aboutsummaryrefslogtreecommitdiffstats
path: root/lib/common_test/doc/src/ct_hooks.xml
blob: c2cf29c530029ae04bd15522c8e7c0f5033d88c5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE erlref SYSTEM "erlref.dtd">

<erlref>
  <header>
    <copyright>
      <year>2010</year><year>2016</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.

    </legalnotice>

    <title>Common Test Hooks</title>
    <prepared>Lukas Larsson</prepared>
    <responsible>Lukas Larsson</responsible>
    <docno></docno>
    <approved></approved>
    <checked></checked>
    <date>2010-12-02</date>
    <rev>PA1</rev>
    <file>ct_hooks.sgml</file>
  </header>
  <module>ct_hooks</module> 
  <modulesummary>A callback interface on top of Common Test.</modulesummary>

  <description>

    <p>The <em>Common Test Hook (CTH)</em> framework allows extensions of the
      default behavior of <c>Common Test</c> by callbacks before and after all
      test suite calls. It is intended for advanced users of <c>Common Test</c>
      who want to abstract out behavior that is common to multiple test suites.
    </p>

    <p>In brief, CTH allows you to:</p>

    <list type="bulleted">
      <item><p>Manipulate the runtime configuration before each suite
        configuration call.</p></item>
      <item><p>Manipulate the return of all suite configuration calls and by
        extension the result of the test themselves.</p></item>
    </list>
    
    <p>The following sections describe the mandatory and optional CTH
      functions that <c>Common Test</c> calls during test execution.
      For more details, see section
      <seealso marker="ct_hooks_chapter">Common Test Hooks</seealso> in the
      User's Guide.</p>

    <p>For information about how to add a CTH to your suite, see section
      <seealso marker="ct_hooks_chapter#installing">Installing a CTH</seealso>
      in the User's Guide.</p>

    <note><p>For a minimal example of a CTH, see section
      <seealso marker="ct_hooks_chapter#example">Example CTH</seealso>
      in the User's Guide.</p></note>

  </description>

  <section>
    <title>Callback Functions</title>
    <p>The following functions define the callback interface for a CTH.</p>
  </section>
  
  <funcs>
    <func>
      <name>Module:init(Id, Opts) -&gt; {ok, State} | {ok, State, Priority}</name>
      <fsummary>Initiates the Common Test Hook.</fsummary>
      <type>
        <v>Id = reference() | term()</v>
        <v>Opts = term()</v>
        <v>State = term()</v>
        <v>Priority = integer()</v>
      </type>
      <desc>	
        <p>MANDATORY</p>

        <p>This function is always called before any other callback function.
          Use it to initiate any common state. It is to return a state for
          this CTH.</p>

        <p><c>Id</c> is either the return value of
          <seealso marker="#Module:id-1"><c>ct_hooks:id/1</c></seealso>,
          or a <c>reference</c> (created using
          <seealso marker="erts:erlang#make_ref-0">erlang:make_ref/0</seealso>
          in ERTS) if
          <seealso marker="#Module:id-1"><c>ct_hooks:id/1</c></seealso>
          is not implemented.</p>

        <p><c>Priority</c> is the relative priority of this hook. Hooks with a
          lower priority are executed first. If no priority is specified, it 
          is set to <c>0</c>.</p>

        <p>For details about when <c>init</c> is called, see section
          <seealso marker="ct_hooks_chapter#scope">CTH Scope</seealso>
          in the User's Guide.</p>    
      </desc>
    </func>

    <func>
      <name>Module:pre_init_per_suite(SuiteName, InitData, CTHState) -&gt; Result</name>
      <fsummary>Called before init_per_suite.</fsummary>
      <type>
        <v>SuiteName = atom()</v>
        <v>InitData = Config | SkipOrFail</v>
        <v>Config = NewConfig = [{Key,Value}]</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {Return, NewCTHState}</v>
        <v>Return = NewConfig | SkipOrFail</v>
        <v>SkipOrFail = {fail, Reason} | {skip, Reason}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called before
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>
          if it exists. It typically contains initialization/logging that must
          be done before <c>init_per_suite</c> is called. If
          <c>{skip,Reason}</c> or <c>{fail,Reason}</c> is returned,
          <c>init_per_suite</c> and all test cases of the suite are skipped
          and <c>Reason</c> printed in the overview log of the suite.</p>

        <p><c>SuiteName</c> is the name of the suite to be run.</p>

        <p><c>InitData</c> is the original configuration list of the test
          suite, or a <c>SkipOrFail</c> tuple if a previous CTH has returned
          this.</p>

