Added support for the fn:innermost Metapath function.

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/DefaultFunctionLibrary.java

@@ -105,6 +105,7 @@ public DefaultFunctionLibrary() { // NOPMD - intentional
     // https://www.w3.org/TR/xpath-functions-31/#func-index-of
     registerFunction(FnIndexOf.SIGNATURE_TWO_ARG);
     // https://www.w3.org/TR/xpath-functions-31/#func-innermost
+    registerFunction(FnInnermost.SIGNATURE);
     // https://www.w3.org/TR/xpath-functions-31/#func-insert-before
     registerFunction(FnInsertBefore.SIGNATURE);
     // https://www.w3.org/TR/xpath-functions-31/#func-iri-to-uri

core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/library/FnInnermost.java

@@ -0,0 +1,91 @@
+/*
+ * SPDX-FileCopyrightText: none
+ * SPDX-License-Identifier: CC0-1.0
+ */
+
+package gov.nist.secauto.metaschema.core.metapath.function.library;
+
+import gov.nist.secauto.metaschema.core.metapath.DynamicContext;
+import gov.nist.secauto.metaschema.core.metapath.MetapathConstants;
+import gov.nist.secauto.metaschema.core.metapath.function.FunctionUtils;
+import gov.nist.secauto.metaschema.core.metapath.function.IArgument;
+import gov.nist.secauto.metaschema.core.metapath.function.IFunction;
+import gov.nist.secauto.metaschema.core.metapath.item.IItem;
+import gov.nist.secauto.metaschema.core.metapath.item.ISequence;
+import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
+import gov.nist.secauto.metaschema.core.util.ObjectUtils;
+
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import edu.umd.cs.findbugs.annotations.NonNull;
+
+/**
+ * /** Implements
+ * <a href= "https://www.w3.org/TR/xpath-functions-31/#func-root">fn:root</a>
+ * functions.
+ */
+public final class FnInnermost {
+  @NonNull
+  private static final String NAME = "innermost";
+  @NonNull
+  static final IFunction SIGNATURE = IFunction.builder()
+      .name(NAME)
+      .namespace(MetapathConstants.NS_METAPATH_FUNCTIONS)
+      .deterministic()
+      .contextIndependent()
+      .focusDependent()
+      .argument(IArgument.builder()
+          .name("nodes")
+          .type(INodeItem.type())
+          .zeroOrMore()
+          .build())
+      .returnType(INodeItem.type())
+      .returnZeroOrMore()
+      .functionHandler(FnInnermost::execute)
+      .build();
+
+  @SuppressWarnings("unused")
+  @NonNull
+  private static ISequence<? extends INodeItem> execute(@NonNull IFunction function,
+      @NonNull List<ISequence<?>> arguments,
+      @NonNull DynamicContext dynamicContext,
+      IItem focus) {
+    ISequence<? extends INodeItem> nodes = FunctionUtils.asType(ObjectUtils.requireNonNull(arguments.get(0)));
+
+    return ISequence.of(fnInnermost(nodes.getValue()));
+  }
+
+  /**
+   * Get every node within the provided list that is not an ancestor of another
+   * member of the provided list.
+   * <p>
+   * The nodes are returned in document order with duplicates eliminated.
+   * <p>
+   * Based on the XPath 3.1 <a href=
+   * "https://www.w3.org/TR/xpath-functions-31/#func-innermost">fn:innermost</a>
+   * function.
+   *
+   * @param arg
+   *          the node items check
+   * @return the nodes that are not an ancestor of another member of the provided
+   *         list
+   */
+  @NonNull
+  public static Stream<? extends INodeItem> fnInnermost(@NonNull List<? extends INodeItem> arg) {
+    Set<? extends INodeItem> ancestors = arg.stream()
+        .distinct()
+        .flatMap(INodeItem::ancestor)
+        .collect(Collectors.toSet());
+
+    return ObjectUtils.notNull(arg.stream()
+        .distinct()
+        .filter(node -> !ancestors.contains(node)));
+  }
+
+  private FnInnermost() {
+    // disable construction
+  }
+}

core/src/test/java/gov/nist/secauto/metaschema/core/metapath/function/library/FnInnermostTest.java

