΓÇÖd get a message saying ΓÇ£[1, 2, 3]#include?(2)ΓÇ¥
instead of the terser ΓÇ£trueΓëáfalseΓÇ¥. It also clearly separates the actual
expectation from the set-up.
The keyword for this kind of expectations is ‹result›. This may be
followed by any of the methods
• ‹#not›
• ‹#to›
• ‹#be›
• ‹#have›
or any other method you will want to call on the result. The methods
‹#to›, ‹#be›, and ‹#have› do nothing except improve readability. The
‹#not› method inverts the expectation.
§ Literal Literals
If you need to literally check against any of the types of objects
otherwise treated specially, that is, any instances of
• ‹Module›
• ‹Range›
• ‹Regexp›
• ‹Exception›
• ‹Symbol›, given that it ends with ‹?›
you can do so by wrapping it in ‹literal(…)›:
expect literal(:empty?) do
:empty?
end
You almost never need to do this, as, for all but symbols, instances will
match accordingly as well.
§ Expectations on Behavior
We expect our objects to be on their best behavior. Lookout allows you
to make sure that they are.
Reception expectations let us verify that a method is called in the way
that we expect it to be:
expect mock.to.receive.to_str(without_arguments){ '123' } do |o|
o.to_str
end
Here, ‹#mock› creates a mock object, an object that doesn’t respond to
anything unless you tell it to. We tell it to expect to receive a call
to ‹#to_str› without arguments and have ‹#to_str› return ‹'123'› when
called. The mock object is then passed in to the block so that the
expectations placed upon it can be fulfilled.
Sometimes we only want to make sure that a method is called in the way
that we expect it to be, but we donΓÇÖt care if any other methods are
called on the object. A stub object, created with ‹#stub›, expects any
method and returns a stub object that, again, expects any method, and
thus fits the bill.
expect stub.to.receive.to_str(without_arguments){ '123' } do |o|
o.to_str if o.convertable?
end
You donΓÇÖt have to use a mock object to verify that a method is called:
expect Object.to.receive.name do
Object.name
end
As you have figured out by now, the expected method call is set up by
calling ‹#receive› after ‹#to›. ‹#Receive› is followed by a call to the
method to expect with any expected arguments. The body of the expected
method can be given as the block to the method. Finally, an expected
invocation count may follow the method. LetΓÇÖs look at this formal
specification in more detail.
The expected method arguments may be given in a variety of ways. LetΓÇÖs
introduce them by giving some examples:
expect mock.to.receive.a do |m|
m.a
end
Here, the method ‹#a› must be called with any number of arguments. It
may be called any number of times, but it must be called at least once.
If a method must receive exactly one argument, you can use ‹Object›, as
the same matching rules apply for arguments as they do for state
expectations:
expect mock.to.receive.a(Object) do |m|
m.a 0
end
If a method must receive a specific argument, you can use that argument:
expect mock.to.receive.a(1..2) do |m|
m.a 1
end
Again, the same matching rules apply for arguments as they do for state
expectations, so the previous example expects a call to ‹#a› with 1, 2,
or the Range 1..2 as an argument on ‹m›.
If a method must be invoked without any arguments you can use
‹without_arguments›:
expect mock.to.receive.a(without_arguments) do |m|
m.a
end
You can of course use both ‹Object› and actual arguments:
expect mock.to.receive.a(Object, 2, Object) do |m|
m.a nil, 2, '3'
end
The body of the expected method may be given as the block. Here, calling
‹#a› on ‹m› will give the result ‹1›:
expect mock.to.receive.a{ 1 } do |m|
raise 'not 1' unless m.a == 1
end
If no body has been given, the result will be a stub object.
To take a block, grab a block parameter and ‹#call› it:
expect mock.to.receive.a{ |&b| b.call(1) } do |m|
j = 0
m.a{ |i| j = i }
raise 'not 1' unless j == 1
end
To simulate an ‹#each›-like method, ‹#call› the block several times.
