Style: Unquote integer constants To make @sublimino and @jasonkarns happy. :-) The one exception: the `"$BATS_TEST_SKIPPED" != '1'` expression. If updated to `"$BATS_TEST_SKIPPED" -ne 1`, the "tap passing and skipping tests" and "skipped tests" test cases fail.
Tuesday, September 19, 2017: This is a mirrored fork of Bats, at 0360811. It was created via git clone --bare and git push --mirror.
The original Bats repository needed new maintainers, and has not been actively maintained since 2013. While there were volunteers for maintainers, attempts to organize issues, and outstanding PRs, the lack of write-access to the repo hindered progress severely.
The rough plan, originally outlined here is to create a new, mirrored mainline (this repo!). An excerpt:
1. Roadmap 1.0: There are already existing high-quality PRs, and often-requested features and issues, especially here at #196. Leverage these and consolidate into a single roadmap.
2. Create or choose a fork or mirror of this repo to use as the new mainline: Repoint existing PRs (whichever ones are possible) to the new mainline, get that repo to a stable 1.0. IMO we should create an organization and grant 2-3 people admin and write access.
Doing it this way accomplishes two things:
#bats on freenodeBats is a TAP-compliant testing framework for Bash. It provides a simple way to verify that the UNIX programs you write behave as expected.
A Bats test file is a Bash script with special syntax for defining test cases. Under the hood, each test case is just a function with a description.
#!/usr/bin/env bats @test "addition using bc" { result="$(echo 2+2 | bc)" [ "$result" -eq 4 ] } @test "addition using dc" { result="$(echo 2 2+p | dc)" [ "$result" -eq 4 ] }
Bats is most useful when testing software written in Bash, but you can use it to test any UNIX program.
Test cases consist of standard shell commands. Bats makes use of Bash's errexit (set -e) option when running test cases. If every command in the test case exits with a 0 status code (success), the test passes. In this way, each line is an assertion of truth.
To run your tests, invoke the bats interpreter with a path to a test file. The file's test cases are run sequentially and in isolation. If all the test cases pass, bats exits with a 0 status code. If there are any failures, bats exits with a 1 status code.
When you run Bats from a terminal, you‘ll see output as each test is performed, with a check-mark next to the test’s name if it passes or an “X” if it fails.
$ bats addition.bats ✓ addition using bc ✓ addition using dc 2 tests, 0 failures
If Bats is not connected to a terminal—in other words, if you run it from a continuous integration system, or redirect its output to a file—the results are displayed in human-readable, machine-parsable TAP format.
You can force TAP output from a terminal by invoking Bats with the --tap option.
$ bats --tap addition.bats 1..2 ok 1 addition using bc ok 2 addition using dc
You can invoke the bats interpreter with multiple test file arguments, or with a path to a directory containing multiple .bats files. Bats will run each test file individually and aggregate the results. If any test case fails, bats exits with a 1 status code.
Each Bats test file is evaluated n+1 times, where n is the number of test cases in the file. The first run counts the number of test cases, then iterates over the test cases and executes each one in its own process.
For more details about how Bats evaluates test files, see Bats Evaluation Process on the wiki.
run: Test other commandsMany Bats tests need to run a command and then make assertions about its exit status and output. Bats includes a run helper that invokes its arguments as a command, saves the exit status and output into special global variables, and then returns with a 0 status code so you can continue to make assertions in your test case.
For example, let‘s say you’re testing that the foo command, when passed a nonexistent filename, exits with a 1 status code and prints an error message.
@test "invoking foo with a nonexistent file prints an error" { run foo nonexistent_filename [ "$status" -eq 1 ] [ "$output" = "foo: no such file 'nonexistent_filename'" ] }
The $status variable contains the status code of the command, and the $output variable contains the combined contents of the command's standard output and standard error streams.
A third special variable, the $lines array, is available for easily accessing individual lines of output. For example, if you want to test that invoking foo without any arguments prints usage information on the first line:
@test "invoking foo without arguments prints usage" { run foo [ "$status" -eq 1 ] [ "${lines[0]}" = "usage: foo <filename>" ] }
load: Share common codeYou may want to share common code across multiple test files. Bats includes a convenient load command for sourcing a Bash source file relative to the location of the current test file. For example, if you have a Bats test in test/foo.bats, the command
load test_helper
will source the script test/test_helper.bash in your test file. This can be useful for sharing functions to set up your environment or load fixtures.
skip: Easily skip testsTests can be skipped by using the skip command at the point in a test you wish to skip.
@test "A test I don't want to execute for now" { skip run foo [ "$status" -eq 0 ] }
Optionally, you may include a reason for skipping:
@test "A test I don't want to execute for now" { skip "This command will return zero soon, but not now" run foo [ "$status" -eq 0 ] }
Or you can skip conditionally:
@test "A test which should run" { if [ foo != bar ]; then skip "foo isn't bar" fi run foo [ "$status" -eq 0 ] }
setup and teardown: Pre- and post-test hooksYou can define special setup and teardown functions, which run before and after each test case, respectively. Use these to load fixtures, set up your environment, and clean up when you're done.
You can include code in your test file outside of @test functions. For example, this may be useful if you want to check for dependencies and fail immediately if they're not present. However, any output that you print in code outside of @test, setup or teardown functions must be redirected to stderr (>&2). Otherwise, the output may cause Bats to fail by polluting the TAP stream on stdout.
