summaryrefslogtreecommitdiff
path: root/itcl/itcl/tests/inherit.test
blob: d391573dee42792e4431440d3d4da2b8f845481b (plain)
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
#
# Tests for inheritance and scope handling
# ----------------------------------------------------------------------
#   AUTHOR:  Michael J. McLennan
#            Bell Labs Innovations for Lucent Technologies
#            mmclennan@lucent.com
#            http://www.tcltk.com/itcl
#
#      RCS:  $Id$
# ----------------------------------------------------------------------
#            Copyright (c) 1993-1998  Lucent Technologies, Inc.
# ======================================================================
# See the file "license.terms" for information on usage and
# redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.

if {[string compare test [info procs test]] == 1} then {source defs}

# ----------------------------------------------------------------------
#  Test construction/destruction with inheritance
# ----------------------------------------------------------------------
test inherit-1.1 {define classes with constructors/destructors} {
    variable ::test_cd_watch ""
    itcl::class test_cd_foo {
        constructor {x y} {
            global ::test_cd_watch
            lappend test_cd_watch "foo: $x $y"
        }
        destructor {
            global ::test_cd_watch
            lappend test_cd_watch "foo destruct"
        }
    }
    itcl::class test_cd_bar {
        constructor {args} {
            global ::test_cd_watch
            lappend test_cd_watch "bar: $args"
        }
        destructor {
            global ::test_cd_watch
            lappend test_cd_watch "bar destruct"
        }
    }
    itcl::class test_cd_foobar {
        inherit test_cd_foo test_cd_bar
        constructor {x y args} {
            test_cd_foo::constructor $x $y
        } {
            global ::test_cd_watch
            lappend test_cd_watch "foobar: $x $y ($args)"
        }
        destructor {
            global ::test_cd_watch
            lappend test_cd_watch "foobar destruct"
        }
    }
    itcl::class test_cd_geek {
        constructor {} {
            global ::test_cd_watch
            lappend test_cd_watch "geek"
        }
        destructor {
            global ::test_cd_watch
            lappend test_cd_watch "geek destruct"
        }
    }
    itcl::class test_cd_mongrel {
        inherit test_cd_foobar test_cd_geek
        constructor {x} {
            eval test_cd_foobar::constructor 1 2 fred $x
        } {
            global ::test_cd_watch
            lappend test_cd_watch "mongrel: $x"
        }
        destructor {
            global ::test_cd_watch
            lappend test_cd_watch "mongrel destruct"
        }
    }
    itcl::class test_cd_none {
        inherit test_cd_bar test_cd_geek
    }
    itcl::class test_cd_skip {
        inherit test_cd_none
        constructor {} {
            global ::test_cd_watch
            lappend test_cd_watch "skip"
        }
        destructor {
            global ::test_cd_watch
            lappend test_cd_watch "skip destruct"
        }
    }
} {}

test inherit-1.2 {constructors should be invoked in the proper order} {
    set ::test_cd_watch ""
    list [test_cd_mongrel #auto bob] [set ::test_cd_watch]
} {test_cd_mongrel0 {{foo: 1 2} {bar: } {foobar: 1 2 (fred bob)} geek {mongrel: bob}}}

test inherit-1.3 {destructors should be invoked in the proper order} {
    set ::test_cd_watch ""
    list [delete object test_cd_mongrel0] [set ::test_cd_watch]
} {{} {{mongrel destruct} {foobar destruct} {foo destruct} {bar destruct} {geek destruct}}}

test inherit-1.4 {constructors are optional} {
    set ::test_cd_watch ""
    list [test_cd_none #auto] [set ::test_cd_watch]
} {test_cd_none0 {geek {bar: }}}

test inherit-1.5 {destructors are optional} {
    set ::test_cd_watch ""
    list [delete object test_cd_none0] [set ::test_cd_watch]
} {{} {{bar destruct} {geek destruct}}}