Invocation count expectations can be set if the default expectation of
ΓÇ£at least onceΓÇ¥ isnΓÇÖt good enough. The following expectations are
possible
• ‹#at_most_once›
• ‹#once›
• ‹#at_least_once›
• ‹#twice›
And, for a given ‹N›,
• ‹#at_most(N)›
• ‹#exactly(N)›
• ‹#at_least(N)›
§ Utilities: Stubs
Method stubs are another useful thing to have in a unit testing
framework. Sometimes you need to override a method that does something a
test shouldnΓÇÖt do, like access and alter bank accounts. We can override
– stub out – a method by using the ‹#stub› method. Let’s assume that we
have an ‹Account› class that has two methods, ‹#slips› and ‹#total›.
‹#Slips› retrieves the bank slips that keep track of your deposits to the
‹Account› from a database. ‹#Total› sums the ‹#slips›. In the following
test we want to make sure that ‹#total› does what it should do without
accessing the database. We therefore stub out ‹#slips› and make it
return something that we can easily control.
expect 6 do |m|
stub(Class.new{
def slips
raise 'database not available'
end
def total
slips.reduce(0){ |m, n| m.to_i + n.to_i }
end
}.new, :slips => [1, 2, 3]){ |account| account.total }
end
To make it easy to create objects with a set of stubbed methods thereΓÇÖs
also a convenience method:
expect 3 do
s = stub(:a => 1, :b => 2)
s.a + s.b
end
This short-hand notation can also be used for the expected value:
expect stub(:a => 1, :b => 2).to.receive.a do |o|
o.a + o.b
end
and also works for mock objects:
expect mock(:a => 2, :b => 2).to.receive.a do |o|
o.a + o.b
end
Blocks are also allowed when defining stub methods:
expect 3 do
s = stub(:a => proc{ |a, b| a + b })
s.a(1, 2)
end
If need be, we can stub out a specific method on an object:
expect 'def' do
stub('abc', :to_str => 'def'){ |a| a.to_str }
end
The stub is active during the execution of the block.
§ Overriding Constants
Sometimes you need to override the value of a constant during the
execution of some code. Use ‹#with_const› to do just that:
expect 'hello' do
with_const 'A::B::C', 'hello' do
A::B::C
end
end
Here, the constant ‹A::B::C› is set to ‹'hello'› during the execution of
the block. None of the constants ‹A›, ‹B›, and ‹C› need to exist for
this to work. If a constant doesnΓÇÖt exist itΓÇÖs created and set to a new,
empty, ‹Module›. The value of ‹A::B::C›, if any, is restored after the
block returns and any constants that didnΓÇÖt previously exist are removed.
§ Overriding Environment Variables
Another thing you often need to control in your tests is the value of
environment variables. Depending on such global values is, of course,
not a good practice, but is often unavoidable when working with external
libraries. ‹#With_env› allows you to override the value of environment
variables during the execution of a block by giving it a ‹Hash› of
key/value pairs where the key is the name of the environment variable and
the value is the value that it should have during the execution of that
block:
expect 'hello' do
with_env 'INTRO' => 'hello' do
ENV['INTRO']
end
end
Any overridden values are restored and any keys that werenΓÇÖt previously a
part of the environment are removed when the block returns.
§ Overriding Globals
You may also want to override the value of a global temporarily:
expect 'hello' do
with_global :$stdout, StringIO.new do
print 'hello'
$stdout.string
end
end
You thus provide the name of the global and a value that it should take
during the execution of a block of code. The block gets passed the
overridden value, should you need it:
expect true do
with_global :$stdout, StringIO.new do |overridden|
$stdout != overridden
end
end
§ Integration
Lookout can be used from Rake┬╣. Simply install Lookout-Rake┬▓:
% gem install lookout-rake
and add the following code to your Rakefile
require 'lookout-rake-3.0'
Lookout::Rake::Tasks::Test.new
Make sure to read up on using Lookout-Rake for further benefits and
customization.
