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
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
|
# Copyright 2017 The Bazel Authors. All rights reserved.
#
# 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.
"""Unit testing support.
Unlike most Skylib files, this exports two modules: `unittest` which contains
functions to declare and define unit tests, and `asserts` which contains the
assertions used to within tests.
"""
load(":new_sets.bzl", new_sets = "sets")
load(":partial.bzl", "partial")
load(":types.bzl", "types")
# The following function should only be called from WORKSPACE files and workspace macros.
# buildifier: disable=unnamed-macro
def register_unittest_toolchains():
"""Registers the toolchains for unittest users."""
native.register_toolchains(
"@bazel_skylib//toolchains/unittest:cmd_toolchain",
"@bazel_skylib//toolchains/unittest:bash_toolchain",
)
TOOLCHAIN_TYPE = "@bazel_skylib//toolchains/unittest:toolchain_type"
_UnittestToolchainInfo = provider(
doc = "Execution platform information for rules in the bazel_skylib repository.",
fields = [
"file_ext",
"success_templ",
"failure_templ",
"join_on",
"escape_chars_with",
"escape_other_chars_with",
],
)
def _unittest_toolchain_impl(ctx):
return [
platform_common.ToolchainInfo(
unittest_toolchain_info = _UnittestToolchainInfo(
file_ext = ctx.attr.file_ext,
success_templ = ctx.attr.success_templ,
failure_templ = ctx.attr.failure_templ,
join_on = ctx.attr.join_on,
escape_chars_with = ctx.attr.escape_chars_with,
escape_other_chars_with = ctx.attr.escape_other_chars_with,
),
),
]
unittest_toolchain = rule(
implementation = _unittest_toolchain_impl,
attrs = {
"failure_templ": attr.string(
mandatory = True,
doc = (
"Test script template with a single `%s`. That " +
"placeholder is replaced with the lines in the " +
"failure message joined with the string " +
"specified in `join_with`. The resulting script " +
"should print the failure message and exit with " +
"non-zero status."
),
),
"file_ext": attr.string(
mandatory = True,
doc = (
"File extension for test script, including leading dot."
),
),
"join_on": attr.string(
mandatory = True,
doc = (
"String used to join the lines in the failure " +
"message before including the resulting string " +
"in the script specified in `failure_templ`."
),
),
"success_templ": attr.string(
mandatory = True,
doc = (
"Test script generated when the test passes. " +
"Should exit with status 0."
),
),
"escape_chars_with": attr.string_dict(
doc = (
"Dictionary of characters that need escaping in " +
"test failure message to prefix appended to escape " +
"those characters. For example, " +
'`{"%": "%", ">": "^"}` would replace `%` with ' +
"`%%` and `>` with `^>` in the failure message " +
"before that is included in `success_templ`."
),
),
"escape_other_chars_with": attr.string(
default = "",
doc = (
"String to prefix every character in test failure " +
"message which is not a key in `escape_chars_with` " +
"before including that in `success_templ`. For " +
'example, `"\"` would prefix every character in ' +
"the failure message (except those in the keys of " +
"`escape_chars_with`) with `\\`."
),
),
},
)
def _impl_function_name(impl):
"""Derives the name of the given rule implementation function.
This can be used for better test feedback.
Args:
impl: the rule implementation function
Returns:
The name of the given function
"""
# Starlark currently stringifies a function as "<function NAME>", so we use
# that knowledge to parse the "NAME" portion out. If this behavior ever
# changes, we'll need to update this.
# TODO(bazel-team): Expose a ._name field on functions to avoid this.
impl_name = str(impl)
impl_name = impl_name.partition("<function ")[-1]
return impl_name.rpartition(">")[0]
def _make(impl, attrs = {}):
"""Creates a unit test rule from its implementation function.
Each unit test is defined in an implementation function that must then be
associated with a rule so that a target can be built. This function handles
the boilerplate to create and return a test rule and captures the
implementation function's name so that it can be printed in test feedback.
The optional `attrs` argument can be used to define dependencies for this
test, in order to form unit tests of rules.
An example of a unit test:
```
def _your_test(ctx):
env = unittest.begin(ctx)
# Assert statements go here
return unittest.end(env)
your_test = unittest.make(_your_test)
```
Recall that names of test rules must end in `_test`.
Args:
impl: The implementation function of the unit test.
attrs: An optional dictionary to supplement the attrs passed to the
unit test's `rule()` constructor.
Returns:
A rule definition that should be stored in a global whose name ends in
`_test`.
