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| 1 // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file | |
| 2 // for details. All rights reserved. Use of this source code is governed by a | |
| 3 // BSD-style license that can be found in the LICENSE file. | |
| 4 | |
| 5 library matcher.core_matchers; | |
| 6 | |
| 7 import 'description.dart'; | |
| 8 import 'interfaces.dart'; | |
| 9 import 'util.dart'; | |
| 10 | |
| 11 /// Returns a matcher that matches empty strings, maps or iterables | |
| 12 /// (including collections) using the isEmpty property. | |
| 13 const Matcher isEmpty = const _Empty(); | |
| 14 | |
| 15 class _Empty extends Matcher { | |
| 16 const _Empty(); | |
| 17 bool matches(item, Map matchState) { | |
| 18 return (item is Map || item is Iterable || item is String) && item.isEmpty; | |
| 19 } | |
| 20 Description describe(Description description) => description.add('empty'); | |
| 21 } | |
| 22 | |
| 23 /// Returns a matcher that matches non-empty strings, maps or iterables | |
| 24 /// (including collections) using the isNotEmpty property. | |
| 25 const Matcher isNotEmpty = const _NotEmpty(); | |
| 26 | |
| 27 class _NotEmpty extends Matcher { | |
| 28 const _NotEmpty(); | |
| 29 | |
| 30 bool matches(item, Map matchState) { | |
| 31 return (item is Map || item is Iterable || item is String) && | |
| 32 item.isNotEmpty; | |
| 33 } | |
| 34 | |
| 35 Description describe(Description description) => description.add('non-empty'); | |
| 36 } | |
| 37 | |
| 38 /// A matcher that matches any null value. | |
| 39 const Matcher isNull = const _IsNull(); | |
| 40 | |
| 41 /// A matcher that matches any non-null value. | |
| 42 const Matcher isNotNull = const _IsNotNull(); | |
| 43 | |
| 44 class _IsNull extends Matcher { | |
| 45 const _IsNull(); | |
| 46 bool matches(item, Map matchState) => item == null; | |
| 47 Description describe(Description description) => description.add('null'); | |
| 48 } | |
| 49 | |
| 50 class _IsNotNull extends Matcher { | |
| 51 const _IsNotNull(); | |
| 52 bool matches(item, Map matchState) => item != null; | |
| 53 Description describe(Description description) => description.add('not null'); | |
| 54 } | |
| 55 | |
| 56 /// A matcher that matches the Boolean value true. | |
| 57 const Matcher isTrue = const _IsTrue(); | |
| 58 | |
| 59 /// A matcher that matches anything except the Boolean value true. | |
| 60 const Matcher isFalse = const _IsFalse(); | |
| 61 | |
| 62 class _IsTrue extends Matcher { | |
| 63 const _IsTrue(); | |
| 64 bool matches(item, Map matchState) => item == true; | |
| 65 Description describe(Description description) => description.add('true'); | |
| 66 } | |
| 67 | |
| 68 class _IsFalse extends Matcher { | |
| 69 const _IsFalse(); | |
| 70 bool matches(item, Map matchState) => item == false; | |
| 71 Description describe(Description description) => description.add('false'); | |
| 72 } | |
| 73 | |
| 74 /// A matcher that matches the numeric value NaN. | |
| 75 const Matcher isNaN = const _IsNaN(); | |
| 76 | |
| 77 /// A matcher that matches any non-NaN value. | |
| 78 const Matcher isNotNaN = const _IsNotNaN(); | |
| 79 | |
| 80 class _IsNaN extends Matcher { | |
| 81 const _IsNaN(); | |
| 82 bool matches(item, Map matchState) => double.NAN.compareTo(item) == 0; | |
| 83 Description describe(Description description) => description.add('NaN'); | |
| 84 } | |
| 85 | |
| 86 class _IsNotNaN extends Matcher { | |
| 87 const _IsNotNaN(); | |
| 88 bool matches(item, Map matchState) => double.NAN.compareTo(item) != 0; | |
| 89 Description describe(Description description) => description.add('not NaN'); | |
| 90 } | |
| 91 | |
| 92 /// Returns a matches that matches if the value is the same instance | |
| 93 /// as [expected], using [identical]. | |
