1 /* 2 * Copyright (C) 2014 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.graph; 18 19 import static com.google.common.graph.GraphConstants.ENDPOINTS_MISMATCH; 20 import static com.google.common.graph.TestUtil.assertEdgeNotInGraphErrorMessage; 21 import static com.google.common.truth.Truth.assertThat; 22 import static com.google.common.truth.TruthJUnit.assume; 23 import static org.junit.Assert.assertThrows; 24 import static org.junit.Assert.assertTrue; 25 import static org.junit.Assert.fail; 26 27 import com.google.common.collect.ImmutableSet; 28 import java.util.Collections; 29 import java.util.Set; 30 import org.junit.After; 31 import org.junit.Test; 32 33 /** 34 * Abstract base class for testing directed {@link Network} implementations defined in this package. 35 */ 36 public abstract class AbstractStandardDirectedNetworkTest extends AbstractNetworkTest { 37 38 @After validateSourceAndTarget()39 public void validateSourceAndTarget() { 40 for (Integer node : network.nodes()) { 41 for (String inEdge : network.inEdges(node)) { 42 EndpointPair<Integer> endpointPair = network.incidentNodes(inEdge); 43 assertThat(endpointPair.source()).isEqualTo(endpointPair.adjacentNode(node)); 44 assertThat(endpointPair.target()).isEqualTo(node); 45 } 46 47 for (String outEdge : network.outEdges(node)) { 48 EndpointPair<Integer> endpointPair = network.incidentNodes(outEdge); 49 assertThat(endpointPair.source()).isEqualTo(node); 50 assertThat(endpointPair.target()).isEqualTo(endpointPair.adjacentNode(node)); 51 } 52 53 for (Integer adjacentNode : network.adjacentNodes(node)) { 54 Set<String> edges = network.edgesConnecting(node, adjacentNode); 55 Set<String> antiParallelEdges = network.edgesConnecting(adjacentNode, node); 56 assertThat(node.equals(adjacentNode) || Collections.disjoint(edges, antiParallelEdges)) 57 .isTrue(); 58 } 59 } 60 } 61 62 @Override 63 @Test nodes_checkReturnedSetMutability()64 public void nodes_checkReturnedSetMutability() { 65 assume().that(graphIsMutable()).isTrue(); 66 67 Set<Integer> nodes = network.nodes(); 68 UnsupportedOperationException e = 69 assertThrows(UnsupportedOperationException.class, () -> nodes.add(N2)); 70 addNode(N1); 71 assertThat(network.nodes()).containsExactlyElementsIn(nodes); 72 } 73 74 @Override 75 @Test edges_checkReturnedSetMutability()76 public void edges_checkReturnedSetMutability() { 77 assume().that(graphIsMutable()).isTrue(); 78 79 Set<String> edges = network.edges(); 80 UnsupportedOperationException e = 81 assertThrows(UnsupportedOperationException.class, () -> edges.add(E12)); 82 addEdge(N1, N2, E12); 83 assertThat(network.edges()).containsExactlyElementsIn(edges); 84 } 85 86 @Override 87 @Test incidentEdges_checkReturnedSetMutability()88 public void incidentEdges_checkReturnedSetMutability() { 89 assume().that(graphIsMutable()).isTrue(); 90 91 addNode(N1); 92 Set<String> incidentEdges = network.incidentEdges(N1); 93 UnsupportedOperationException e = 94 assertThrows(UnsupportedOperationException.class, () -> incidentEdges.add(E12)); 95 addEdge(N1, N2, E12); 96 assertThat(network.incidentEdges(N1)).containsExactlyElementsIn(incidentEdges); 97 } 98 99 @Override 100 @Test adjacentNodes_checkReturnedSetMutability()101 public void adjacentNodes_checkReturnedSetMutability() { 102 