Metadata-Version: 1.1
Name: pbbt
Version: 0.1.3
Summary: Pluggable Black-Box Testing toolkit
Home-page: http://bitbucket.org/prometheus/pbbt
Author: Kirill Simonov (Prometheus Research, LLC)
Author-email: xi@resolvent.net
License: MIT
Download-URL: http://pypi.python.org/pypi/pbbt
Description: ***********************************************
          PBBT -- Pluggable Black-Box Testing toolkit
        ***********************************************
        
        .. contents:: Table of Contents
        
        
        Overview
        ========
        
        PBBT is a regression test harness for *black-box testing*.  It is
        suitable for testing complex software components with well-defined input
        and output interfaces.
        
        ::
        
              input    +----------+   output
            o--------> | Software | --------->o
                       +----------+
        
        In black-box testing, a *test case* is a combination of *input* and
        expected *output* data.  The test harness executes the software with the
        given input and verifies that the produced output coincides with the
        expected output.
        
        Black-box testing could be implemented for many different types of
        software.  For example,
        
        * *a database system:* the input is a SQL statement, the output is a set
          of records;
        * *a web service:* the input is an HTTP request, the output is an HTTP
          response;
        * *a command-line utility:* the input is a sequence of command-line
          parameters and ``stdin``, the output is ``stdout``;
        * *a GUI application:* different approaches are possible; for instance,
          the input could be a sequence of user actions, and the output could be
          the state of a particular widget.
        
        PBBT is a Python library and an application which allows you to:
        
        * use built-in test types for testing command-line scripts and Python
          code;
        * register custom test types;
        * prepare test input in a succinct YAML_ format;
        * in the *train* mode, run the test cases and record expected output;
        * in the *check* mode, run the test cases and verify that the produced
          output coincides with the pre-recorded expected output.
        
        PBBT is a free software released under MIT license.  PBBT is created by
        Clark C. Evans and Kirill Simonov from `Prometheus Research, LLC`_.
        
        
        Using PBBT
        ==========
        
        To install PBBT, you can use pip_ package manager::
        
            # pip install pbbt
        
        This command downloads and installs the latest version of PBBT from
        `Python Package Index`_.  After successful installation, you should be
        able to import ``pbbt`` Python module and run ``pbbt`` command-line
        utility.
        
        To start using PBBT, you need to create a file with input data.  For
        example, create ``input.yaml`` with the following content::
        
            py: |
              print "Hello, World!"
        
        This file is in YAML_ format, which is a data serialization language
        similar to JSON_, and, in fact, a superset of JSON.  The file above
        could be represented in JSON as::
        
            { "py": "print \"Hello, World!\"\n" }
        
        For description of YAML syntax and semantics, see http://yaml.org/.
        
        Next, execute PBBT in *training* mode to generate expected output data.
        Run::
        
            $ pbbt input.yaml output.yaml --train
        
        and accept new output when asked.  PBBT will write output data to
        ``output.yaml``::
        
            py: print-hello-world
            stdout: |
              Hello, World!
        
        Now you can start PBBT in *checking* mode, in which it executes test
        cases and verifies that expected and actual output data coincide::
        
            $ pbbt input.yaml output.yaml
        
        To add more test cases to ``input.yaml``, you need to convert it to a
        *test suite*::
        
            title: My Tests
            tests:
            - py: |
                print "Hello, World!"
            - sh: echo Hello, World!
        
        The file now contains a test suite *My Tests* with two test cases: one
        as in the previous example, and another that executes a shell command
        ``echo Hello, World!``::
        
            sh: echo Hello, World!
        
        The output of this test case is ``stdout`` produced by the shell
        command.  To record expected output, run ``pbbt`` in training mode
        again.
        
        
        Built-in Test Types
        ===================
        
        Out of the box, PBBT supports a small set of predefined test types:
        
        * test Python code;
        * test a shell command;
        * file manipulation tests.
        
