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ruby--ruby/spec/ruby/library/stringio/truncate_spec.rb
2019-07-27 12:40:09 +02:00

70 lines
1.9 KiB
Ruby

require_relative '../../spec_helper'
require "stringio"
describe "StringIO#truncate when passed [length]" do
before :each do
@io = StringIO.new('123456789')
end
# TODO: Report to Ruby-Core: The RDoc says it always returns 0
it "returns the passed length" do
@io.truncate(4).should eql(4)
@io.truncate(10).should eql(10)
end
it "truncated the underlying string down to the passed length" do
@io.truncate(4)
@io.string.should == "1234"
end
it "does not create a copy of the underlying string" do
io = StringIO.new(str = "123456789")
io.truncate(4)
io.string.should equal(str)
end
it "does not change the position" do
@io.pos = 7
@io.truncate(4)
@io.pos.should eql(7)
end
it "can grow a string to a larger size, padding it with \\000" do
@io.truncate(12)
@io.string.should == "123456789\000\000\000"
end
it "raises an Errno::EINVAL when the passed length is negative" do
-> { @io.truncate(-1) }.should raise_error(Errno::EINVAL)
-> { @io.truncate(-10) }.should raise_error(Errno::EINVAL)
end
it "tries to convert the passed length to an Integer using #to_int" do
obj = mock("to_int")
obj.should_receive(:to_int).and_return(4)
@io.truncate(obj)
@io.string.should == "1234"
end
it "returns the passed length Object, NOT the result of #to_int" do
obj = mock("to_int")
obj.should_receive(:to_int).and_return(4)
@io.truncate(obj).should equal(obj)
end
it "raises a TypeError when the passed length can't be converted to an Integer" do
-> { @io.truncate(Object.new) }.should raise_error(TypeError)
end
end
describe "StringIO#truncate when self is not writable" do
it "raises an IOError" do
io = StringIO.new("test", "r")
-> { io.truncate(2) }.should raise_error(IOError)
io = StringIO.new("test")
io.close_write
-> { io.truncate(2) }.should raise_error(IOError)
end
end