        <p><c>CTHState</c> is the current internal state of the CTH.</p>

        <p><c>Return</c> is the result of the <c>init_per_suite</c> function.
          If it is <c>{skip,Reason}</c> or <c>{fail,Reason}</c>, 
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>
          is never called, instead the initiation is considered to be
          skipped or failed, respectively. If a <c>NewConfig</c> list is
          returned,
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>
          is called with that <c>NewConfig</c> list. For more details, see
          section <seealso marker="ct_hooks_chapter#pre">Pre Hooks</seealso>
          in the User's Guide.</p>

        <p>This function is called only if the CTH is added before
          <c>init_per_suite is run</c>. For details, see section
          <seealso marker="ct_hooks_chapter#scope">CTH Scope</seealso>
          in the User's Guide.</p>
      </desc>
    </func>

    <func>
      <name>Module:post_init_per_suite(SuiteName, Config, Return, CTHState) -&gt; Result</name>
      <fsummary>Called after init_per_suite.</fsummary>
      <type>
        <v>SuiteName = atom()</v>
        <v>Config = [{Key,Value}]</v>
        <v>Return = NewReturn = Config | SkipOrFail | term()</v>
        <v>SkipOrFail = {fail, Reason} | {skip, Reason} | term()</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewReturn, NewCTHState}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called after
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>
          if it exists. It typically contains extra checks to ensure that all
          the correct dependencies are started correctly.</p>

        <p><c>Return</c> is what
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>
          returned, that is, <c>{fail,Reason}</c>, <c>{skip,Reason}</c>, a
          <c>Config</c> list, or a term describing how
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>
          failed.</p>

        <p><c>NewReturn</c> is the possibly modified return value of
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>.
          To recover from a failure in
          <seealso marker="common_test#Module:init_per_suite-1"><c>init_per_suite</c></seealso>,
          return <c>ConfigList</c> with the <c>tc_status</c> element removed.
          For more details, see
          <seealso marker="ct_hooks_chapter#post"> Post Hooks</seealso> in
          section "Manipulating Tests" in the User's Guide.</p>

        <p><c>CTHState</c> is the current internal state of the CTH.</p>

        <p>This function is called only if the CTH is added before or in
          <c>init_per_suite</c>. For details, see section
          <seealso marker="ct_hooks_chapter#scope">CTH Scope</seealso>
          in the User's Guide.</p>
      </desc>
    </func>

    <func>
      <name>Module:pre_init_per_group(GroupName, InitData, CTHState) -&gt; Result</name>
      <fsummary>Called before init_per_group.</fsummary>
      <type>
        <v>GroupName = atom()</v>
        <v>InitData = Config | SkipOrFail</v>
        <v>Config = NewConfig = [{Key,Value}]</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewConfig | SkipOrFail, NewCTHState}</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called before
          <seealso marker="common_test#Module:init_per_group-2"><c>init_per_group</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:pre_init_per_suite-3"><c>pre_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:init_per_group-2"><c>init_per_group</c></seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:post_init_per_group(GroupName, Config, Return, CTHState) -&gt; Result</name>
      <fsummary>Called after init_per_group.</fsummary>
      <type>
        <v>GroupName = atom()</v>
        <v>Config = [{Key,Value}]</v>
        <v>Return = NewReturn = Config | SkipOrFail | term()</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewReturn, NewCTHState}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called after
          <seealso marker="common_test#Module:init_per_group-2"><c>init_per_group</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:post_init_per_suite-4"><c>post_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:init_per_group-2"><c>init_per_group</c></seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:pre_init_per_testcase(TestcaseName, InitData, CTHState) -&gt; Result</name>
      <fsummary>Called before init_per_testcase.</fsummary>
      <type>
        <v>TestcaseName = atom()</v>
        <v>InitData = Config | SkipOrFail</v>
        <v>Config = NewConfig = [{Key,Value}]</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewConfig | SkipOrFail, NewCTHState}</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called before
          <seealso marker="common_test#Module:init_per_testcase-2"><c>init_per_testcase</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:pre_init_per_suite-3"><c>pre_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:init_per_testcase-2"><c>init_per_testcase</c></seealso>
          instead.</p>

        <p>CTHs cannot be added here right now. That feature may be added in
          a later release, but it would right now break backwards
          compatibility.</p>
      </desc>
    </func>