@@ -0,0 +1,83 @@
+/*
+/*
+ * SPDX-FileCopyrightText: none
+ * SPDX-License-Identifier: CC0-1.0
+ */
+
+package gov.nist.secauto.metaschema.core.metapath.function.library;
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import gov.nist.secauto.metaschema.core.metapath.DynamicContext;
+import gov.nist.secauto.metaschema.core.metapath.ExpressionTestBase;
+import gov.nist.secauto.metaschema.core.metapath.IMetapathExpression;
+import gov.nist.secauto.metaschema.core.metapath.MetapathException;
+import gov.nist.secauto.metaschema.core.metapath.function.library.impl.MockedDocumentGenerator;
+import gov.nist.secauto.metaschema.core.metapath.item.ISequence;
+import gov.nist.secauto.metaschema.core.metapath.item.atomic.IStringItem;
+import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
+import gov.nist.secauto.metaschema.core.metapath.type.InvalidTypeMetapathException;
+import gov.nist.secauto.metaschema.core.metapath.type.TypeMetapathException;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.stream.Stream;
+
+import edu.umd.cs.findbugs.annotations.NonNull;
+
+class FnInnermostTest
+    extends ExpressionTestBase {
+
+  private static Stream<Arguments> provideValues() { // NOPMD - false positive
+    return Stream.of(
+        Arguments.of(
+            "(/root/assembly/@assembly-flag,/root/field/@field-flag)",
+            "innermost((.,/root,/root/assembly,/root/assembly/@assembly-flag,/root/field,/root/field/@field-flag))"),
+        Arguments.of(
+            "(/root/assembly,/root/field)",
+            "innermost((.,/root,/root/assembly,/root/field))"),
+        Arguments.of(
+            "(/root/assembly/@assembly-flag,/root/field/@field-flag)",
+            "innermost((.,/root,/root/assembly,/root/assembly/@assembly-flag,/root/field,/root/field/@field-flag," +
+                ".,/root,/root/assembly,/root/assembly/@assembly-flag,/root/field,/root/field/@field-flag))"));
+  }
+
+  @ParameterizedTest
+  @MethodSource("provideValues")
+  void test(@NonNull String expectedMetapath, @NonNull String metapath) {
+    DynamicContext dynamicContext = newDynamicContext();
+    INodeItem node = MockedDocumentGenerator.generateDocumentNodeItem(getContext());
+
+    ISequence<? extends INodeItem> expected
+        = IMetapathExpression.compile(expectedMetapath, dynamicContext.getStaticContext())
+            .evaluate(node, dynamicContext);
+
+    ISequence<? extends INodeItem> actual = IMetapathExpression.compile(metapath, dynamicContext.getStaticContext())
+        .evaluate(node, dynamicContext);
+    assertEquals(expected, actual);
+  }
+
+  @Test
+  void testNotANode() {
+    DynamicContext dynamicContext = newDynamicContext();
+
+    MetapathException ex = assertThrows(MetapathException.class, () -> {
+      IMetapathExpression.compile("innermost('test')", dynamicContext.getStaticContext())
+          .evaluateAs(IStringItem.valueOf("test"), IMetapathExpression.ResultType.ITEM, dynamicContext);
+    });
+    Throwable cause = ex.getCause() != null ? ex.getCause().getCause() : null;
+
+    assertAll(
+        () -> assertEquals(InvalidTypeMetapathException.class, cause == null
+            ? null
+            : cause.getClass()),
+        () -> assertEquals(TypeMetapathException.INVALID_TYPE_ERROR, cause instanceof TypeMetapathException
+            ? ((TypeMetapathException) cause).getCode()
+            : null));
+  }
+}

core/src/test/java/gov/nist/secauto/metaschema/core/testing/AbstractModelBuilder.java

@@ -131,6 +131,12 @@ protected void applyDefinition(@NonNull IDefinition definition) {
     applyModelElement(definition);
     applyNamed(definition);
     applyAttributable(definition);
+    getContext().checking(new Expectations() {
+      {
+        allowing(definition).getDefinitionQName();
+        will(returnValue(IEnhancedQName.of(ObjectUtils.notNull(namespace), ObjectUtils.notNull(name))));
+      }
+    });
   }
 
   /**