対話的なCLIのテストにIO.popenを使う
IO.popenを利用することでREPLのテストが書ける
Let's Build a Simple Databaseで知った
code:ruby
def run_script(commands)
raw_output = nil
IO.popen("./db test.db", "r+") do |pipe|
commands.each do |command|
begin
pipe.puts command
rescue Errno::EPIPE
break
end
end
pipe.close_write
# Read entire output
raw_output = pipe.gets(nil)
end
raw_output.split("\n")
end
it 'inserts and retrieves a row' do
result = run_script([
"insert 1 user1 person1@example.com",
"select",
".exit",
])
expect(result).to match_array([
"db > Executed.",
"db > (1, user1, person1@example.com)",
"Executed.",
"db > ",
])
end