NAME

       bats - Bats test file format

DESCRIPTION

       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 ]
           }

       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.

THE RUN HELPER

       Usage: run [OPTIONS] [--] <command...> Options: ! check for non zero exit  code  -N  check
       that  exit  code  is N --separate-stderr split stderr and stdout --keep-empty-lines retain
       emtpy lines in ${lines[@]}/${stderr_lines[@]}

       Many 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  (optionally)  checks  exit  status
       against a given expected value. If successful, run 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 -1 foo nonexistent_filename
             [ "$output" = "foo: no such file ´nonexistent_filename´" ]
           }

       The  -1  as  first  argument  tells  run to expect 1 as an exit status, and to fail if the
       command exits with any other value. On failure, both actual and expected  values  will  be
       displayed, along with the invoked command and its output:

           (in test file test.bats, line 2)
            `run -1 foo nonexistent_filename´ failed, expected exit code 1, got 127

       This  error  indicates  a  possible problem with the installation or configuration of foo;
       note that a simple [ $status != 0 ] test would not have caught this kind of failure.

       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 -1 foo
             [ "${lines[0]}" = "usage: foo <filename>" ]
           }

       By default run leaves out empty lines in ${lines[@]}. Use run --keep-empty-lines to retain
       them.

       Additionally,   you   can   use   --separate-stderr   to  split  stdout  and  stderr  into
       $output/$stderr and ${lines[@]}/${stderr_lines[@]}.

       All additional parameters to run should come before the command. If  you  want  to  run  a
       command that starts with -, prefix it with -- to prevent run from parsing it as an option.

THE LOAD COMMAND

       You  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.

THE SKIP COMMAND

       Tests 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 -0 foo
           }

       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 -0 foo
           }

       Or you can skip conditionally:

           @test "A test which should run" {
             if [ foo != bar ]; then
               skip "foo isn´t bar"
             fi

             run -0 foo
           }

SETUP AND TEARDOWN FUNCTIONS

       You 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.

CODE OUTSIDE OF TEST CASES

       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.

SPECIAL VARIABLES

       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_SUITE_TEST_NUMBER is the (1-based) index of the current test case  in  the  test
           suite (over all files).

       •   $BATS_TMPDIR  is  the  base  temporary  directory used by bats to create its temporary
           files / directories. (default: $TMPDIR. If $TMPDIR is not set, /tmp is used.)

       •   $BATS_RUN_TMPDIR is the location to the temporary directory used by bats to store  all
           its      internal      temporary     files     during     the     tests.     (default:
           $BATS_TMPDIR/bats-run-$BATS_ROOT_PID-XXXXXX)

       •   $BATS_FILE_EXTENSION (default: bats) specifies the extension of test files that should
           be found when running a suite (via bats [-r] suite_folder/)

       •   $BATS_SUITE_TMPDIR  is  a temporary directory common to all tests of a suite. Could be
           used to create files required by multiple tests.

       •   $BATS_FILE_TMPDIR is a temporary directory common to all tests of a test  file.  Could
           be used to create files required by multiple tests in the same test file.

       •   $BATS_TEST_TMPDIR  is  a  temporary  directory  unique for each test. Could be used to
           create files required only for specific tests.

       •   $BATS_VERSION is the version of Bats running the test.

SEE ALSO

       bash(1), bats(1)