"""
attrs = dict(attrs)
attrs["_impl_name"] = attr.string(default = _impl_function_name(impl))
return rule(
impl,
attrs = attrs,
_skylark_testable = True,
test = True,
toolchains = [TOOLCHAIN_TYPE],
)
_ActionInfo = provider(
doc = "Information relating to the target under test.",
fields = ["actions", "bin_path"],
)
def _action_retrieving_aspect_impl(target, ctx):
return [
_ActionInfo(
actions = target.actions,
bin_path = ctx.bin_dir.path,
),
]
_action_retrieving_aspect = aspect(
attr_aspects = [],
implementation = _action_retrieving_aspect_impl,
)
# TODO(cparsons): Provide more full documentation on analysis testing in README.
def _make_analysis_test(
impl,
doc = "",
expect_failure = False,
attrs = {},
fragments = [],
config_settings = {},
extra_target_under_test_aspects = []):
"""Creates an analysis test rule from its implementation function.
An analysis test verifies the behavior of a "real" rule target by examining
and asserting on the providers given by the real target.
Each analysis test is defined in an implementation function that must then be
associated with a rule so that a target can be built. This function handles
the boilerplate to create and return a test rule and captures the
implementation function's name so that it can be printed in test feedback.
An example of an analysis test:
```
def _your_test(ctx):
env = analysistest.begin(ctx)
# Assert statements go here
return analysistest.end(env)
your_test = analysistest.make(_your_test)
```
Recall that names of test rules must end in `_test`.
Args:
impl: The implementation function of the unit test.
doc: A description of the rule that can be extracted by documentation generating tools.
expect_failure: If true, the analysis test will expect the target_under_test
to fail. Assertions can be made on the underlying failure using asserts.expect_failure
attrs: An optional dictionary to supplement the attrs passed to the
unit test's `rule()` constructor.
fragments: An optional list of fragment names that can be used to give rules access to
language-specific parts of configuration.
config_settings: A dictionary of configuration settings to change for the target under
test and its dependencies. This may be used to essentially change 'build flags' for
the target under test, and may thus be utilized to test multiple targets with different
flags in a single build
extra_target_under_test_aspects: An optional list of aspects to apply to the target_under_test
in addition to those set up by default for the test harness itself.
Returns:
A rule definition that should be stored in a global whose name ends in
`_test`.
"""
attrs = dict(attrs)
attrs["_impl_name"] = attr.string(default = _impl_function_name(impl))
changed_settings = dict(config_settings)
if expect_failure:
changed_settings["//command_line_option:allow_analysis_failures"] = "True"
target_attr_kwargs = {}
if changed_settings:
test_transition = analysis_test_transition(
settings = changed_settings,
)
target_attr_kwargs["cfg"] = test_transition
attrs["target_under_test"] = attr.label(
aspects = [_action_retrieving_aspect] + extra_target_under_test_aspects,
mandatory = True,
**target_attr_kwargs
)
return rule(
impl,
doc = doc,
attrs = attrs,
fragments = fragments,
test = True,
toolchains = [TOOLCHAIN_TYPE],
analysis_test = True,
)
def _suite(name, *test_rules):
"""Defines a `test_suite` target that contains multiple tests.
After defining your test rules in a `.bzl` file, you need to create targets
from those rules so that `blaze test` can execute them. Doing this manually
in a BUILD file would consist of listing each test in your `load` statement
and then creating each target one by one. To reduce duplication, we recommend
writing a macro in your `.bzl` file to instantiate all targets, and calling
that macro from your BUILD file so you only have to load one symbol.
You can use this function to create the targets and wrap them in a single
test_suite target. If a test rule requires no arguments, you can simply list
it as an argument. If you wish to supply attributes explicitly, you can do so
using `partial.make()`. For instance, in your `.bzl` file, you could write:
```
def your_test_suite():
unittest.suite(
"your_test_suite",
your_test,
your_other_test,
partial.make(yet_another_test, timeout = "short"),
)
```
Then, in your `BUILD` file, simply load the macro and invoke it to have all
of the targets created:
```
load("//path/to/your/package:tests.bzl", "your_test_suite")
your_test_suite()
```
If you pass _N_ unit test rules to `unittest.suite`, _N_ + 1 targets will be
created: a `test_suite` target named `${name}` (where `${name}` is the name
argument passed in here) and targets named `${name}_test_${i}`, where `${i}`
is the index of the test in the `test_rules` list, which is used to uniquely
name each target.
