1Test::Stream::Plugin::CUosmeprarCeo(n3t)ributed Perl DocTuemsetn:t:aSttiroenam::Plugin::Compare(3)
2
3
4

NAME

6       Test::Stream::Plugin::Compare - Tools for comparing deep data
7       structures.
8

DEPRECATED

10       This distribution is deprecated in favor of Test2, Test2::Suite, and
11       Test2::Workflow.
12
13       See Test::Stream::Manual::ToTest2 for a conversion guide.
14

DESCRIPTION

16       Test::More had "is_deeply()". This library is the Test::Stream version.
17       This library can be used to compare data structures. This library goes
18       a step further though, it provides tools for building a data structure
19       specification against which you can verify your data. There are both
20       'strict' and 'relaxed' versions of the tools.
21

SYNOPSIS

23           use Test::Stream 'Compare';
24
25           # Hash for demonstration purposes
26           my $some_hash = {a => 1, b => 2, c => 3};
27
28           # Strict checking, everything must match
29           is(
30               $some_hash,
31               {a => 1, b => 2, c => 3},
32               "The hash we got matches our expectations"
33           );
34
35           # Relaxed Checking, only fields we care about are checked, and we can use a
36           # regex to approximate a field.
37           like(
38               $some_hash,
39               {a => 1, b => qr/\d+/},
40               "'a' is 1, 'b' is an integer, we don't care about 'c'."
41           );
42
43   ADVANCED
44       Declarative hash, array, and objects builders are available that allow
45       you to generate specifications. These are more verbose than simply
46       providing a hash, but have the advantage that every component you
47       specify has a line number associated. This is helpful for debugging as
48       the failure output will tell you not only which fields was incorrect,
49       but also the line on which you declared the field.
50
51           use Test::Stream 'Compare' => '*';
52
53           is(
54               $some_hash,
55               hash {
56                   field a => 1;
57                   field b => 2;
58                   field c => 3;
59               },
60               "Hash matches spec"
61           );
62