test inherit-1.6 {construction ok if constructors are missing} {
    set ::test_cd_watch ""
    list [test_cd_skip #auto] [set ::test_cd_watch]
} {test_cd_skip0 {geek {bar: } skip}}

test inherit-1.7 {destruction ok if destructors are missing} {
    set ::test_cd_watch ""
    list [delete object test_cd_skip0] [set ::test_cd_watch]
} {{} {{skip destruct} {bar destruct} {geek destruct}}}

test inherit-1.8 {errors during construction are cleaned up and reported} {
    global errorInfo test_cd_watch
    set test_cd_watch ""
    body test_cd_bar::constructor {args} {error "bar: failed"}
    list [catch {test_cd_mongrel #auto bob} msg] $msg \
        $errorInfo $test_cd_watch
} {1 {bar: failed} {bar: failed
    while executing
"error "bar: failed""
    while constructing object "::test_cd_mongrel1" in ::test_cd_bar::constructor (body line 1)
    while constructing object "::test_cd_mongrel1" in ::test_cd_foobar::constructor (body line 1)
    invoked from within
"test_cd_foobar::constructor 1 2 fred bob"
    ("eval" body line 1)
    invoked from within
"eval test_cd_foobar::constructor 1 2 fred $x"
    while constructing object "::test_cd_mongrel1" in ::test_cd_mongrel::constructor (body line 2)
    invoked from within
"test_cd_mongrel #auto bob"} {{foo: 1 2} {mongrel destruct} {foobar destruct} {foo destruct} {bar destruct} {geek destruct}}}

test inherit-1.9 {errors during destruction prevent object delete} {
    global errorInfo test_cd_watch
    body test_cd_bar::constructor {args} {return "bar: $args"}
    body test_cd_bar::destructor {} {error "bar: failed"}
    test_cd_mongrel mongrel1 ted
    set test_cd_watch ""
    list [catch {delete object mongrel1} msg] $msg \
        $errorInfo $test_cd_watch [find objects mongrel*]
} {1 {bar: failed} {bar: failed
    while executing
"error "bar: failed""
    while deleting object "::mongrel1" in ::test_cd_bar::destructor (body line 1)
    invoked from within
"delete object mongrel1"} {{mongrel destruct} {foobar destruct} {foo destruct}} mongrel1}

test inherit-1.10 {errors during destruction prevent class delete} {
    list [catch {delete class test_cd_foo} msg] $msg
} {1 {bar: failed}}

eval namespace delete [find classes test_cd_*]

# ----------------------------------------------------------------------
#  Test data member access and scoping
# ----------------------------------------------------------------------
test inherit-2.1 {define classes with data members} {
    itcl::class test_cd_foo {
        protected variable x "foo-x"
        method do {args} {eval $args}
    }
    itcl::class test_cd_bar {
        protected variable x "bar-x"
        method do {args} {eval $args}
    }
    itcl::class test_cd_foobar {
        inherit test_cd_foo test_cd_bar
        method do {args} {eval $args}
    }
    itcl::class test_cd_geek {
        method do {args} {eval $args}
    }
    itcl::class test_cd_mongrel {
        inherit test_cd_foobar test_cd_geek
        protected variable x "mongrel-x"
        method do {args} {eval $args}
    }
} {}

test inherit-2.2 {"info" provides access to shadowed data members} {
    test_cd_mongrel #auto
    list [lsort [test_cd_mongrel0 info variable]] \
         [test_cd_mongrel0 info variable test_cd_foo::x] \
         [test_cd_mongrel0 info variable test_cd_bar::x] \
         [test_cd_mongrel0 info variable test_cd_mongrel::x] \
         [test_cd_mongrel0 info variable x]
} {{::test_cd_bar::x ::test_cd_foo::x ::test_cd_mongrel::this ::test_cd_mongrel::x} {protected variable ::test_cd_foo::x foo-x foo-x} {protected variable ::test_cd_bar::x bar-x bar-x} {protected variable ::test_cd_mongrel::x mongrel-x mongrel-x} {protected variable ::test_cd_mongrel::x mongrel-x mongrel-x}}

test inherit-2.3 {variable resolution works properly in methods} {
    list [test_cd_mongrel0 test_cd_foo::do set x] \
         [test_cd_mongrel0 test_cd_bar::do set x] \
         [test_cd_mongrel0 test_cd_foobar::do set x] \
         [test_cd_mongrel0 test_cd_mongrel::do set x]
} {foo-x bar-x foo-x mongrel-x}

test inherit-2.4 {methods have access to shadowed data members} {
    list [test_cd_mongrel0 test_cd_foobar::do set x] \
         [test_cd_mongrel0 test_cd_foobar::do set test_cd_foo::x] \
         [test_cd_mongrel0 test_cd_foobar::do set test_cd_bar::x] \
         [test_cd_mongrel0 test_cd_mongrel::do set test_cd_foo::x] \
         [test_cd_mongrel0 test_cd_mongrel::do set test_cd_bar::x]
} {foo-x foo-x bar-x foo-x bar-x}

eval namespace delete [find classes test_cd_*]

# ----------------------------------------------------------------------
#  Test public variables and "configure" method
# ----------------------------------------------------------------------
test inherit-3.1 {define classes with public variables} {
    variable ::test_cd_watch ""
    itcl::class test_cd_foo {
        public variable x "foo-x" {
            global test_cd_watch
            lappend test_cd_watch "foo: $x in scope [namespace current]"
        }
        method do {args} {eval $args}
    }
    itcl::class test_cd_bar {
        public variable x "bar-x" {
            global test_cd_watch
            lappend test_cd_watch "bar: $x in scope [namespace current]"
        }
        method do {args} {eval $args}
    }
    itcl::class test_cd_foobar {
        inherit test_cd_foo test_cd_bar
        method do {args} {eval $args}
    }
    itcl::class test_cd_geek {
        method do {args} {eval $args}
    }
    itcl::class test_cd_mongrel {
        inherit test_cd_foobar test_cd_geek
        public variable x "mongrel-x" {
            global test_cd_watch
            lappend test_cd_watch "mongrel: $x in scope [namespace current]"
        }
        method do {args} {eval $args}
    }
} {}

test inherit-3.2 {create an object with public variables} {
    test_cd_mongrel #auto
} {test_cd_mongrel0}

test inherit-3.3 {"configure" lists all public variables} {
    lsort [test_cd_mongrel0 configure]
} {{-test_cd_bar::x bar-x bar-x} {-test_cd_foo::x foo-x foo-x} {-x mongrel-x mongrel-x}}

test inherit-3.4 {"configure" treats simple names as "most specific"} {
    lsort [test_cd_mongrel0 configure -x]
} {-x mongrel-x mongrel-x}

test inherit-3.5 {"configure" treats simple names as "most specific"} {
    set ::test_cd_watch ""
    list [test_cd_mongrel0 configure -x hello] \
         [set ::test_cd_watch]
} {{} {{mongrel: hello in scope ::test_cd_mongrel}}}

test inherit-3.6 {"configure" allows access to shadowed options} {
    set ::test_cd_watch ""
    list [test_cd_mongrel0 configure -test_cd_foo::x hello] \
         [test_cd_mongrel0 configure -test_cd_bar::x there] \
         [set ::test_cd_watch]
} {{} {} {{foo: hello in scope ::test_cd_foo} {bar: there in scope ::test_cd_bar}}}

test inherit-3.7 {"configure" will change several variables at once} {
    set ::test_cd_watch ""
    list [test_cd_mongrel0 configure -x one \
                                     -test_cd_foo::x two \
                                     -test_cd_bar::x three] \
         [set ::test_cd_watch]
} {{} {{mongrel: one in scope ::test_cd_mongrel} {foo: two in scope ::test_cd_foo} {bar: three in scope ::test_cd_bar}}}

test inherit-3.8 {"cget" does proper name resolution} {
    list [test_cd_mongrel0 cget -x] \
         [test_cd_mongrel0 cget -test_cd_foo::x] \
         [test_cd_mongrel0 cget -test_cd_bar::x] \
         [test_cd_mongrel0 cget -test_cd_mongrel::x]
} {one two three one}

eval namespace delete [find classes test_cd_*]