| 94 Matcher same(expected) => new _IsSameAs(expected); | |
| 95 | |
| 96 class _IsSameAs extends Matcher { | |
| 97 final _expected; | |
| 98 const _IsSameAs(this._expected); | |
| 99 bool matches(item, Map matchState) => identical(item, _expected); | |
| 100 // If all types were hashable we could show a hash here. | |
| 101 Description describe(Description description) => | |
| 102 description.add('same instance as ').addDescriptionOf(_expected); | |
| 103 } | |
| 104 | |
| 105 /// Returns a matcher that matches if the value is structurally equal to | |
| 106 /// [expected]. | |
| 107 /// | |
| 108 /// If [expected] is a [Matcher], then it matches using that. Otherwise it tests | |
| 109 /// for equality using `==` on the expected value. | |
| 110 /// | |
| 111 /// For [Iterable]s and [Map]s, this will recursively match the elements. To | |
| 112 /// handle cyclic structures a recursion depth [limit] can be provided. The | |
| 113 /// default limit is 100. [Set]s will be compared order-independently. | |
| 114 Matcher equals(expected, [int limit=100]) => | |
| 115 expected is String | |
| 116 ? new _StringEqualsMatcher(expected) | |
| 117 : new _DeepMatcher(expected, limit); | |
| 118 | |
| 119 class _DeepMatcher extends Matcher { | |
| 120 final _expected; | |
| 121 final int _limit; | |
| 122 var count; | |
| 123 | |
| 124 _DeepMatcher(this._expected, [int limit = 1000]) : this._limit = limit; | |
| 125 | |
| 126 // Returns a pair (reason, location) | |
| 127 List _compareIterables(expected, actual, matcher, depth, location) { | |
| 128 if (actual is! Iterable) return ['is not Iterable', location]; | |
| 129 | |
| 130 var expectedIterator = expected.iterator; | |
| 131 var actualIterator = actual.iterator; | |
| 132 for (var index = 0; ; index++) { | |
| 133 // Advance in lockstep. | |
| 134 var expectedNext = expectedIterator.moveNext(); | |
| 135 var actualNext = actualIterator.moveNext(); | |
| 136 | |
| 137 // If we reached the end of both, we succeeded. | |
| 138 if (!expectedNext && !actualNext) return null; | |
| 139 | |
| 140 // Fail if their lengths are different. | |
| 141 var newLocation = '${location}[${index}]'; | |
| 142 if (!expectedNext) return ['longer than expected', newLocation]; | |
| 143 if (!actualNext) return ['shorter than expected', newLocation]; | |
| 144 | |
| 145 // Match the elements. | |
| 146 var rp = matcher(expectedIterator.current, actualIterator.current, | |
| 147 newLocation, depth); | |
| 148 if (rp != null) return rp; | |
| 149 } | |
| 150 } | |
| 151 | |
| 152 List _compareSets(Set expected, actual, matcher, depth, location) { | |
| 153 if (actual is! Iterable) return ['is not Iterable', location]; | |
| 154 actual = actual.toSet(); | |
| 155 | |
| 156 for (var expectedElement in expected) { | |
| 157 if (actual.every((actualElement) => | |
| 158 matcher(expectedElement, actualElement, location, depth) != null)) { | |
| 159 return ['does not contain $expectedElement', location]; | |
| 160 } | |
| 161 } | |
| 162 | |
| 163 if (actual.length > expected.length) { | |
| 164 return ['larger than expected', location]; | |
| 165 } else if (actual.length < expected.length) { | |
| 166 return ['smaller than expected', location]; | |
| 167 } else { | |
| 168 return null; | |
| 169 } | |
| 170 } | |
| 171 | |
| 172 List _recursiveMatch(expected, actual, String location, int depth) { | |
| 173 // If the expected value is a matcher, try to match it. | |
| 174 if (expected is Matcher) { | |
| 175 var matchState = {}; | |
| 176 if (expected.matches(actual, matchState)) return null; | |
| 177 | |
| 178 var description = new StringDescription(); | |
| 179 expected.describe(description); | |
| 180 return ['does not match $description', location]; | |
| 181 } else { | |
