discourse/bin/turbo_rspec
Alan Guo Xiang Tan 39da9106ba
DEV: Introduce automatic reruns to RSpec tests on Github actions (#24811)
What motivated this change?

Our builds on Github actions have been extremely flaky mostly due to system tests. This has led to a drop in confidence
in our test suite where our developers tend to assume that a failed job is due to a flaky system test. As a result, we
have had occurrences where changes that resulted in legitimate test failures are merged into the `main` branch because developers
assumed it was a flaky test.

What does this change do?

This change seeks to reduce the flakiness of our builds on Github Actions by automatically re-running RSpec tests once when
they fail. If a failed test passes subsequently in the re-run, we mark the test as flaky by logging it into a file on disk
which is then uploaded as an artifact of the Github workflow run. We understand that automatically re-runs will lead to 
lower accuracy of our tests but we accept this as an acceptable trade-off since a fragile build has a much greater impact
on our developers' time. Internally, the Discourse development team will be running a service to fetch the flaky tests 
which have been logged for internal monitoring.

How is the change implemented?

1. A `--retry-and-log-flaky-tests` CLI flag is added to the `bin/turbo_rspec` CLI which will then initialize `TurboTests::Runner` 
with the `retry_and_log_flaky_tests` kwarg set to `true`. 

2. When the `retry_and_log_flaky_tests` kwarg is set to `true` for `TurboTests::Runner`, we will register an additional 
formatter `Flaky::FailuresLoggerFormatter` to the `TurboTests::Reporter` in the `TurboTests::Runner#run` method. 
The `Flaky::FailuresLoggerFormatter` has a simple job of logging all failed examples to a file on disk when running all the 
tests. The details of the failed example which are logged can be found in `TurboTests::Flaky::FailedExample.to_h`.

3. Once all the tests have been run once, we check the result for any failed examples and if there are, we read the file on
disk to fetch the `location_rerun_location` of the failed examples which is then used to run the tests in a new RSpec process.
In the rerun, we configure a `TurboTests::Flaky::FlakyDetectorFormatter` with RSpec which removes all failed examples from the log file on disk since those examples are not flaky tests. Note that if there are too many failed examples on the first run, we will deem the failures to likely not be due to flaky tests and not re-run the test failures. As of writing, the threshold of failed examples is set to 10. If there are more than 10 failed examples, we will not re-run the failures.
2023-12-13 07:18:27 +08:00

134 lines
3.4 KiB
Ruby
Executable File

#!/usr/bin/env ruby
# frozen_string_literal: true
ENV["RAILS_ENV"] ||= "test"
require "./lib/turbo_tests"
require "optparse"
requires = []
formatters = []
verbose = false
fail_fast = nil
seed = rand(2**16)
profile = false
profile_print_slowest_examples_count = 10
use_runtime_info = nil
enable_system_tests = nil
disable_system_tests = nil
retry_and_log_flaky_tests = false
OptionParser
.new do |opts|
opts.on("-r", "--require PATH", "Require a file.") { |filename| requires << filename }
opts.on("-f", "--format FORMATTER", "Choose a formatter.") do |name|
formatters << { name: name, outputs: [] }
end
opts.on("-o", "--out FILE", "Write output to a file instead of $stdout") do |filename|
formatters << { name: "progress", outputs: [] } if formatters.empty?
formatters.last[:outputs] << filename
end
opts.on("-v", "--verbose", "More output") { verbose = true }
opts.on(
"-p",
"--profile=[COUNT]",
"Benchmark the runtime of each example and list the slowest examples (default: 10)",
) do |count|
profile = true
profile_print_slowest_examples_count = count.to_i if count
end
opts.on("--fail-fast=[N]") do |n|
n =
begin
Integer(n)
rescue StandardError
nil
end
fail_fast = (n.nil? || n < 1) ? 1 : n
end
opts.on(
"--retry-and-log-flaky-tests",
"Retry failed tests and log if test is deemed to be flaky",
) { retry_and_log_flaky_tests = true }
opts.on("--seed SEED", "The seed for the random order") { |s| seed = s.to_i }
opts.on("--use-runtime-info", "Use runtime info for tests group splitting") do
use_runtime_info = true
end
opts.on("--enable-system-tests", "Run the system tests (defaults false)") do
enable_system_tests = true
end
opts.on("--disable-system-tests", "Don't run the system tests (defaults true)") do
disable_system_tests = true
end
end
.parse!(ARGV)
if enable_system_tests && disable_system_tests
STDERR.puts "Error: I'm not sure how to enable and disable system tests simultaneously"
exit 1
end
# OptionParser modifies ARGV, leaving the leftover arguments in ARGV
if ARGV.empty?
if !enable_system_tests && !disable_system_tests
STDERR.puts "Not running system tests since it wasn't explicitly specified"
end
run_system_tests = !!enable_system_tests
files =
if run_system_tests
["#{Rails.root}/spec"]
else
TurboTests::Runner.default_spec_folders
end
use_runtime_info = true if use_runtime_info.nil?
else
if enable_system_tests || disable_system_tests
STDERR.puts "Ignoring system test options since files were specified"
end
files = ARGV
use_runtime_info = false if use_runtime_info.nil?
end
requires.each { |f| require(f) }
formatters << { name: "progress", outputs: [] } if formatters.empty?
formatters.each { |formatter| formatter[:outputs] << "-" if formatter[:outputs].empty? }
puts "::group::Run turbo_rspec" if ENV["GITHUB_ACTIONS"]
puts "Running turbo_rspec (seed: #{seed}) using files in: #{files}"
puts "::endgroup::" if ENV["GITHUB_ACTIONS"]
success =
TurboTests::Runner.run(
formatters: formatters,
files: files,
verbose: verbose,
fail_fast: fail_fast,
use_runtime_info: use_runtime_info,
seed: seed.to_s,
profile:,
profile_print_slowest_examples_count:,
retry_and_log_flaky_tests:,
)
if success
exit 0
else
exit 1
end