fix: add unit tests for TreeViewerFilter

Author: acke

tests/src/test/java/io/snyk/eclipse/plugin/views/snyktoolview/TreeViewerFilterTest.java

@@ -0,0 +1,97 @@
+package io.snyk.eclipse.plugin.views.snyktoolview;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.function.Predicate;
+
+import org.eclipse.jface.viewers.ITreeContentProvider;
+import org.eclipse.jface.viewers.TreeViewer;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import io.snyk.languageserver.protocolextension.messageObjects.scanResults.Issue;
+
+class TreeViewerFilterTest {
+
+    private TreeViewerFilter filter;
+    private TreeViewer mockViewer;
+    private ITreeContentProvider mockContentProvider;
+
+    @BeforeEach
+    void setUp() {
+        filter = new TreeViewerFilter();
+        mockViewer = mock(TreeViewer.class);
+        mockContentProvider = mock(ITreeContentProvider.class);
+        when(mockViewer.getContentProvider()).thenReturn(mockContentProvider);
+    }
+
+    @Test
+    void testSelect_IssueTreeNodeWithNoFilters() {
+        IssueTreeNode issueNode = mock(IssueTreeNode.class);
+        Issue issue = mock(Issue.class);
+        when(issueNode.getIssue()).thenReturn(issue);
+
+        assertTrue(filter.select(mockViewer, null, issueNode));
+    }
+
+    @Test
+    void testSelect_IssueTreeNodeWithMatchingFilter() {
+        IssueTreeNode issueNode = mock(IssueTreeNode.class);
+        Issue issue = mock(Issue.class);
+        when(issueNode.getIssue()).thenReturn(issue);
+
+        Predicate<Issue> predicate = i -> true; // Always matches
+        filter.setFilterPredicate("test", predicate);
+
+        assertTrue(filter.select(mockViewer, null, issueNode));
+    }
+
+    @Test
+    void testSelect_IssueTreeNodeWithNonMatchingFilter() {
+        IssueTreeNode issueNode = mock(IssueTreeNode.class);
+        Issue issue = mock(Issue.class);
+        when(issueNode.getIssue()).thenReturn(issue);
+
+        Predicate<Issue> predicate = i -> false; // Never matches
+        filter.setFilterPredicate("test", predicate);
+
+        assertFalse(filter.select(mockViewer, null, issueNode));
+    }
+
+    @Test
+    void testSelect_FileTreeNodeWithVisibleChildren() {
+        FileTreeNode fileNode = mock(FileTreeNode.class);
+        IssueTreeNode visibleChild = mock(IssueTreeNode.class);
+        
+        when(mockContentProvider.getChildren(fileNode)).thenReturn(new Object[] { visibleChild });
+        
+        Issue issue = mock(Issue.class);
+        when(visibleChild.getIssue()).thenReturn(issue);
+
+        assertTrue(filter.select(mockViewer, null, fileNode));
+    }
+
+    @Test
+    void testSelect_FileTreeNodeWithNoVisibleChildren() {
+        FileTreeNode fileNode = mock(FileTreeNode.class);
+        
+        when(mockContentProvider.getChildren(fileNode)).thenReturn(new Object[] {});
+
+        assertFalse(filter.select(mockViewer, null, fileNode));
+    }
+
+    @Test
+    void testRemoveFilterPredicate() {
+        Predicate<Issue> predicate = i -> false;
+        filter.setFilterPredicate("test", predicate);
+
+        assertTrue(filter.select(mockViewer, null, mock(IssueTreeNode.class)));
+
+        filter.removeFilterPredicate("test");
+
+        assertTrue(filter.select(mockViewer, null, mock(IssueTreeNode.class)));
+    }
+}