Args:
name: The name of the `test_suite` target, and the prefix of all the test
target names.
*test_rules: A list of test rules defines by `unittest.test`.
"""
test_names = []
for index, test_rule in enumerate(test_rules):
test_name = "%s_test_%d" % (name, index)
if partial.is_instance(test_rule):
partial.call(test_rule, name = test_name)
else:
test_rule(name = test_name)
test_names.append(test_name)
native.test_suite(
name = name,
tests = [":%s" % t for t in test_names],
)
def _begin(ctx):
"""Begins a unit test.
This should be the first function called in a unit test implementation
function. It initializes a "test environment" that is used to collect
assertion failures so that they can be reported and logged at the end of the
test.
Args:
ctx: The Starlark context. Pass the implementation function's `ctx` argument
in verbatim.
Returns:
A test environment struct that must be passed to assertions and finally to
`unittest.end`. Do not rely on internal details about the fields in this
struct as it may change.
"""
return struct(ctx = ctx, failures = [])
def _end_analysis_test(env):
"""Ends an analysis test and logs the results.
This must be called and returned at the end of an analysis test implementation function so
that the results are reported.
Args:
env: The test environment returned by `analysistest.begin`.
Returns:
A list of providers needed to automatically register the analysis test result.
"""
return [AnalysisTestResultInfo(
success = (len(env.failures) == 0),
message = "\n".join(env.failures),
)]
def _end(env):
"""Ends a unit test and logs the results.
This must be called and returned at the end of a unit test implementation function so
that the results are reported.
Args:
env: The test environment returned by `unittest.begin`.
Returns:
A list of providers needed to automatically register the test result.
"""
tc = env.ctx.toolchains[TOOLCHAIN_TYPE].unittest_toolchain_info
testbin = env.ctx.actions.declare_file(env.ctx.label.name + tc.file_ext)
if env.failures:
failure_message_lines = "\n".join(env.failures).split("\n")
escaped_failure_message_lines = [
"".join([
tc.escape_chars_with.get(c, tc.escape_other_chars_with) + c
for c in line.elems()
])
for line in failure_message_lines
]
cmd = tc.failure_templ % tc.join_on.join(escaped_failure_message_lines)
else:
cmd = tc.success_templ
env.ctx.actions.write(
output = testbin,
content = cmd,
is_executable = True,
)
return [DefaultInfo(executable = testbin)]
def _fail(env, msg):
"""Unconditionally causes the current test to fail.
Args:
env: The test environment returned by `unittest.begin`.
msg: The message to log describing the failure.
"""
full_msg = "In test %s: %s" % (env.ctx.attr._impl_name, msg)
# There isn't a better way to output the message in Starlark, so use print.
# buildifier: disable=print
print(full_msg)
env.failures.append(full_msg)
def _assert_true(
env,
condition,
msg = "Expected condition to be true, but was false."):
"""Asserts that the given `condition` is true.
Args:
env: The test environment returned by `unittest.begin`.
condition: A value that will be evaluated in a Boolean context.
msg: An optional message that will be printed that describes the failure.
If omitted, a default will be used.
"""
if not condition:
_fail(env, msg)
def _assert_false(
env,
condition,
msg = "Expected condition to be false, but was true."):
"""Asserts that the given `condition` is false.
Args:
env: The test environment returned by `unittest.begin`.
condition: A value that will be evaluated in a Boolean context.
msg: An optional message that will be printed that describes the failure.
If omitted, a default will be used.
"""
if condition:
_fail(env, msg)
def _assert_equals(env, expected, actual, msg = None):
"""Asserts that the given `expected` and `actual` values are equal.
Args:
env: The test environment returned by `unittest.begin`.
expected: The expected value of some computation.
actual: The actual value returned by some computation.
msg: An optional message that will be printed that describes the failure.
If omitted, a default will be used.
"""
if expected != actual:
expectation_msg = 'Expected "%s", but got "%s"' % (expected, actual)
if msg:
full_msg = "%s (%s)" % (msg, expectation_msg)
else:
full_msg = expectation_msg
_fail(env, full_msg)
def _assert_set_equals(env, expected, actual, msg = None):
"""Asserts that the given `expected` and `actual` sets are equal.
Args:
env: The test environment returned by `unittest.begin`.
expected: The expected set resulting from some computation.
actual: The actual set returned by some computation.
msg: An optional message that will be printed that describes the failure.
If omitted, a default will be used.