| 182 // Otherwise, test for equality. | |
| 183 try { | |
| 184 if (expected == actual) return null; | |
| 185 } catch (e, s) { | |
| 186 // TODO(gram): Add a test for this case. | |
| 187 return ['== threw "$e"', location]; | |
| 188 } | |
| 189 } | |
| 190 | |
| 191 if (depth > _limit) return ['recursion depth limit exceeded', location]; | |
| 192 | |
| 193 // If _limit is 1 we can only recurse one level into object. | |
| 194 if (depth == 0 || _limit > 1) { | |
| 195 if (expected is Set) { | |
| 196 return _compareSets(expected, actual, _recursiveMatch, depth + 1, | |
| 197 location); | |
| 198 } else if (expected is Iterable) { | |
| 199 return _compareIterables(expected, actual, _recursiveMatch, depth + 1, | |
| 200 location); | |
| 201 } else if (expected is Map) { | |
| 202 if (actual is! Map) return ['expected a map', location]; | |
| 203 | |
| 204 var err = (expected.length == actual.length) ? '' : | |
| 205 'has different length and '; | |
| 206 for (var key in expected.keys) { | |
| 207 if (!actual.containsKey(key)) { | |
| 208 return ["${err}is missing map key '$key'", location]; | |
| 209 } | |
| 210 } | |
| 211 | |
| 212 for (var key in actual.keys) { | |
| 213 if (!expected.containsKey(key)) { | |
| 214 return ["${err}has extra map key '$key'", location]; | |
| 215 } | |
| 216 } | |
| 217 | |
| 218 for (var key in expected.keys) { | |
| 219 var rp = _recursiveMatch(expected[key], actual[key], | |
| 220 "${location}['${key}']", depth + 1); | |
| 221 if (rp != null) return rp; | |
| 222 } | |
| 223 | |
| 224 return null; | |
| 225 } | |
| 226 } | |
| 227 | |
| 228 var description = new StringDescription(); | |
| 229 | |
| 230 // If we have recursed, show the expected value too; if not, expect() will | |
| 231 // show it for us. | |
| 232 if (depth > 0) { | |
| 233 description.add('was '). | |
| 234 addDescriptionOf(actual). | |
| 235 add(' instead of '). | |
| 236 addDescriptionOf(expected); | |
| 237 return [description.toString(), location]; | |
| 238 } | |
| 239 | |
| 240 // We're not adding any value to the actual value. | |
| 241 return ["", location]; | |
| 242 } | |
| 243 | |
| 244 String _match(expected, actual, Map matchState) { | |
| 245 var rp = _recursiveMatch(expected, actual, '', 0); | |
| 246 if (rp == null) return null; | |
| 247 var reason; | |
| 248 if (rp[0].length > 0) { | |
| 249 if (rp[1].length > 0) { | |
| 250 reason = "${rp[0]} at location ${rp[1]}"; | |
| 251 } else { | |
| 252 reason = rp[0]; | |
| 253 } | |
| 254 } else { | |
| 255 reason = ''; | |
| 256 } | |
| 257 // Cache the failure reason in the matchState. | |
| 258 addStateInfo(matchState, {'reason': reason}); | |
| 259 return reason; | |
| 260 } | |
| 261 | |
| 262 bool matches(item, Map matchState) => | |
| 263 _match(_expected, item, matchState) == null; | |
| 264 | |
| 265 Description describe(Description description) => | |
| 266 description.addDescriptionOf(_expected); | |
| 267 | |
| 268 Description describeMismatch(item, Description mismatchDescription, | |
| 269 Map matchState, bool verbose) { | |
| 270 var reason = matchState['reason']; | |
| 271 // If we didn't get a good reason, that would normally be a | |
| 272 // simple 'is <value>' message. We only add that if the mismatch | |
| 273 // description is non empty (so we are supplementing the mismatch | |
| 274 // description). | |
| 275 if (reason.length == 0 && mismatchDescription.length > 0) { | |
| 276 mismatchDescription.add('is ').addDescriptionOf(item); | |
| 277 } else { | |
| 278 mismatchDescription.add(reason); | |
| 279 } | |
| 280 return mismatchDescription; | |
| 281 } | |
| 282 } | |
| 283 | |
| 284 /// A special equality matcher for strings. | |
| 285 class _StringEqualsMatcher extends Matcher { | |
| 286 final String _value; | |
