Results for should-equal

Paint your strings for prettier console output. Description should not equal summary.

Sum of rounded elements in the array should be equal the rounded sum of elements

JumpStart is a script runner and template parser written in Ruby with Ruby projects in mind. It should function equally well for any project where there are many configuration steps to get up and running.

FlexCoerce - is a gem which allow you create operator-dependent coercion logic. It's useful when your type should be treated in a different way for different binary operations (including arithmetic operators, bitwise operators and comparison operators except equality checks: `==`, `===`).

DataMapper core library where one row in the data-store should equal one object reference. Pretty simple idea. Pretty profound impact.

The Nodeum API makes it easy to tap into the digital data mesh that runs across your organisation. Make requests to our API endpoints and we’ll give you everything you need to interconnect your business workflows with your storage. All production API requests are made to: http://nodeumhostname/api/ The current production version of the API is v1. **REST** The Nodeum API is a RESTful API. This means that the API is designed to allow you to get, create, update, & delete objects with the HTTP verbs GET, POST, PUT, PATCH, & DELETE. **JSON** The Nodeum API speaks exclusively in JSON. This means that you should always set the Content-Type header to application/json to ensure that your requests are properly accepted and processed by the API. **Authentication** All API calls require user-password authentication. **Cross-Origin Resource Sharing** The Nodeum API supports CORS for communicating from Javascript for these endpoints. You will need to specify an Origin URI when creating your application to allow for CORS to be whitelisted for your domain. **Pagination** Some endpoints such as File Listing return a potentially lengthy array of objects. In order to keep the response sizes manageable the API will take advantage of pagination. Pagination is a mechanism for returning a subset of the results for a request and allowing for subsequent requests to “page” through the rest of the results until the end is reached. Paginated endpoints follow a standard interface that accepts two query parameters, limit and offset, and return a payload that follows a standard form. These parameters names and their behavior are borrowed from SQL LIMIT and OFFSET keywords. **Versioning** The Nodeum API is constantly being worked on to add features, make improvements, and fix bugs. This means that you should expect changes to be introduced and documented. However, there are some changes or additions that are considered backwards-compatible and your applications should be flexible enough to handle them. These include: - Adding new endpoints to the API - Adding new attributes to the response of an existing endpoint - Changing the order of attributes of responses (JSON by definition is an object of unordered key/value pairs) **Filter parameters** When browsing a list of items, multiple filter parameters may be applied. Some operators can be added to the value as a prefix: - `=` value is equal. Default operator, may be omitted - `!=` value is different - `>` greater than - `>=` greater than or equal - `<` lower than - `>=` lower than or equal - `><` included in list, items should be separated by `|` - `!><` not included in list, items should be separated by `|` - `~` pattern matching, may include `%` (any characters) and `_` (one character) - `!~` pattern not matching, may include `%` (any characters) and `_` (one character)