assume().that(graphIsMutable()).isTrue(); 103 104 addNode(N1); 105 Set<Integer> adjacentNodes = network.adjacentNodes(N1); 106 UnsupportedOperationException e = 107 assertThrows(UnsupportedOperationException.class, () -> adjacentNodes.add(N2)); 108 addEdge(N1, N2, E12); 109 assertThat(network.adjacentNodes(N1)).containsExactlyElementsIn(adjacentNodes); 110 } 111 112 @Override adjacentEdges_checkReturnedSetMutability()113 public void adjacentEdges_checkReturnedSetMutability() { 114 assume().that(graphIsMutable()).isTrue(); 115 116 addEdge(N1, N2, E12); 117 Set<String> adjacentEdges = network.adjacentEdges(E12); 118 try { 119 adjacentEdges.add(E23); 120 fail(ERROR_MODIFIABLE_COLLECTION); 121 } catch (UnsupportedOperationException e) { 122 addEdge(N2, N3, E23); 123 assertThat(network.adjacentEdges(E12)).containsExactlyElementsIn(adjacentEdges); 124 } 125 } 126 127 @Override 128 @Test edgesConnecting_checkReturnedSetMutability()129 public void edgesConnecting_checkReturnedSetMutability() { 130 assume().that(graphIsMutable()).isTrue(); 131 132 addNode(N1); 133 addNode(N2); 134 Set<String> edgesConnecting = network.edgesConnecting(N1, N2); 135 UnsupportedOperationException e = 136 assertThrows(UnsupportedOperationException.class, () -> edgesConnecting.add(E23)); 137 addEdge(N1, N2, E12); 138 assertThat(network.edgesConnecting(N1, N2)).containsExactlyElementsIn(edgesConnecting); 139 } 140 141 @Override 142 @Test inEdges_checkReturnedSetMutability()143 public void inEdges_checkReturnedSetMutability() { 144 assume().that(graphIsMutable()).isTrue(); 145 146 addNode(N2); 147 Set<String> inEdges = network.inEdges(N2); 148 UnsupportedOperationException e = 149 assertThrows(UnsupportedOperationException.class, () -> inEdges.add(E12)); 150 addEdge(N1, N2, E12); 151 assertThat(network.inEdges(N2)).containsExactlyElementsIn(inEdges); 152 } 153 154 @Override 155 @Test outEdges_checkReturnedSetMutability()156 public void outEdges_checkReturnedSetMutability() { 157 assume().that(graphIsMutable()).isTrue(); 158 159 addNode(N1); 160 Set<String> outEdges = network.outEdges(N1); 161 UnsupportedOperationException e = 162 assertThrows(UnsupportedOperationException.class, () -> outEdges.add(E12)); 163 addEdge(N1, N2, E12); 164 assertThat(network.outEdges(N1)).containsExactlyElementsIn(outEdges); 165 } 166 167 @Override 168 @Test predecessors_checkReturnedSetMutability()169 public void predecessors_checkReturnedSetMutability() { 170 assume().that(graphIsMutable()).isTrue(); 171 172 addNode(N2); 173 Set<Integer> predecessors = network.predecessors(N2); 174 UnsupportedOperationException e = 175 assertThrows(UnsupportedOperationException.class, () -> predecessors.add(N1)); 176 addEdge(N1, N2, E12); 177 assertThat(network.predecessors(N2)).containsExactlyElementsIn(predecessors); 178 } 179 180 @Override 181 @Test successors_checkReturnedSetMutability()182 public void successors_checkReturnedSetMutability() { 183 assume().that(graphIsMutable()).isTrue(); 184 185 addNode(N1); 186 Set<Integer> successors = network.successors(N1); 187 UnsupportedOperationException e = 188 assertThrows(UnsupportedOperationException.class, () -> successors.add(N2)); 189 addEdge(N1, N2, E12); 190 assertThat(successors).containsExactlyElementsIn(network.successors(N1)); 191 } 