| 287 | |
| 288 _StringEqualsMatcher(this._value); | |
| 289 | |
| 290 bool get showActualValue => true; | |
| 291 | |
| 292 bool matches(item, Map matchState) => _value == item; | |
| 293 | |
| 294 Description describe(Description description) => | |
| 295 description.addDescriptionOf(_value); | |
| 296 | |
| 297 Description describeMismatch(item, Description mismatchDescription, | |
| 298 Map matchState, bool verbose) { | |
| 299 if (item is! String) { | |
| 300 return mismatchDescription.addDescriptionOf(item).add('is not a string'); | |
| 301 } else { | |
| 302 var buff = new StringBuffer(); | |
| 303 buff.write('is different.'); | |
| 304 var escapedItem = _escape(item); | |
| 305 var escapedValue = _escape(_value); | |
| 306 int minLength = escapedItem.length < escapedValue.length ? | |
| 307 escapedItem.length : escapedValue.length; | |
| 308 int start; | |
| 309 for (start = 0; start < minLength; start++) { | |
| 310 if (escapedValue.codeUnitAt(start) != escapedItem.codeUnitAt(start)) { | |
| 311 break; | |
| 312 } | |
| 313 } | |
| 314 if (start == minLength) { | |
| 315 if (escapedValue.length < escapedItem.length) { | |
| 316 buff.write(' Both strings start the same, but the given value also' | |
| 317 ' has the following trailing characters: '); | |
| 318 _writeTrailing(buff, escapedItem, escapedValue.length); | |
| 319 } else { | |
| 320 buff.write(' Both strings start the same, but the given value is' | |
| 321 ' missing the following trailing characters: '); | |
| 322 _writeTrailing(buff, escapedValue, escapedItem.length); | |
| 323 } | |
| 324 } else { | |
| 325 buff.write('\nExpected: '); | |
| 326 _writeLeading(buff, escapedValue, start); | |
| 327 _writeTrailing(buff, escapedValue, start); | |
| 328 buff.write('\n Actual: '); | |
| 329 _writeLeading(buff, escapedItem, start); | |
| 330 _writeTrailing(buff, escapedItem, start); | |
| 331 buff.write('\n '); | |
| 332 for (int i = (start > 10 ? 14 : start); i > 0; i--) buff.write(' '); | |
| 333 buff.write('^\n Differ at offset $start'); | |
| 334 } | |
| 335 | |
| 336 return mismatchDescription.replace(buff.toString()); | |
| 337 } | |
| 338 } | |
| 339 | |
| 340 static String _escape(String s) => | |
| 341 s.replaceAll('\n', '\\n').replaceAll('\r', '\\r').replaceAll('\t', '\\t'); | |
| 342 | |
| 343 static void _writeLeading(StringBuffer buff, String s, int start) { | |
| 344 if (start > 10) { | |
| 345 buff.write('... '); | |
| 346 buff.write(s.substring(start - 10, start)); | |
| 347 } else { | |
| 348 buff.write(s.substring(0, start)); | |
| 349 } | |
| 350 } | |
| 351 | |
| 352 static void _writeTrailing(StringBuffer buff, String s, int start) { | |
| 353 if (start + 10 > s.length) { | |
| 354 buff.write(s.substring(start)); | |
| 355 } else { | |
| 356 buff.write(s.substring(start, start + 10)); | |
| 357 buff.write(' ...'); | |
| 358 } | |
| 359 } | |
| 360 } | |
| 361 | |
| 362 /// A matcher that matches any value. | |
| 363 const Matcher anything = const _IsAnything(); | |
| 364 | |
| 365 class _IsAnything extends Matcher { | |
| 366 const _IsAnything(); | |
| 367 bool matches(item, Map matchState) => true; | |
| 368 Description describe(Description description) => description.add('anything'); | |
| 369 } | |
| 370 | |
| 371 /// Returns a matcher that matches if an object is an instance | |
| 372 /// of [type] (or a subtype). | |
| 373 /// | |
| 374 /// As types are not first class objects in Dart we can only | |
| 375 /// approximate this test by using a generic wrapper class. | |
| 376 /// | |
| 377 /// For example, to test whether 'bar' is an instance of type | |
| 378 /// 'Foo', we would write: | |
| 379 /// | |
| 380 /// expect(bar, new isInstanceOf<Foo>()); | |
| 381 /// | |
| 382 /// To get better error message, supply a name when creating the | |
