xctool

xctool is a replacement for Apple's xcodebuild that makes it easier to build and test iOS and Mac products. It's especially helpful for continuous integration.

[ Features • Requirements • Usage • Continuous Integration • Reporters • Configuration • Contributing • Known Issues & Tips • License ]

Features

xctool is drop-in replacement for xcodebuild that adds a few extra features:

• Runs the same tests as Xcode.app.

  Surprisingly, Apple's command-line xcodebuild tool does not run your product's tests the same way as Xcode.app. xcodebuild doesn't understand which targets in your scheme are test targets, which test suites or cases you might have disabled in your scheme, or how to run simulator-based, application tests.

  If you use application tests, you've probably seen xcodebuild skipping them with this message:

   Skipping tests; the iPhoneSimulator platform does not currently support
   application-hosted tests (TEST_HOST set).
  

  xctool fixes this - it looks at your Xcode scheme and is able to reproduce the same test run you would get with Xcode.app via Cmd-U or Product → Test, including running application tests that require the iOS simulator.

• Structured output of build and test results.

  xctool captures all build events and test results as structured JSON objects. If you're building a continuous integration system, this means you don't have to regex parse xcodebuild output anymore.

  Try one of the Reporters to customize the output or get the full event stream with the -reporter json-stream option.

• Human-friendly, ANSI-colored output.

  xcodebuild is incredibly verbose, printing the full compile command and output for every source file. By default, xctool is only verbose if something goes wrong, making it much easier to identify where the problems are.

  Example:

  

• Faster, parallelized test runs.

  xctool can optionally run all of your test bundles in parallel, speeding up your test runs significantly. At Facebook, we've seen 2x and 3x speed ups by parallelizing our runs.

  Use the -parallelize option with run-tests or test to enable. See Parallelizing Test Runs for more info.

Requirements

You'll need Xcode's Command Line Tools installed. From Xcode, install via Xcode → Preferences → Downloads.

Usage

xctool's commands and options are mostly a superset of xcodebuild's. In most cases, you can just swap xcodebuild with xctool and things will run as expected but with more attractive output.

You can always get help and a full list of options with:

path/to/xctool.sh -help

Building

Building products with xctool is the same as building them with xcodebuild.

If you use workspaces and schemes:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  build

If you use projects and schemes:

path/to/xctool.sh \
  -project YourProject.xcodeproj \
  -scheme YourScheme \
  build

All of the common options like -configuration, -sdk, -arch work just as they do with xcodebuild.

NOTE: xctool doesn't support directly building targets using -target; you must use schemes.

Testing

xctool has a test action which knows how to build and run the tests in your scheme. You can optionally limit what tests are run or change the SDK they're run against.

To build and run all tests in your scheme, you would use:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  test

To build and run just the tests in a specific target, use the -only option:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  test -only SomeTestTarget

You can go further and just run a specific test class:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  test -only SomeTestTarget:SomeTestClass

Or, even further and run just a single test method:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  test -only SomeTestTarget:SomeTestClass/testSomeMethod

You can also run tests against a different SDK:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  test -test-sdk iphonesimulator5.1

Building Tests

While test will build and run your tests, sometimes you want to build them without running them. For that, use build-tests.

For example:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  build-tests

You can optionally just build a single test target with the -only option:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  build-tests -only SomeTestTarget

Running Tests

If you've already built tests with build-tests, you can use run-tests to run them. This is helpful if you want to build tests once but run them against multiple SDKs.

To run all tests, you would use:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  run-tests

Just as with the test action, you can limit which tests are run with the -only. And, you can change which SDK they're run against with the -test-sdk.

Parallelizing Test Runs

xctool can optionally run unit tests in parallel, making better use of otherwise idle CPU cores. At Facebook, we've seen 2x and 3x gains by parallelizing our test runs.

To allow test bundles to run concurrently, use the -parallelize option:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  run-tests -parallelize

The above gives you parallelism, but you're bounded by your slowest test bundle. For example, if you had two test bundles ('A' and 'B'), but 'B' took 10 times as long to run because it contained 10 times as many tests, then the above parallelism won't help much.

You can get further gains by breaking your test execution into buckets using the -logicTestBucketSize option:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  run-tests -parallelize -logicTestBucketSize 20

The above will break your test execution into buckets of 20 test cases each, and those bundles will be run concurrently. If some of your test bundles are much larger than others, this will help even things out and speed up the overall test run.

Continuous Integration

xctool is an excellent choice for running your tests under a continuous integration server such as Travis CI or Jenkins. In order to your run your tests within a continuous integration environment, you must create Shared Schemes for your application target and ensure that all dependencies (such as CocoaPods) are added explicitly to the Scheme. To do so:

1. Open up the Manage Schemes sheet by selecting the Product menu > Schemes > Manage Schemes...
2. Locate your application target in the list. Ensure that the Shared checkbox in far right hand column of the sheet is checked.
3. If your application or test targets include cross-project dependencies such as CocoaPods, then you will need to ensure that they have been configured as explicit dependencies. To do so:
   1. Highlight your application target and hit the Edit... button to open the Scheme editing sheet.
   2. Click the Build tab in the left-hand panel of the Scheme editor.
   3. Click the + button and add each dependency to the project. CocoaPods will appears as static library named Pods.
   4. Drag the dependency above your application target so that it is built first.