┬╣ Read more about Rake at http://rake.rubyforge.org/
┬▓ Get information on Lookout-Rake at http://disu.se/software/lookout-rake/
§ API
Lookout comes with an API┬╣ that letΓÇÖs you create things such as new
expected values, difference reports for your types, and so on.
┬╣ See http://disu.se/software/lookout/api/
§ Interface Design
The default output of Lookout can Spartanly be described as Spartan. If no
errors or failures occur, no output is generated. This is unconventional,
as unit testing frameworks tend to dump a lot of information on the user,
concerning things such as progress, test count summaries, and flamboyantly
colored text telling you that your tests passed. None of this output is
needed. Your tests should run fast enough to not require progress reports.
The lack of output provides you with the same amount of information as
reporting success. Test count summaries are only useful if youΓÇÖre worried
that your tests arenΓÇÖt being run, but if you worry about that, then
providing such output doesnΓÇÖt really help. Testing your tests requires
something beyond reporting some arbitrary count that you would have to
verify by hand anyway.
When errors or failures do occur, however, the relevant information is
output in a format that can easily be parsed by an ‹'errorformat'› for Vim
or with {Compilation Mode}┬╣ for Emacs┬▓. Diffs are generated for Strings,
Arrays, Hashes, and I/O.
┬╣ Read up on Compilation mode for Emacs at http://www.emacswiki.org/emacs/CompilationMode
┬▓ Visit The GNU FoundationΓÇÖs EmacsΓÇÖ software page at http://www.gnu.org/software/emacs/
§ External Design
LetΓÇÖs now look at some of the points made in the introduction in greater
detail.
Lookout only allows you to set one expectation per test. If youΓÇÖre testing
behavior with a reception expectation, then only one method-invocation
expectation can be set. If youΓÇÖre testing state, then only one result can
be verified. It may seem like this would cause unnecessary duplication
between tests. While this is certainly a possibility, when you actually
begin to try to avoid such duplication you find that you often do so by
improving your interfaces. This kind of restriction tends to encourage the
use of value objects, which are easy to test, and more focused objects,
which require simpler tests, as they have less behavior to test, per
method. By keeping your interfaces focused youΓÇÖre also keeping your tests
focused.
Keeping your tests focused improves, in itself, test isolation, but letΓÇÖs
look at something that hinders it: setup and tear-down methods. Most unit
testing frameworks encourage test fragmentation by providing setup and
tear-down methods.
Setup methods create objects and, perhaps, just their behavior for a set of
tests. This means that you have to look in two places to figure out whatΓÇÖs
being done in a test. This may work fine for few methods with simple
set-ups, but makes things complicated when the number of tests increases
and the set-up is complex. Often, each test further adjusts the previously
set-up object before performing any verifications, further complicating the
process of figuring out what state an object has in a given test.
Tear-down methods clean up after tests, perhaps by removing records from a
database or deleting files from the file-system.
The duplication that setup methods and tear-down methods hope to remove is
better avoided by improving your interfaces. This can be done by providing
better set-up methods for your objects and using idioms such as {Resource
Acquisition Is Initialization}┬╣ for guaranteed clean-up, test or no test.
By not using setup and tear-down methods we keep everything pertinent to a
test in the test itself, thus improving test isolation. (You also wonΓÇÖt
{slow down your tests}┬▓ by keeping unnecessary state.)
Most unit test frameworks also allow you to create arbitrary test helper
methods. Lookout doesnΓÇÖt. The same rationale as that that has been
crystallized in the preceding paragraphs applies. If you need helpers
youΓÇÖre interface isnΓÇÖt good enough. It really is as simple as that.
