1require_relative '../../spec_helper' 2require_relative 'fixtures/classes' 3 4describe "Kernel#instance_variable_get" do 5 before :each do 6 @obj = Object.new 7 @obj.instance_variable_set("@test", :test) 8 end 9 10 it "tries to convert the passed argument to a String using #to_str" do 11 obj = mock("to_str") 12 obj.should_receive(:to_str).and_return("@test") 13 @obj.instance_variable_get(obj) 14 end 15 16 it "returns the value of the passed instance variable that is referred to by the conversion result" do 17 obj = mock("to_str") 18 obj.stub!(:to_str).and_return("@test") 19 @obj.instance_variable_get(obj).should == :test 20 end 21 22 it "returns nil when the referred instance variable does not exist" do 23 @obj.instance_variable_get(:@does_not_exist).should be_nil 24 end 25 26 it "raises a TypeError when the passed argument does not respond to #to_str" do 27 lambda { @obj.instance_variable_get(Object.new) }.should raise_error(TypeError) 28 end 29 30 it "raises a TypeError when the passed argument can't be converted to a String" do 31 obj = mock("to_str") 32 obj.stub!(:to_str).and_return(123) 33 lambda { @obj.instance_variable_get(obj) }.should raise_error(TypeError) 34 end 35 36 it "raises a NameError when the conversion result does not start with an '@'" do 37 obj = mock("to_str") 38 obj.stub!(:to_str).and_return("test") 39 lambda { @obj.instance_variable_get(obj) }.should raise_error(NameError) 40 end 41 42 it "raises a NameError when passed just '@'" do 43 obj = mock("to_str") 44 obj.stub!(:to_str).and_return('@') 45 lambda { @obj.instance_variable_get(obj) }.should raise_error(NameError) 46 end 47end 48 49describe "Kernel#instance_variable_get when passed Symbol" do 50 before :each do 51 @obj = Object.new 52 @obj.instance_variable_set("@test", :test) 53 end 54 55 it "returns the value of the instance variable that is referred to by the passed Symbol" do 56 @obj.instance_variable_get(:@test).should == :test 57 end 58 59 it "raises a NameError when passed :@ as an instance variable name" do 60 lambda { @obj.instance_variable_get(:"@") }.should raise_error(NameError) 61 end 62 63 it "raises a NameError when the passed Symbol does not start with an '@'" do 64 lambda { @obj.instance_variable_get(:test) }.should raise_error(NameError) 65 end 66 67 it "raises a NameError when the passed Symbol is an invalid instance variable name" do 68 lambda { @obj.instance_variable_get(:"@0") }.should raise_error(NameError) 69 end 70end 71 72describe "Kernel#instance_variable_get when passed String" do 73 before :each do 74 @obj = Object.new 75 @obj.instance_variable_set("@test", :test) 76 end 77 78 it "returns the value of the instance variable that is referred to by the passed String" do 79 @obj.instance_variable_get("@test").should == :test 80 end 81 82 it "raises a NameError when the passed String does not start with an '@'" do 83 lambda { @obj.instance_variable_get("test") }.should raise_error(NameError) 84 end 85 86 it "raises a NameError when the passed String is an invalid instance variable name" do 87 lambda { @obj.instance_variable_get("@0") }.should raise_error(NameError) 88 end 89 90 it "raises a NameError when passed '@' as an instance variable name" do 91 lambda { @obj.instance_variable_get("@") }.should raise_error(NameError) 92 end 93end 94 95describe "Kernel#instance_variable_get when passed Fixnum" do 96 before :each do 97 @obj = Object.new 98 @obj.instance_variable_set("@test", :test) 99 end 100 101 it "raises a TypeError" do 102 lambda { @obj.instance_variable_get(10) }.should raise_error(TypeError) 103 lambda { @obj.instance_variable_get(-10) }.should raise_error(TypeError) 104 end 105end 106