You will now have a new file in the xcshareddata/xcschemes directory underneath your Xcode project. This is the shared Scheme that you just configured. Check this file into your repository and xctool will be able to find and execute your tests on the next CI build.

Example Travis CI Configuration

Travis CI is a very popular continuous integration system offered for free to Open Source projects. It integrates well with Github, and it now uses xctool as the default build and test tool for Objective-C projects. Once you have set up your shared Scheme for use with xctool, you will need to configure a .travis.yml file.

If you're using workspaces, your .travis.yml might be:

language: objective-c
xcode_workspace: path/to/YourApp.xcworkspace
xcode_scheme: YourApp

If you're using projects, your .travis.yml might be:

language: objective-c
xcode_project: path/to/YourApp.xcodeproj
xcode_scheme: YourApp

For more flexibility, you can also control how Travis installs and invokes xctool:

language: objective-c
before_install:
    - brew update
    - brew install xctool
script: xctool -workspace MyApp.xcworkspace -scheme MyApp test

You can learn more about the Travis CI environment for iOS and OS X application by referring to the About OS X Travis CI Environment document and find in-depth documentation for configuring your project by consulting the Getting Started page.

Reporters

xctool has reporters that output build and test results in different formats. By default, xctool always uses the pretty reporter.

You can change or add reporters with the -reporter option:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  -reporter plain \
  build

By default, reporters output to standard out, but you can also direct the output to a file by adding :OUTPUT_PATH after the reporter name:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  -reporter plain:/path/to/plain-output.txt \
  build

Included Reporters

• pretty: a text-based reporter that uses ANSI colors and unicode symbols for pretty output (the default).
• plain: like pretty, but with with no colors or unicode.
• phabricator: outputs a JSON array of build/test results which can be fed into the Phabricator code-review tool.
• junit: produces a JUnit/xUnit compatible XML file with test results.
• json-stream: a stream of build/test events as JSON dictionaries, one per line (example output).
• json-compilation-database: outputs a JSON Compilation Database of build events which can be used by Clang Tooling based tools, e.g. OCLint.

Implementing Your Own Reporters

You can also implement your own reporters using whatever language you like. Reporters in xctool are separate executables that read JSON objects from STDIN and write formatted results to STDOUT.

You can invoke reporters by passing their full path via the -reporter option:

path/to/xctool.sh \
  -workspace YourWorkspace.xcworkspace \
  -scheme YourScheme \
  -reporter /path/to/your/reporter \
  test

For example, here's a simple reporter in Python that outputs a period for every passing test and an exclamation mark for every failing test:

#!/usr/bin/python

import fileinput
import json
import sys

for line in fileinput.input():
    obj = json.loads(line)

    if obj['event'] == 'end-test':
        if obj['succeeded']:
            sys.stdout.write('.')
        else:
            sys.stdout.write('!')

sys.stdout.write('\n')

If you're writing a reporter in Objective-C, you'll find the Reporter class helpful - see Reporter.h.

Configuration (.xctool-args)

If you routinely need to pass many arguments to xctool on the command-line, you can use an .xctool-args file to speed up your workflow. If xctool finds an .xctool-args file in the current directory, it will automatically pre-populate its arguments from there.

The format is just a JSON array of arguments:

[
  "-workspace", "YourWorkspace.xcworkspace",
  "-scheme", "YourScheme",
  "-configuration", "Debug",
  "-sdk", "iphonesimulator",
  "-arch", "i386"
]

Any extra arguments you pass on the command-line will take precendence over those in the .xctool-args file.

Contributing

Bug fixes, improvements, and especially new Reporter implementations are welcome. Before submitting a pull request, please be sure to sign the Facebook Contributor License Agreement. We can't accept pull requests unless it's been signed.

Workflow

1. Fork.
2. Make a feature branch: git checkout -b my-feature
3. Make your feature. Keep things tidy so you have one commit per self contained change (squashing can help).
4. Push your branch to your fork: git push -u origin my-feature
5. Open GitHub, under "Your recently pushed branches", click Pull Request for my-feature.

Be sure to use a separate feature branch and pull request for every self-contained feature. If you need to make changes from feedback, make the changes in place rather than layering on commits (use interactive rebase to edit your earlier commits). Then use git push --force origin my-feature to update your pull request.

Workflow (for Facebook people, other committers)

Mostly the same, but use branches in the main xctool repo if you prefer. It's a nice way to keep things together.

1. Make a feature branch: git checkout -b myusername/my-feature
2. Push your branch: git push -u origin myusername/my-feature
3. Open GitHub to facebook/xctool, under "Your recently pushed branches", click Pull Request for myusername/my-feature.

Known Issues & Tips

• Use shared schemes and disable the Autocreate Schemes feature.

  Xcode has two kinds of schemes: shared, and user. User schemes are the default, and they're stored under a folder called USERNAME.xcuserdatad, which most people correctly add to their .gitignore.

  Use shared schemes instead, and commit them to your repo. This way everyone on your team (and your build server) are working from the same information, and are building in the same way.

  

License

Copyright 2013 Facebook

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License. You may obtain a copy of the License in the LICENSE file, or at:

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.