192 193 @Test edges_containsOrderMismatch()194 public void edges_containsOrderMismatch() { 195 addEdge(N1, N2, E12); 196 EndpointPair<Integer> endpointsN1N2 = EndpointPair.unordered(N1, N2); 197 EndpointPair<Integer> endpointsN2N1 = EndpointPair.unordered(N2, N1); 198 assertThat(network.asGraph().edges()).doesNotContain(endpointsN1N2); 199 assertThat(network.asGraph().edges()).doesNotContain(endpointsN2N1); 200 } 201 202 @Test edgesConnecting_orderMismatch()203 public void edgesConnecting_orderMismatch() { 204 addEdge(N1, N2, E12); 205 IllegalArgumentException e = 206 assertThrows( 207 IllegalArgumentException.class, 208 () -> { 209 Set<String> unused = network.edgesConnecting(EndpointPair.unordered(N1, N2)); 210 }); 211 assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH); 212 } 213 214 @Test edgeConnectingOrNull_orderMismatch()215 public void edgeConnectingOrNull_orderMismatch() { 216 addEdge(N1, N2, E12); 217 IllegalArgumentException e = 218 assertThrows( 219 IllegalArgumentException.class, 220 () -> { 221 String unused = network.edgeConnectingOrNull(EndpointPair.unordered(N1, N2)); 222 }); 223 assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH); 224 } 225 226 @Override 227 @Test incidentNodes_oneEdge()228 public void incidentNodes_oneEdge() { 229 addEdge(N1, N2, E12); 230 assertThat(network.incidentNodes(E12).source()).isEqualTo(N1); 231 assertThat(network.incidentNodes(E12).target()).isEqualTo(N2); 232 } 233 234 @Test edgesConnecting_oneEdge()235 public void edgesConnecting_oneEdge() { 236 addEdge(N1, N2, E12); 237 assertThat(network.edgesConnecting(N1, N2)).containsExactly(E12); 238 // Passed nodes should be in the correct edge direction, first is the 239 // source node and the second is the target node 240 assertThat(network.edgesConnecting(N2, N1)).isEmpty(); 241 } 242 243 @Test inEdges_oneEdge()244 public void inEdges_oneEdge() { 245 addEdge(N1, N2, E12); 246 assertThat(network.inEdges(N2)).containsExactly(E12); 247 // Edge direction handled correctly 248 assertThat(network.inEdges(N1)).isEmpty(); 249 } 250 251 @Test outEdges_oneEdge()252 public void outEdges_oneEdge() { 253 addEdge(N1, N2, E12); 254 assertThat(network.outEdges(N1)).containsExactly(E12); 255 // Edge direction handled correctly 256 assertThat(network.outEdges(N2)).isEmpty(); 257 } 258 259 @Test predecessors_oneEdge()260 public void predecessors_oneEdge() { 261 addEdge(N1, N2, E12); 262 assertThat(network.predecessors(N2)).containsExactly(N1); 263 // Edge direction handled correctly 264 assertThat(network.predecessors(N1)).isEmpty(); 265 } 266 267 @Test successors_oneEdge()268 public void successors_oneEdge() { 269 addEdge(N1, N2, E12); 270 assertThat(network.successors(N1)).containsExactly(N2); 271 // Edge direction handled correctly 272 assertThat(network.successors(N2)).isEmpty(); 273 } 274 275 @Test source_oneEdge()276 public void source_oneEdge() { 277 addEdge(N1, N2, E12); 278 assertThat(network.incidentNodes(E12).source()).isEqualTo(N1); 279 } 280 281 @Test source_edgeNotInGraph()282 public void source_edgeNotInGraph() { 283 IllegalArgumentException e = 284 assertThrows( 285 IllegalArgumentException.class, 286 () -> network.incidentNodes(EDGE_NOT_IN_GRAPH).source()); 287 assertEdgeNotInGraphErrorMessage(e); 288 } 289 290 @Test