# ----------------------------------------------------------------------
#  Test inheritance info
# ----------------------------------------------------------------------
test inherit-4.1 {define classes for inheritance info} {
    itcl::class test_cd_foo {
        method do {args} {eval $args}
    }
    itcl::class test_cd_bar {
        method do {args} {eval $args}
    }
    itcl::class test_cd_foobar {
        inherit test_cd_foo test_cd_bar
        method do {args} {eval $args}
    }
    itcl::class test_cd_geek {
        method do {args} {eval $args}
    }
    itcl::class test_cd_mongrel {
        inherit test_cd_foobar test_cd_geek
        method do {args} {eval $args}
    }
} {}

test inherit-4.2 {create an object for inheritance tests} {
    test_cd_mongrel #auto
} {test_cd_mongrel0}

test inherit-4.3 {"info class" should be virtual} {
    list [test_cd_mongrel0 info class] \
         [test_cd_mongrel0 test_cd_foo::do info class] \
         [test_cd_mongrel0 test_cd_geek::do info class]
} {::test_cd_mongrel ::test_cd_mongrel ::test_cd_mongrel}

test inherit-4.4 {"info inherit" depends on class scope} {
    list [test_cd_mongrel0 info inherit] \
         [test_cd_mongrel0 test_cd_foo::do info inherit] \
         [test_cd_mongrel0 test_cd_foobar::do info inherit]
} {{::test_cd_foobar ::test_cd_geek} {} {::test_cd_foo ::test_cd_bar}}

test inherit-4.5 {"info heritage" depends on class scope} {
    list [test_cd_mongrel0 info heritage] \
         [test_cd_mongrel0 test_cd_foo::do info heritage] \
         [test_cd_mongrel0 test_cd_foobar::do info heritage]
} {{::test_cd_mongrel ::test_cd_foobar ::test_cd_foo ::test_cd_bar ::test_cd_geek} ::test_cd_foo {::test_cd_foobar ::test_cd_foo ::test_cd_bar}}

test inherit-4.6 {built-in "isa" method works} {
    set status ""
    foreach c [test_cd_mongrel0 info heritage] {
        lappend status [test_cd_mongrel0 isa $c]
    }
    set status
} {1 1 1 1 1}

test inherit-4.7 {built-in "isa" method works within methods} {
    set status ""
    foreach c [test_cd_mongrel0 info heritage] {
        lappend status [test_cd_mongrel0 test_cd_foo::do isa $c]
    }
    set status
} {1 1 1 1 1}

test inherit-4.8 {built-in "isa" method recognizes bad classes} {
    class test_cd_other {}
    test_cd_mongrel0 isa test_cd_other
} {0}

test inherit-4.9 {built-in "isa" method recognizes bad classes} {
    list [catch {test_cd_mongrel0 isa test_cd_bogus} msg] $msg
} {1 {class "test_cd_bogus" not found in context "::test_cd_foo"}}

eval namespace delete [find classes test_cd_*]

