module RSpec::Core::Hooks
Constants
- HOOK_TYPES
- SCOPES
Public Instance Methods
@api public @overload after(&block) @overload after(scope, &block) @overload after(scope, conditions, &block) @overload after(conditions, &block)
@param [Symbol] scope `:each`, `:all`, or `:suite` (defaults to `:each`) @param [Hash] conditions
constrains this hook to examples matching these conditions e.g. %xafter(:each, :ui => true) { ... }` will only run with examples or groups declared with %x:ui => true`.
@see before @see around @see ExampleGroup @see SharedContext @see SharedExampleGroup @see Configuration
Declare a block of code to be run after each example (using `:each`) or once after all examples (using `:all`). See [#before](Hooks#before-instance_method) for more information about ordering.
### Exceptions
`after` hooks are guaranteed to run even when there are exceptions in `before` hooks or examples. When an exception is raised in an after block, the exception is captured for later reporting, and subsequent `after` blocks are run.
### Order
`after` hooks are stored in three scopes, which are run in order: `:each`, `:all`, and `:suite`. They can also be declared in several different places: `RSpec.configure`, a parent group, the current group. They are run in the following order:
after(:each) # declared in the current group after(:each) # declared in a parent group after(:each) # declared in RSpec.configure after(:all) # declared in the current group after(:all) # declared in a parent group after(:all) # declared in RSpec.configure
This is the reverse of the order in which `before` hooks are run. Similarly, if more than one `after` is declared within any one scope, they are run in reverse order of that in which they are declared.
# File lib/rspec/core/hooks.rb, line 379 def after(*args, &block) register_hook :prepend, :after, *args, &block end
Adds `block` to the back of the list of `after` blocks in the same scope (`:each`, `:all`, or `:suite`).
See after for scoping semantics.
# File lib/rspec/core/hooks.rb, line 389 def append_after(*args, &block) register_hook :append, :after, *args, &block end
@api public @overload around(&block) @overload around(scope, &block) @overload around(scope, conditions, &block) @overload around(conditions, &block)
@param [Symbol] scope `:each` (defaults to `:each`)
present for syntax parity with `before` and `after`, but `:each` is the only supported value.
@param [Hash] conditions
constrains this hook to examples matching these conditions e.g. %xaround(:each, :ui => true) { ... }` will only run with examples or groups declared with %x:ui => true`.
@yield [Example] the example to run
@note the syntax of `around` is similar to that of `before` and `after`
but the semantics are quite different. `before` and `after` hooks are run in the context of of the examples with which they are associated, whereas `around` hooks are actually responsible for running the examples. Consequently, `around` hooks do not have direct access to resources that are made available within the examples and their associated `before` and `after` hooks.
@note `:each` is the only supported scope.
Declare a block of code, parts of which will be run before and parts after the example. It is your responsibility to run the example:
around(:each) do |ex| # do some stuff before ex.run # do some stuff after end
The yielded example aliases `run` with `call`, which lets you treat it like a `Proc`. This is especially handy when working with libaries that manage their own setup and teardown using a block or proc syntax, e.g.
around(:each) {|ex| Database.transaction(&ex)} around(:each) {|ex| FakeFS(&ex)}
# File lib/rspec/core/hooks.rb, line 437 def around(*args, &block) register_hook :prepend, :around, *args, &block end
@private
# File lib/rspec/core/hooks.rb, line 450 def around_each_hooks_for(example, initial_procsy=nil) AroundHookCollection.new(parent_groups.map {|a| a.hooks[:around][:each]}.flatten).for(example, initial_procsy) end
@api public @overload before(&block) @overload before(scope, &block) @overload before(scope, conditions, &block) @overload before(conditions, &block)
@param [Symbol] scope `:each`, `:all`, or `:suite` (defaults to `:each`) @param [Hash] conditions
constrains this hook to examples matching these conditions e.g. %xbefore(:each, :ui => true) { ... }` will only run with examples or groups declared with %x:ui => true`.
@see after @see around @see ExampleGroup @see SharedContext @see SharedExampleGroup @see Configuration
Declare a block of code to be run before each example (using `:each`) or once before any example (using `:all`). These are usually declared directly in the {ExampleGroup} to which they apply, but they can also be shared across multiple groups.
You can also use `before(:suite)` to run a block of code before any example groups are run. This should be declared in {RSpec.configure}
Instance variables declared in `before(:each)` or `before(:all)` are accessible within each example.
### Order
`before` hooks are stored in three scopes, which are run in order: `:suite`, `:all`, and `:each`. They can also be declared in several different places: `RSpec.configure`, a parent group, the current group. They are run in the following order:
before(:suite) # declared in RSpec.configure before(:all) # declared in RSpec.configure before(:all) # declared in a parent group before(:all) # declared in the current group before(:each) # declared in RSpec.configure before(:each) # declared in a parent group before(:each) # declared in the current group
If more than one `before` is declared within any one scope, they are run in the order in which they are declared.
### Conditions
When you add a conditions hash to `before(:each)` or `before(:all)`, RSpec will only apply that hook to groups or examples that match the conditions. e.g.
