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Diffstat (limited to 'spec/ruby/core/kernel/instance_variable_set_spec.rb')
-rw-r--r-- | spec/ruby/core/kernel/instance_variable_set_spec.rb | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/spec/ruby/core/kernel/instance_variable_set_spec.rb b/spec/ruby/core/kernel/instance_variable_set_spec.rb new file mode 100644 index 0000000000..bac1bb5f99 --- /dev/null +++ b/spec/ruby/core/kernel/instance_variable_set_spec.rb @@ -0,0 +1,93 @@ +require File.expand_path('../../../spec_helper', __FILE__) +require File.expand_path('../fixtures/classes', __FILE__) + +describe "Kernel#instance_variable_set" do + it "sets the value of the specified instance variable" do + class Dog + def initialize(p1, p2) + @a, @b = p1, p2 + end + end + Dog.new('cat', 99).instance_variable_set(:@a, 'dog').should == "dog" + end + + it "sets the value of the instance variable when no instance variables exist yet" do + class NoVariables; end + NoVariables.new.instance_variable_set(:@a, "new").should == "new" + end + + it "raises a NameError exception if the argument is not of form '@x'" do + class NoDog; end + lambda { NoDog.new.instance_variable_set(:c, "cat") }.should raise_error(NameError) + end + + it "raises a NameError exception if the argument is an invalid instance variable name" do + class DigitDog; end + lambda { DigitDog.new.instance_variable_set(:"@0", "cat") }.should raise_error(NameError) + end + + it "raises a NameError when the argument is '@'" do + class DogAt; end + lambda { DogAt.new.instance_variable_set(:"@", "cat") }.should raise_error(NameError) + end + + it "raises a TypeError if the instance variable name is a Fixnum" do + lambda { "".instance_variable_set(1, 2) }.should raise_error(TypeError) + end + + it "raises a TypeError if the instance variable name is an object that does not respond to to_str" do + class KernelSpecs::A; end + lambda { "".instance_variable_set(KernelSpecs::A.new, 3) }.should raise_error(TypeError) + end + + it "raises a NameError if the passed object, when coerced with to_str, does not start with @" do + class KernelSpecs::B + def to_str + ":c" + end + end + lambda { "".instance_variable_set(KernelSpecs::B.new, 4) }.should raise_error(NameError) + end + + it "raises a NameError if pass an object that cannot be a symbol" do + lambda { "".instance_variable_set(:c, 1) }.should raise_error(NameError) + end + + it "accepts as instance variable name any instance of a class that responds to to_str" do + class KernelSpecs::C + def initialize + @a = 1 + end + def to_str + "@a" + end + end + KernelSpecs::C.new.instance_variable_set(KernelSpecs::C.new, 2).should == 2 + end + + describe "on frozen objects" do + before :each do + klass = Class.new do + attr_reader :ivar + def initialize + @ivar = :origin + end + end + + @frozen = klass.new.freeze + end + + it "keeps stored object after any exceptions" do + lambda { @frozen.instance_variable_set(:@ivar, :replacement) }.should raise_error(Exception) + @frozen.ivar.should equal(:origin) + end + + it "raises a RuntimeError when passed replacement is identical to stored object" do + lambda { @frozen.instance_variable_set(:@ivar, :origin) }.should raise_error(RuntimeError) + end + + it "raises a RuntimeError when passed replacement is different from stored object" do + lambda { @frozen.instance_variable_set(:@ivar, :replacement) }.should raise_error(RuntimeError) + end + end +end |