    <func>
      <name>Module:post_init_per_testcase(TestcaseName, Config, Return, CTHState) -&gt; Result</name>
      <fsummary>Called after init_per_testcase.</fsummary>
      <type>
        <v>TestcaseName = atom()</v>
        <v>Config = [{Key,Value}]</v>
        <v>Return = NewReturn = Config | SkipOrFail | term()</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewReturn, NewCTHState}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called after
          <seealso marker="common_test#Module:init_per_testcase-2"><c>init_per_testcase</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:post_init_per_suite-4"><c>post_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:init_per_testcase-2"><c>init_per_testcase</c></seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:pre_end_per_testcase(TestcaseName, InitData, CTHState) -&gt; Result</name>
      <fsummary>Called before end_per_testcase.</fsummary>
      <type>
        <v>TestcaseName = atom()</v>
        <v>InitData = Config</v>
        <v>Config = NewConfig = [{Key,Value}]</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewConfig, NewCTHState}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called before
          <seealso marker="common_test#Module:end_per_testcase-2"><c>end_per_testcase</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:pre_end_per_suite-3"><c>pre_end_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:end_per_testcase-2"><c>end_per_testcase</c></seealso>
          instead.</p>

        <p>This function can not change the result of the test case by returning skip or fail
	tuples, but it may insert items in <c>Config</c> that can be read in
	<c>end_per_testcase/2</c> or in <c>post_end_per_testcase/4</c>.</p>
      </desc>
    </func>

    <func>
      <name>Module:post_end_per_testcase(TestcaseName, Config, Return, CTHState) -&gt; Result</name>
      <fsummary>Called after end_per_testcase.</fsummary>
      <type>
        <v>TestcaseName = atom()</v>
        <v>Config = [{Key,Value}]</v>
        <v>Return = NewReturn = Config | SkipOrFail | term()</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewReturn, NewCTHState}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called after
          <seealso marker="common_test#Module:end_per_testcase-2"><c>end_per_testcase</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:post_end_per_suite-4"><c>post_end_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:end_per_testcase-2"><c>end_per_testcase</c></seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:pre_end_per_group(GroupName, EndData, CTHState) -&gt; Result</name>
      <fsummary>Called before end_per_group.</fsummary>
      <type>
        <v>GroupName = atom()</v>
        <v>EndData = Config | SkipOrFail</v>
        <v>Config = NewConfig = [{Key,Value}]</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewConfig | SkipOrFail, NewCTHState}</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called before
          <seealso marker="common_test#Module:end_per_group-2"><c>end_per_group</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:pre_init_per_suite-3"><c>pre_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:end_per_group-2"><c>end_per_group</c></seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:post_end_per_group(GroupName, Config, Return, CTHState) -&gt; Result</name>
      <fsummary>Called after end_per_group.</fsummary>
      <type>
        <v>GroupName = atom()</v>
        <v>Config = [{Key,Value}]</v>
        <v>Return = NewReturn = Config | SkipOrFail | term()</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewReturn, NewCTHState}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called after
          <seealso marker="common_test#Module:end_per_group-2"><c>end_per_group</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:post_init_per_suite-4"><c>post_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:end_per_group-2">end_per_group</seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:pre_end_per_suite(SuiteName, EndData, CTHState) -&gt; Result</name>
      <fsummary>Called before end_per_suite.</fsummary>
      <type>
        <v>SuiteName = atom()</v>
        <v>EndData = Config | SkipOrFail</v>
        <v>Config = NewConfig = [{Key,Value}]</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewConfig | SkipOrFail, NewCTHState}</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called before
          <seealso marker="common_test#Module:end_per_suite-1"><c>end_per_suite</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:pre_init_per_suite-3"><c>pre_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:end_per_suite-1"><c>end_per_suite</c></seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:post_end_per_suite(SuiteName, Config, Return, CTHState) -&gt; Result</name>
      <fsummary>Called after end_per_suite.</fsummary>
      <type>
        <v>SuiteName = atom()</v>
        <v>Config = [{Key,Value}]</v>
        <v>Return = NewReturn = Config | SkipOrFail | term()</v>
        <v>SkipOrFail = {fail,Reason} | {skip, Reason}</v>
        <v>CTHState = NewCTHState = term()</v>
        <v>Result = {NewReturn, NewCTHState}</v>
        <v>Key = atom()</v>
        <v>Value = term()</v>
        <v>Reason = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called after
          <seealso marker="common_test#Module:end_per_suite-1"><c>end_per_suite</c></seealso>
          if it exists. It behaves the same way as
          <seealso marker="ct_hooks#Module:post_init_per_suite-4"><c>post_init_per_suite</c></seealso>,
          but for function
          <seealso marker="common_test#Module:end_per_suite-1"><c>end_per_suite</c></seealso>
          instead.</p>
      </desc>
    </func>