Value Value is a library for defining immutable value objects in Ruby. A value object is an object whose equality to other objects is determined by its value, not its identity, think dates and amounts of money. A value object should also be immutable, as you don’t want the date “2013-04-22” itself to change but the current date to change from “2013-04-22” to “2013-04-23”. That is, you don’t want entries in a calendar for 2013-04-22 to move to 2013-04-23 simply because the current date changes from 2013-04-22 to 2013-04-23. A value object consists of one or more attributes stored in instance variables. Value sets up an #initialize method for you that let’s you set these attributes, as, value objects being immutable, this’ll be your only chance to do so. Value also adds equality checks ‹#==› and ‹#eql?› (which are themselves equivalent), a ‹#hash› method, a nice ‹#inspect› method, and a protected attribute reader for each attribute. You may of course add any additional methods that your value object will benefit from. That’s basically all there’s too it. Let’s now look at using the Value library. § Usage You create value object class by invoking ‹#Value› inside the class (module) you wish to make into a value object class. Let’s create a class that represent points on a plane: class Point Value :x, :y end A ‹Point› is thus a value object consisting of two sub-values ‹x› and ‹y› (the coordinates). Just from invoking ‹#Value›, a ‹Point› object will have a constructor that takes two arguments to set instance variables ‹@x› and ‹@y›, equality checks ‹#==› and ‹#eql?› (which are the same), a ‹#hash› method, a nice ‹#inspect› method, and two protected attribute readers ‹#x› and ‹#y›. We can thus already creat ‹Point›s: origo = Point.new(0, 0) The default of making the attribute readers protected is often good practice, but for a ‹Point› it probably makes sense to be able to access its coordinates: class Point public(*attributes) end This’ll make all attributes of ‹Point› public. You can of course choose to only make certain attributes public: class Point public :x end Note that this public is standard Ruby functionality. Adding a method to ‹Point› is of course also possible and very much Rubyish: class Point def distance(other) Math.sqrt((other.x - x)**2 + (other.y - y)**2) end end For some value object classes you might want to support optional attributes. This is done by providing a default value for the attribute, like so: class Money Value :amount, [:currency, :USD] end Here, the ‹currency› attribute will default to ‹:USD›. You can create ‹Money› via dollars = Money.new(2) but also kronor = Money.new(2, :SEK) All required attributes must come before any optional attributes. Splat attributes are also supported: class List Value :'*elements' end empty = List.new suits = List.new(:spades, :hearts, :diamonds, :clubs) Splat attributes are optional. Finally, block attributes are also available: class Block Value :'&block' end block = Block.new{ |e| e * 2 } Block attributes are optional. Comparison beyond ‹#==› is possible by specifingy the ‹:comparable› option to ‹#Value›, listing one or more attributes that should be included in the comparison: class Vector Value :a, :b, :comparable => :a end Note that equality (‹#==› and ‹#eql?›) is always defined based on all attributes, regardless of arguments to ‹:comparable›. Here we say that comparisons between ‹Vector›s should be made between the values of the ‹a› attribute only. We can also make comparisons between all attributes of a value object: class Vector Value :a, :b, :comparable => true end To sum things up, let’s use all possible arguments to ‹#Value› at once: class Method Value :file, :line, [:name, 'unnamed'], :'*args', :'&block', :comparable => [:file, :line] end A ‹Method› consists of file and line information, a possible name, some arguments, possibly a block, and is comparable on the file and line on which they appear. Check out the {full API documentation}¹ for a more explicit description, should you need it or should you want to extend it. ¹ See http://disu.se/software/value/api/ § 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.se¹. Thanks! Your support won’t go unnoticed! ¹ Send a donation: https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=now%40disu%2ese&item_name=Value § Reporting Bugs Please report any bugs that you encounter to the {issue tracker}¹. ¹ See https://github.com/now/value/issues § Authors Nikolai Weibull wrote the code, the tests, the manual pages, and this README. § Licensing Value is free software: you may redistribute it and/or modify it under the terms of the {GNU Lesser General Public License, version 3}¹ or later², as published by the {Free Software Foundation}³. ¹ See http://disu.se/licenses/lgpl-3.0/ ² See http://gnu.org/licenses/ ³ See http://fsf.org/