| 383 /// Type wrapper; e.g.: | |
| 384 /// | |
| 385 /// expect(bar, new isInstanceOf<Foo>('Foo')); | |
| 386 /// | |
| 387 /// Note that this does not currently work in dart2js; it will | |
| 388 /// match any type, and isNot(new isInstanceof<T>()) will always | |
| 389 /// fail. This is because dart2js currently ignores template type | |
| 390 /// parameters. | |
| 391 class isInstanceOf<T> extends Matcher { | |
| 392 final String _name; | |
| 393 const isInstanceOf([name = 'specified type']) : this._name = name; | |
| 394 bool matches(obj, Map matchState) => obj is T; | |
| 395 // The description here is lame :-( | |
| 396 Description describe(Description description) => | |
| 397 description.add('an instance of ${_name}'); | |
| 398 } | |
| 399 | |
| 400 /// A matcher that matches a function call against no exception. | |
| 401 /// | |
| 402 /// The function will be called once. Any exceptions will be silently swallowed. | |
| 403 /// The value passed to expect() should be a reference to the function. | |
| 404 /// Note that the function cannot take arguments; to handle this | |
| 405 /// a wrapper will have to be created. | |
| 406 const Matcher returnsNormally = const _ReturnsNormally(); | |
| 407 | |
| 408 class _ReturnsNormally extends Matcher { | |
| 409 const _ReturnsNormally(); | |
| 410 | |
| 411 bool matches(f, Map matchState) { | |
| 412 try { | |
| 413 f(); | |
| 414 return true; | |
| 415 } catch (e, s) { | |
| 416 addStateInfo(matchState, {'exception': e, 'stack': s}); | |
| 417 return false; | |
| 418 } | |
| 419 } | |
| 420 | |
| 421 Description describe(Description description) => | |
| 422 description.add("return normally"); | |
| 423 | |
| 424 Description describeMismatch(item, Description mismatchDescription, | |
| 425 Map matchState, | |
| 426 bool verbose) { | |
| 427 mismatchDescription.add('threw ').addDescriptionOf(matchState['exception']); | |
| 428 if (verbose) { | |
| 429 mismatchDescription.add(' at ').add(matchState['stack'].toString()); | |
| 430 } | |
| 431 return mismatchDescription; | |
| 432 } | |
| 433 } | |
| 434 | |
| 435 /* | |
| 436 * Matchers for different exception types. Ideally we should just be able to | |
| 437 * use something like: | |
| 438 * | |
| 439 * final Matcher throwsException = | |
| 440 * const _Throws(const isInstanceOf<Exception>()); | |
| 441 * | |
| 442 * Unfortunately instanceOf is not working with dart2js. | |
| 443 * | |
| 444 * Alternatively, if static functions could be used in const expressions, | |
| 445 * we could use: | |
| 446 * | |
| 447 * bool _isException(x) => x is Exception; | |
| 448 * final Matcher isException = const _Predicate(_isException, "Exception"); | |
| 449 * final Matcher throwsException = const _Throws(isException); | |
| 450 * | |
| 451 * But currently using static functions in const expressions is not supported. | |
| 452 * For now the only solution for all platforms seems to be separate classes | |
| 453 * for each exception type. | |
| 454 */ | |
| 455 | |
| 456 abstract class TypeMatcher extends Matcher { | |
| 457 final String _name; | |
| 458 const TypeMatcher(this._name); | |
| 459 Description describe(Description description) => description.add(_name); | |
| 460 } | |
| 461 | |
| 462 /// A matcher for Map types. | |
| 463 const Matcher isMap = const _IsMap(); | |
| 464 | |
| 465 class _IsMap extends TypeMatcher { | |
| 466 const _IsMap() : super("Map"); | |
| 467 bool matches(item, Map matchState) => item is Map; | |
| 468 } | |
| 469 | |
| 470 /// A matcher for List types. | |
| 471 const Matcher isList = const _IsList(); | |
| 472 | |
| 473 class _IsList extends TypeMatcher { | |
| 474 const _IsList() : super("List"); | |
| 475 bool matches(item, Map matchState) => item is List; | |