To clarify: thereΓÇÖs nothing inherently wrong with test helper methods, but
they should be general enough that they reside in their own library. The
support for mocks in Lookout is provided through a set of test helper
methods that make it easier to create mocks than it would have been without
them. Lookout-rack┬│ is another example of a library providing test helper
methods (well, one method, actually) that are very useful in testing web
applications that use Rack⁴.
A final point at which some unit test frameworks try to fragment tests
further is documentation. These frameworks provide ways of describing the
whats and hows of whatΓÇÖs being tested, the rationale being that this will
provide documentation of both the test and the code being tested.
Describing how a stack data structure is meant to work is a common example.
A stack is, however, a rather simple data structure, so such a description
provides little, if any, additional information that canΓÇÖt be extracted
from the implementation and its tests themselves. The implementation and
its tests is, in fact, its own best documentation. Taking the points made
in the previous paragraphs into account, we should already have simple,
self-describing, interfaces that have easily understood tests associated
with them. Rationales for the use of a given data structure or
system-design design documentation is better suited in separate
documentation focused at describing exactly those issues.
┬╣ Read the Wikipedia entry for Resource Acquisition Is Initialization at
http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization
┬▓ Read how 37signals had problems with slow Test::Unit tests at
http://37signals.com/svn/posts/2742-the-road-to-faster-tests/
┬│ Visit the Lookout-rack home page at
http://disu.se/software/lookout-rack/
⁴ Visit the Rack Rubyforge project page at
http://rack.rubyforge.org/
§ Internal Design
The internal design of Lookout has had a couple of goals.
ΓÇó As few external dependencies as possible
ΓÇó As few internal dependencies as possible
ΓÇó Internal extensibility provides external extensibility
ΓÇó As fast load times as possible
ΓÇó As high a ratio of value objects to mutable objects as possible
ΓÇó Each object must have a simple, obvious name
ΓÇó Use mix-ins, not inheritance for shared behavior
ΓÇó As few responsibilities per object as possible
ΓÇó Optimizing for speed can only be done when you have all the facts
§ External Dependencies
Lookout used to depend on Mocha for mocks and stubs. While benchmarking I
noticed that a method in Mocha was taking up more than 300 percent of the
runtime. It turned out that MochaΓÇÖs method for cleaning up back-traces
generated when a mock failed was doing something incredibly stupid:
backtrace.reject{ |l| Regexp.new(@lib).match(File.expand_path(l)) }
Here ‹@lib› is a ‹String› containing the path to the lib sub-directory in
the Mocha installation directory. I reported it, provided a patch five
days later, then waited. Nothing happened. {254 days later}┬╣, according
to {Wolfram Alpha}┬▓, half of my patch was, apparently ΓÇô I say ΓÇ£apparentlyΓÇ¥,
as I received no notification ΓÇô applied. By that time I had replaced the
whole mocking-and-stubbing subsystem and dropped the dependency.
Many Ruby developers claim that Ruby and its gems are too fast-moving for
normal package-managing systems to keep up. This is testament to the fact
that this isnΓÇÖt the case and that the real problem is instead related to
sloppy practices.
Please note that I donΓÇÖt want to single out the Mocha library nor its
developers. I only want to provide an example where relying on external
dependencies can be ΓÇ£considered harmfulΓÇ¥.
┬╣ See the Wolfram Alpha calculation at http://www.wolframalpha.com/input/?i=days+between+march+17%2C+2010+and+november+26%2C+2010
┬▓ Check out the Wolfram Alpha computational knowledge engine at http://www.wolframalpha.com/
§ Internal Dependencies
Lookout has been designed so as to keep each subsystem independent of any
other. The diff subsystem is, for example, completely decoupled from any
other part of the system as a whole and could be moved into its own library
at a time where that would be of interest to anyone. WhatΓÇÖs perhaps more
interesting is that the diff subsystem is itself very modular. The data
passes through a set of filters that depends on what kind of diff has been
requested, each filter yielding modified data as it receives it. If you
want to read some rather functional Ruby I can highly recommend looking at
the code in the ‹lib/lookout/diff› directory.