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# Quick Start The Owner API uses the JSON format, and must be accessed over a [secure connection](https://en.wikipedia.org/wiki/HTTPS). Let’s assume that the access token provided by your account manager is “TOKEN”. Here’s how to get the list of ids of all your invoices from the first week of August with a shell script: ```bash query="end_date=2018-08-08T00%3A00%3A00%2B00%3A00&start_date=2018-08-01T00%3A00%3A00%2B00%3A00" curl -i "https://api-eu.getaround.com/owner/v1/invoices?${query}" \ -H "Authorization: Bearer TOKEN" \ -H "Accept:application/json" \ -H "Content-Type:application/json" ``` And here’s how to get the invoice with the id 12345: ```bash curl -i "https://api-eu.getaround.com/owner/v1/invoices/12345" \ -H "Authorization: Bearer TOKEN" \ -H "Accept: application/json" \ -H "Content-Type: application/json"" ``` See the [endpoints section](#tag/Invoices) of this guide for details about the response format. Dates in request params should follow the ISO 8601 standard. # Authentication All requests must be authenticated with a [bearer token header](https://tools.ietf.org/html/rfc6750#section-2.1). You token will be sent to you by your account manager. Unauthenticated requests will return a 401 status. # Pagination The page number and the number of items per page can be set with the “page” and “per_page” params. For example, this request will return the second page of invoices, and 50 invoices per page: `https://api-eu.getaround.com/owner/v1/invoices?page=2&per_page=50` Both of these params are optional. The default page size is 30 items. The Getaround Owner API follows the [RFC 8288 convention](https://datatracker.ietf.org/doc/html/rfc8288) of using the `Link` header to provide the `next` page URL. Please don't build the pagination URLs yourself. The `next` page will be missing when you are requesting the last available page. Here's an example response header from requesting the second page of invoices `https://api-eu.getaround.com/owner/v1/invoices?page=2&per_page=50` ``` Link: <https://api-eu.getaround.com/owner/v1/invoices?page=3&per_page=50>; rel="next" ``` # Throttling policy and Date range limitation We have throttling policy that prevents you to perform more than 100 requests per min from the same IP. Also, there is a limitation on the size of the range of dates given in params in some requests. All requests that need start_date and end_date, do not accept a range bigger than 30 days. # Webhooks Getaround can send webhook events that notify your application when certain events happen on your account. This is especially useful to follow the lifecycle of rentals, tracking for example bookings or cancellations. ### Setup To set up an endpoint, you need to define a route on your server for receiving events, and then <a href="mailto:owner-api@getaround.com">ask Getaround</a> to add this URL to your account. To acknowledge receipt of a event, your endpoint must: - Return a `2xx` HTTP status code. - Be a secure `https` endpoint with a valid SSL certificate. ### Testing Once Getaround has set up the endpoint, and it is properly configured as described above, a test `ping` event can be sent by clicking the button below: <form action="/docs/api/owner/fire_ping_webhook" method="post"><input type="submit" value="Send Ping Event"></form> You should receive the following JSON payload: ```json { "data": { "ping": "pong" }, "type": "ping", "occurred_at": "2019-04-18T08:30:05Z" } ``` ### Retries Webhook deliveries will be attempted for up to three days with an exponential back off. After that point the delivery will be abandoned. ### Verifying Signatures Getaround will also provide you with a secret token, which is used to create a hash signature with each payload. This hash signature is passed along with each request in the headers as `X-Drivy-Signature`. Suppose you have a basic server listening to webhooks that looks like this: ```ruby require 'sinatra' require 'json' post '/payload' do push = JSON.parse(params[:payload]) "I got some JSON: #{push.inspect}" end ``` The goal is to compute a hash using your secret token, and ensure that the hash from Getaround matches. Getaround uses an HMAC hexdigest to compute the hash, so you could change your server to look a little like this: ```ruby post '/payload' do request.body.rewind payload_body = request.body.read verify_signature(payload_body) push = JSON.parse(params[:payload]) "I got some JSON: #{push.inspect}" end def verify_signature(payload_body) signature = 'sha1=' + OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha1'), ENV['SECRET_TOKEN'], payload_body) return halt 500, "Signatures didn't match!" unless Rack::Utils.secure_compare(signature, request.env['HTTP_X_DRIVY_SIGNATURE']) end ``` Obviously, your language and server implementations may differ from this code. There are a couple of important things to point out, however: No matter which implementation you use, the hash signature starts with `sha1=`, using the key of your secret token and your payload body. Using a plain `==` operator is not advised. A method like secure_compare performs a "constant time" string comparison, which renders it safe from certain timing attacks against regular equality operators. ### Best Practices - **Acknowledge events immediately**. If your webhook script performs complex logic, or makes network calls, it’s possible that the script would time out before Getaround sees its complete execution. Ideally, your webhook handler code (acknowledging receipt of an event by returning a `2xx` status code) is separate of any other logic you do for that event. - **Handle duplicate events**. Webhook endpoints might occasionally receive the same event more than once. We advise you to guard against duplicated event receipts by making your event processing idempotent. One way of doing this is logging the events you’ve processed, and then not processing already-logged events. - **Do not expect events in order**. Getaround does not guarantee delivery of events in the order in which they are generated. Your endpoint should therefore handle this accordingly. We do provide an `occurred_at` timestamp for each event, though, to help reconcile ordering.

