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

       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 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>" ]
           }

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 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 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_TMPDIR is the location to a directory that may be used to store temporary files.

SEE ALSO

       bash(1), bats(1)

                                          November 2013                                   BATS(7)