        Also available are special test types:
        
        * test suite;
        * include;
        * conditional variables.
        * gateway to other test systems.
        
        Each test type defines the structure of input and output records, that
        is, the set of mandatory and optional fields and the type of field
        values.  In this section, we list all available test types and describe
        their input fields.
        
        Common Fields
        -------------
        
        The following optional fields are available for all test types where
        they make sense:
        
        ``skip``: ``true`` or ``false``
            On ``true``, skip this test case.
        
        ``if``: variable, list of variables or Python expression
            On a *variable name*, run this test case only if the variable is
            defined and not false.
        
            On a *list of variables*, run this test case only if at least one
            variable is defined and not false.
        
            On a *Python expression*, run this test case if the expression
            evaluates to true.  You can use any conditional variables in the
            expression.
        
        ``unless``: variable, list of variables or Python expression
            On a *variable name*, skip this test case if the variable is defined
            and not false.
        
            On a *list of variables*, skip this test case if at least one
            variable is defined and not false.
        
            On a *Python expression*, skip this test case if the expression
            evaluates to true.  You can use any conditional variables in the
            expression.
        
        ``ignore``: ``true``, ``false`` or regular expression
            On ``true``, permit the actual and expected output to be unequal.
            The test case must still execute without any errors.
        
            On a *regular expression*, pre-process the actual and expected
            output before comparing them:
        
            1. Run the regular expression against the output data and find
               all matches.
            2. If the regular expression does not contain ``()`` subgroups,
               erase all the matches from the output.
            3. If the regular expression contains one or more ``()`` subgroups,
               erase the content of the subgroups from the output.
        
            The regular expression is compiled with ``MULTILINE`` and
            ``VERBOSE`` flags.
        
        Example::
        
            title: Integration with MySQL
            if: has_mysql
            tests:
            - set:
                MYSQL_HOST: localhost
                MYSQL_PORT: 3306
              unless: [MYSQL_HOST, MYSQL_PORT]
            - read: /etc/mysql/my.cnf
              if: MYSQL_HOST == 'localhost'
            - py: test-scalar-types.py
              ignore: |
                ^Today:.(\d\d\d\d)-(\d\d)-(\d\d)$
            - py: test-array-types.py
              skip: true    # No array type in MySQL
        
        Test Suite
        ----------
        
        A test suite is a collection of test cases.
        
        A suite may contain other suites and thus all test suites form a tree
        structure.  A *path* formed from suite identifiers can uniquely locate
        any suite.  We use file-system notation for suite paths (e.g.
        ``/path/to/suite``).
        
        Fields:
        
        ``title``: text
            The title of the suite.
        
        ``suite``: identifier (optional)
            The identifier of the suite.  If not set, generated from the title.
        
        ``tests``: list of input records
            The content of the suite.
        
        ``output``: path (optional)
            If set, the expected output of the suite is loaded from the given
            file.
        
        Example::
        
            title: All Tests
            suite: all
            output: output.yaml
            tests:
            - py: ./test/core.py
            - py: ./test/ext.py
            - title: Database Tests
              tests:
              - py: ./test/sqlite.py
              - py: ./test/pgsql.py
              - py: ./test/mysql.py
        
        In this example, the path to the *Database Tests* suite is
        ``/all/database-tests``.
        
        Conditional Variables
        ---------------------
        
        This test case defines a conditional variable.
        
        Variables could be used in ``if`` and ``unless`` clauses to
        conditionally enable or disable a test case.  Variables could also be
        set or read in Python tests via a global dictionary ``__pbbt__``.
        
        Conditional variables could also be set from command line using ``-D``
        option.
        
        Setting a conditional variable affects all subsequent test cases within
        the same test suite.  Variable values are reset on exit from the suite.
        
        Fields:
        
        ``set``: variable or dictionary of variables
            On a *variable name*, set the value of the given variable to
            ``True``.
        
            On a *dictionary*, set the values of the given variables.
        