Twitterpunch =============== Twitterpunch is designed to work with PhotoBooth and OS X Folder Actions. When this script is called with the name of an image file, it will post the image to Twitter, along with a message randomly chosen from a list and a specified hashtag. If you call the script with the `--stream` argument instead, it will listen for tweets to that hashtag and download them to a specified directory. If the tweet came from another user, Twitterpunch will speak it aloud. Typically, you'll run one copy on an OSX laptop with PhotoBooth, and a separate copy on another machine (either Windows or OSX) for the viewer. You can also use a mobile device as a remote control, if you like. This will allow the user to enter a custom message for each photo that gets tweeted out, if they'd like. Configuration =========== Configure the program via the `~/.twitterpunch/config.yaml` YAML file. This file should look similar to the example below. --- :twitter: # twitter configuration :consumer_key: &lt;consumer key&gt; :consumer_secret: &lt;consumer secret&gt; :access_token: &lt;access token&gt; :access_token_secret: &lt;access secret&gt; :messages: # list of messages to attach - Hello there # to outgoing tweets - I'm a posting fool - minimally viable product :hashtag: Twitterpunch # The hashtag to post and listen to :handle: Twitterpunch # The twitter username to post as :photodir: ~/Pictures/twitterpunch/ # Where to save downloaded images :logfile: ~/.twitterpunch/activity.log # Where to save logs :viewer: # Use the built-in slideshow viewer :count: 5 # How many images to have onscreen at once :remote: :timeout: 45 # How long the button should remain disabled for :apptitle: dslrBooth # The photo booth application title :hotkey: space # Which hotkey to send to trigger a photo 1. Generate a skeleton configuration file * `twitterpunch --configure` 1. Edit the configuration file as needed. You'll be prompted with the path. * If you have your own Twitter application credentials, you're welcome to use them. 1. Authorize the application with the Twitter API. * `twitterpunch --authorize` Usage ========== ### Using OS X PhotoBooth 1. Start PhotoBooth at least once to generate its library. 1. Install the Twitterpunch Folder Action * `twitterpunch --install` * It may claim that it could not be attached, fear not. 1. Profit! * _and by that, I mean take some shots with PhotoBooth!_ *Note*: if the folder action doesn't seem to work and photos aren't posted to Twitter, here are some troubleshooting steps to take: 1. Run Twitterpunch by hand with photos as arguments. This may help you isolate configuration or authorization issues. * `twitterpunch foo.jpg` 1. Correct the path in the workflow. * `which twitterpunch` * Edit the Twitterpunch folder action to include that path. #### Using the remote web app Configure the remote web app using the `:remote` hash in `config.yaml`. You can usually find the title of the app using `system_profiler -detailLevel full SPApplicationsDataType` and grepping for the name or path to the `.app`. In this example, the title is _dslrBooth_. [ben@ganymede] ~ $ system_profiler -detailLevel full SPApplicationsDataType | grep -B8 dslrBooth.app dslrBooth: Version: 2.9 Obtained from: Identified Developer Last Modified: 10/14/17, 9:50 PM Kind: Intel 64-Bit (Intel): Yes Signed by: Developer ID Application: Hope Pictures LLC (MZR5GHAQX4), Developer ID Certification Authority, Apple Root CA Location: /Applications/dslrBooth.app 1. Run the app with `twitterpunch --remote` 1. Browse to the app with http://{address}:8080 1. [optional] If on an iOS device, add to your homescreen * This will give you "app behaviour", such as full screen, and a nice icon #### Troubleshooting. 