This lookout on the design of the library also makes it easy to extend
Lookout. Lookout-rack was, for example, written in about four hours and
about 5 of those 240 minutes were spent on setting up the interface between
the two.
§ Optimizing For Speed
The following paragraph is perhaps a bit personal, but might be interesting
nonetheless.
IΓÇÖve always worried about speed. The original Expectations library used
‹extend› a lot to add new behavior to objects. Expectations, for example,
used to hold the result of their execution (what we now term ΓÇ£evaluationΓÇ¥)
by being extended by a module representing success, failure, or error. For
the longest time I used this same method, worrying about the increased
performance cost that creating new objects for results would incur. I
finally came to a point where I felt that the code was so simple and clean
that rewriting this part of the code for a benchmark wouldnΓÇÖt take more
than perhaps ten minutes. Well, ten minutes later I had my results and
they confirmed that creating new objects wasnΓÇÖt harming performance. I was
very pleased.
§ Naming
I hate low lines (underscores). I try to avoid them in method names and I
always avoid them in file names. Since the current ΓÇ£best practiceΓÇ¥ in the
Ruby community is to put ‹BeginEndStorage› in a file called
‹begin_end_storage.rb›, I only name constants using a single noun. This
has had the added benefit that classes seem to have acquired less behavior,
as using a single noun doesnΓÇÖt allow you to tack on additional behavior
without questioning if itΓÇÖs really appropriate to do so, given the rather
limited range of interpretation for that noun. It also seems to encourage
the creation of value objects, as something named ‹Range› feels a lot more
like a value than ‹BeginEndStorage›. (To reach object-oriented-programming
Nirvana you must achieve complete value.)
§ News
§ 3.0.0
The ‹xml› expectation has been dropped. It wasn’t documented, didn’t
suit very many use cases, and can be better implemented by an external
library.
The ‹arg› argument matcher for mock method arguments has been removed, as
it didnΓÇÖt provide any benefit over using Object.
The ‹#yield› and ‹#each› methods on stub and mock methods have been
removed. They were slightly weird and their use case can be implemented
using block parameters instead.
The ‹stub› method inside ‹expect› blocks now stubs out the methods during
the execution of a provided block instead of during the execution of the
whole except block.
When a mock method is called too many times, this is reported
immediately, with a full backtrace. This makes it easier to pin down
whatΓÇÖs wrong with the code.
Query expectations were added.
Explicit query expectations were added.
Fluent boolean expectations, for example, ‹expect nil.to.be.nil?› have
been replaced by query expectations (‹expect :nil? do nil end›) and
explicit query expectations (‹expect result.to.be.nil? do nil end›).
This was done to discourage creating objects as the expected value and
creating objects that change during the course of the test.
The ‹literal› expectation was added.
Equality (‹#==›) is now checked before “caseity” (‹#===›) for modules,
ranges, and regular expressions to match the documentation.
§ Financing
Currently, most of my time is spent at my day job and in my rather busy
private life. Please motivate me to spend time on this piece of software
by donating some of your money to this project. Yeah, I realize that
requesting money to develop software is a bit, well, capitalistic of me.
But please realize that I live in a capitalistic society and I need money
to have other people give me the things that I need to continue living
under the rules of said society. So, if you feel that this piece of
software has helped you out enough to warrant a reward, please PayPal a
donation to now@disu.se┬╣. Thanks! Your support wonΓÇÖt go unnoticed!
┬╣ Send a donation:
https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=now%40disu%2ese&item_name=Lookout
§ Reporting Bugs
Please report any bugs that you encounter to the {issue tracker}┬╣.
┬╣ See https://github.com/now/lookout/issues
§ Contributors
Contributors to the original expectations codebase are mentioned there. We
hope no one on that list feels left out of this list. Please
{let us know}┬╣ if you do.