# ----------------------------------------------------------------------
#  Test "find objects"
# ----------------------------------------------------------------------
test inherit-5.1 {define classes for inheritance info} {
    itcl::class test_cd_foo {
    }
    itcl::class test_cd_bar {
    }
    itcl::class test_cd_foobar {
        inherit test_cd_foo test_cd_bar
    }
    itcl::class test_cd_geek {
    }
    itcl::class test_cd_mongrel {
        inherit test_cd_foobar test_cd_geek
    }
} {}

test inherit-5.2 {create objects for info tests} {
    list [test_cd_foo #auto] [test_cd_foo #auto] \
         [test_cd_foobar #auto] \
         [test_cd_geek #auto] \
         [test_cd_mongrel #auto]
} {test_cd_foo0 test_cd_foo1 test_cd_foobar0 test_cd_geek0 test_cd_mongrel0}

test inherit-5.3 {find objects: -class qualifier} {
    lsort [find objects -class test_cd_foo]
} {test_cd_foo0 test_cd_foo1}

test inherit-5.4 {find objects: -class qualifier} {
    lsort [find objects -class test_cd_mongrel]
} {test_cd_mongrel0}

test inherit-5.5 {find objects: -isa qualifier} {
    lsort [find objects -isa test_cd_foo]
} {test_cd_foo0 test_cd_foo1 test_cd_foobar0 test_cd_mongrel0}

test inherit-5.6 {find objects: -isa qualifier} {
    lsort [find objects -isa test_cd_mongrel]
} {test_cd_mongrel0}

test inherit-5.7 {find objects: name qualifier} {
    lsort [find objects test_cd_foo*]
} {test_cd_foo0 test_cd_foo1 test_cd_foobar0}

test inherit-5.8 {find objects: -class and -isa qualifiers} {
    lsort [find objects -isa test_cd_foo -class test_cd_foobar]
} {test_cd_foobar0}

test inherit-5.9 {find objects: -isa and name qualifiers} {
    lsort [find objects -isa test_cd_foo *0]
} {test_cd_foo0 test_cd_foobar0 test_cd_mongrel0}

test inherit-5.10 {find objects: usage errors} {
    list [catch {find objects -xyzzy} msg] $msg
} {1 {wrong # args: should be "find objects ?-class className? ?-isa className? ?pattern?"}}

eval namespace delete [find classes test_cd_*]

# ----------------------------------------------------------------------
#  Test method scoping and execution
# ----------------------------------------------------------------------
test inherit-6.1 {define classes for scope tests} {
    itcl::class test_cd_foo {
        method check {} {return "foo"}
        method do {args} {return "foo says: [eval $args]"}
    }
    itcl::class test_cd_bar {
        method check {} {return "bar"}
        method do {args} {return "bar says: [eval $args]"}
    }
    itcl::class test_cd_foobar {
        inherit test_cd_foo test_cd_bar
        method check {} {return "foobar"}
        method do {args} {return "foobar says: [eval $args]"}
    }
    itcl::class test_cd_geek {
        method check {} {return "geek"}
        method do {args} {return "geek says: [eval $args]"}
    }
    itcl::class test_cd_mongrel {
        inherit test_cd_foobar test_cd_geek
        method check {} {return "mongrel"}
        method do {args} {return "mongrel says: [eval $args]"}
    }
} {}

test inherit-6.2 {create objects for scoping tests} {
    list [test_cd_mongrel #auto] [test_cd_foobar #auto]
} {test_cd_mongrel0 test_cd_foobar0}

test inherit-6.3 {methods are "virtual" outside of the class} {
    test_cd_mongrel0 check
} {mongrel}

test inherit-6.4 {specific methods can be accessed by name} {
    test_cd_mongrel0 test_cd_foo::check
} {foo}

test inherit-6.5 {methods are "virtual" within a class too} {
    test_cd_mongrel0 test_cd_foobar::do check
} {foobar says: mongrel}

test inherit-6.6 {methods are executed where they were defined} {
    list [test_cd_mongrel0 test_cd_foo::do namespace current] \
         [test_cd_mongrel0 test_cd_foobar::do namespace current] \
         [test_cd_mongrel0 do namespace current] \
} {{foo says: ::test_cd_foo} {foobar says: ::test_cd_foobar} {mongrel says: ::test_cd_mongrel}}