COMPARISON TOOLS

64       $bool = is($got, $expect)
65       $bool = is($got, $expect, $name)
66       $bool = is($got, $expect, $name, @diag)
67           $got is the data structure you want to check. $expect is what you
68           want $got to look like. $name is an optional name for the test.
69           @diag is optional diagnostics messages that will be printed to
70           STDERR in event of failure, they will not be displayed when the
71           comparison is successful. The boolean true/false result of the
72           comparison is returned.
73
74           This is the strict checker. The strict checker requires a perfect
75           match between $got and $expect. All hash fields must be specfied,
76           all array items must be present, etc. All
77           non-scalar/hash/array/regex references must be identical (same
78           memory address). Scalar, hash and array references will be
79           traversed and compared. Regex references will be compared to see if
80           they have the same pattern.
81
82               is(
83                   $some_hash,
84                   {a => 1, b => 2, c => 3},
85                   "The hash we got matches our expectations"
86               );
87
88           The only exception to strictness is when it is given an $expect
89           object that was built from a specification, in which case the
90           specification determines the strictness. Strictness only applies to
91           literal values/references that are provided and converted to a
92           specification for you.
93
94               is(
95                   $some_hash,
96                   hash {    # Note: the hash function is not exported by default
97                       field a => 1;
98                       field b => match(qr/\d+/);    # Note: The match function is not exported by default
99                       # Don't care about other fields.
100                   },
101                   "The hash comparison is not strict"
102               );
103
104           This works for both deep and shallow structures. For instance you
105           can use this to compare 2 strings:
106
107               is('foo', 'foo', "strings match");
108
109           Note: This is not the tool to use if you want to check if 2
110           references are the same exact reference, use "ref_is()" from the
111           Test::Stream::Plugin::Core plugin instead. Most of the time this
112           will work as well, however there are problems if your reference
113           contains a cyle and refers back to itself at some point, if this
114           happens an exception will be thrown to break an otherwise infinite
115           recursion.
116
117           Note: Non-reference values will be compared as strings using "eq",
118           that means '2.0' and '2' will match.
119
120       like($got, $expect)
121       like($got, $expect, $name)
122       like($got, $expect, $name, @diag)
123           $got is the data structure you want to check. $expect is what you
124           want $got to look like. $name is an optional name for the test.
125           @diag is optional diagnostics messages that will be printed to
126           STDERR in event of failure, they will not be displayed when the
127           comparison is successful. The boolean true/false result of the
128           comparison is returned.
129
130           This is the relaxed checker. This will ignore hash keys or array
131           indexes that you do not actually specify in your $expect structure.
132           In addition regex and sub references will be used as validators. If
133           you provide a regex using "qr/.../", the regex itself will be used
134           to validate the corresponding value in the $got structure. The same
135           is true for coderefs, the value is passed in as the first argument
136           (and in $_) and the sub should return a boolean value.  In this
137           tool regexes will stringify the thing they are checking.
138
139               like(
140                   $some_hash,
141                   {a => 1, b => qr/\d+/},
142                   "'a' is 1, 'b' is an integer, we don't care about other fields"
143               );
144
145           This works for both deep and shallow structures. For instance you
146           can use this to compare 2 strings:
147
148               like('foo bar', qr/^foo/, "string matches the pattern");
149
150   QUICK CHECKS
151       Note: None of these are exported by default, you need to request them.
152
153       Quick checks are a way to quickly generate a common value
154       specification. These can be used in structures passed into "is" and
155       "like" through the $expect argument.
156
157       Example:
158
159           is($foo, T(), '$foo has a true value');
160
161       $check = T()
162           This verifies that the value in the corresponding $got structure is
163           true, any true value will do.
164
165               is($foo, T(), '$foo has a true value');
166
167               is(
168                   { a => 'xxx' },
169                   { a => T() },
170                   "The 'a' key is true"
171               );
172
173       $check = F()
174           This verifies that the value in the corresponding $got structure is
175           false, any false value will do, but the value must exist.
176
177               is($foo, F(), '$foo has a false value');
178
179               is(
180                   { a => 0 },
181                   { a => F() },
182                   "The 'a' key is false"
183               );
184
185           It is important to note that a non-existant value does not count as
