1tdc - Adding plugins for tdc
2
3Author: Brenda J. Butler - bjb@mojatatu.com
4
5ADDING PLUGINS
6--------------
7
8A new plugin should be written in python as a class that inherits from TdcPlugin.
9There are some examples in plugin-lib.
10
11The plugin can be used to add functionality to the test framework,
12such as:
13
14- adding commands to be run before and/or after the test suite
15- adding commands to be run before and/or after the test cases
16- adding commands to be run before and/or after the execute phase of the test cases
17- ability to alter the command to be run in any phase:
18    pre        (the pre-suite stage)
19    prepare
20    execute
21    verify
22    teardown
23    post       (the post-suite stage)
24- ability to add to the command line args, and use them at run time
25
26
27The functions in the class should follow the following interfaces:
28
29    def __init__(self)
30    def pre_suite(self, testcount, testidlist)     # see "PRE_SUITE" below
31    def post_suite(self, ordinal)                  # see "SKIPPING" below
32    def pre_case(self, test_ordinal, testid)       # see "PRE_CASE" below
33    def post_case(self)
34    def pre_execute(self)
35    def post_execute(self)
36    def adjust_command(self, stage, command)       # see "ADJUST" below
37    def add_args(self, parser)                     # see "ADD_ARGS" below
38    def check_args(self, args, remaining)          # see "CHECK_ARGS" below
39
40
41PRE_SUITE
42
43This method takes a testcount (number of tests to be run) and
44testidlist (array of test ids for tests that will be run).  This is
45useful for various things, including when an exception occurs and the
46rest of the tests must be skipped.  The info is stored in the object,
47and the post_suite method can refer to it when dumping the "skipped"
48TAP output.  The tdc.py script will do that for the test suite as
49defined in the test case, but if the plugin is being used to run extra
50tests on each test (eg, check for memory leaks on associated
51co-processes) then that other tap output can be generated in the
52post-suite method using this info passed in to the pre_suite method.
53
54
55SKIPPING
56
57The post_suite method will receive the ordinal number of the last
58test to be attempted.  It can use this info when outputting
59the TAP output for the extra test cases.
60
61
62PRE_CASE
63
64The pre_case method will receive the ordinal number of the test
65and the test id.  Useful for outputing the extra test results.
66
67
68ADJUST
69
70The adjust_command method receives a string representing
71the execution stage and a string which is the actual command to be
72executed.  The plugin can adjust the command, based on the stage of
73execution.
74
75The stages are represented by the following strings:
76
77    'pre'
78    'setup'
79    'command'
80    'verify'
81    'teardown'
82    'post'
83
84The adjust_command method must return the adjusted command so tdc
85can use it.
86
87
88ADD_ARGS
89
90The add_args method receives the argparser object and can add
91arguments to it.  Care should be taken that the new arguments do not
92conflict with any from tdc.py or from other plugins that will be used
93concurrently.
94
95The add_args method should return the argparser object.
96
97
98CHECK_ARGS
99
100The check_args method is so that the plugin can do validation on
101the args, if needed.  If there is a problem, and Exception should
102be raised, with a string that explains the problem.
103
104eg:  raise Exception('plugin xxx, arg -y is wrong, fix it')
105