        Example::
        
            title: MySQL Tests
            tests:
            - set: MYSQL
            - set:
                MYSQL_HOST: localhost
                MYSQL_PORT: 3306
              unless: [MYSQL_HOST, MYSQL_PORT]
            - py: |
                # Determine the version of the MySQL server
                import MySQLdb
                connection = MySQLdb.connect(host=__pbbt__['MYSQL_HOST'],
                                             port=int(__pbbt__['MYSQL_PORT']),
                                             db='mysql')
                cursor = connection.cursor()
                cursor.execute("""SELECT VERSION()""")
                version_string = cursor.fetchone()[0]
                version = tuple(map(int, version_string.split('-')[0].split('.')))
                __pbbt__['MYSQL_VERSION'] = version
            - py: test-ddl.py
            - py: test-dml.py
            - py: test-select.py
            - py: test-new-features.py
              if: MYSQL_VERSION >= (5, 5)
        
        Include Test
        ------------
        
        This test case loads and executes a test case from a file.
        
        Fields:
        
        ``include``: path
            The file to load.  The file should contain an input test record in
            YAML format.
        
        Example::
        
            title: All Tests
            tests:
            - include: test/core.yaml
            - include: test/ext.yaml
            - include: test/sqlite.yaml
            - include: test/pgsql.yaml
            - include: test/mysql.yaml
        
        Python Code
        -----------
        
        This test case executes Python code and produces ``stdout``.
        
        Fields:
        
        ``py``: path or Python code
            On *Python code*, the source code to execute.
        
            On a *file name*, the file which contains source code to execute.
        
        ``stdin``: text (optional)
            Content of the standard input.
        
        ``except``: exception type (optional)
            If set, indicates that the code is expected to raise an exception of
            the given type.
        
        Example::
        
            title: Python tests
            tests:
            - py: hello.py
            - py: &sum |
                # Sum of two numbers
                import sys
                a = int(sys.stdin.readline())
                b = int(sys.stdin.readline())
                c = a+b
                sys.stdout.write("%s\n" % c)
              stdin: |
                2
                2
            - py: *sum
              stdin: |
                1
                -5
            - py: *sum
              stdin: |
                one
                three
              except: ValueError
        
        Note that we use a YAML anchor (denoted by ``&sum``) and aliases
        (denoted by ``*sum``) to use the same piece of code in several tests.
        
        Shell Command
        -------------
        
        This test case executes a shell command and produces ``stdout``.
        
        Fields:
        
        ``sh``: command or executable with a list of parameters
            The shell command to execute.
        
        ``stdin``: text (optional)
            Content of the standard input.
        
        ``cd``: path (optional)
            Change the current working directory to the given path before
            executing the command.
        
        ``environ``: dictionary of variables (optional)
            Add the given variables to the command environment.
        
        ``exit``: integer (optional)
            The expected exit code; ``0`` by default.
        
        Example::
        
            title: Shell tests
            tests:
            - sh: echo Hello, World!
            - sh: cat
              stdin: |
                Hello, World!
            - sh: [cat, /etc/shadow]
              exit: 1   # Permission denied
        
        Write to File
        -------------
        
        This test case creates a file with the given content.
        
        Fields:
        
        ``write``: path
            The file to create.
        
        ``data``: text
            The file content.
        
        Example::
        
            write: test/tmp/data.txt
            data: |
                Hello, World!
        
        Read from File
        --------------
        
        The output of this test is the content of a file.
        
        Fields:
        
        ``read``: path
            The file to read.
        
        Example::
        
            read: test/tmp/data.txt
        
        Remove File
        -----------
        
        This test case removes a file.  It is not an error if the file does not
        exist.
        
        Fields:
        
        ``rm``: path or list of paths
            File(s) to remove.
        
        Example::
        
            rm: test/tmp/data.txt
        
        Make Directory
        --------------
        
        This test case creates a directory.
        
