*         <li>{@code predecessors(node)}: Connecting edge insertion order
   *         <li>{@code successors(node)}: Connecting edge insertion order
   *         <li>{@code incidentEdges(node)}: Stable order
   *         <li>{@code inEdges(node)}: Edge insertion order
   *         <li>{@code outEdges(node)}: Edge insertion order
   *         <li>{@code adjacentEdges(edge)}: Stable order

/**
 * Tests for SmbFilenameFilter interface behaviors via simple implementations.
 * Each test creates a concrete filter to validate expected contract semantics
 * including normal operation, null handling, edge cases, and exception flow.
 */
@ExtendWith(MockitoExtension.class)
class SmbFilenameFilterTest {

    @Mock
    SmbFile mockDir;

    /**
     * Happy-path: a filter that accepts any name.
     */

- ✅ Error messages include file type context

---

### 2. FilenameExtractorEnhancedTest.java
**Purpose**: Test FilenameExtractor edge cases and new documentation.

**Key Test Areas**:
- Parameter handling (null, empty, missing)
- Special character handling
- Input stream validation (not consumption)
- Edge cases (long filenames, paths, whitespace)

**Test Count**: 10 tests

**Key Scenarios**:
- ✅ Valid filename extraction

        when(session.isInUse()).thenReturn(inUse);

        boolean result = session.isInUse();

        assertEquals(inUse, result);
        verify(session, times(1)).isInUse();
    }

    // Happy path + edge: getSessionKey returns bytes, empty and null
    @Test
    @DisplayName("getSessionKey returns bytes, empty, then null")
    void getSessionKey_variants() throws CIFSException {
        byte[] key = new byte[] { 10, 20 };

package jcifs.smb1.smb1;

/**
 * Unit tests for {@link FileEntry}. The interface itself has no
 * implementation, so the tests exercise the contract via Mockito mocks.
 * Each method is exercised for normal inputs, extreme or edge cases, and
 * interaction verification.
 */
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.mockito.Mockito.mock;

    }

    @Test
    @DisplayName("Arrays: non-null, same length, and exact contents")
    void arrays_are_well_formed_and_match() {
        // Validate arrays existence and alignment (edge and structure checks)
        assertNotNull(WinError.WINERR_CODES, "WINERR_CODES should not be null");
        assertNotNull(WinError.WINERR_MESSAGES, "WINERR_MESSAGES should not be null");

        checkArgument(edges().contains(edge));
        N nodeU = edge.nodeU();
        N nodeV = edge.nodeV();
        Set<EndpointPair<N>> endpointPairIncidentEdges =
            Sets.union(incidentEdges(nodeU), incidentEdges(nodeV));
        return nodePairInvalidatableSet(
            Sets.difference(endpointPairIncidentEdges, ImmutableSet.of(edge)), nodeU, nodeV);
      }

      mutableValueGraph.addNode(node);
      return this;
    }

    /**
     * Adds an edge connecting {@code nodeU} to {@code nodeV} if one is not already present, and
     * sets a value for that edge to {@code value} (overwriting the existing value, if any).
     *
     * <p>If the graph is directed, the resultant edge will be directed; otherwise, it will be
     * undirected.
     *

      Collections.shuffle(edgeList, gen);
      int numEdgesToRemove = gen.nextInt(NUM_EDGES);
      for (int i = 0; i < numEdgesToRemove; ++i) {
        Object edge = edgeList.get(i);
        assertThat(network.removeEdge(edge)).isTrue();
      }

      assertThat(network.nodes()).hasSize(NUM_NODES);
      assertThat(network.edges()).hasSize(NUM_EDGES - numEdgesToRemove);

import org.mockito.junit.jupiter.MockitoExtension;

@ExtendWith(MockitoExtension.class)
class SmbUnsupportedOperationExceptionTest {

    // Provides a variety of messages including edge cases
    static Stream<String> messages() {
        return Stream.of("custom message", "", " ", "αβγ", "x".repeat(1000), null);
    }

    @Test