Metadata-Version: 1.0
Name: python-subunit
Version: 0.0.16
Summary: Python implementation of subunit test streaming protocol
Home-page: http://launchpad.net/subunit
Author: Robert Collins
Author-email: subunit-dev@lists.launchpad.net
License: UNKNOWN
Description: 
          subunit: A streaming protocol for test results
          Copyright (C) 2005-2013 Robert Collins <robertc@robertcollins.net>
        
          Licensed under either the Apache License, Version 2.0 or the BSD 3-clause
          license at the users choice. A copy of both licenses are available in the
          project source as Apache-2.0 and BSD. You may not use this file except in
          compliance with one of these two licences.
        
          Unless required by applicable law or agreed to in writing, software
          distributed under these licenses is distributed on an "AS IS" BASIS, WITHOUT
          WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
          license you chose for the specific language governing permissions and
          limitations under that license.
        
          See the COPYING file for full details on the licensing of Subunit.
        
          subunit reuses iso8601 by Michael Twomey, distributed under an MIT style
          licence - see python/iso8601/LICENSE for details.
        
        Subunit
        -------
        
        Subunit is a streaming protocol for test results.
        
        There are two major revisions of the protocol. Version 1 was trivially human
        readable but had significant defects as far as highly parallel testing was
        concerned - it had no room for doing discovery and execution in parallel,
        required substantial buffering when multiplexing and was fragile - a corrupt
        byte could cause an entire stream to be misparsed. Version 1.1 added
        encapsulation of binary streams which mitigated some of the issues but the
        core remained.
        
        Version 2 shares many of the good characteristics of Version 1 - it can be
        embedded into a regular text stream (e.g. from a build system) and it still
        models xUnit style test execution. It also fixes many of the issues with
        Version 1 - Version 2 can be multiplexed without excessive buffering (in
        time or space), it has a well defined recovery mechanism for dealing with
        corrupted streams (e.g. where two processes write to the same stream
        concurrently, or where the stream generator suffers a bug).
        
        More details on both protocol version s can be found in the 'Protocol' section
        of this document.
        
        Subunit comes with command line filters to process a subunit stream and
        language bindings for python, C, C++ and shell. Bindings are easy to write
        for other languages.
        
        A number of useful things can be done easily with subunit:
         * Test aggregation: Tests run separately can be combined and then
           reported/displayed together. For instance, tests from different languages
           can be shown as a seamless whole, and tests running on multiple machines
           can be aggregated into a single stream through a multiplexer.
         * Test archiving: A test run may be recorded and replayed later.
         * Test isolation: Tests that may crash or otherwise interact badly with each
           other can be run seperately and then aggregated, rather than interfering
           with each other or requiring an adhoc test->runner reporting protocol.
         * Grid testing: subunit can act as the necessary serialisation and
           deserialiation to get test runs on distributed machines to be reported in
           real time.
        
        Subunit supplies the following filters:
         * tap2subunit - convert perl's TestAnythingProtocol to subunit.
         * subunit2csv - convert a subunit stream to csv.
         * subunit2pyunit - convert a subunit stream to pyunit test results.
         * subunit2gtk - show a subunit stream in GTK.
         * subunit2junitxml - convert a subunit stream to JUnit's XML format.
         * subunit-diff - compare two subunit streams.
         * subunit-filter - filter out tests from a subunit stream.
         * subunit-ls - list info about tests present in a subunit stream.
         * subunit-stats - generate a summary of a subunit stream.
         * subunit-tags - add or remove tags from a stream.
        
        Integration with other tools
        ----------------------------
        
        Subunit's language bindings act as integration with various test runners like
        'check', 'cppunit', Python's 'unittest'. Beyond that a small amount of glue
        (typically a few lines) will allow Subunit to be used in more sophisticated
        ways.
        
        Python
        ======
        
        Subunit has excellent Python support: most of the filters and tools are written
        in python and there are facilities for using Subunit to increase test isolation
        seamlessly within a test suite.
        