    <func>
      <name>Module:on_tc_fail(TestName, Reason, CTHState) -&gt; NewCTHState</name>
      <fsummary>Called after the CTH scope ends.</fsummary>
      <type>
        <v>TestName = init_per_suite | end_per_suite | {init_per_group,GroupName} | {end_per_group,GroupName} | {FuncName,GroupName} | FuncName</v>
        <v>FuncName = atom()</v>
        <v>GroupName = atom()</v>
        <v>Reason = term()</v>
        <v>CTHState = NewCTHState = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called whenever a test case (or configuration
          function) fails. It is called after the post function is called
          for the failed test case, that is:</p>

        <list type="bulleted">
          <item><p>If <c>init_per_suite</c> fails, this function is called after
            <seealso marker="#Module:post_init_per_suite-4"><c>post_init_per_suite</c></seealso>.</p></item>
          <item><p>If a test case fails, this funcion is called after
          <seealso marker="#Module:post_end_per_testcase-4"><c>post_end_per_testcase</c></seealso>.</p></item>
        </list>

         <p>If the failed test case belongs to a test case group, the first
          argument is a tuple <c>{FuncName,GroupName}</c>, otherwise only
          the function name.</p>

        <p>The data that comes with <c>Reason</c> follows the same format as
          <seealso marker="event_handler_chapter#failreason"><c>FailReason</c></seealso>
          in event
          <seealso marker="event_handler_chapter#tc_done"><c>tc_done</c></seealso>.
          For details, see section
          <seealso marker="event_handler_chapter#events">Event Handling</seealso>
          in the User's Guide.</p>
      </desc>
    </func>

    <func>
      <name>Module:on_tc_skip(TestName, Reason, CTHState) -&gt; NewCTHState</name>
      <fsummary>Called after the CTH scope ends.</fsummary>
      <type>
        <v>TestName = init_per_suite | end_per_suite | {init_per_group,GroupName} | {end_per_group,GroupName} | {FuncName,GroupName} | FuncName</v>
        <v>FuncName = atom()</v>
        <v>GroupName = atom()</v>
        <v>Reason = {tc_auto_skip | tc_user_skip, term()}</v>
        <v>CTHState = NewCTHState = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called whenever a test case (or configuration
          function) is skipped. It is called after the post function is called
          for the skipped test case, that is:</p>

        <list type="bulleted">
          <item><p>If <c>init_per_group</c> is skipped, this function is
            called after 
            <seealso marker="#Module:post_init_per_group-4"><c>post_init_per_group</c></seealso>.</p></item>
          <item><p>If a test case is skipped, this function is called after
          <seealso marker="#Module:post_end_per_testcase-4"><c>post_end_per_testcase</c></seealso>.</p></item>
        </list>

        <p>If the skipped test case belongs to a test case group, the first
          argument is a tuple <c>{FuncName,GroupName}</c>, otherwise only
          the function name.</p>

        <p>The data that comes with <c>Reason</c> follows the same format as
          events
          <seealso marker="event_handler_chapter#tc_auto_skip"><c>tc_auto_skip</c></seealso>
          and
          <seealso marker="event_handler_chapter#tc_user_skip"><c>tc_user_skip</c></seealso>
          For details, see section
          <seealso marker="event_handler_chapter#events">Event Handling</seealso>
          in the User's Guide.</p>
      </desc>
    </func>

    <func>
      <name>Module:terminate(CTHState)</name>
      <fsummary>Called after the CTH scope ends.</fsummary>
      <type>
        <v>CTHState = term()</v>
      </type>
      <desc>	
        <p>OPTIONAL</p>

        <p>This function is called at the end of a CTH
          <seealso marker="ct_hooks_chapter#scope">scope</seealso>.</p>
      </desc>
    </func>

    <func>
      <name>Module:id(Opts) -&gt; Id</name>
      <fsummary>Called before the init function of a CTH.</fsummary>
      <type>
        <v>Opts = term()</v>
        <v>Id = term()</v>
      </type>
      <desc>
       <p>OPTIONAL</p>
	
       <p>The <c>Id</c> identifies a CTH instance uniquely. If two CTHs return
         the same <c>Id</c>, the second CTH is ignored and subsequent calls to
         the CTH are only made to the first instance. For details, see section
         <seealso marker="ct_hooks_chapter#installing">Installing a CTH</seealso>
         in the User's Guide.</p>

       <p>This function is <em>not</em> to have any side effects, as it can 
         be called multiple times by <c>Common Test</c>.</p>

       <p>If not implemented, the CTH acts as if this function returned a call
         to <c>make_ref/0</c>.</p>
       </desc>
    </func>
  </funcs>

</erlref>