1. Make sure the folder action is installed properly 1. Use the Finder to navigate to `~/Pictures/` 1. Right click on the `Photo Booth Library` icon and choose _Show Package Contents_. 1. Right click on the `Pictures` folder and choose `Services &gt; Folder Actions Setup` 1. Make sure that the `Twitterpunch` action is attached. 1. Install the folder action 1. Open the `resources` folder of this gem. * Likely to be found in `/Library/Ruby/Gems/{version}/gems/twitterpunch-#{version}/resources/`. 1. Double click on the `Twitterpunch` folder action and install it. * It may claim that it could not be attached, fear not. ### Using something besides PhotoBooth Configure the program you are using for your photo shoot to call Twitterpunch each time it snaps a photo. Pass the name of the new photo as a command line argument. Alternatively, you could batch them, as Twitterpunch can accept multiple files at once. [ben@ganymede] ~ $ twitterpunch photo.jpg [photo2.jpg photo3.jpg photo4.jpg] You can manually install the Folder Action, or you can follow the automated install process after tweaking the workflow slightly. 1. Identify where the app stores the resulting image files. 1. Edit the Twitterpunch folder action to include that path. 1. Follow the steps above to install the Folder Action. ### Viewing the Twitter stream Twitterpunch will run on OS X or Windows equally well. Simply configure it on the computer that will act as the Twitter display and then run in streaming mode. [ben@ganymede] ~ $ twitterpunch --stream There are two modes that Twitterpunch can operate in. 1. If a `:hashtag` is defined then all images tweeted to the configured hashtag will be displayed in the slideshow. 1. Otherwise, Twitterpunch will stream the `:handle` Twitter user's stream and display all images either posted by that user or addressed to that user. With protected tweets, you can have rudimentary access control. In either mode, tweets that come from any other user will also be spoken aloud. If you don't want to use the built-in slideshow viewer, you can disable it by removing the `:viewer` key from your `~/.twitterpunch/config.yaml` config file. Twitterpunch will then simply download the tweeted images and save them into the `:photodir` directory. You can then use anything you like to view them. There are currently two decent viewing options I am aware of. * Windows background image: * Configure the Windows background to randomly cycle through photos in a directory. * Hide desktop icons. * Hide the taskbar. * Disable screensaver and power savings. * Drawbacks: You're using Windows and you have to install Ruby &amp; RubyGems manually. * OS X screensaver: * Choose one of the sexy screensavers and configure it to show photos from the `:photodir` * Set screensaver to a super short timeout. * Disable power savings. * Drawbacks: The screensaver doesn't reload dynamically, so I have to kick it and you'll see it reloading each time a new tweet comes in. Limitations =========== * It currently requires manual setup for Folder Actions. * Rubygame is kind of a pain to set up. Contact ======= * Author: Ben Ford * Email: binford2k@gmail.com * Twitter: @binford2k * IRC (Freenode): binford2k