186           false, this check will generate a failing test result:
187
188               is(
189                   { a => 1 },
190                   { a => 1, b => F() },
191                   "The 'b' key is false"
192               );
193
194           This will produce the following output:
195
196               not ok 1 - The b key is false
197               # Failed test "The 'b' key is false"
198               # at some_file.t line 10.
199               # +------+------------------+-------+---------+
200               # | PATH | GOT              | OP    | CHECK   |
201               # +------+------------------+-------+---------+
202               # | {b}  | <DOES NOT EXIST> | FALSE | FALSE() |
203               # +------+------------------+-------+---------+
204
205           In perl you can have behavior that is different for a missing key
206           vs a false key, as such it was decided not to count a completely
207           absent value as false.  See the "DNE()" shortcut below for checking
208           that a field is missing.
209
210           If you want to check for false and/or DNE use the "FDNE()" check.
211
212       $check = D()
213           This is to verify that the value in the $got structure is defined.
214           Any value other than "undef" will pass.
215
216           This will pass:
217
218               is('foo', D(), 'foo is defined');
219
220           This will fail:
221
222               is(undef, D(), 'foo is defined');
223
224       $check = DNE()
225           This can be used to check that no value exists. This is useful to
226           check the end bound of an array, or to check that a key does not
227           exist in a hash.
228
229           These pass:
230
231               is(['a', 'b'], ['a', 'b', DNE()], "There is no third item in the array");
232               is({a => 1}, {a => 1, b => DNE()}, "The 'b' key does not exist in the hash");
233
234           These will fail:
235
236               is(['a', 'b', 'c'], ['a', 'b', DNE()], "No third item");
237               is({a => 1, b => 2}, {a => 1, b => DNE()}, "No 'b' key");
238
239       $check = FDNE()
240           This is a combination of "F()" and "DNE()". This will pass for a
241           false value, or a non-existant value.
242
243   VALUE SPECIFICATIONS
244       Note: None of these are exported by default, you need to request them.
245
246       $check = string "..."
247           Verify that the value matches the given string using the "eq"
248           operator.
249
250       $check = number ...;
251           Verify that the value matches the given number using the "=="
252           operator.
253
254       $check = match qr/.../
255           Verify that the value matches the regex pattern. This form of
256           pattern check will NOT stringify references being checked.
257
258       $check = mismatch qr/.../
259           Verify that the value does not match the regex pattern. This form
260           of pattern check will NOT stringify references being checked.
261
262       $check = validator(sub{ ... })
263       $check = validator($NAME => sub{ ... })
264       $check = validator($OP, $NAME, sub{ ... })
265           The coderef is the only required argument. The coderef should check
266           that the value is what you expect, it should return a boolean true
267           or false. Optionally you can specify a name and operator that are
268           used in diagnostics, they are also provided to the sub itself as
269           named parameters.
270
271           Check the value using this sub. The sub gets the value in $_, as
272           well it received the value and several other items as named
273           parameters.
274
275               my $check = validator(sub {
276                   my %params = @_;
277
278                   # These both work:
279                   my $got = $_;
280                   my $got = $params{got};
281
282                   # Check if a value exists at all
283                   my $exists = $params{exists}
284
285                   # What $OP (if any) did we specify when creating the validator
286                   my $operator = $params{operator};
287
288                   # What name (if any) did we specify when creating the validator
289                   my $name = $params{name};
290
291                   ...
292
293                   return $bool;
294               }
295
296       $check = exact_ref($ref)
297           Check that the value is exactly the same reference as the one
298           provided.
299
300   SET BUILDERS
301       Note: None of these are exported by default, you need to request them.
302
303       my $check = check_set($check1, $check2, ...)
304           Check that the value matches ALL of the specified checks.
305
306       my $check = in_set($check1, $check2, ...)
307           Check that the value matches 1 OR MORE of the specified checks.
308
309       not_in_set($check1, $check2, ...)
310           Check that the value DOES NOT match ANY of the specified checks.
311
312       check $thing
313           Check that the value matches the specified thing.
314
315   HASH BUILDER
316       Note: None of these are exported by default, you need to request them.
317
318           $check = hash {
319               field foo => 1;
320               field bar => 2;
321
322               # Ensure the 'baz' keys does not even exist in the hash.
323               field baz => DNE();
324
325               # Ensure the key exists, but is set to undef
326               field bat => undef;
327
328               # Any check can be used
329               field boo => $check;
330
331               ...
332
333               end(); # optional, enforces that no other keys are present.
334           };
335
336       $check = hash { ... }
337           This is used to define a hash check.
338
339       field $NAME => $VAL
340       field $NAME => $CHECK
341           Specify a field check. This will check the hash key specified by
342           $NAME and ensure it matches the value in $VAL. You can put any
343           valid check in $VAL, such as the result of another call to "array {
344           ... }", "DNE()", etc.
345
346           Note: This function can only be used inside a hash builder sub, and
347           must be called in void context.
348
349       end()
350           Enforce that no keys are found in the hash other than those
351           specified. This is essentually the 'use strict' of a hash check.
352           This can be used anywhere in the hash builder, though typically it
353           is placed at the end.
354
355       DNE()
356           This is a handy check that can be used with "field()" to ensure
357           that a field (D)oes (N)not (E)xist.
358
359               field foo => DNE();
360
361   ARRAY BUILDER
362       Note: None of these are exported by default, you need to request them.
363
364           $check = hash {
365               # Uses the next index, in this case index 0;
366               item 'a';
367
368               # Gets index 1 automatically
369               item 'b';
370
371               # Specify the index
372               item 2 => 'c';
373
374               # We skipped index 3, which means we don't care what it is.
375               item 4 => 'e';
376
377               # Gets index 5.
378               item 'f';
379
380               # Remove any REMAINING items that contain 0-9.
381               filter_items { grep {m/\D/} @_ };
382
383               # Of the remaining items (after the filter is applied) the next one
384               # (which is now index 6) should be 'g'.
385               item 6 => 'g';
386
387               item 7 => DNE; # Ensure index 7 does not exist.
388
389               end(); # Ensure no other indexes exist.
390           };
391
392       $check = array { ... }
393       item $VAL
394       item $CHECK
395       item $IDX, $VAL
396       item $IDX, $CHECK
397           Add an expected item to the array. If $IDX is not specified it will
398           automatically calculate it based on the last item added. You can
399           skip indexes, which means you do not want them to be checked.
400
401           You can provide any value to check in $VAL, or you can provide any
402           valid check object.
403
404           Note: Items MUST be added in order.
405
406           Note: This function can only be used inside an array builder sub,
407           and must be called in void context.
408
409       filter_items { my @remaining = @_; ...; return @filtered }
410           This function adds a filter, all items remaining in the array from
411           the point the filter is reached will be passed into the filter sub
412           as arguments, the sub should return only the items that should be
413           checked.
414
415           Note: This function can only be used inside an array builder sub,
416           and must be called in void context.
417
418       end()
419           Enforce that there are no indexes after the last one specified.
420           This will not force checking of skipped indexes.
421
422       DNE()
423           This is a handy check that can be used with "item()" to ensure that
424           an index (D)oes (N)not (E)xist.
425
426               item 5 => DNE();
427
428   META BUILDER
429       Note: None of these are exported by default, you need to request them.
430
431           my $check = meta {
432               prop blessed => 'My::Module'; # Ensure value is blessed as our package
433               prop reftype => 'HASH';       # Ensure value is a blessed hash
434               prop size    => 4;            # Check the number of hash keys
435               prop this    => ...;          # Check the item itself
436           };
437
438       meta { ... }
439           Build a meta check
440
441       prop $NAME => $VAL
442       prop $NAME => $CHECK
443           Check the property specified by $name against the value or check.
444
445           Valid properties are:
446
447           'blessed'
448               What package (if any) the thing is blessed as.
449
450           'reftype'
451               Reference type (if any) the thing is.
452
453           'this'
454               The thing itself.
455
456           'size'
457               For array references this returns the number of elements. For
458               hashes this returns the number of keys. For everything else
459               this returns undef.
460
461   OBJECT BUILDER
462       Note: None of these are exported by default, you need to request them.
463
464           my $check = object {
465               call foo => 1; # Call the 'foo' method, check the result.
466
467               # Call the specified sub-ref as a method on the object, check the
468               # result. This is useful for wrapping methods that return multiple
469               # values.
470               call sub { [ shift->get_list ] } => [...];
471
472               # This can be used to ensure a method does not exist.
473               call nope => DNE();
474
475               # Check the hash key 'foo' of the underlying reference, this only works
476               # on blessed hashes.
477               field foo => 1;
478
479               # Check the value of index 4 on the underlying reference, this only
480               # works on blessed arrays.
481               item 4 => 'foo';
482
483               # Check the meta-property 'blessed' of the object.
484               prop blessed => 'My::Module';
485
486               # Ensure only the specified hash keys or array indexes are present in
487               # the underlying hash. Has no effect on meta-property checks or method
488               # checks.
489               end();
490           };
491
492       $check = object { ... }
493           Specify an object check for use in comparisons.
494
495       call $METHOD_NAME => $RESULT
496       call $METHOD_NAME => $CHECK
497       call sub { ... }, $RESULT
498       call sub { ... }, $CHECK
499           Call the specified method (or coderef) and verify the result. The
500           coderef form us useful if you want to check a method that returns a
501           list as it allows you to wrap the result in a reference.
502
503               my $ref = sub {
504                   my $self = shift;
505                   my @result = $self->get_list;
506                   return \@result;
507               };
508
509               call $ref => [ ... ];
510
511       field $NAME => $VAL
512           Works just like it does for hash checks.
513
514       item $VAL
515       item $IDX, $VAL
516           Works just like it does for array checks.
517
518       prop $NAME => $VAL
519       prop $NAME => $CHECK
520           Check the property specified by $name against the value or check.
521
522           Valid properties are:
523
524           'blessed'
525               What package (if any) the thing is blessed as.
526
527           'reftype'
528               Reference type (if any) the thing is.
529
530           'this'
531               The thing itself.
532
533           'size'
534               For array references this returns the number of elements. For
535               hashes this returns the number of keys. For everything else
536               this returns undef.
537
538       DNE()
539           Can be used with "item", or "field" to ensure the hash field or
540           array index does not exist. Can also be used with "call" to ensure
541           a method does not exist.
542
543       end()
544           Turn on strict array/hash checking, that is ensure that no extra
545           keys/indexes are present.
546
547   EVENT BUILDER
548       Note: None of these are exported by default, you need to request them.
549
550       Check that we got an event of a specified type:
551
552           my $check = event 'Ok';
553
554       Check for details about the event:
555
556           my $check = event Ok => sub {
557               # Check for a failure
558               call pass => 0;
559
560               # Effective pass after TODO/SKIP are accounted for.
561               call effective_pass => 1;
562
563               # Check the diagnostics
564               call diag => [ match qr/Failed test foo/ ];
565
566               # Check the file the event reports to
567               prop file => 'foo.t';
568
569               # Check the line number the event reports o
570               prop line => '42';
571
572               # You can check the todo/skip values as well:
573               prop skip => 'broken';
574               prop todo => 'fixme';
575
576               # Thread-id and process-id where event was generated
577               prop tid => 123;
578               prop pid => 123;
579           };
580
581       You can also provide a fully qualified event package with the '+'
582       prefix:
583
584           my $check = event '+My::Event' => sub { ... }
585
586       $check = event $TYPE;
587       $check = event $TYPE => sub { ... };
588           This works just like an object builder. In addition to supporting
589           everything the object check supports, you also have to specify the
590           event type, and many extra meta-properties are available.
591
592           Extra properties are:
593
594           'file'
595               File name to which the event reports (for use in diagnostics).
596
597           'line'
598               Line number to which the event reports (for use in
599               diagnostics).
600
601           'package'
602               Package to which the event reports (for use in diagnostics).
603
604           'subname'
605               Sub that was called to generate the event (example: "ok()").
606
607           'skip'
608               Set to the skip value if the result was generated by skipping
609               tests.
610
611           'todo'
612               Set to the todo value if TODO was set when the event was
613               generated.
614
615           'trace'
616               The 'at file foo.t line 42' string that will be used in
617               diagnostics.
618
619           'tid'
620               Thread id in which the event was generated.
621
622           'pid'
623               PRocess id in which the event was generated.
624

SOURCE

626       The source code repository for Test::Stream can be found at
627       http://github.com/Test-More/Test-Stream/.
628

MAINTAINERS

630       Chad Granum <exodist@cpan.org>
631

AUTHORS

633       Chad Granum <exodist@cpan.org>
634
636       Copyright 2015 Chad Granum <exodist7@gmail.com>.
637
638       This program is free software; you can redistribute it and/or modify it
639       under the same terms as Perl itself.
640
641       See http://dev.perl.org/licenses/
642
643
644
645perl v5.30.1                      2020-01-30  Test::Stream::Plugin::Compare(3)
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