        Parent directories are also created if necessary.  It is not an error if
        the directory already exists.
        
        Fields:
        
        ``mkdir``: path
            The directory to create.
        
        Example::
        
            mkdir: test/tmp
        
        Remove Directory
        ----------------
        
        This test case removes a directory with all its content.
        
        It is not an error if the directory does not exist.
        
        Fields:
        
        ``rmdir``: path
            The directory to delete.
        
        Example::
        
            rmdir: test/tmp
        
        Doctest
        -------
        
        This test case executes ``doctest`` on a set of files.
        
        Fields:
        
        ``doctest``: path pattern
            Files with doctest sessions.
        
        Example::
        
            doctest: test/test_*.rst
        
        Unittest
        --------
        
        This test case executes ``unittest`` test suite.
        
        Fields:
        
        ``unittest``: path pattern
            Files with unittest tests.
        
        Example::
        
            unittest: test/test_*.py
        
        
        Pytest
        ------
        
        This test case executes ``py.test`` test suite.
        
        Package ``pytest`` from http://pytest.org/ must be installed.
        
        Fields:
        
        ``pytest``: path pattern
            Files with py.test tests.
        
        Example::
        
            pytest: test/test_*.py
        
        Coverage
        --------
        
        This test case starts coverage of Python code.
        
        Package ``coverage`` from http://nedbatchelder.com/code/coverage/ must
        be installed.
        
        Fields:
        
        ``coverage``: file name or ``None``
            Path to the configuration file.
        
        ``data_file``: file name
            Where to save coverage data.
        
        ``timid``: ``false`` or ``true`` (optional)
            Use a simpler trace function.
        
        ``branch``: ``false`` or ``true`` (optional)
            Enable branch coverage.
        
        ``source``: file paths of package names (optional)
            Source files or packages to measure.
        
        ``include``: file patterns
            Files to measure.
        
        ``omit``: file patterns
            Files to omit.
        
        Example::
        
            coverage:
            source: pbbt
            branch: true
        
        Coverage check
        --------------
        
        This test case stops coverage and reports measurement summary.
        
        Fields:
        
        ``coverage-check``: float
            Expected coverage percentage.
        
        Example::
        
            coverage-check: 99.0
        
        Coverage report
        ---------------
        
        This test case stops coverage and saves coverage report to a file.
        
        Fields:
        
        ``coverage-report``: directory
            Where to save the report.
        
        Example::
        
            coverage-report: coverage
        
        
        Custom Test Types
        =================
        
        In this section, we discuss how to add custom test types to PBBT.
        
        Suppose we want to test a SQL database by running a series of SQL
        queries and validating that we get expected output.  To implement this
        testing scheme, we need a way to:
        
        * open a connection to the database;
        * execute a SQL statement and produce a sequence of records.
        
        The input file may look like this::
        
            title: Database tests
            tests:
            # Remove the database file left after the last testing session.
            - rm: test.sqlite
            # Create a new SQLite database.
            - connect: test.sqlite
            # Run a series of SQL commands.
            - sql: |
                SELECT 'Hello, World!';
            - sql: |
                CREATE TABLE student (
                    id      INTEGER PRIMARY KEY,
                    name    TEXT NOT NULL,
                    gender  CHAR(1) NOT NULL
                            CHECK (gender in ('f', 'i', 'm')),
                    dob     DATE NOT NULL
                );
            - sql: |
                INSERT INTO student (id, name, gender, dob)
                VALUES (1001, 'Linda Wright', 'f', '1988-10-03'),
                       (1002, 'Beth Thompson', 'f', '1988-01-24'),
                       (1003, 'Mark Melton', 'm', '1984-06-05'),
                       (1004, 'Judy Flynn', 'f', '1986-09-02'),
                       (1005, 'Jonathan Bouchard', 'm', '1982-02-12');
            - sql: |
                SELECT *
                FROM student
                ORDER BY dob;
            - sql: |
                SELECT name
                FROM student
                WHERE id = 1003;
        
        In this input file, we use two new types of test cases:
        
        ``connect``
            Specifies the connection to a SQLite database.
        ``sql``
            Specifies a SQL statement to execute.
        