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Lookout Lookout is a unit testing framework for Ruby¹ 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 – force, even – unit testing best practices such as • Setting up only one expectation per test • Not setting expectations on non-public APIs • Test isolation This is done by • Only allowing one expectation to be set per test • Providing no (additional) way of accessing private state • Providing no setup and tear-down methods, nor a method of providing test helpers Other important points are • Putting the expected outcome of a test in focus with the steps of the calculation of the actual result only as a secondary concern • A focus on code readability by providing no mechanism for describing an expectation other than the code in the expectation itself • A unified syntax for setting up both state-based and behavior-based expectations The way Lookout works has been heavily influenced by expectations², by {Jay Fields}³. 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. ¹ Ruby: http://ruby-lang.org/ ² Expectations: http://expectations.rubyforge.org/ ³ Jay Fields’s 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 object’s state or behavior. We’ll 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 isn’t 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 don’t 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 – and in, but that’s a different story – 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 isn’t 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 expectation’s intent a lot clearer. § Queries By Proxy There’s 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 doesn’t 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, you’d get a message saying “[1, 2, 3]#include?(2)” instead of the terser “true≠false”. 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 don’t 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 don’t 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. Let’s look at this formal specification in more detail. The expected method arguments may be given in a variety of ways. Let’s 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 “at least once” isn’t 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 shouldn’t 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 there’s 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 doesn’t exist it’s 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 didn’t 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 weren’t 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 Rake¹. Simply install Lookout-Rake²: % 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. ¹ Read more about Rake at http://rake.rubyforge.org/ ² Get information on Lookout-Rake at http://disu.se/software/lookout-rake/ § API Lookout comes with an API¹ that let’s you create things such as new expected values, difference reports for your types, and so on. ¹ 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 you’re worried that your tests aren’t being run, but if you worry about that, then providing such output doesn’t 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}¹ for Emacs². Diffs are generated for Strings, Arrays, Hashes, and I/O. ¹ Read up on Compilation mode for Emacs at http://www.emacswiki.org/emacs/CompilationMode ² Visit The GNU Foundation’s Emacs’ software page at http://www.gnu.org/software/emacs/ § External Design Let’s 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 you’re testing behavior with a reception expectation, then only one method-invocation expectation can be set. If you’re 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 you’re also keeping your tests focused. Keeping your tests focused improves, in itself, test isolation, but let’s 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 what’s 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}¹ 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 won’t {slow down your tests}² by keeping unnecessary state.) Most unit test frameworks also allow you to create arbitrary test helper methods. Lookout doesn’t. The same rationale as that that has been crystallized in the preceding paragraphs applies. If you need helpers you’re interface isn’t good enough. It really is as simple as that. To clarify: there’s 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-rack³ 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 what’s 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 can’t 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. ¹ Read the Wikipedia entry for Resource Acquisition Is Initialization at http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization ² Read how 37signals had problems with slow Test::Unit tests at http://37signals.com/svn/posts/2742-the-road-to-faster-tests/ ³ 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. • As few external dependencies as possible • As few internal dependencies as possible • Internal extensibility provides external extensibility • As fast load times as possible • As high a ratio of value objects to mutable objects as possible • Each object must have a simple, obvious name • Use mix-ins, not inheritance for shared behavior • As few responsibilities per object as possible • 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 Mocha’s 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}¹, according to {Wolfram Alpha}², half of my patch was, apparently – I say “apparently”, as I received no notification – 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 isn’t the case and that the real problem is instead related to sloppy practices. Please note that I don’t want to single out the Mocha library nor its developers. I only want to provide an example where relying on external dependencies can be “considered harmful”. ¹ See the Wolfram Alpha calculation at http://www.wolframalpha.com/input/?i=days+between+march+17%2C+2010+and+november+26%2C+2010 ² 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. What’s 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. I’ve 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 “evaluation”) 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 wouldn’t take more than perhaps ten minutes. Well, ten minutes later I had my results and they confirmed that creating new objects wasn’t 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 “best practice” 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 doesn’t allow you to tack on additional behavior without questioning if it’s 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 didn’t 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 what’s 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.se¹. Thanks! Your support won’t go unnoticed! ¹ 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}¹. ¹ 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}¹ if you do. • Nikolai Weibull ¹ 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}¹ or later², as published by the {Free Software Foundation}³. ¹ See http://disu.se/licenses/lgpl-3.0/ ² See http://gnu.org/licenses/ ³ See http://fsf.org/

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