ΓÇó Nikolai Weibull
┬╣ Add an issue to the Lookout issue tracker at https://github.com/now/lookout/issues
§ Licensing
Lookout is free software: you may redistribute it and/or modify it under
the terms of the {GNU Lesser General Public License, version 3}┬╣ or later┬▓,
as published by the {Free Software Foundation}┬│.
┬╣ See http://disu.se/licenses/lgpl-3.0/
┬▓ See http://gnu.org/licenses/
┬│ See http://fsf.org/
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.0
Allows you check if an object match a class expression. It is typically
used to check the type of method paraameters. It is an alternative to using
Ruby-3 .rbs files but with a different syntax and only dynamic checks
Typically you'll include the Constrain module and use #constrain to check
the type of method parameters:
include Constrain
# f takes a String and an array of Integer objects. Raise a Constrain::Error
# if parameters doesn't have the expected types
def f(a, b)
constrain a, String
constrain b, [Integer]
end
Constrain works with ruby-2 (and maybe ruby-3)
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.0
rubber-c-binder allows a rubyish means of generating bindings for C libraries,
including (but not limited to) GObject based libraries.
It allows C code to be written in the context of a ruby style class/method layout
and eases type checking and conversion between Ruby & C datatypes.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.08
Enums, properties, generics, structured objects and runtime type checking.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.01
Check yardoc format like tag type.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.0
RubyLess is an interpreter for "safe ruby". The idea is to transform some "unsafe" ruby code into safe, type checked ruby, eventually rewriting some variables or methods.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.21
A type coercion lib works with Sorbet's static type checker and type definitions; raises an error if the coercion fails.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.01
The Preconditions library provides a simple set of methods for checking arguments being passed into a method. Instead of writing custom checks and raising exceptions directly in your code you can use Preconditions to verify basic properties of your arguments (not-nil, satisfying a boolean expression, being of a certain type/duck-type) and raise the appropriate exception for you.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.0
Create and manage configuration files in Ruby for Ruby. Jeckyl can be used to create a parameters hash
from a simple config file written in Ruby, having run whatever checks you want on the file to ensure
the values passed in are valid. All you need to do is define a class inheriting from Jeckyl, methods for
each parameter, its default, whatever checking rules are appropriate and even a comment for generating templates etc.
This is then used to parse a Ruby config file and create the parameters hash. Jeckyl
comes complete with a utility to check a config file against a given class and to generate a default file for you to tailor.
Type 'jeckyl readme' for more information.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.0
Composable type-safety checks
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.0
When making an api that uses objects that belong to another object, it is possible to create objects that don't belong to any object. What this gem does is it checks to make sure the id and type map to an object before creation and if it does not it will create an error on the record. If an object is imageable, no worries it still works!
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.0
Dynamic type checker
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.02
A puppet-lint plugin to check that Optional class/defined type parameters don't default to anything other than `undef`.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.02
A new check for puppet-lint that validates that all parameters are typed.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.0
An on-demand arbitrary check and conversion library that won't destroy your data.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.06
Type check JSON objects
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.0
# Rake::ToolkitProgram
Create toolkit programs easily with `Rake` and `OptionParser` syntax. Bash completions and usage help are baked in.
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'rake-toolkit_program'
```
And then execute:
$ bundle
Or install it yourself as:
$ gem install rake-toolkit_program
## Quickstart
* Shebang it up (in a file named `awesome_tool.rb`)
```ruby
#!/usr/bin/env ruby
```
* Require the library
```ruby
require 'rake/toolkit_program'
```
* Make your life easier
```ruby
Program = Rake::ToolkitProgram
```
* Define your command tasks
```ruby
Program.command_tasks do
desc "Build it"
task 'build' do
# Ruby code here
end
desc "Test it"
task 'test' => ['build'] do
# Rake syntax ↑↑↑↑↑↑↑ for dependencies
# Ruby code here
end
end
```
You can use `Program.args` in your tasks to access the other arguments on the command line. For argument parsing integrated into the help provided by the program, see the use of `Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args` below.