        We will write a PBBT extension implementing these test types.
        
        Create a file ``sql.py`` with the following content::
        
            from pbbt import Test, Field, BaseCase, MatchCase, listof
            import sqlite3, traceback, csv, StringIO
        
            @Test
            class ConnectCase(BaseCase):
        
                class Input:
                    connect = Field(str)
        
                def check(self):
                    self.state['connect'] = None
                    try:
                        self.state['connect'] = sqlite3.connect(self.input.connect)
                    except:
                        self.ui.literal(traceback.format_exc())
                        self.ui.warning("exception occurred while"
                                        " connecting to the database")
                        self.ctl.failed()
                    else:
                        self.ctl.passed()
        
            @Test
            class SQLCase(MatchCase):
        
                class Input:
                    sql = Field(str)
        
                class Output:
                    sql = Field(str)
                    rows = Field(listof(listof(object)))
        
                def render(self, output):
                    stream = StringIO.StringIO()
                    writer = csv.writer(stream, lineterminator='\n')
                    writer.writerows(output.rows)
                    return stream.getvalue()
        
                def run(self):
                    connection = self.state.get('connect')
                    if not connection:
                        self.ui.warning("database connection is not defined")
                        return
                    rows = []
                    try:
                        cursor = connection.cursor()
                        cursor.execute(self.input.sql)
                        for row in cursor.fetchall():
                            rows.append(list(row))
                    except:
                        self.ui.literal(traceback.format_exc())
                        self.ui.warning("exception occurred while"
                                        " executing a SQL query")
                        connection.rollback()
                        new_output = None
                    else:
                        connection.commit()
                        new_output = self.Output(sql=self.input.sql, rows=rows)
                    return new_output
        
        To use this extension, add parameter ``-E sql.py`` to all PBBT
        invocations.  For example::
        
            $ pbbt -E sql.py input.yaml output.yaml --train
        
        Now we will explain the content of ``sql.py`` line by line.
        
        The first line imports some classes and decorators we will use::
        
            from pbbt import Test, Field, BaseCase, MatchCase
        
        To register a test type, use ``@Test`` decorator.  Here is a most
        general template::
        
            @Test
            class CustomCase(object):
        
                class Input:
                    some_field = Field(...)
                    [...]
        
                class Output:
                    some_field = Field(...)
                    [...]
        
                def __init__(self, ctl, input, output):
                    self.ctl = ctl
                    self.input = input
                    self.output = output
        
                def __call__(self):
                    [...]
                    return new_output
        
        The argument of the decorator must be a class that adheres the following
        rules:
        
        * The structure of input and output records is described with nested
          classes ``Input`` and ``Output``.  Record fields are specified using
          ``Field`` descriptor.
        
        * To create a test case, the test harness makes an instance of the class.
          The class constructor accepts three arguments:
        
          ``ctl``
              Test harness controller.  It is used for user interaction,
              reporting test success or failure, and as a storage for
              conditional variables.
          ``input``
              The input record.
          ``output``
              The expected output record or ``None``.
        
        * The test case is executed by calling its ``__call__()`` method.  This
          method must run the test case, generate a new output record, and compare
          it with the given expected output record.
        
          If the expected and actual output record do not coincide:
        
          * In the *check* mode, the method must report a failure.
          * In the *train* mode, the method may ask the user for permission to
            update expected output.  If expected output is to be updated, the
            method should return the new output record.
        
        PBBT also provides two mixin classes: ``BaseCase`` and ``MatchCase``.
        These classes implement most of the necessary functionality for common
        types of tests.
        
        Let's review ``connect`` test type, which is implemented by
        ``ConnectCase`` class::
        
            @Test
            class ConnectCase(BaseCase):
        
                class Input:
                    connect = Field(str)
        
                def check(self):
                    [...]
        