| 476 } | |
| 477 | |
| 478 /// Returns a matcher that matches if an object has a length property | |
| 479 /// that matches [matcher]. | |
| 480 Matcher hasLength(matcher) => new _HasLength(wrapMatcher(matcher)); | |
| 481 | |
| 482 class _HasLength extends Matcher { | |
| 483 final Matcher _matcher; | |
| 484 const _HasLength([Matcher matcher = null]) : this._matcher = matcher; | |
| 485 | |
| 486 bool matches(item, Map matchState) { | |
| 487 try { | |
| 488 // This is harmless code that will throw if no length property | |
| 489 // but subtle enough that an optimizer shouldn't strip it out. | |
| 490 if (item.length * item.length >= 0) { | |
| 491 return _matcher.matches(item.length, matchState); | |
| 492 } | |
| 493 } catch (e) {} | |
| 494 return false; | |
| 495 } | |
| 496 | |
| 497 Description describe(Description description) => | |
| 498 description.add('an object with length of '). | |
| 499 addDescriptionOf(_matcher); | |
| 500 | |
| 501 Description describeMismatch(item, Description mismatchDescription, | |
| 502 Map matchState, bool verbose) { | |
| 503 try { | |
| 504 // We want to generate a different description if there is no length | |
| 505 // property; we use the same trick as in matches(). | |
| 506 if (item.length * item.length >= 0) { | |
| 507 return mismatchDescription.add('has length of '). | |
| 508 addDescriptionOf(item.length); | |
| 509 } | |
| 510 } catch (e) {} | |
| 511 return mismatchDescription.add('has no length property'); | |
| 512 } | |
| 513 } | |
| 514 | |
| 515 /// Returns a matcher that matches if the match argument contains the expected | |
| 516 /// value. | |
| 517 /// | |
| 518 /// For [String]s this means substring matching; | |
| 519 /// for [Map]s it means the map has the key, and for [Iterable]s | |
| 520 /// it means the iterable has a matching element. In the case of iterables, | |
| 521 /// [expected] can itself be a matcher. | |
| 522 Matcher contains(expected) => new _Contains(expected); | |
| 523 | |
| 524 class _Contains extends Matcher { | |
| 525 final _expected; | |
| 526 | |
| 527 const _Contains(this._expected); | |
| 528 | |
| 529 bool matches(item, Map matchState) { | |
| 530 if (item is String) { | |
| 531 return item.indexOf(_expected) >= 0; | |
| 532 } else if (item is Iterable) { | |
| 533 if (_expected is Matcher) { | |
| 534 return item.any((e) => _expected.matches(e, matchState)); | |
| 535 } else { | |
| 536 return item.contains(_expected); | |
| 537 } | |
| 538 } else if (item is Map) { | |
| 539 return item.containsKey(_expected); | |
| 540 } | |
| 541 return false; | |
| 542 } | |
| 543 | |
| 544 Description describe(Description description) => | |
| 545 description.add('contains ').addDescriptionOf(_expected); | |
| 546 | |
| 547 Description describeMismatch(item, Description mismatchDescription, | |
| 548 Map matchState, bool verbose) { | |
| 549 if (item is String || item is Iterable || item is Map) { | |
| 550 return super.describeMismatch(item, mismatchDescription, matchState, | |
| 551 verbose); | |
| 552 } else { | |
| 553 return mismatchDescription.add('is not a string, map or iterable'); | |
| 554 } | |
| 555 } | |
| 556 } | |
| 557 | |
| 558 /// Returns a matcher that matches if the match argument is in | |
| 559 /// the expected value. This is the converse of [contains]. | |
| 560 Matcher isIn(expected) => new _In(expected); | |
| 561 | |
| 562 class _In extends Matcher { | |
| 563 final _expected; | |
| 564 | |
| 565 const _In(this._expected); | |
| 566 | |
| 567 bool matches(item, Map matchState) { | |
| 568 if (_expected is String) { | |
| 569 return _expected.indexOf(item) >= 0; | |
| 570 } else if (_expected is Iterable) { | |
| 571 return _expected.any((e) => e == item); | |
| 572 } else if (_expected is Map) { | |
