> For the complete documentation index, see [llms.txt](https://jacky-chen.gitbook.io/jackychen/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jacky-chen.gitbook.io/jackychen/wwdc/2018-wwdc/whats-new-in-testing.md).

# What's New in Testing

## Code coverage

* Performance and accurancy
* Target selection
* xccov
  * Command line tool
  * coverage report (include JSON)
* Source editor

## Test selection

* Automatically include new tests
  * check: Test to skip 
  * uncheck: Test to run (Explicit opt-in)
* Test to run
  * Explicit opt-in tests

## Test ordering

* Randomize execution (by class)

## Parallel Distributed Testing (Xcode 10 support)

* Excute tests in parallel on a single destination (by class)
* Unit Test
  * Multiple instances of app running unit tests
* On Simulator
  * Multiple simulator clones running UI tests

## Parallel Destination Testing (Xcode 9 support)

* Ability to run all of your tests on multiple destinations simultaneously
* only xcodebuild use (command line)

```
xcodebuild test
    -destination 'platform=iOS,name=iPhone X'
    -destination 'platform=iOS,name=iPad'
```