* Wire the mainline
```ruby
Program.run(on_error: :exit_program!) if $0 == __FILE__
```
* In the shell, prepare to run the program (UNIX/Linux systems only)
```console
$ chmod +x awesome_tool.rb
$ ./awesome_tool.rb --install-completions
Completions installed in /home/rtweeks/.bashrc
Source /home/rtweeks/.bash-complete/awesome_tool.rb-completions for immediate availability.
$ source /home/rtweeks/.bash-complete/awesome_tool.rb-completions
```
* Ask for help
```console
$ ./awesome_tool.rb help
*** ./awesome_tool.rb Toolkit Program ***
.
.
.
```
## Usage
Let's look at a short sample toolkit program -- put this in `awesome.rb`:
```ruby
#!/usr/bin/env ruby
require 'rake/toolkit_program'
require 'ostruct'
ToolkitProgram = Rake::ToolkitProgram
ToolkitProgram.title = "My Awesome Toolkit of Awesome"
ToolkitProgram.command_tasks do
desc <<-END_DESC.dedent
Fooing myself
I'm not sure what I'm doing, but I'm definitely fooing!
END_DESC
task :foo do
a = ToolkitProgram.args
puts "I'm fooed#{' on a ' if a.implement}#{a.implement}"
end.parse_args(into: OpenStruct.new) do |parser, args|
parser.no_positional_args!
parser.on('-i', '--implement IMPLEMENT', 'An implement on which to be fooed') do |val|
args.implement = val
end
end
end
if __FILE__ == $0
ToolkitProgram.run(on_error: :exit_program!)
end
```
Make sure to `chmod +x awesome.rb`!
What does this support?
$ ./awesome.rb foo
I'm fooed
$ ./awesome.rb --help
*** My Awesome Toolkit of Awesome ***
Usage: ./awesome.rb COMMAND [OPTION ...]
Avaliable options vary depending on the command given. For details
of a particular command, use:
./awesome.rb help COMMAND
Commands:
foo Fooing myself
help Show a list of commands or details of one command
Use help COMMAND to get more help on a specific command.
$ ./awesome.rb help foo
*** My Awesome Toolkit of Awesome ***
Usage: ./awesome.rb foo [OPTION ...]
Fooing myself
I'm not sure what I'm doing, but I'm definitely fooing!
Options:
-i, --implement IMPLEMENT An implement on which to be fooed
$ ./awesome.rb --install-completions
Completions installed in /home/rtweeks/.bashrc
Source /home/rtweeks/.bash-complete/awesome.rb-completions for immediate availability.
$ source /home/rtweeks/.bash-complete/awesome.rb-completions
$ ./awesome.rb <tab><tab>
foo help
$ ./awesome.rb f<tab>
↳ ./awesome.rb foo
$ ./awesome.rb foo <tab>
↳ ./awesome.rb foo --
$ ./awesome.rb foo --<tab><tab>
--help --implement
$ ./awesome.rb foo --i<tab>
↳ ./awesome.rb foo --implement
$ ./awesome.rb foo --implement <tab><tab>
--help awesome.rb
$ ./awesome.rb foo --implement spoon
I'm fooed on a spoon
### Defining Toolkit Commands
Just define tasks in the block of `Rake::ToolkitProgram.command_tasks` with `task` (i.e. `Rake::DSL#task`). If `desc` is used to provide a description, the task will become visible in help and completions.
When a command task is initially defined, positional arguments to the command are available as an `Array` through `Rake::ToolkitProgram.args`.
### Option Parsing
This gem extends `Rake::Task` with a `#parse_args` method that creates a `Rake::ToolkitProgram::CommandOptionParser` (derived from the standard library's `OptionParser`) and an argument accumulator and `yield`s them to its block.