target_oneEdge()291 public void target_oneEdge() { 292 addEdge(N1, N2, E12); 293 assertThat(network.incidentNodes(E12).target()).isEqualTo(N2); 294 } 295 296 @Test target_edgeNotInGraph()297 public void target_edgeNotInGraph() { 298 IllegalArgumentException e = 299 assertThrows( 300 IllegalArgumentException.class, 301 () -> network.incidentNodes(EDGE_NOT_IN_GRAPH).target()); 302 assertEdgeNotInGraphErrorMessage(e); 303 } 304 305 @Test inDegree_oneEdge()306 public void inDegree_oneEdge() { 307 addEdge(N1, N2, E12); 308 assertThat(network.inDegree(N2)).isEqualTo(1); 309 // Edge direction handled correctly 310 assertThat(network.inDegree(N1)).isEqualTo(0); 311 } 312 313 @Test outDegree_oneEdge()314 public void outDegree_oneEdge() { 315 addEdge(N1, N2, E12); 316 assertThat(network.outDegree(N1)).isEqualTo(1); 317 // Edge direction handled correctly 318 assertThat(network.outDegree(N2)).isEqualTo(0); 319 } 320 321 @Test edges_selfLoop()322 public void edges_selfLoop() { 323 assume().that(network.allowsSelfLoops()).isTrue(); 324 325 addEdge(N1, N1, E11); 326 assertThat(network.edges()).containsExactly(E11); 327 } 328 329 @Test incidentEdges_selfLoop()330 public void incidentEdges_selfLoop() { 331 assume().that(network.allowsSelfLoops()).isTrue(); 332 333 addEdge(N1, N1, E11); 334 assertThat(network.incidentEdges(N1)).containsExactly(E11); 335 } 336 337 @Test incidentNodes_selfLoop()338 public void incidentNodes_selfLoop() { 339 assume().that(network.allowsSelfLoops()).isTrue(); 340 341 addEdge(N1, N1, E11); 342 assertThat(network.incidentNodes(E11).source()).isEqualTo(N1); 343 assertThat(network.incidentNodes(E11).target()).isEqualTo(N1); 344 } 345 346 @Test adjacentNodes_selfLoop()347 public void adjacentNodes_selfLoop() { 348 assume().that(network.allowsSelfLoops()).isTrue(); 349 350 addEdge(N1, N1, E11); 351 addEdge(N1, N2, E12); 352 assertThat(network.adjacentNodes(N1)).containsExactly(N1, N2); 353 } 354 355 @Test adjacentEdges_selfLoop()356 public void adjacentEdges_selfLoop() { 357 assume().that(network.allowsSelfLoops()).isTrue(); 358 359 addEdge(N1, N1, E11); 360 addEdge(N1, N2, E12); 361 assertThat(network.adjacentEdges(E11)).containsExactly(E12); 362 } 363 364 @Test edgesConnecting_selfLoop()365 public void edgesConnecting_selfLoop() { 366 assume().that(network.allowsSelfLoops()).isTrue(); 367 368 addEdge(N1, N1, E11); 369 assertThat(network.edgesConnecting(N1, N1)).containsExactly(E11); 370 addEdge(N1, N2, E12); 371 assertThat(network.edgesConnecting(N1, N2)).containsExactly(E12); 372 assertThat(network.edgesConnecting(N1, N1)).containsExactly(E11); 373 } 374 375 @Test inEdges_selfLoop()376 public void inEdges_selfLoop() { 377 assume().that(network.allowsSelfLoops()).isTrue(); 378 379 addEdge(N1, N1, E11); 380 assertThat(network.inEdges(N1)).containsExactly(E11); 381 addEdge(N4, N1, E41); 382 assertThat(network.inEdges(N1)).containsExactly(E11, E41); 383 } 384 385 @Test outEdges_selfLoop()386 public void outEdges_selfLoop() { 387 assume().that(network.allowsSelfLoops()).isTrue(); 388 389 addEdge(N1, N1, E11); 390 assertThat(network.outEdges(N1)).containsExactly(E11); 391 addEdge(N1, N2, E12); 392 assertThat(network.outEdges(N1)).containsExactly(E11, E12); 393 } 394 395 @Test predecessors_selfLoop()396 public void