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ruby--ruby/spec/ruby/core/io/sysread_spec.rb
2022-09-28 18:37:17 +02:00

132 lines
3.5 KiB
Ruby

require_relative '../../spec_helper'
require_relative 'fixtures/classes'
describe "IO#sysread on a file" do
before :each do
@file_name = tmp("IO_sysread_file") + $$.to_s
File.open(@file_name, "w") do |f|
# write some stuff
f.write("012345678901234567890123456789\nabcdef")
end
@file = File.open(@file_name, "r+")
end
after :each do
@file.close
rm_r @file_name
end
it "reads the specified number of bytes from the file" do
@file.sysread(15).should == "012345678901234"
end
it "reads the specified number of bytes from the file to the buffer" do
buf = "" # empty buffer
@file.sysread(15, buf).should == buf
buf.should == "012345678901234"
@file.rewind
buf = "ABCDE" # small buffer
@file.sysread(15, buf).should == buf
buf.should == "012345678901234"
@file.rewind
buf = "ABCDE" * 5 # large buffer
@file.sysread(15, buf).should == buf
buf.should == "012345678901234"
end
it "coerces the second argument to string and uses it as a buffer" do
buf = "ABCDE"
(obj = mock("buff")).should_receive(:to_str).any_number_of_times.and_return(buf)
@file.sysread(15, obj).should == buf
buf.should == "012345678901234"
end
it "advances the position of the file by the specified number of bytes" do
@file.sysread(15)
@file.sysread(5).should == "56789"
end
it "raises an error when called after buffered reads" do
@file.readline
-> { @file.sysread(5) }.should raise_error(IOError)
end
it "reads normally even when called immediately after a buffered IO#read" do
@file.read(15)
@file.sysread(5).should == "56789"
end
it "does not raise error if called after IO#read followed by IO#write" do
@file.read(5)
@file.write("abcde")
-> { @file.sysread(5) }.should_not raise_error(IOError)
end
it "does not raise error if called after IO#read followed by IO#syswrite" do
@file.read(5)
@file.syswrite("abcde")
-> { @file.sysread(5) }.should_not raise_error(IOError)
end
it "reads updated content after the flushed buffered IO#write" do
@file.write("abcde")
@file.flush
@file.sysread(5).should == "56789"
File.open(@file_name) do |f|
f.sysread(10).should == "abcde56789"
end
end
it "raises IOError on closed stream" do
-> { IOSpecs.closed_io.sysread(5) }.should raise_error(IOError)
end
it "immediately returns an empty string if the length argument is 0" do
@file.sysread(0).should == ""
end
it "immediately returns the given buffer if the length argument is 0" do
buffer = "existing content"
@file.sysread(0, buffer).should == buffer
buffer.should == "existing content"
end
it "discards the existing buffer content upon successful read" do
buffer = "existing content"
@file.sysread(11, buffer)
buffer.should == "01234567890"
end
it "discards the existing buffer content upon error" do
buffer = "existing content"
@file.seek(0, :END)
-> { @file.sysread(1, buffer) }.should raise_error(EOFError)
buffer.should be_empty
end
end
describe "IO#sysread" do
before do
@read, @write = IO.pipe
end
after do
@read.close
@write.close
end
it "returns a smaller string if less than size bytes are available" do
@write.syswrite "ab"
@read.sysread(3).should == "ab"
end
guard_not -> { platform_is :windows and ruby_version_is ""..."3.2" } do # https://bugs.ruby-lang.org/issues/18880
it "raises ArgumentError when length is less than 0" do
-> { @read.sysread(-1) }.should raise_error(ArgumentError)
end
end
end