        ``ConnectCase`` is inherited from ``BaseCase``, which is suitable for
        test which produce no output data and are executed for their side
        effects.  The nested ``Input`` class definition is used to declare the
        fields of the input record.  In this case, the input record has just one
        text field ``connect``, which contains the name of the database.
        
        Test types inherited from ``BaseCase`` must override abstract method
        ``check()``::
        
            import sqlite3, traceback
            [...]
        
            @Test
            class ConnectCase(BaseCase):
                [...]
        
                def check(self):
                    self.state['connect'] = None
                    try:
                        self.state['connect'] = sqlite3.connect(self.input.connect)
                    except:
                        self.ui.literal(traceback.format_exc())
                        self.ui.warning("exception occurred while"
                                        " connecting to the database")
                        self.ctl.failed()
                    else:
                        self.ctl.passed()
        
        This code attempts to create a new database connection and store it as a
        conditional variable ``connect``.  If the attempt fails, it calls
        ``ui.literal()`` to display the exception traceback and ``ctl.failed()``
        to report test failure.  Otherwise, ``ctl.passed()`` is called to
        indicate that the test succeeded.
        
        Next, let's review ``sql`` test type::
        
            @Test
            class SQLCase(MatchCase):
        
                class Input:
                    sql = Field(str)
        
                class Output:
                    sql = Field(str)
                    rows = Field(listof(listof(object)))
        
                def run(self):
                    [...]
        
                def render(self, output):
                    [...]
        
        This test type has both input and output records, which are described
        with ``Input`` and ``Output`` nested classes.  The input record contains
        one field ``sql``, a SQL query to execute.  The output record contains
        two fields: ``sql`` and ``rows``.  Field ``sql`` contains the same SQL
        query and is used for matching the output record with the complementary
        input record.  Field ``rows`` contains a list of output rows generated
        by the SQL query.
        
        ``SQLCase`` is inherited from ``MatchCase``, which is a mixin class
        for test types that produce text output.  Test types inherited from
        ``MatchCase`` must override two methods:
        
        ``run()``
            Executes the test case and returns the produced output record.
        ``render(output)``
            Convert an output record to printable form.
        
        In ``SQLCase``, ``render()`` is implemented by converting output rows to
        CSV format::
        
            import csv, StringIO
            [...]
        
            @Test
            class SQLCase(MatchCase):
                [...]
        
                def render(self, output):
                    stream = StringIO.StringIO()
                    writer = csv.writer(stream, lineterminator='\n')
                    writer.writerows(output.rows)
                    return stream.getvalue()
        
        Method ``run()`` is implemented as follows::
        
            @Test
            class SQLCase(MatchCase):
                [...]
        
                def run(self):
                    connection = self.state.get('connect')
                    if not connection:
                        self.ui.warning("database connection is not defined")
                        return
                    rows = []
                    try:
                        cursor = connection.cursor()
                        cursor.execute(self.input.sql)
                        for row in cursor.fetchall():
                            rows.append(list(row))
                    except:
                        self.ui.literal(traceback.format_exc())
                        self.ui.warning("exception occurred while"
                                        " executing a SQL query")
                        connection.rollback()
                        new_output = None
                    else:
                        connection.commit()
                        new_output = self.Output(sql=self.input.sql, rows=rows)
                    return new_output
        
        
        Command-line Interface
        ======================
        
        Usage::
        
            pbbt [<options>] INPUT [OUTPUT]
        
        Here, ``INPUT`` and ``OUTPUT`` are files which contain input and output
        test data respectively.
        
        The following options are available:
        
        ``-h``, ``--help``
            Display usage information and exit.
        
        ``-q``, ``--quiet``
            Show only warnings and errors.
        
        ``-T``, ``--train``
            Run tests in the training mode.
        
        ``-P``, ``--purge``
            Purge stale output data.
        
        ``-M N``, ``--max-errors N``
            Halt after ``N`` tests failed; ``0`` means "never".
        
        ``-D VAR``, ``-D VAR=VALUE``, ``--define VAR``, ``--define VAR=VALUE``
            Set a conditional variable.
        
        ``-E FILE``, ``-E MODULE``, ``--extend FILE``, ``--extend MODULE``
            Load a PBBT extension from a file or a Python module.
        
        ``-S ID``, ``--suite ID``
            Run a specific test suite.
        
        PBBT can also read configuration from the following files:
        
        ``setup.cfg``
            This file is in INI format with PBBT settings defined in section
            ``[pbbt]``.  The following parameters are recognized: ``extend``,
            ``input``, ``output``, ``define``, ``suite``, ``train``, ``purge``,
            ``max_errors``, ``quiet``.
        
        ``pbbt.yaml``
            This file must be a YAML file with the following keys: ``extend``,
            ``input``, ``output``, ``define``, ``suite``, ``train``, ``purge``,
            ``max-errors``, ``quiet``.
        
        PBBT can also be executed as a Distutils command::
        
            python setup.py pbbt
        
        In this case, PBBT configuration could be specified in ``setup.cfg``
        or via command-line parameters.
        
        
        API Reference
        =============
        
        ``pbbt.maybe(T)``
            Pseudo-type for ``isinstance(X, ...)``: checks if ``X`` is an
            instance of ``T`` or equal to ``None``.
        
        ``pbbt.oneof(T1, T2, ...)``
            Pseudo-type for ``isinstance(X, ...)``: checks if ``X`` is an
            instance of ``T1`` or an instance of ``T2``, etc.
        
        ``pbbt.choiceof(values)``
            Pseudo-type for ``isinstance(X, ...)``: checks if ``X`` is equal to
            one of the given values.
        
        ``pbbt.listof(T, length=None)``
            Pseudo-type for ``isinstance(X, ...)``: checks if ``X`` is a list of
            elements of ``T``.
        
        ``pbbt.tupleof(T1, T2, ...)``
            Pseudo-type for ``isinstance(X, ...)``: checks if ``X`` is a tuple
            with fields of types ``T1``, ``T2``, etc.
        
        ``pbbt.dictof(T1, T2)``
            Pseudo-type for ``isinstance(X, ...)``: checks if ``X`` is a
            dictionary with keys of type ``T1`` and values of type ``T2``.
        
        ``pbbt.raises(E)``
            Use with ``with`` clause to verify that the nested block raises an
            exception of the given type.
        
        ``pbbt.raises(E, fn, *args, **kwds)``
            Verifies that the function call ``fn(*args, **kwds)`` raises an
            exception of the given type.
        
        ``pbbt.Test(CaseType)``
            Registers the given class as a test type.
        
        ``pbbt.Field(check=None, default=REQUIRED, order=None, hint=None)``
            Describes a field of an input or an output record.
        
            ``check``
                The type of the field value.
        
            ``default``
                Default value if the field is missing.  If not set, the
                field is mandatory.
        
            ``order``
                If set, allows you to override the default field order.
        
            ``hint``
                Short description of the field.
        
        ``pbbt.Record(*p_fields, **kv_fields)``
            Base class for all input and output records.
        
            The ``Test`` decorator converts nested ``Input`` and ``Output``
            classes to ``Record`` subclasses.
        
            The following methods could be used or overridden:
        
            ``classmethod __recognizes__(keys)``
                Checks if the set of keys is compatible with the record type.
        
                The default implementation checks if the set of keys contains
                all mandatory record fields.
        
            ``classmethod __load__(mapping)``
                Generates a record instance from a mapping of record keys and
                values.
        
            ``__dump__()``
                Generates a list of field keys and values.
        
            ``__complements__(other)``
                Checks if two records are complementary input and output records
                for the same test case.
        
            ``__clone__(**kv_fields)``
                Makes a copy of the record with new values for the given fields.
        
            ``__str__()``
                Generates a printable representation.
        
        ``pbbt.Control(...)``
            Test harness.
        
            The test harness object is passed to test cases as the first
            argument of the constructor.  The following methods and attributes
            could be used by test case objects.
        
            Attributes:
        
            ``ui``
                Provides user interaction services.
        
            ``training``
                If set, the harness is in training mode.
        
            ``purging``
                If set, the harness is in purging mode.
        
            ``quiet``
                If set, only warnings and errors are displayed.
        
            ``halted``
                If set, the test process has been halted.
        
            ``state``
                Conditional variables.
        
            ``selection``
                Selected suites.
        
            Methods:
        
            ``passed(text=None)``
                Attests that the current test case has passed.
        
            ``failed(text=None)``
                Attests that the current test case has failed.
        
            ``updated(text=None)``
                Attests that output data for the current test case has been
                updated.
        
            ``halt(text=None)``
                Halts testing process.
        
            ``load_input(path)``
                Loads input test data from the given file.
        
            ``load_output(path)``
                Loads output test data from the given file.
        
            ``dump_output(path, data)``
                Saves output test data to the given file.
        
            ``run(case)``
                Executes a test case.
        
            ``__call__(input_path, output_path)``
                Runs testing process with the given input and output.
        
        ``pbbt.locate(record)``
            Finds the location of the given record.
        
        ``pbbt.Location(filename, line)``
            Position of an input or output record in the YAML document.
        
        ``pbbt.run(input_path, output_path=None, **configuration)``
            Loads test data from the given files and runs the tests.
        
            Configuration:
        
            ``ui``
                User interaction controller.
            ``variables``
                Predefined conditional variables.
            ``targets``
                Selected suites.
            ``training``
                Set the harness into training mode.
            ``purging``
                Purge stale output data.
            ``max_errors``
                Maximum permitted number of failures before the harness halts.
            ``quiet``
                Display only warnings and errors.
        
        ``pbbt.main()``
            Implements the ``pbbt`` command-line utility.
        
        ``pbbt.BaseCase``
            Template class suitable for most test types.
        
            Subclasses need to override the following methods:
        
            ``check()``
                Runs the test case in check mode.
        
            ``train()``
                Runs the test case in train mode.  The default implementation
                simply calls ``check()``.
        
        ``pbbt.MatchCase``
            Template class for test types which produce output.
        
            Subclasses need to override the following methods:
        
            ``run()``
                Executes the case; returns produced output.
        
            ``render(output)``
                Converts output record to text.
        
        ``pbbt.UI``
            Abstract class for user interaction services.
        
            Methods:
        
            ``part()``
                Starts a new section.
        
            ``section()``
                Starts a subsection.
        
            ``header(text)``
                Shows a section header.
        
            ``notice(text)``
                Shows a notice.
        
            ``warning(text)``
                Shows a warning.
        
            ``error(text)``
                Shows an error.
        
            ``literal(text)``
                Shows a literal text.
        
            ``choice(text, *choices)``
                Asks a single-choice question.
        
        ``pbbt.ConsoleUI(stdin=None, stdout=None, stderr=None)``
            Implements ``UI`` for console input/output.
        
        ``pbbt.SilentUI(backend)``
            Implements ``UI`` for use with ``--quiet`` option.
        
        
        .. _YAML: http://yaml.org/
        .. _Prometheus Research, LLC: http://prometheusresearch.com/
        .. _pip: http://pip-installer.org/
        .. _Python Package Index: http://pypi.python.org/pypi/pbbt
        .. _JSON: http://json.org/
        
        .. vim: set spell spelllang=en textwidth=72:
        
Platform: UNKNOWN
Classifier: Development Status :: 2 - Pre-Alpha
Classifier: Environment :: Console
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: POSIX :: Linux
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 3
Classifier: Topic :: Utilities