predecessors_selfLoop() { 397 assume().that(network.allowsSelfLoops()).isTrue(); 398 399 addEdge(N1, N1, E11); 400 assertThat(network.predecessors(N1)).containsExactly(N1); 401 addEdge(N4, N1, E41); 402 assertThat(network.predecessors(N1)).containsExactly(N1, N4); 403 } 404 405 @Test successors_selfLoop()406 public void successors_selfLoop() { 407 assume().that(network.allowsSelfLoops()).isTrue(); 408 409 addEdge(N1, N1, E11); 410 assertThat(network.successors(N1)).containsExactly(N1); 411 addEdge(N1, N2, E12); 412 assertThat(network.successors(N1)).containsExactly(N1, N2); 413 } 414 415 @Test source_selfLoop()416 public void source_selfLoop() { 417 assume().that(network.allowsSelfLoops()).isTrue(); 418 419 addEdge(N1, N1, E11); 420 assertThat(network.incidentNodes(E11).source()).isEqualTo(N1); 421 } 422 423 @Test target_selfLoop()424 public void target_selfLoop() { 425 assume().that(network.allowsSelfLoops()).isTrue(); 426 427 addEdge(N1, N1, E11); 428 assertThat(network.incidentNodes(E11).target()).isEqualTo(N1); 429 } 430 431 @Test degree_selfLoop()432 public void degree_selfLoop() { 433 assume().that(network.allowsSelfLoops()).isTrue(); 434 435 addEdge(N1, N1, E11); 436 assertThat(network.degree(N1)).isEqualTo(2); 437 addEdge(N1, N2, E12); 438 assertThat(network.degree(N1)).isEqualTo(3); 439 } 440 441 @Test inDegree_selfLoop()442 public void inDegree_selfLoop() { 443 assume().that(network.allowsSelfLoops()).isTrue(); 444 445 addEdge(N1, N1, E11); 446 assertThat(network.inDegree(N1)).isEqualTo(1); 447 addEdge(N4, N1, E41); 448 assertThat(network.inDegree(N1)).isEqualTo(2); 449 } 450 451 @Test outDegree_selfLoop()452 public void outDegree_selfLoop() { 453 assume().that(network.allowsSelfLoops()).isTrue(); 454 455 addEdge(N1, N1, E11); 456 assertThat(network.outDegree(N1)).isEqualTo(1); 457 addEdge(N1, N2, E12); 458 assertThat(network.outDegree(N1)).isEqualTo(2); 459 } 460 461 // Element Mutation 462 463 @Test addEdge_existingNodes()464 public void addEdge_existingNodes() { 465 assume().that(graphIsMutable()).isTrue(); 466 467 // Adding nodes initially for safety (insulating from possible future 468 // modifications to proxy methods) 469 addNode(N1); 470 addNode(N2); 471 assertThat(networkAsMutableNetwork.addEdge(N1, N2, E12)).isTrue(); 472 assertThat(network.edges()).contains(E12); 473 assertThat(network.edgesConnecting(N1, N2)).containsExactly(E12); 474 // Direction of the added edge is correctly handled 475 assertThat(network.edgesConnecting(N2, N1)).isEmpty(); 476 } 477 478 @Test addEdge_existingEdgeBetweenSameNodes()479 public void addEdge_existingEdgeBetweenSameNodes() { 480 assume().that(graphIsMutable()).isTrue(); 481 482 addEdge(N1, N2, E12); 483 ImmutableSet<String> edges = ImmutableSet.copyOf(network.edges()); 484 assertThat(networkAsMutableNetwork.addEdge(N1, N2, E12)).isFalse(); 485 assertThat(network.edges()).containsExactlyElementsIn(edges); 486 } 487 488 @Test addEdge_existingEdgeBetweenDifferentNodes()489 public void addEdge_existingEdgeBetweenDifferentNodes() { 490 assume().that(graphIsMutable()).isTrue(); 491 492 addEdge(N1, N2, E12); 493 IllegalArgumentException e = 494 assertThrows( 495 IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N4, N5, E12)); 496 assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE); 497 e = assertThrows(IllegalArgumentException.class, () -> addEdge(N2, N1, E12)); 498 assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE); 499 } 500 501 @Test addEdge_parallelEdge_notAllowed()502 public void addEdge_parallelEdge_notAllowed() { 503 assume().that(graphIsMutable()).isTrue(); 504 assume().that(network.allowsParallelEdges()).isFalse(); 505 506 addEdge(N1, N2, E12); 507 IllegalArgumentException e = 508 assertThrows( 509 IllegalArgumentException.class, 510 () -> networkAsMutableNetwork.addEdge(N1, N2, EDGE_NOT_IN_GRAPH)); 511 assertThat(e).hasMessageThat().contains(ERROR_PARALLEL_EDGE); 512 } 513 514 @Test addEdge_parallelEdge_allowsParallelEdges()515 public void addEdge_parallelEdge_allowsParallelEdges() { 516 assume().that(graphIsMutable()).isTrue(); 517 assume().that(network.allowsParallelEdges()).isTrue(); 518 519 assertTrue(networkAsMutableNetwork.addEdge(N1, N2, E12)); 520 assertTrue(networkAsMutableNetwork.addEdge(N1, N2, E12_A)); 521 assertThat(network.edgesConnecting(N1, N2)).containsExactly(E12, E12_A); 522 } 523 524 @Test addEdge_orderMismatch()525 public void addEdge_orderMismatch() { 526 assume().that(graphIsMutable()).isTrue(); 527 528 EndpointPair<Integer> endpoints = EndpointPair.unordered(N1, N2); 529 IllegalArgumentException e = 530 assertThrows( 531 IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(endpoints, E12)); 532 assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH); 533 } 534 535 @Test addEdge_selfLoop_notAllowed()536 public void addEdge_selfLoop_notAllowed() { 537 assume().that(graphIsMutable()).isTrue(); 538 assume().that(network.allowsSelfLoops()).isFalse(); 539 540 IllegalArgumentException e = 541 assertThrows( 542 IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N1, N1, E11)); 543 assertThat(e).hasMessageThat().contains(ERROR_SELF_LOOP); 544 } 545 546 /** 547 * This test checks an implementation dependent feature. It tests that the method {@code addEdge} 548 * will silently add the missing nodes to the graph, then add the edge connecting them. We are not 549 * using the proxy methods here as we want to test {@code addEdge} when the end-points are not 550 * elements of the graph. 551 */ 552 @Test addEdge_nodesNotInGraph()553 public void addEdge_nodesNotInGraph() { 554 assume().that(graphIsMutable()).isTrue(); 555 556 networkAsMutableNetwork.addNode(N1); 557 assertTrue(networkAsMutableNetwork.addEdge(N1, N5, E15)); 558 assertTrue(networkAsMutableNetwork.addEdge(N4, N1, E41)); 559 assertTrue(networkAsMutableNetwork.addEdge(N2, N3, E23)); 560 assertThat(network.nodes()).containsExactly(N1, N5, N4, N2, N3); 561 assertThat(network.edges()).containsExactly(E15, E41, E23); 562 assertThat(network.edgesConnecting(N1, N5)).containsExactly(E15); 563 assertThat(network.edgesConnecting(N4, N1)).containsExactly(E41); 564 assertThat(network.edgesConnecting(N2, N3)).containsExactly(E23); 565 // Direction of the added edge is correctly handled 566 assertThat(network.edgesConnecting(N3, N2)).isEmpty(); 567 } 568 569 @Test addEdge_selfLoop_allowed()570 public void addEdge_selfLoop_allowed() { 571 assume().that(graphIsMutable()).isTrue(); 572 assume().that(network.allowsSelfLoops()).isTrue(); 573 574 assertThat(networkAsMutableNetwork.addEdge(N1, N1, E11)).isTrue(); 575 