On 5 Jul 2010, at 08:00, Wincent Colaiuta wrote:
> Hi folks,
>
> I've been unhappy with routing specs for a long time now and last night when
> updating some old 1.3 specs for 2.0 I decided to see if I could come up with
> something that didn't make me feel unhappy.
>
> Principal causes of unhappiness:
>
> 1. Historically we had "route_for" and "params_from", which felt awfully
> repetitive because we ended up doing:
>
> route_for(lengthy_hash_of_params).should ==
> string_or_hash_describing_destination
> params_from(list_describing_destination).should == lengthy_hash_of_params
>
> Of course, it was worse than that in practice because those two lines usually
> appeared in separate example blocks with the associated boilerplate. It felt
> like a lot of work for testing such a simple thing. It also felt irritating
> to have to repeat basically the same thing twice but in a different order.
>
> 2. So then RSpec gave us "route_to", which is a wrapper for Rails'
> "assert_routing"; being a bi-directional test that encompasses the function
> of both "assert_recognizes" and "assert_generates", this allows us to avoid
> some, or even all, of the repetition:
>
> { :get => 'foo' }.should route_to(:controller => 'foo', :action => 'index')
>
> The unhappiness here comes from three causes:
>
> One is that { :get => 'foo' } feels inconsistent with other places in RSpec
> like controller specs where "get" is a method, so we can do things like "get
> 'thing'".
>
> The second issue is that the "to" in "route_to" feels misleadingly
> uni-directional when in reality it is a bi-directional test.
>
> The third issue is that for routes which don't actually have that
> bi-directional mapping, "route_to" can't be used and we must instead drop
> down to Rails' assert_recognizes() and/or assert_generates() methods, or wrap
> them using our own matchers.
>
> So I thought about what I would rather be writing and in my first cut came up
> with this:
>
> describe ArticlesController do
> describe 'routing' do
> example 'GET /wiki' do
> get('/wiki').should map_to(:controller => 'articles', :action =>
> 'index')
> get('/wiki').should map_from(:controller => 'articles', :action =>
> 'index')
> articles_path.should == '/wiki'
> end
> end
> end
>
> Things to note:
>
> - make the bi-directionality of the mapping explicit by having separate
> "map_to" and "map_from" lines.
>
> - for ease of readability and writability, keep the order as "method -> path
> -> destination" for both assertions by using "to" and "from", rather than
> swapping the order around
>
> - "map" here is the right verb because we've always used that language to
> talk about how a given URL "maps to" a given controller#action. And remember
> how in the router DSL prior to Rails 3 everything in config/routes.rb started
> with "map"?
>
> - I've tacked a test for the "articles_path" URL helper in there, because as
> a user of the Rails router I generally want to know two things: firstly, that
> requests get mapped to the appropriate controller#action; and secondly, that
> when I generate URLs (almost exclusively with named helpers; I use "url_for"
> in only 4 places in my entire app) that they take me where I think they take
> me. In the end, however, I moved this into a separate "describe 'URL
> helpers'" block.
>
> - conscious use of "example" rather than "it" because I want my specs to be
> identified as "ArticlesController routing GET /wiki" and not
> "ArticlesController routing recognizes and generates #index".
>
> - the repetition is a conscious choice because I value
> readability/scannability over DRYness-at-all-costs, especially in specs; the
> following is more DRY, for example, but less readable/scannable:
>
> path = '/wiki'
> destination = { :controller => 'articles, :action => 'index' }
> get(path).should map_to(destination)
> get(path).should map_from(destination)
>
> So I went ahead and converted a bunch of specs to this syntax and found that,
> surprise, surprise, in an application like this one where almost everything
> consists of a "standard" RESTful resource, over 90% of routes were testable
> in the bi-directional sense and in a typical routing spec file I needed to
> use "map_to" with no corresponding "map_from" for only one or two cases. So I
> needed a new method that meant "map_to_and_from".
>
> Funnily, I just can't decide on a name for this method. As a placeholder I am
> just using "map" for now:
>
> get('/wiki').should map(:controller => 'articles', :action => 'index')
>
> But others I have tried are:
>
> get('/wiki').should map_as(:controller => 'articles', :action => 'index')
> get('/wiki').should map_via(:controller => 'articles', :action => 'index')
> get('/wiki').should map_with(:controller => 'articles', :action => 'index')
> get('/wiki').should map_to_and_from(:controller => 'articles', :action =>
> 'index')
> get('/wiki').should map_both(:controller => 'articles', :action => 'index')
> get('/wiki').should map_both_ways(:controller => 'articles', :action =>
> 'index')
> get('/wiki').should have_routing(:controller => 'articles', :action =>
> 'index')
> get('/wiki').should have_route(:controller => 'articles', :action => 'index')
> get('/wiki').should be_route(:controller => 'articles', :action => 'index')
> get('/wiki').should be_routing(:controller => 'articles', :action => 'index')
> get('/wiki').should route_as(:controller => 'articles', :action => 'index')
> get('/wiki').should route_via(:controller => 'articles', :action => 'index')
> get('/wiki').should route(:controller => 'articles', :action => 'index')
> get('/wiki').should <=> (:controller => 'articles', :action => 'index')
> get('/wiki').should > (:controller => 'articles', :action => 'index') #
> map_to
> get('/wiki').should < (:controller => 'articles', :action => 'index') #
> map_from
>
> If anybody has a suitable suggestion please let me know.
>
> In the meantime, here is an example of a spec file that has been converted to
> use this new "API":
>
> http://gist.github.com/464081
>
> It also includes the supporting code that adds these new "map", "map_to",
> "map_from" matchers, and the "get", "post", "put" and "delete" methods. All
> of this for Rails 3/RSpec 2 only.
>
> I'm going to convert more routing specs and see if any more changes are
> needed to handle edge cases, but for a first cut I am pretty happy with the
> results, apart from my inability to decide on the right name for the
> bi-directional "map" matcher.
>
> Cheers,
> Wincent
Seems like progress. One thought: Why not use a macro-style syntax to eliminate
the boring boilerplate call to #it / #example and generate examples instead?
>
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