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| -rw-r--r-- | guides/source/testing.md | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/guides/source/testing.md b/guides/source/testing.md index f0a1a8a3f0..02b60a395b 100644 --- a/guides/source/testing.md +++ b/guides/source/testing.md @@ -474,12 +474,11 @@ takes your entire test suite to run. The default parallelization method is to fork processes using Ruby's DRb system. The processes are forked based on the number of workers provided. The default is 2, but can be changed by the -number passed to the parallelize method. Active Record automatically handles creating and -migrating a new database for each worker to use. +number passed to the parallelize method. To enable parallelization add the following to your `test_helper.rb`: -``` +```ruby class ActiveSupport::TestCase parallelize(workers: 2) end @@ -489,32 +488,32 @@ The number of workers passed is the number of times the process will be forked. parallelize your local test suite differently from your CI, so an environment variable is provided to be able to easily change the number of workers a test run should use: -``` +```bash PARALLEL_WORKERS=15 rails test ``` -When parallelizing tests, Active Record automatically handles creating and migrating a database for each +When parallelizing tests, Active Record automatically handles creating a database and loading the schema into the database for each process. The databases will be suffixed with the number corresponding to the worker. For example, if you have 2 workers the tests will create `test-database-0` and `test-database-1` respectively. If the number of workers passed is 1 or fewer the processes will not be forked and the tests will not be parallelized and the tests will use the original `test-database` database. -Two hooks are provided, one runs when the process is forked, and one runs before the processes are closed. +Two hooks are provided, one runs when the process is forked, and one runs before the forked process is closed. These can be useful if your app uses multiple databases or perform other tasks that depend on the number of workers. The `parallelize_setup` method is called right after the processes are forked. The `parallelize_teardown` method is called right before the processes are closed. -``` +```ruby class ActiveSupport::TestCase parallelize_setup do |worker| # setup databases end parallelize_teardown do |worker| - # cleanup database + # cleanup databases end parallelize(workers: 2) @@ -530,7 +529,7 @@ parallelizer is backed by Minitest's `Parallel::Executor`. To change the parallelization method to use threads over forks put the following in your `test_helper.rb` -``` +```ruby class ActiveSupport::TestCase parallelize(workers: 2, with: :threads) end @@ -542,7 +541,7 @@ The number of workers passed to `parallelize` determines the number of threads t want to parallelize your local test suite differently from your CI, so an environment variable is provided to be able to easily change the number of workers a test run should use: -``` +```bash PARALLEL_WORKERS=15 rails test ``` |