From 37f4980b3918831eed2ff68f3327cecd99fd9ba1 Mon Sep 17 00:00:00 2001
From: David Waltermire <david.waltermire@gsa.gov>
Date: Wed, 11 Dec 2024 20:32:39 -0500
Subject: [PATCH] Improved the error handling for constraint message
 replacements using Metapath expressions. Resolves #289.

---
 .../function/impl/AbstractFunction.java       |  2 +
 .../DefaultConstraintValidator.java           | 40 ++++++++++---------
 ...AbstractConfigurableMessageConstraint.java | 13 +++++-
 3 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/impl/AbstractFunction.java b/core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/impl/AbstractFunction.java
index 069f7a8ab..0a7a77181 100644
--- a/core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/impl/AbstractFunction.java
+++ b/core/src/main/java/gov/nist/secauto/metaschema/core/metapath/function/impl/AbstractFunction.java
@@ -259,6 +259,8 @@ public ISequence<?> execute(
         result = executeInternal(convertedArguments, dynamicContext, contextItem);
 
         if (callingContext != null) {
+          // ensure the result sequence is list backed
+          result.getValue();
           // add result to cache
           dynamicContext.cacheResult(callingContext, result);
         }
diff --git a/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/DefaultConstraintValidator.java b/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/DefaultConstraintValidator.java
index 63a22be4e..0fadac1dc 100644
--- a/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/DefaultConstraintValidator.java
+++ b/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/DefaultConstraintValidator.java
@@ -676,28 +676,32 @@ private void validateExpect(
       @NonNull INodeItem node,
       @NonNull ISequence<? extends INodeItem> targets,
       @NonNull DynamicContext dynamicContext) {
-    IMetapathExpression metapath = IMetapathExpression.compile(
-        constraint.getTest(),
-        dynamicContext.getStaticContext());
+    try {
+      IMetapathExpression metapath = IMetapathExpression.compile(
+          constraint.getTest(),
+          dynamicContext.getStaticContext());
 
-    IConstraintValidationHandler handler = getConstraintValidationHandler();
-    targets.stream()
-        .forEachOrdered(item -> {
-          assert item != null;
+      IConstraintValidationHandler handler = getConstraintValidationHandler();
+      targets.stream()
+          .forEachOrdered(item -> {
+            assert item != null;
 
-          if (item.hasValue()) {
-            try {
-              ISequence<?> result = metapath.evaluate(item, dynamicContext);
-              if (FnBoolean.fnBoolean(result).toBoolean()) {
-                handlePass(constraint, node, item, dynamicContext);
-              } else {
-                handler.handleExpectViolation(constraint, node, item, dynamicContext);
+            if (item.hasValue()) {
+              try {
+                ISequence<?> result = metapath.evaluate(item, dynamicContext);
+                if (FnBoolean.fnBoolean(result).toBoolean()) {
+                  handlePass(constraint, node, item, dynamicContext);
+                } else {
+                  handler.handleExpectViolation(constraint, node, item, dynamicContext);
+                }
+              } catch (MetapathException ex) {
+                handleError(constraint, item, ex, dynamicContext);
               }
-            } catch (MetapathException ex) {
-              handleError(constraint, item, ex, dynamicContext);
             }
-          }
-        });
+          });
+    } catch (MetapathException ex) {
+      handleError(constraint, node, ex, dynamicContext);
+    }
   }
 
   /**
diff --git a/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/impl/AbstractConfigurableMessageConstraint.java b/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/impl/AbstractConfigurableMessageConstraint.java
index fe7a34a90..7738a9144 100644
--- a/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/impl/AbstractConfigurableMessageConstraint.java
+++ b/core/src/main/java/gov/nist/secauto/metaschema/core/model/constraint/impl/AbstractConfigurableMessageConstraint.java
@@ -9,6 +9,7 @@
 import gov.nist.secauto.metaschema.core.datatype.markup.MarkupMultiline;
 import gov.nist.secauto.metaschema.core.metapath.DynamicContext;
 import gov.nist.secauto.metaschema.core.metapath.IMetapathExpression;
+import gov.nist.secauto.metaschema.core.metapath.MetapathException;
 import gov.nist.secauto.metaschema.core.metapath.item.node.INodeItem;
 import gov.nist.secauto.metaschema.core.model.IAttributable;
 import gov.nist.secauto.metaschema.core.model.ISource;
@@ -95,8 +96,16 @@ public String generateMessage(@NonNull INodeItem item, @NonNull DynamicContext c
 
     return ObjectUtils.notNull(ReplacementScanner.replaceTokens(message, METAPATH_VALUE_TEMPLATE_PATTERN, match -> {
       String metapath = ObjectUtils.notNull(match.group(2));
-      IMetapathExpression expr = IMetapathExpression.compile(metapath, context.getStaticContext());
-      return expr.evaluateAs(item, IMetapathExpression.ResultType.STRING, context);
+      try {
+        IMetapathExpression expr = IMetapathExpression.compile(metapath, context.getStaticContext());
+        return expr.evaluateAs(item, IMetapathExpression.ResultType.STRING, context);
+      } catch (MetapathException ex) {
+        throw new MetapathException(
+            String.format("Unable to evaluate the message replacement expression '%s'. %s",
+                metapath,
+                ex.getLocalizedMessage()),
+            ex);
+      }
     }).toString());
   }
 }