RSpec.configure do |config| config.before(:each, :authorized => true) do log_in_as :authorized_user end end describe Something, :authorized => true do # the before hook will run in before each example in this group end describe SomethingElse do it "does something", :authorized => true do # the before hook will run before this example end it "does something else" do # the hook will not run before this example end end
### Warning: `before(:suite, :with => :conditions)`
The conditions hash is used to match against specific examples. Since `before(:suite)` is not run in relation to any specific example or group, conditions passed along with `:suite` are effectively ignored.
### Exceptions
When an exception is raised in a `before` block, RSpec skips any subsequent `before` blocks and the example, but runs all of the `after(:each)` and `after(:all)` hooks.
### Warning: implicit before blocks
`before` hooks can also be declared in shared contexts which get included implicitly either by you or by extension libraries. Since RSpec runs these in the order in which they are declared within each scope, load order matters, and can lead to confusing results when one before block depends on state that is prepared in another before block that gets run later.
### Warning: `before(:all)`
It is very tempting to use `before(:all)` to speed things up, but we recommend that you avoid this as there are a number of gotchas, as well as things that simply don't work.
#### context
`before(:all)` is run in an example that is generated to provide group context for the block.
#### instance variables
Instance variables declared in `before(:all)` are shared across all the examples in the group. This means that each example can change the state of a shared object, resulting in an ordering dependency that can make it difficult to reason about failures.
#### unsupported rspec constructs
RSpec has several constructs that reset state between each example automatically. These are not intended for use from within `before(:all)`:
* `let` declarations * `subject` declarations * Any mocking, stubbing or test double declaration
### other frameworks
Mock object frameworks and database transaction managers (like ActiveRecord) are typically designed around the idea of setting up before an example, running that one example, and then tearing down. This means that mocks and stubs can (sometimes) be declared in `before(:all)`, but get torn down before the first real example is ever run.
You can create database-backed model objects in a `before(:all)` in rspec-rails, but it will not be wrapped in a transaction for you, so you are on your own to clean up in an `after(:all)` block.
@example before(:each) declared in an {ExampleGroup}
describe Thing do before(:each) do @thing = Thing.new end it "does something" do # here you can access @thing end end
@example before(:all) declared in an {ExampleGroup}
describe Parser do before(:all) do File.open(file_to_parse, 'w') do |f| f.write <<-CONTENT stuff in the file CONTENT end end it "parses the file" do Parser.parse(file_to_parse) end after(:all) do File.delete(file_to_parse) end end
# File lib/rspec/core/hooks.rb, line 317 def before(*args, &block) register_hook :append, :before, *args, &block end
@private
# File lib/rspec/core/hooks.rb, line 143 def hooks @hooks ||= { :around => { :each => AroundHookCollection.new }, :before => { :each => HookCollection.new, :all => HookCollection.new, :suite => HookCollection.new }, :after => { :each => HookCollection.new, :all => HookCollection.new, :suite => HookCollection.new } }.extend(RegistersGlobals) end
Adds `block` to the front of the list of `before` blocks in the same scope (`:each`, `:all`, or `:suite`).
See before for scoping semantics.
# File lib/rspec/core/hooks.rb, line 327 def prepend_before(*args, &block) register_hook :prepend, :before, *args, &block end
@private
Runs all of the blocks stored with the hook in the context of the example. If no example is provided, just calls the hook directly.
# File lib/rspec/core/hooks.rb, line 445 def run_hook(hook, scope, example_or_group=ExampleGroup.new, initial_procsy=nil) find_hook(hook, scope, example_or_group, initial_procsy).run end
Private Instance Methods
# File lib/rspec/core/hooks.rb, line 470 def after_all_hooks_for(group) GroupHookCollection.new(hooks[:after][:all]).for(group) end
# File lib/rspec/core/hooks.rb, line 478 def after_each_hooks_for(example) HookCollection.new(parent_groups.map {|a| a.hooks[:after][:each]}.flatten).for(example) end
# File lib/rspec/core/hooks.rb, line 466 def before_all_hooks_for(group) GroupHookCollection.new(hooks[:before][:all]).for(group) end
# File lib/rspec/core/hooks.rb, line 474 def before_each_hooks_for(example) HookCollection.new(parent_groups.reverse.map {|a| a.hooks[:before][:each]}.flatten).for(example) end
# File lib/rspec/core/hooks.rb, line 508 def extract_scope_from(args) if SCOPES.include?(args.first) args.shift elsif args.any? { |a| a.is_a?(Symbol) } raise ArgumentError.new("You must explicitly give a scope (:each, :all, or :suite) when using symbols as metadata for a hook.") else :each end end
# File lib/rspec/core/hooks.rb, line 487 def find_hook(hook, scope, example_or_group, initial_procsy) case [hook, scope] when [:before, :all] before_all_hooks_for(example_or_group) when [:after, :all] after_all_hooks_for(example_or_group) when [:around, :each] around_each_hooks_for(example_or_group, initial_procsy) when [:before, :each] before_each_hooks_for(example_or_group) when [:after, :each] after_each_hooks_for(example_or_group) when [:before, :suite], [:after, :suite] hooks[hook][:suite].with(example_or_group) end end
# File lib/rspec/core/hooks.rb, line 482 def register_hook prepend_or_append, hook, *args, &block scope, options = scope_and_options_from(*args) hooks[hook][scope].send(prepend_or_append, HOOK_TYPES[hook][scope].new(block, options)) end
# File lib/rspec/core/hooks.rb, line 504 def scope_and_options_from(*args) return extract_scope_from(args), build_metadata_hash_from(args) end