Calculate the moment when someone has lived for 10^9 seconds.
A gigasecond is 10^9 (1,000,000,000) seconds.
Execute the tests with:
$ mix test
In the test suites, all but the first test have been skipped.
Once you get a test passing, you can unskip the next one by
commenting out the relevant @tag :pending
with a #
symbol.
For example:
# @tag :pending
test "shouting" do
assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
end
Or, you can enable all the tests by commenting out the
ExUnit.configure
line in the test suite.
# ExUnit.configure exclude: :pending, trace: true
If you're stuck on something, it may help to look at some of the available resources out there where answers might be found.
Chapter 9 in Chris Pine's online Learn to Program tutorial. http://pine.fm/LearnToProgram/?Chapter=09
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
defmodule GigasecondTest do
use ExUnit.Case
# @tag :pending
test "from 4/25/2011" do
assert Gigasecond.from({{2011, 4, 25}, {0, 0, 0}}) == {{2043, 1, 1}, {1, 46, 40}}
end
@tag :pending
test "from 6/13/1977" do
assert Gigasecond.from({{1977, 6, 13}, {0, 0, 0}}) == {{2009, 2, 19}, {1, 46, 40}}
end
@tag :pending
test "from 7/19/1959" do
assert Gigasecond.from({{1959, 7, 19}, {0, 0, 0}}) == {{1991, 3, 27}, {1, 46, 40}}
end
@tag :pending
test "yourself" do
# customize these values for yourself
# your_birthday = {{year1, month1, day1}, {0, 0, 0}}
# assert Gigasecond.from(your_birthday) == {{year2, month2, day2}, {hours, minutes, seconds}}
end
end
ExUnit.start()
ExUnit.configure(exclude: :pending, trace: true)
defmodule Gigasecond do
@gigasecond 1_000_000_000
@spec from({{pos_integer, pos_integer, pos_integer}, {pos_integer, pos_integer, pos_integer}}) ::
:calendar.datetime()
def from({{_, _, _}, {_, _, _}} = erl_datetime) do
erl_datetime
|> :calendar.datetime_to_gregorian_seconds()
|> Kernel.+(@gigasecond)
|> :calendar.gregorian_seconds_to_datetime()
end
end
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