// TODO(user): Consider adding both error messages from here and {@link AbstractNetworkTest}
  // in one class (may be a utility class for error messages).
  private static final String ERROR_PARALLEL_EDGE = "connected by a different edge";
  private static final String ERROR_NEGATIVE_COUNT = "is non-negative";
  private static final String ERROR_ADDED_PARALLEL_EDGE =
      "Should not be allowed to add a parallel edge.";

            IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N4, N5, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
    e = assertThrows(IllegalArgumentException.class, () -> addEdge(N2, N1, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
  }

  @Test
  public void addEdge_parallelEdge_notAllowed() {
    assume().that(graphIsMutable()).isTrue();

    assertEquals(RUNTIME_EXCEPTION, expected);
  }

  public void testGetCheckedUntimed_Error() throws TwoArgConstructorException {
    try {
      getChecked(ERROR_FUTURE, TwoArgConstructorException.class);
    } catch (Error expected) {
      assertEquals(ERROR, expected);
      return;
    }
    fail();
  }

  // identifiable substrings of expected error messages, from Strings that we've defined
  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_MODIFIABLE_SET = "Set returned is unexpectedly modifiable";
  static final String ERROR_SELF_LOOP = "self-loops are not allowed";

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import static com.google.common.graph.TestUtil.ERROR_ELEMENT_NOT_IN_GRAPH;
import static com.google.common.truth.Truth.assertWithMessage;

import com.google.common.testing.AbstractPackageSanityTests;
import junit.framework.AssertionFailedError;

/**

/** Utility methods used in various common.graph tests. */
final class TestUtil {
  static final String ERROR_ELEMENT_NOT_IN_GRAPH = "not an element of this graph";
  static final String ERROR_NODE_NOT_IN_GRAPH =
      "Should not be allowed to pass a node that is not an element of the graph.";
  static final String ERROR_ELEMENT_REMOVED = "used to generate this set";
  private static final String NODE_STRING = "Node";

/** Utility methods used in various common.graph tests. */
final class TestUtil {
  static final String ERROR_ELEMENT_NOT_IN_GRAPH = "not an element of this graph";
  static final String ERROR_NODE_NOT_IN_GRAPH =
      "Should not be allowed to pass a node that is not an element of the graph.";
  static final String ERROR_ELEMENT_REMOVED = "used to generate this set";
  private static final String NODE_STRING = "Node";

        if (shouldSkipViolationCheckFor(member) || getRepository().isSince(getCurrentVersion(), member)) {
            return null;
        }

        return acceptOrReject(member, Violation.error(member, SINCE_ERROR_MESSAGE + getCurrentVersion()));
    }

    private boolean shouldSkipViolationCheckFor(JApiCompatibility member) {
        return !isClassFieldConstructorOrMethod(member) ||
            isInject(member) ||

      fail();
    } catch (RuntimeException expected) {
      assertEquals(RUNTIME_EXCEPTION, expected);
    }
  }

  public void testGetUnchecked_Error() {
    try {
      getUnchecked(ERROR_FUTURE);
    } catch (Error expected) {
      assertEquals(ERROR, expected);
      return;
    }
    fail();
  }

    assertThat(e).hasMessageThat().contains(ERROR_PARALLEL_EDGE);
    e =
        assertThrows(
            IllegalArgumentException.class,
            () -> networkAsMutableNetwork.addEdge(N2, N1, EDGE_NOT_IN_GRAPH));
    assertThat(e).hasMessageThat().contains(ERROR_PARALLEL_EDGE);
  }

  @Test
  public void addEdge_parallelEdge_allowsParallelEdges() {