"""
if not new_sets.is_equal(expected, actual):
missing = new_sets.difference(expected, actual)
unexpected = new_sets.difference(actual, expected)
expectation_msg = "Expected %s, but got %s" % (new_sets.str(expected), new_sets.str(actual))
if new_sets.length(missing) > 0:
expectation_msg += ", missing are %s" % (new_sets.str(missing))
if new_sets.length(unexpected) > 0:
expectation_msg += ", unexpected are %s" % (new_sets.str(unexpected))
if msg:
full_msg = "%s (%s)" % (msg, expectation_msg)
else:
full_msg = expectation_msg
_fail(env, full_msg)
_assert_new_set_equals = _assert_set_equals
def _expect_failure(env, expected_failure_msg = ""):
"""Asserts that the target under test has failed with a given error message.
This requires that the analysis test is created with `analysistest.make()` and
`expect_failures = True` is specified.
Args:
env: The test environment returned by `analysistest.begin`.
expected_failure_msg: The error message to expect as a result of analysis failures.
"""
dep = _target_under_test(env)
if AnalysisFailureInfo in dep:
actual_errors = ""
for cause in dep[AnalysisFailureInfo].causes.to_list():
actual_errors += cause.message + "\n"
if actual_errors.find(expected_failure_msg) < 0:
expectation_msg = "Expected errors to contain '%s' but did not. " % expected_failure_msg
expectation_msg += "Actual errors:%s" % actual_errors
_fail(env, expectation_msg)
else:
_fail(env, "Expected failure of target_under_test, but found success")
def _target_actions(env):
"""Returns a list of actions registered by the target under test.
Args:
env: The test environment returned by `analysistest.begin`.
Returns:
A list of actions registered by the target under test
"""
# Validate?
return _target_under_test(env)[_ActionInfo].actions
def _target_bin_dir_path(env):
"""Returns ctx.bin_dir.path for the target under test.
Args:
env: The test environment returned by `analysistest.begin`.
Returns:
Output bin dir path string.
"""
return _target_under_test(env)[_ActionInfo].bin_path
def _target_under_test(env):
"""Returns the target under test.
Args:
env: The test environment returned by `analysistest.begin`.
Returns:
The target under test.
"""
result = getattr(env.ctx.attr, "target_under_test")
if types.is_list(result):
if result:
return result[0]
else:
fail("test rule does not have a target_under_test")
return result
def _loading_test_impl(ctx):
tc = ctx.toolchains[TOOLCHAIN_TYPE].unittest_toolchain_info
content = tc.success_templ
if ctx.attr.failure_message:
content = tc.failure_templ % ctx.attr.failure_message
testbin = ctx.actions.declare_file("loading_test_" + ctx.label.name + tc.file_ext)
ctx.actions.write(
output = testbin,
content = content,
is_executable = True,
)
return [DefaultInfo(executable = testbin)]
_loading_test = rule(
implementation = _loading_test_impl,
attrs = {
"failure_message": attr.string(),
},
toolchains = [TOOLCHAIN_TYPE],
test = True,
)
def _loading_make(name):
"""Creates a loading phase test environment and test_suite.
Args:
name: name of the suite of tests to create
Returns:
loading phase environment passed to other loadingtest functions
"""
native.test_suite(
name = name + "_tests",
tags = [name + "_test_case"],
)
return struct(name = name)
def _loading_assert_equals(env, test_case, expected, actual):
"""Creates a test case for asserting state at LOADING phase.
Args:
env: Loading test env created from loadingtest.make
test_case: Name of the test case
expected: Expected value to test
actual: Actual value received.
Returns:
None, creates test case
"""
msg = None
if expected != actual:
msg = 'Expected "%s", but got "%s"' % (expected, actual)
_loading_test(
name = "%s_%s" % (env.name, test_case),
failure_message = msg,
tags = [env.name + "_test_case"],
)
asserts = struct(
expect_failure = _expect_failure,
equals = _assert_equals,
false = _assert_false,
set_equals = _assert_set_equals,
new_set_equals = _assert_new_set_equals,
true = _assert_true,
)
unittest = struct(
make = _make,
suite = _suite,
begin = _begin,
end = _end,
fail = _fail,
)
analysistest = struct(
make = _make_analysis_test,
begin = _begin,
end = _end_analysis_test,
fail = _fail,
target_actions = _target_actions,
target_bin_dir_path = _target_bin_dir_path,
target_under_test = _target_under_test,
)
loadingtest = struct(
make = _loading_make,
equals = _loading_assert_equals,
)
|