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require File.expand_path('../../../spec_helper', __FILE__)
require File.expand_path('../fixtures/classes', __FILE__)
describe "Kernel.catch" do
before :each do
ScratchPad.clear
end
it "executes its block and catches a thrown value matching its argument" do
catch :thrown_key do
ScratchPad.record :catch_block
throw :thrown_key
ScratchPad.record :throw_failed
end
ScratchPad.recorded.should == :catch_block
end
it "returns the second value passed to throw" do
catch(:thrown_key) { throw :thrown_key, :catch_value }.should == :catch_value
end
it "returns the last expression evaluated if throw was not called" do
catch(:thrown_key) { 1; :catch_block }.should == :catch_block
end
it "passes the given symbol to its block" do
catch :thrown_key do |tag|
ScratchPad.record tag
end
ScratchPad.recorded.should == :thrown_key
end
ruby_version_is ""..."1.9" do
it "matches strings as symbols" do
catch "thrown_key" do
ScratchPad.record :catch_block
throw :thrown_key
end
ScratchPad.recorded.should == :catch_block
end
it "matches strings that are the same value" do
catch "thrown_key" do
ScratchPad.record :catch_block
throw "thrown_key"
end
ScratchPad.recorded.should == :catch_block
end
it "raises a TypeError if the argument is an Object" do
lambda { catch(Object.new) {} }.should raise_error(TypeError)
end
it "raises an ArgumentError if called without an argument" do
lambda { catch {} }.should raise_error(ArgumentError)
end
it "passes a symbol converted from the given string to its block" do
catch("thrown_key") { |tag| tag }.should == :thrown_key
end
end
ruby_version_is "1.9" do
it "raises an ArgumentError if a Symbol is thrown for a String catch value" do
lambda { catch("exit") { throw :exit } }.should raise_error(ArgumentError)
end
it "raises an ArgumentError if a String with different identity is thrown" do
lambda { catch("exit") { throw "exit" } }.should raise_error(ArgumentError)
end
it "catches a Symbol when thrown a matching Symbol" do
catch :thrown_key do
ScratchPad.record :catch_block
throw :thrown_key
end
ScratchPad.recorded.should == :catch_block
end
it "catches a String when thrown a String with the same identity" do
key = "thrown_key"
catch key do
ScratchPad.record :catch_block
throw key
end
ScratchPad.recorded.should == :catch_block
end
it "accepts an object as an argument" do
catch(Object.new) { :catch_block }.should == :catch_block
end
it "yields an object when called without arguments" do
catch { |tag| tag }.should be_an_instance_of(Object)
end
end
it "can be used even in a method different from where throw is called" do
class CatchSpecs
def self.throwing_method
throw :blah, :thrown_value
end
def self.catching_method
catch :blah do
throwing_method
end
end
end
CatchSpecs.catching_method.should == :thrown_value
end
describe "when nested" do
before :each do
ScratchPad.record []
end
it "catches across invocation boundaries" do
catch :one do
ScratchPad << 1
catch :two do
ScratchPad << 2
catch :three do
ScratchPad << 3
throw :one
ScratchPad << 4
end
ScratchPad << 5
end
ScratchPad << 6
end
ScratchPad.recorded.should == [1, 2, 3]
end
it "catches in the nested invocation with the same key object" do
catch :thrown_key do
ScratchPad << 1
catch :thrown_key do
ScratchPad << 2
throw :thrown_key
ScratchPad << 3
end
ScratchPad << 4
end
ScratchPad.recorded.should == [1, 2, 4]
end
end
it "raises LocalJumpError if no block is given" do
lambda { catch :blah }.should raise_error(LocalJumpError)
end
end
describe "Kernel#catch" do
it "is a private method" do
Kernel.should have_private_instance_method(:catch)
end
end
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