* The arguments accumulated through the `Rake::ToolkitProgram::CommandOptionParser` are available to the task in `Rake::ToolkitProgram.args`, replacing the normal `Array` of positional arguments.
* Use the `into:` keyword of `#parse_args` to provide a custom argument accumulator object for the associated command. The default argument accumulator constructor can be defined with `Rake::ToolkitProgram.default_parsed_args`. Without either of these, the default accumulator is a `Hash`.
* Options defined using `OptionParser#on` (or any of the variants) will print in the help for the associated command.
### Positional Arguments
Accessing positional arguments given after the command name depends on whether or not `Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args` has been called on the command task. If this method is not called, positional arguments will be an `Array` accessible through `Rake::ToolkitProgram.args`.
When `Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args` is used:
* `Rake::ToolkitProgram::CommandOptionParser#capture_positionals` can be used to define how positional arguments are accumulated.
* If the argument accumulator is a `Hash`, the default (without calling this method) is to assign the `Array` of positional arguments to the `nil` key of the `Hash`.
* For other types of accumulators, the positional arguments are only accessible if `Rake::ToolkitProgram::CommandOptionParser#capture_positionals` is used to define how they are captured.
* If a block is given to this method, the block of the method will receive the `Array` of positional arguments. If it is passed an argument value, that value is used as the key under which to store the positional arguments if the argument accumulator is a `Hash`.
* `Rake::ToolkitProgram::CommandOptionParser#expect_positional_cardinality` can be used to set a rule for the count of positional arguments. This will affect the _usage_ presented in the help for the associated command.
* `Rake::ToolkitProgram::CommandOptionParser#map_positional_args` may be used to transform (or otherwise process) positional arguments one at a time and in the context of options and/or arguments appearing earlier on the command line.
### Convenience Methods
* `Rake::Task(Rake::ToolkitProgram::TaskExt)#prohibit_args` is a quick way, for commands that accept no options or positional arguments, to declare this so the help and bash completions reflect this. It is equivalent to using `#parse_args` and telling the parser `parser.expect_positional_cardinality(0)`.
* `Rake::ToolkitProgram::CommandOptionParser#no_positional_args!` is a shortcut for calling `#expect_positional_cardinality(0)` on the same object.
* `Rake::Task(Rake::ToolkitProgram::TaskExt)#invalid_args!` and `Rake::ToolkitProgram::CommandOptionParser#invalid_args!` are convenient ways to raise `Rake::ToolkitProgram::InvalidCommandLine` with a message.
## OptionParser in Rubies Before and After v2.4
The `OptionParser` class was extended in Ruby 2.4 to simplify capturing options into a `Hash` or other container implementing `#[]=` in a similar way. This gem supports that, but it means that behavior varies somewhat between the pre-2.4 era and the 2.4+ era. To have consistent behavior across that version change, the recommendation is to use a `Struct`, `OpenStruct`, or custom class to hold program options rather than `Hash`.
## Development
After checking out the repo, run `bin/setup` to install dependencies. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
To run the tests, use `rake`, `rake test`, or `rspec spec`. Tests can only be run on systems that support `Kernel#fork`, as this is used to present a pristine and isolated environment for setting up the tool. If run using Ruby 2.3 or earlier, some tests will be pending because functionality expects Ruby 2.4's `OptionParser`.
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/PayTrace/rake-toolkit_program. For further details on contributing, see [CONTRIBUTING.md](./CONTRIBUTING.md).
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
0.04
MooseX is an extension of Ruby object DSL. The main goal of MooseX is to make Ruby Object Oriented programming easier, more consistent, and less tedious. With MooseX you can think more about what you want to do and less about the mechanics of OOP. It is a port of Moose/Moo from Perl to Ruby world, providing method delegation, type check, traits, monads, plugins, lazy attributes, aspects and much more.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity
0.01
All the flexibility of a Ruby Struct, but with type checking on its properties. Also benefit from being able to define complex types using RBS type notation.
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
Activity