Bats makes a separation between output from the code under test and output that forms the TAP stream (which is produced by Bats internals). This is done in order to produce TAP-compliant output. In the Printing to the terminal section, there are details on how to use file descriptor 3 to print custom text properly.
A side effect of using file descriptor 3 is that, under some circumstances, it can cause Bats to block and execution to seem dead without reason. This can happen if a child process is spawned in the background from a test. In this case, the child process will inherit file descriptor 3. Bats, as the parent process, will wait for the file descriptor to be closed by the child process before continuing execution. If the child process takes a lot of time to complete (eg if the child process is a sleep 100 command or a background service that will run indefinitely), Bats will be similarly blocked for the same amount of time.
To prevent this from happening, close FD 3 explicitly when running any command that may launch long-running child processes, e.g. command_name 3>- &.
Bats produces output compliant with version 12 of the TAP protocol. The produced TAP stream is by default piped to a pretty formatter for human consumption, but if Bats is called with the -t flag, then the TAP stream is directly printed to the console.
This has implications if you try to print custom text to the terminal. As mentioned in File descriptor 3, bats provides a special file descriptor, &3, that you should use to print your custom text. Here are some detailed guidelines to refer to:
echo 'text' >&3. This output will become part of the TAP stream. You are encouraged to prepend text printed this way with a hash (eg echo '# text' >&3) in order to produce 100% TAP compliant output. Otherwise, depending on the 3rd-party tools you use to analyze the TAP stream, you can encounter unexpected behavior or errors.echo 'text' is considered part of the test function output and is printed only on test failures for diagnostic purposes, regardless of the formatter used (TAP or pretty).setup or teardown functions: The same hold true as for printing with test functions.setup/teardown functions:There are several global variables you can use to introspect on Bats tests:
$BATS_TEST_FILENAME is the fully expanded path to the Bats test file.$BATS_TEST_DIRNAME is the directory in which the Bats test file is located.$BATS_TEST_NAMES is an array of function names for each test case.$BATS_TEST_NAME is the name of the function containing the current test case.$BATS_TEST_DESCRIPTION is the description of the current test case.$BATS_TEST_NUMBER is the (1-based) index of the current test case in the test file.$BATS_TMPDIR is the location to a directory that may be used to store temporary files.The following is a list of Bash versions that are currently supported by Bats. This list is composed of platforms that Bats has been tested on and is known to work on without issues.
3.2.57(1) and higher10.x and 11.xCheck out a copy of the Bats repository. Then, either add the Bats bin directory to your $PATH, or run the provided install.sh command with the location to the prefix in which you want to install Bats. For example, to install Bats into /usr/local,
$ git clone https://github.com/bats-core/bats-core.git $ cd bats-core $ ./install.sh /usr/local
Note that you may need to run install.sh with sudo if you do not have permission to write to the installation prefix.
Check out a copy of the Bats repository, then build a container image:
$ git clone https://github.com/bats-core/bats-core.git $ cd bats-core $ docker build --tag bats:latest .
This creates a local Docker image called bats:latest based on Alpine Linux. To run Bats' internal test suite (which is in the container image at /opt/bats/test):
$ docker run -it bats:latest /opt/bats/test
To run a test suite from your local machine, mount in a volume and direct Bats to its path inside the container:
$ docker run -it -v "$(pwd):/code" bats:latest /code/test
This is a minimal image. If more tools are required this can be used as a base image in a Dockerfile using FROM <Docker image>. In the future there may be images based on Debian, and/or with more tools installed (curl and openssl, for example). If you require a specific configuration please search and +1 an issue or raise a new issue.
Bats comes with two manual pages. After installation you can view them with man 1 bats (usage manual) and man 7 bats (writing test files manual). Also, you can view the available command line options that Bats supports by calling Bats with the -h or --help options. These are the options that Bats currently supports:
Bats 0.4.0 Usage: bats [-c] [-p | -t] <test> [<test> ...] <test> is the path to a Bats test file, or the path to a directory containing Bats test files. -c, --count Count the number of test cases without running any tests -h, --help Display this help message -p, --pretty Show results in pretty format (default for terminals) -t, --tap Show results in TAP format -v, --version Display the version number
The Bats source code repository is hosted on GitHub. There you can file bugs on the issue tracker or submit tested pull requests for review.
For real-world examples from open-source projects using Bats, see Projects Using Bats on the wiki.
To learn how to set up your editor for Bats syntax highlighting, see Syntax Highlighting on the wiki.
Bats is SemVer compliant.
0.4.0 (August 13, 2014)
load helper.@test definitions.bats command to default to TAP output when the $CI variable is set, to better support environments such as Travis CI.0.3.1 (October 28, 2013)
0.3.0 (October 21, 2013)
--tap flag, output is displayed in standard TAP format.skip command.bats with multiple filename or directory arguments to run all the specified tests in aggregate.-e.0.2.0 (November 16, 2012)
bats command accepts a directory name containing multiple test files to be run in aggregate.-c flag to bats.0.1.0 (December 30, 2011)
© 2018 bats-core organization
© 2014 Sam Stephenson
Bats is released under an MIT-style license; see LICENSE for details.