test inherit-6.7 {"virtual" command no longer exists} {
    list [catch {
        test_cd_mongrel0 test_cd_foobar::do virtual namespace current
    } msg] $msg
} {1 {invalid command name "virtual"}}

test inherit-6.8 {"previous" command no longer exists} {
    list [catch {
        test_cd_mongrel0 test_cd_foobar::do previous check
    } msg] $msg
} {1 {invalid command name "previous"}}

test inherit-6.9 {errors are detected and reported across class boundaries} {
    list [catch {
        test_cd_mongrel0 do test_cd_foobar0 do error "test" "some error"
    } msg] $msg [set ::errorInfo]
} {1 test {some error
    ("eval" body line 1)
    invoked from within
"eval $args"
    (object "::test_cd_foobar0" method "::test_cd_foobar::do" body line 1)
    invoked from within
"test_cd_foobar0 do error test {some error}"
    ("eval" body line 1)
    invoked from within
"eval $args"
    (object "::test_cd_mongrel0" method "::test_cd_mongrel::do" body line 1)
    invoked from within
"test_cd_mongrel0 do test_cd_foobar0 do error "test" "some error""}}

test inherit-6.10 {errors codes are preserved across class boundaries} {
    list [catch {
        test_cd_mongrel0 do test_cd_foobar0 do error "test" "problem" CODE-BLUE
    } msg] $msg [set ::errorCode]
} {1 test CODE-BLUE}

test inherit-6.11 {multi-value error codes are preserved across class boundaries} {
    list [catch {
        test_cd_mongrel0 do test_cd_foobar0 do error "test" "problem" "CODE BLUE 123"
    } msg] $msg [set ::errorCode]
} {1 test {CODE BLUE 123}}

eval namespace delete [find classes test_cd_*]

# ----------------------------------------------------------------------
#  Test inheritance errors
# ----------------------------------------------------------------------
test inherit-7.1 {cannot inherit from non-existant class} {
    list [catch {
        itcl::class bogus {
            inherit non_existant_class_xyzzy
        }
    } msg] $msg
} {1 {cannot inherit from "non_existant_class_xyzzy" (class "non_existant_class_xyzzy" not found in context "::")}}

test inherit-7.2 {cannot inherit from procs} {
    proc inherit_test_proc {x y} {
        error "never call this"
    }
    list [catch {
        itcl::class bogus {
            inherit inherit_test_proc
        }
    } msg] $msg
} {1 {cannot inherit from "inherit_test_proc" (class "inherit_test_proc" not found in context "::")}}

test inherit-7.3 {cannot inherit from yourself} {
    list [catch {
        itcl::class bogus {
            inherit bogus
        }
    } msg] $msg
} {1 {class "bogus" cannot inherit from itself}}

test inherit-7.4 {cannot have more than one inherit statement} {
    list [catch {
        itcl::class test_inherit_base1 { }
        itcl::class test_inherit_base2 { }
        itcl::class bogus {
            inherit test_inherit_base1
            inherit test_inherit_base2
        }
    } msg] $msg
} {1 {inheritance "test_inherit_base1 " already defined for class "::bogus"}}

# ----------------------------------------------------------------------
#  Multiple base class error detection
# ----------------------------------------------------------------------
test inherit-8.1 {cannot inherit from the same base class more than once} {
    class test_mi_base {}
    class test_mi_foo {inherit test_mi_base}
    class test_mi_bar {inherit test_mi_base}
    list [catch {
        class test_mi_foobar {inherit test_mi_foo test_mi_bar}
    } msg] $msg
} {1 {class "::test_mi_foobar" inherits base class "::test_mi_base" more than once:
  test_mi_foobar->test_mi_foo->test_mi_base
  test_mi_foobar->test_mi_bar->test_mi_base}}

delete class test_mi_base