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Diffstat (limited to 'spec/ruby/core/kernel/catch_spec.rb')
-rw-r--r-- | spec/ruby/core/kernel/catch_spec.rb | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/spec/ruby/core/kernel/catch_spec.rb b/spec/ruby/core/kernel/catch_spec.rb new file mode 100644 index 0000000000..35a4860f38 --- /dev/null +++ b/spec/ruby/core/kernel/catch_spec.rb @@ -0,0 +1,127 @@ +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 + + 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 + + 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 |