| 573 return _expected.containsKey(item); | |
| 574 } | |
| 575 return false; | |
| 576 } | |
| 577 | |
| 578 Description describe(Description description) => | |
| 579 description.add('is in ').addDescriptionOf(_expected); | |
| 580 } | |
| 581 | |
| 582 /// Returns a matcher that uses an arbitrary function that returns | |
| 583 /// true or false for the actual value. | |
| 584 /// | |
| 585 /// For example: | |
| 586 /// | |
| 587 /// expect(v, predicate((x) => ((x % 2) == 0), "is even")) | |
| 588 Matcher predicate(bool f(value), [String description = 'satisfies function']) => | |
| 589 new _Predicate(f, description); | |
| 590 | |
| 591 typedef bool _PredicateFunction(value); | |
| 592 | |
| 593 class _Predicate extends Matcher { | |
| 594 final _PredicateFunction _matcher; | |
| 595 final String _description; | |
| 596 | |
| 597 const _Predicate(this._matcher, this._description); | |
| 598 | |
| 599 bool matches(item, Map matchState) => _matcher(item); | |
| 600 | |
| 601 Description describe(Description description) => | |
| 602 description.add(_description); | |
| 603 } | |
| 604 | |
| 605 /// A useful utility class for implementing other matchers through inheritance. | |
| 606 /// Derived classes should call the base constructor with a feature name and | |
| 607 /// description, and an instance matcher, and should implement the | |
| 608 /// [featureValueOf] abstract method. | |
| 609 /// | |
| 610 /// The feature description will typically describe the item and the feature, | |
| 611 /// while the feature name will just name the feature. For example, we may | |
| 612 /// have a Widget class where each Widget has a price; we could make a | |
| 613 /// [CustomMatcher] that can make assertions about prices with: | |
| 614 /// | |
| 615 /// class HasPrice extends CustomMatcher { | |
| 616 /// const HasPrice(matcher) : | |
| 617 /// super("Widget with price that is", "price", matcher); | |
| 618 /// featureValueOf(actual) => actual.price; | |
| 619 /// } | |
| 620 /// | |
| 621 /// and then use this for example like: | |
| 622 /// | |
| 623 /// expect(inventoryItem, new HasPrice(greaterThan(0))); | |
| 624 class CustomMatcher extends Matcher { | |
| 625 final String _featureDescription; | |
| 626 final String _featureName; | |
| 627 final Matcher _matcher; | |
| 628 | |
| 629 CustomMatcher(this._featureDescription, this._featureName, matcher) | |
| 630 : this._matcher = wrapMatcher(matcher); | |
| 631 | |
| 632 /// Override this to extract the interesting feature. | |
| 633 featureValueOf(actual) => actual; | |
| 634 | |
| 635 bool matches(item, Map matchState) { | |
| 636 var f = featureValueOf(item); | |
| 637 if (_matcher.matches(f, matchState)) return true; | |
| 638 addStateInfo(matchState, {'feature': f}); | |
| 639 return false; | |
| 640 } | |
| 641 | |
| 642 Description describe(Description description) => | |
| 643 description.add(_featureDescription).add(' ').addDescriptionOf(_matcher); | |
| 644 | |
| 645 Description describeMismatch(item, Description mismatchDescription, | |
| 646 Map matchState, bool verbose) { | |
| 647 mismatchDescription.add('has ').add(_featureName).add(' with value '). | |
| 648 addDescriptionOf(matchState['feature']); | |
| 649 var innerDescription = new StringDescription(); | |
| 650 _matcher.describeMismatch(matchState['feature'], innerDescription, | |
| 651 matchState['state'], verbose); | |
| 652 if (innerDescription.length > 0) { | |
| 653 mismatchDescription.add(' which ').add(innerDescription.toString()); | |
| 654 } | |
| 655 return mismatchDescription; | |
| 656 } | |
| 657 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 807193003:
Re-apply "Remove unittest and matcher from the repo." (Closed)
Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart