@Test
public void removeEdge_edgeNotPresent() {
addEdge(E12, N1, N2);
ImmutableSet<String> edges = ImmutableSet.copyOf(network.edges());
assertFalse(network.removeEdge(EDGE_NOT_IN_GRAPH));
assertThat(network.edges()).containsExactlyElementsIn(edges);
}
@Test
public void addNode_existingNode() {
addNode(N1);
ImmutableSet<Integer> nodes = ImmutableSet.copyOf(network.nodes());
assertFalse(addNode(N1));
assertThat(network.nodes()).containsExactlyElementsIn(nodes);
}
@Test
public void removeNode_nodeNotPresent() {
addNode(N1);
ImmutableSet<Integer> nodes = ImmutableSet.copyOf(network.nodes());
assertFalse(network.removeNode(NODE_NOT_IN_GRAPH));
assertThat(network.nodes()).containsExactlyElementsIn(nodes);
}
@Test
public void edges_noEdges() {
assertThat(network.edges()).isEmpty();
// Network with no edges, given disconnected nodes
addNode(N1);
addNode(N2);
assertThat(network.edges()).isEmpty();
}
@Test
public void removeNode_existingNode() {
addEdge(E12, N1, N2);
addEdge(E41, N4, N1);
assertTrue(network.removeNode(N1));
assertThat(network.nodes()).containsExactly(N2, N4);
assertThat(network.edges()).doesNotContain(E12);
assertThat(network.edges()).doesNotContain(E41);
}
@Test
public void removeEdge_oneOfMany() {
addEdge(E12, N1, N2);
addEdge(E13, N1, N3);
addEdge(E14, N1, N4);
assertThat(network.edges()).containsExactly(E12, E13, E14);
assertTrue(network.removeEdge(E13));
assertThat(network.edges()).containsExactly(E12, E14);
}
@Test
public void removeEdge_queryAfterRemoval() {
addEdge(E12, N1, N2);
Endpoints<Integer> unused = network.incidentNodes(E12); // ensure cache (if any) is populated
assertTrue(network.removeEdge(E12));
try {
network.incidentNodes(E12);
fail(ERROR_EDGE_NOT_IN_GRAPH);
} catch (IllegalArgumentException e) {
assertEdgeNotInGraphErrorMessage(e);
}
}
@Test
public void removeNode_queryAfterRemoval() {
addNode(N1);
Set<Integer> unused = network.adjacentNodes(N1); // ensure cache (if any) is populated
assertTrue(network.removeNode(N1));
try {
network.adjacentNodes(N1);
fail(ERROR_NODE_NOT_IN_GRAPH);
} catch (IllegalArgumentException e) {
assertNodeNotInGraphErrorMessage(e);
}
}
@Test
public void adjacentEdges_addEdges() {
addEdge(E12, N1, N2);
addEdge(E13, N1, N3);
addEdge(E23, N2, N3);
assertThat(network.adjacentEdges(E12)).containsExactly(E13, E23);
}
@Test
public void successors_nodeNotInGraph() {
try {
network.successors(NODE_NOT_IN_GRAPH);
fail(ERROR_NODE_NOT_IN_GRAPH);
} catch (IllegalArgumentException e) {
assertNodeNotInGraphErrorMessage(e);
}
}
@Test
public void adjacentEdges_nodeNotInGraph() {
try {
network.adjacentEdges(EDGE_NOT_IN_GRAPH);
fail(ERROR_EDGE_NOT_IN_GRAPH);
} catch (IllegalArgumentException e) {
assertEdgeNotInGraphErrorMessage(e);
}
}
@Test
public void edgesConnecting_nodesNotInGraph() {
addNode(N1);
addNode(N2);
try {
network.edgesConnecting(N1, NODE_NOT_IN_GRAPH);
fail(ERROR_NODE_NOT_IN_GRAPH);
} catch (IllegalArgumentException e) {
assertNodeNotInGraphErrorMessage(e);
}
try {
network.edgesConnecting(NODE_NOT_IN_GRAPH, N2);
fail(ERROR_NODE_NOT_IN_GRAPH);
} catch (IllegalArgumentException e) {
assertNodeNotInGraphErrorMessage(e);
}
try {
network.edgesConnecting(NODE_NOT_IN_GRAPH, NODE_NOT_IN_GRAPH);
fail(ERROR_NODE_NOT_IN_GRAPH);
} catch (IllegalArgumentException e) {
assertNodeNotInGraphErrorMessage(e);
}
}
@Test
public void nodes_noNodes() {
assertThat(network.nodes()).isEmpty();
}
@Test
public void addNode_newNode() {
assertTrue(addNode(N1));
assertThat(network.nodes()).contains(N1);
}
@Test
public void successors_noSuccessors() {
addNode(N1);
assertThat(network.successors(N1)).isEmpty();
}
@Test
public void predecessors_noPredecessors() {
addNode(N1);
assertThat(network.predecessors(N1)).isEmpty();
}
@Test
public void incidentNodes_oneEdge() {
addEdge(E12, N1, N2);
assertThat(network.incidentNodes(E12)).containsExactly(N1, N2);
}
/**
* A proxy method that adds the edge {@code e} to the graph being tested. In case of Immutable
* graph implementations, this method should add {@code e} to the graph builder and build a new
* graph with the current builder state.
*
* <p>This method should be used in tests of specific implementations if you want to ensure
* uniform behavior (including side effects) with how edges are added elsewhere in the tests. For
* example, the existing implementations of this method explicitly add the supplied nodes to the
* graph, and then call {@code graph.addEdge()} to connect the edge to the nodes; this is not part
* of the contract of {@code graph.addEdge()} and is done for convenience. In cases where you want
* to avoid such side effects (e.g., if you're testing what happens in your implementation if you
* add an edge whose end-points don't already exist in the graph), you should <b>not</b> use this
* method.
*
* @return {@code true} iff the graph was modified as a result of this call TODO(user): Consider
* changing access modifier to be protected.
*/
@CanIgnoreReturnValue
boolean addEdge(String e, Integer n1, Integer n2) {
network.addNode(n1);
network.addNode(n2);
return network.addEdge(e, n1, n2);
}
@Test
public void edges_oneEdge() {
addEdge(E12, N1, N2);
assertThat(network.edges()).containsExactly(E12);
}
@Test
public void adjacentEdges_noAdjacentEdges() {
addEdge(E12, N1, N2);
assertThat(network.adjacentEdges(E12)).isEmpty();
}
@Test
public void adjacentNodes_noAdjacentNodes() {
addNode(N1);
assertThat(network.adjacentNodes(N1)).isEmpty();
}
@Test
public void adjacentNodes_oneEdge() {
addEdge(E12, N1, N2);
assertThat(network.adjacentNodes(N1)).containsExactly(N2);
assertThat(network.adjacentNodes(N2)).containsExactly(N1);
}
@Test
public void nodes_oneNode() {
addNode(N1);
assertThat(network.nodes()).containsExactly(N1);
}
@After
public void validateGraphState() {
new EqualsTester()
.addEqualityGroup(network, Graphs.copyOf(network), ImmutableNetwork.copyOf(network))
.testEquals();
String networkString = network.toString();
assertThat(networkString).contains("isDirected: " + network.isDirected());
assertThat(networkString).contains("allowsParallelEdges: " + network.allowsParallelEdges());
assertThat(networkString).contains("allowsSelfLoops: " + network.allowsSelfLoops());
int nodeStart = networkString.indexOf("nodes:");
int edgeStart = networkString.indexOf("edges:");
String nodeString = networkString.substring(nodeStart, edgeStart);
String edgeString = networkString.substring(edgeStart);
Graph<Integer> asGraph = network.asGraph();
assertThat(network.nodes()).isEqualTo(asGraph.nodes());
assertThat(network.nodeOrder()).isEqualTo(asGraph.nodeOrder());
assertThat(network.isDirected()).isEqualTo(asGraph.isDirected());
assertThat(network.allowsSelfLoops()).isEqualTo(asGraph.allowsSelfLoops());
for (String edge : network.edges()) {
// TODO(b/27817069): Consider verifying the edge's incident nodes in the string.
assertThat(edgeString).contains(edge);
Iterator<Integer> endpointsIterator = network.incidentNodes(edge).iterator();
Integer nodeA = endpointsIterator.next();
Integer nodeB = endpointsIterator.next();
assertThat(network.edgesConnecting(nodeA, nodeB)).contains(edge);
assertThat(network.successors(nodeA)).contains(nodeB);
assertThat(network.adjacentNodes(nodeA)).contains(nodeB);
assertThat(network.outEdges(nodeA)).contains(edge);
assertThat(network.incidentEdges(nodeA)).contains(edge);
assertThat(network.predecessors(nodeB)).contains(nodeA);
assertThat(network.adjacentNodes(nodeB)).contains(nodeA);
assertThat(network.inEdges(nodeB)).contains(edge);
assertThat(network.incidentEdges(nodeB)).contains(edge);
for (Integer incidentNode : network.incidentNodes(edge)) {
assertThat(network.nodes()).contains(incidentNode);
for (String adjacentEdge : network.incidentEdges(incidentNode)) {
assertTrue(
edge.equals(adjacentEdge) || network.adjacentEdges(edge).contains(adjacentEdge));
}
}
}
for (Integer node : network.nodes()) {
assertThat(nodeString).contains(node.toString());
assertThat(network.adjacentNodes(node)).isEqualTo(asGraph.adjacentNodes(node));
assertThat(network.predecessors(node)).isEqualTo(asGraph.predecessors(node));
assertThat(network.successors(node)).isEqualTo(asGraph.successors(node));
for (Integer otherNode : network.nodes()) {
Set<String> edgesConnecting = network.edgesConnecting(node, otherNode);
boolean isSelfLoop = node.equals(otherNode);
if (network.isDirected() || !isSelfLoop) {
assertThat(edgesConnecting)
.isEqualTo(Sets.intersection(network.outEdges(node), network.inEdges(otherNode)));
}
if (!network.allowsParallelEdges()) {
assertThat(edgesConnecting.size()).isAtMost(1);
}
if (!network.allowsSelfLoops() && isSelfLoop) {
assertThat(edgesConnecting).isEmpty();
}
for (String edge : edgesConnecting) {
assertThat(network.incidentNodes(edge)).isEqualTo(Endpoints.of(network, node, otherNode));
}
}
for (String incidentEdge : network.incidentEdges(node)) {
assertTrue(
network.inEdges(node).contains(incidentEdge)
|| network.outEdges(node).contains(incidentEdge));
assertThat(network.edges()).contains(incidentEdge);
assertThat(network.incidentNodes(incidentEdge)).contains(node);
}
for (String inEdge : network.inEdges(node)) {
assertThat(network.incidentEdges(node)).contains(inEdge);
assertThat(network.outEdges(network.incidentNodes(inEdge).adjacentNode(node)))
.contains(inEdge);
}
for (String outEdge : network.outEdges(node)) {
assertThat(network.incidentEdges(node)).contains(outEdge);
assertThat(network.inEdges(network.incidentNodes(outEdge).adjacentNode(node)))
.contains(outEdge);
}
for (Integer adjacentNode : network.adjacentNodes(node)) {
assertTrue(
network.predecessors(node).contains(adjacentNode)
|| network.successors(node).contains(adjacentNode));
assertTrue(
!network.edgesConnecting(node, adjacentNode).isEmpty()
|| !network.edgesConnecting(adjacentNode, node).isEmpty());
}
for (Integer predecessor : network.predecessors(node)) {
assertThat(network.successors(predecessor)).contains(node);
assertThat(network.edgesConnecting(predecessor, node)).isNotEmpty();
}
for (Integer successor : network.successors(node)) {
assertThat(network.predecessors(successor)).contains(node);
assertThat(network.edgesConnecting(node, successor)).isNotEmpty();
}
}
}
@Test
public void inEdges_noInEdges() {
addNode(N1);
assertThat(network.inEdges(N1)).isEmpty();
}
@Test
public void outEdges_noOutEdges() {
addNode(N1);
assertThat(network.outEdges(N1)).isEmpty();
}
@Test
public void incidentEdges_isolatedNode() {
addNode(N1);
assertThat(network.incidentEdges(N1)).isEmpty();
}
@Test
public void edgesConnecting_disconnectedNodes() {
addNode(N1);
addNode(N2);
assertThat(network.edgesConnecting(N1, N2)).isEmpty();
}
/**
* A proxy method that adds the node {@code n} to the graph being tested. In case of Immutable
* graph implementations, this method should add {@code n} to the graph builder and build a new
* graph with the current builder state.
*
* @return {@code true} iff the graph was modified as a result of this call TODO(user): Consider
* changing access modifier to be protected.
*/
@CanIgnoreReturnValue
boolean addNode(Integer n) {
return network.addNode(n);
}