assertThat(network.edges()).contains(E11); 576 assertThat(network.edgesConnecting(N1, N1)).containsExactly(E11); 577 } 578 579 @Test addEdge_existingSelfLoopEdgeBetweenSameNodes()580 public void addEdge_existingSelfLoopEdgeBetweenSameNodes() { 581 assume().that(graphIsMutable()).isTrue(); 582 assume().that(network.allowsSelfLoops()).isTrue(); 583 584 addEdge(N1, N1, E11); 585 ImmutableSet<String> edges = ImmutableSet.copyOf(network.edges()); 586 assertThat(networkAsMutableNetwork.addEdge(N1, N1, E11)).isFalse(); 587 assertThat(network.edges()).containsExactlyElementsIn(edges); 588 } 589 590 @Test addEdge_existingEdgeBetweenDifferentNodes_selfLoops()591 public void addEdge_existingEdgeBetweenDifferentNodes_selfLoops() { 592 assume().that(graphIsMutable()).isTrue(); 593 assume().that(network.allowsSelfLoops()).isTrue(); 594 595 addEdge(N1, N1, E11); 596 IllegalArgumentException e = 597 assertThrows( 598 IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N1, N2, E11)); 599 assertThat(e.getMessage()).contains(ERROR_REUSE_EDGE); 600 e = 601 assertThrows( 602 IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N2, N2, E11)); 603 assertThat(e.getMessage()).contains(ERROR_REUSE_EDGE); 604 addEdge(N1, N2, E12); 605 e = 606 assertThrows( 607 IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N1, N1, E12)); 608 assertThat(e.getMessage()).contains(ERROR_REUSE_EDGE); 609 } 610 611 @Test addEdge_parallelSelfLoopEdge_notAllowed()612 public void addEdge_parallelSelfLoopEdge_notAllowed() { 613 assume().that(graphIsMutable()).isTrue(); 614 assume().that(network.allowsSelfLoops()).isTrue(); 615 assume().that(network.allowsParallelEdges()).isFalse(); 616 617 addEdge(N1, N1, E11); 618 IllegalArgumentException e = 619 assertThrows( 620 IllegalArgumentException.class, 621 () -> networkAsMutableNetwork.addEdge(N1, N1, EDGE_NOT_IN_GRAPH)); 622 assertThat(e.getMessage()).contains(ERROR_PARALLEL_EDGE); 623 } 624 625 @Test addEdge_parallelSelfLoopEdge_allowsParallelEdges()626 public void addEdge_parallelSelfLoopEdge_allowsParallelEdges() { 627 assume().that(graphIsMutable()).isTrue(); 628 assume().that(network.allowsSelfLoops()).isTrue(); 629 assume().that(network.allowsParallelEdges()).isTrue(); 630 631 assertTrue(networkAsMutableNetwork.addEdge(N1, N1, E11)); 632 assertTrue(networkAsMutableNetwork.addEdge(N1, N1, E11_A)); 633 assertThat(network.edgesConnecting(N1, N1)).containsExactly(E11, E11_A); 634 } 635 636 @Test removeNode_existingNodeWithSelfLoopEdge()637 public void removeNode_existingNodeWithSelfLoopEdge() { 638 assume().that(graphIsMutable()).isTrue(); 639 assume().that(network.allowsSelfLoops()).isTrue(); 640 641 addNode(N1); 642 addEdge(N1, N1, E11); 643 assertThat(networkAsMutableNetwork.removeNode(N1)).isTrue(); 644 assertThat(network.nodes()).isEmpty(); 645 assertThat(network.edges()).doesNotContain(E11); 646 } 647 648 @Test removeEdge_existingSelfLoopEdge()649 public void removeEdge_existingSelfLoopEdge() { 650 assume().that(graphIsMutable()).isTrue(); 651 assume().that(network.allowsSelfLoops()).isTrue(); 652 653 addEdge(N1, N1, E11); 654 assertThat(networkAsMutableNetwork.removeEdge(E11)).isTrue(); 655 assertThat(network.edges()).doesNotContain(E11); 656 assertThat(network.edgesConnecting(N1, N1)).isEmpty(); 657 } 658 } 659