        The most common way is to run an existing python test suite and have it output
        subunit via the ``subunit.run`` module::
        
          $ python -m subunit.run mypackage.tests.test_suite
        
        For more information on the Python support Subunit offers , please see
        ``pydoc subunit``, or the source in ``python/subunit/``
        
        C
        =
        
        Subunit has C bindings to emit the protocol. The 'check' C unit testing project
        has included subunit support in their project for some years now. See
        'c/README' for more details.
        
        C++
        ===
        
        The C library is includable and usable directly from C++. A TestListener for
        CPPUnit is included in the Subunit distribution. See 'c++/README' for details.
        
        shell
        =====
        
        There are two sets of shell tools. There are filters, which accept a subunit
        stream on stdin and output processed data (or a transformed stream) on stdout.
        
        Then there are unittest facilities similar to those for C : shell bindings
        consisting of simple functions to output protocol elements, and a patch for
        adding subunit output to the 'ShUnit' shell test runner. See 'shell/README' for
        details.
        
        Filter recipes
        --------------
        
        To ignore some failing tests whose root cause is already known::
        
          subunit-filter --without 'AttributeError.*flavor'
        
        
        The xUnit test model
        --------------------
        
        Subunit implements a slightly modified xUnit test model. The stock standard
        model is that there are tests, which have an id(), can be run, and when run
        start, emit an outcome (like success or failure) and then finish.
        
        Subunit extends this with the idea of test enumeration (find out about tests
        a runner has without running them), tags (allow users to describe tests in
        ways the test framework doesn't apply any semantic value to), file attachments
        (allow arbitrary data to make analysing a failure easy) and timestamps.
        
        The protocol
        ------------
        
        Version 2, or v2 is new and still under development, but is intended to
        supercede version 1 in the very near future. Subunit's bundled tools accept
        only version 2 and only emit version 2, but the new filters subunit-1to2 and
        subunit-2to1 can be used to interoperate with older third party libraries.
        
        Version 2
        =========
        
        Version 2 is a binary protocol consisting of independent packets that can be
        embedded in the output from tools like make - as long as each packet has no
        other bytes mixed in with it (which 'make -j N>1' has a tendency of doing).
        Version 2 is currently in draft form, and early adopters should be willing
        to either discard stored results (if protocol changes are made), or bulk
        convert them back to v1 and then to a newer edition of v2.
        
        The protocol synchronises at the start of the stream, after a packet, or
        after any 0x0A byte. That is, a subunit v2 packet starts after a newline or
        directly after the end of the prior packet.
        
        Subunit is intended to be transported over a reliable streaming protocol such
        as TCP. As such it does not concern itself with out of order delivery of
        packets. However, because of the possibility of corruption due to either
        bugs in the sender, or due to mixed up data from concurrent writes to the same
        fd when being embedded, subunit strives to recover reasonably gracefully from
        damaged data.
        
        A key design goal for Subunit version 2 is to allow processing and multiplexing
        without forcing buffering for semantic correctness, as buffering tends to hide
        hung or otherwise misbehaving tests. That said, limited time based buffering
        for network efficiency is a good idea - this is ultimately implementator
        choice. Line buffering is also discouraged for subunit streams, as dropping
        into a debugger or other tool may require interactive traffic even if line
        buffering would not otherwise be a problem.
        
        In version two there are two conceptual events - a test status event and a file
        attachment event. Events may have timestamps, and the path of multiplexers that
        an event is routed through is recorded to permit sending actions back to the
        source (such as new tests to run or stdin for driving debuggers and other
        interactive input). Test status events are used to enumerate tests, to report
        tests and test helpers as they run. Tests may have tags, used to allow
        tunnelling extra meanings through subunit without requiring parsing of
        arbitrary file attachments. Things that are not standalone tests get marked
        as such by setting the 'Runnable' flag to false. (For instance, individual
        assertions in TAP are not runnable tests, only the top level TAP test script
        is runnable).
        
        File attachments are used to provide rich detail about the nature of a failure.
        File attachments can also be used to encapsulate stdout and stderr both during
        and outside tests.
        
        Most numbers are stored in network byte order - Most Significant Byte first
        encoded using a variation of http://www.dlugosz.com/ZIP2/VLI.html. The first
        byte's top 2 high order bits encode the total number of octets in the number.
        This encoding can encode values from 0 to 2**30-1, enough to encode a
        nanosecond. Numbers that are not variable length encoded are still stored in
        MSB order.
        
         prefix   octets   max       max
        +-------+--------+---------+------------+
        | 00    |      1 |  2**6-1 |         63 |
        | 01    |      2 | 2**14-1 |      16383 |
        | 10    |      3 | 2**22-1 |    4194303 |
        | 11    |      4 | 2**30-1 | 1073741823 |
        +-------+--------+---------+------------+
        
        All variable length elements of the packet are stored with a length prefix
        number allowing them to be skipped over for consumers that don't need to
        interpret them.
        
        UTF-8 strings are with no terminating NUL and should not have any embedded NULs
        (implementations SHOULD validate any such strings that they process and take
        some remedial action (such as discarding the packet as corrupt).
        
        In short the structure of a packet is:
        PACKET := SIGNATURE FLAGS PACKET_LENGTH TIMESTAMP? TESTID? TAGS? MIME?
                  FILECONTENT? ROUTING_CODE? CRC32
        
        In more detail...
        
        Packets are identified by a single byte signature - 0xB3, which is never legal
        in a UTF-8 stream as the first byte of a character. 0xB3 starts with the first
        bit set and the second not, which is the UTF-8 signature for a continuation
        byte. 0xB3 was chosen as 0x73 ('s' in ASCII') with the top two bits replaced by
        the 1 and 0 for a continuation byte.
        
        If subunit packets are being embedded in a non-UTF-8 text stream, where 0x73 is
        a legal character, consider either recoding the text to UTF-8, or using
        subunit's 'file' packets to embed the text stream in subunit, rather than the
        other way around.
        
        Following the signature byte comes a 16-bit flags field, which includes a
        4-bit version field - if the version is not 0x2 then the packet cannot be
        read. It is recommended to signal an error at this point (e.g. by emitting
        a synthetic error packet and returning to the top level loop to look for
        new packets, or exiting with an error). If recovery is desired, treat the
        packet signature as an opaque byte and scan for a new synchronisation point.
        NB: Subunit V1 and V2 packets may legitimately included 0xB3 internally,
        as they are an 8-bit safe container format, so recovery from this situation
        may involve an arbitrary number of false positives until an actual packet
        is encountered : and even then it may still be false, failing after passing
        the version check due to coincidence.
        
        Flags are stored in network byte order too.
        +-------------------------+------------------------+
        | High byte               | Low byte               |
        | 15 14 13 12 11 10  9  8 | 7  6  5  4  3  2  1  0 |
        | VERSION    |feature bits|                        |
        +------------+------------+------------------------+
        
        Valid version values are:
        0x2 - version 2
        
        Feature bits:
        Bit 11 - mask 0x0800 - Test id present.
        Bit 10 - mask 0x0400 - Routing code present.
        Bit  9 - mask 0x0200 - Timestamp present.
        Bit  8 - mask 0x0100 - Test is 'runnable'.
        Bit  7 - mask 0x0080 - Tags are present.
        Bit  6 - mask 0x0040 - File content is present.
        Bit  5 - mask 0x0020 - File MIME type is present.
        Bit  4 - mask 0x0010 - EOF marker.
        Bit  3 - mask 0x0008 - Must be zero in version 2.
        
        Test status gets three bits:
        Bit 2 | Bit 1 | Bit 0 - mask 0x0007 - A test status enum lookup:
        000 - undefined / no test
        001 - Enumeration / existence
        002 - In progress
        003 - Success
        004 - Unexpected Success
        005 - Skipped
        006 - Failed
        007 - Expected failure
        
        After the flags field is a number field giving the length in bytes for the
        entire packet including the signature and the checksum. This length must
        be less than 4MiB - 4194303 bytes. The encoding can obviously record a larger
        number but one of the goals is to avoid requiring large buffers, or causing
        large latency in the packet forward/processing pipeline. Larger file
        attachments can be communicated in multiple packets, and the overhead in such a
        4MiB packet is approximately 0.2%.
        
        The rest of the packet is a series of optional features as specified by the set
        feature bits in the flags field. When absent they are entirely absent.
        
        Forwarding and multiplexing of packets can be done without interpreting the
        remainder of the packet until the routing code and checksum (which are both at
        the end of the packet). Additionally, routers can often avoid copying or moving
        the bulk of the packet, as long as the routing code size increase doesn't force
        the length encoding to take up a new byte (which will only happen to packets
        less than or equal to 16KiB in length) - large packets are very efficient to
        route.
        
        Timestamp when present is a 32 bit unsigned integer for secnods, and a variable
        length number for nanoseconds, representing UTC time since Unix Epoch in
        seconds and nanoseconds.
        
        Test id when present is a UTF-8 string. The test id should uniquely identify
        runnable tests such that they can be selected individually. For tests and other
        actions which cannot be individually run (such as test
        fixtures/layers/subtests) uniqueness is not required (though being human
        meaningful is highly recommended).
        
        Tags when present is a length prefixed vector of UTF-8 strings, one per tag.
        There are no restrictions on tag content (other than the restrictions on UTF-8
        strings in subunit in general). Tags have no ordering.
        
        When a MIME type is present, it defines the MIME type for the file across all
        packets same file (routing code + testid + name uniquely identifies a file,
        reset when EOF is flagged). If a file never has a MIME type set, it should be
        treated as application/octet-stream.
        
        File content when present is a UTF-8 string for the name followed by the length
        in bytes of the content, and then the content octets.
        
        If present routing code is a UTF-8 string. The routing code is used to
        determine which test backend a test was running on when doing data analysis,
        and to route stdin to the test process if interaction is required.
        
        Multiplexers SHOULD add a routing code if none is present, and prefix any
        existing routing code with a routing code ('/' separated) if one is already
        present. For example, a multiplexer might label each stream it is multiplexing
        with a simple ordinal ('0', '1' etc), and given an incoming packet with route
        code '3' from stream '0' would adjust the route code when forwarding the packet
        to be '0/3'.
        
        Following the end of the packet is a CRC-32 checksum of the contents of the
        packet including the signature.
        
        Example packets
        ~~~~~~~~~~~~~~~
        
        Trivial test "foo" enumeration packet, with test id, runnable set,
        status=enumeration. Spaces below are to visually break up signature / flags /
        length / testid / crc32
        
        b3 2901 0c 03666f6f 08555f1b
        
        
        Version 1 (and 1.1)
        ===================
        
        Version 1 (and 1.1) are mostly human readable protocols.
        
        Sample subunit wire contents
        ----------------------------
        
        The following::
          test: test foo works
          success: test foo works.
          test: tar a file.
          failure: tar a file. [
          ..
           ]..  space is eaten.
          foo.c:34 WARNING foo is not defined.
          ]
          a writeln to stdout
        
        When run through subunit2pyunit::
          .F
          a writeln to stdout
        
          ========================
          FAILURE: tar a file.
          -------------------
          ..
          ]..  space is eaten.
          foo.c:34 WARNING foo is not defined.
        
        
        Subunit protocol description
        ============================
        
        This description is being ported to an EBNF style. Currently its only partly in
        that style, but should be fairly clear all the same. When in doubt, refer the
        source (and ideally help fix up the description!). Generally the protocol is
        line orientated and consists of either directives and their parameters, or
        when outside a DETAILS region unexpected lines which are not interpreted by
        the parser - they should be forwarded unaltered.
        
        test|testing|test:|testing: test LABEL
        success|success:|successful|successful: test LABEL
        success|success:|successful|successful: test LABEL DETAILS
        failure: test LABEL
        failure: test LABEL DETAILS
        error: test LABEL
        error: test LABEL DETAILS
        skip[:] test LABEL
        skip[:] test LABEL DETAILS
        xfail[:] test LABEL
        xfail[:] test LABEL DETAILS
        uxsuccess[:] test LABEL
        uxsuccess[:] test LABEL DETAILS
        progress: [+|-]X
        progress: push
        progress: pop
        tags: [-]TAG ...
        time: YYYY-MM-DD HH:MM:SSZ
        
        LABEL: UTF8*
        NAME: UTF8*
        DETAILS ::= BRACKETED | MULTIPART
        BRACKETED ::= '[' CR UTF8-lines ']' CR
        MULTIPART ::= '[ multipart' CR PART* ']' CR
        PART ::= PART_TYPE CR NAME CR PART_BYTES CR
        PART_TYPE ::= Content-Type: type/sub-type(;parameter=value,parameter=value)
        PART_BYTES ::= (DIGITS CR LF BYTE{DIGITS})* '0' CR LF
        
        unexpected output on stdout -> stdout.
        exit w/0 or last test completing -> error
        
        Tags given outside a test are applied to all following tests
        Tags given after a test: line and before the result line for the same test
        apply only to that test, and inherit the current global tags.
        A '-' before a tag is used to remove tags - e.g. to prevent a global tag
        applying to a single test, or to cancel a global tag.
        
        The progress directive is used to provide progress information about a stream
        so that stream consumer can provide completion estimates, progress bars and so
        on. Stream generators that know how many tests will be present in the stream
        should output "progress: COUNT". Stream filters that add tests should output
        "progress: +COUNT", and those that remove tests should output
        "progress: -COUNT". An absolute count should reset the progress indicators in
        use - it indicates that two separate streams from different generators have
        been trivially concatenated together, and there is no knowledge of how many
        more complete streams are incoming. Smart concatenation could scan each stream
        for their count and sum them, or alternatively translate absolute counts into
        relative counts inline. It is recommended that outputters avoid absolute counts
        unless necessary. The push and pop directives are used to provide local regions
        for progress reporting. This fits with hierarchically operating test
        environments - such as those that organise tests into suites - the top-most
        runner can report on the number of suites, and each suite surround its output
        with a (push, pop) pair. Interpreters should interpret a pop as also advancing
        the progress of the restored level by one step. Encountering progress
        directives between the start and end of a test pair indicates that a previous
        test was interrupted and did not cleanly terminate: it should be implicitly
        closed with an error (the same as when a stream ends with no closing test
        directive for the most recently started test).
        
        The time directive acts as a clock event - it sets the time for all future
        events. The value should be a valid ISO8601 time.
        
        The skip, xfail and uxsuccess outcomes are not supported by all testing
        environments. In Python the testttools (https://launchpad.net/testtools)
        library is used to translate these automatically if an older Python version
        that does not support them is in use. See the testtools documentation for the
        translation policy.
        
        skip is used to indicate a test was discovered but not executed. xfail is used
        to indicate a test that errored in some expected fashion (also know as "TODO"
        tests in some frameworks). uxsuccess is used to indicate and unexpected success
        where a test though to be failing actually passes. It is complementary to
        xfail.
        
        Hacking on subunit
        ------------------
        
        Releases
        ========
        
        * Update versions in configure.ac and python/subunit/__init__.py.
        * Make PyPI and regular tarball releases. Upload the regular one to LP, the
          PyPI one to PyPI.
        * Push a tagged commit.
        
        
Keywords: python test streaming
Platform: UNKNOWN
Classifier: Intended Audience :: Developers
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python
Classifier: Topic :: Software Development :: Testing
