Fix error message for missing attribute

common/src/main/java/dev/cel/common/exceptions/CelAttributeNotFoundException.java

@@ -39,6 +39,11 @@ public static CelAttributeNotFoundException forFieldResolution(Collection<String
     return new CelAttributeNotFoundException(formatErrorMessage(fields));
   }
 
+  public static CelAttributeNotFoundException forMissingAttributes(Collection<String> attributes) {
+    return new CelAttributeNotFoundException(
+        "No such attribute(s): " + String.join(", ", attributes));
+  }
+
   private static String formatErrorMessage(Collection<String> fields) {
     String maybePlural = "";
     if (fields.size() > 1) {

runtime/src/main/java/dev/cel/runtime/planner/MissingAttribute.java

@@ -22,26 +22,44 @@
 final class MissingAttribute implements Attribute {
 
   private final ImmutableSet<String> missingAttributes;
+  private final Kind kind;
 
   @Override
   public Object resolve(GlobalResolver ctx, ExecutionFrame frame) {
-    throw CelAttributeNotFoundException.forFieldResolution(missingAttributes);
+    switch (kind) {
+      case ATTRIBUTE_NOT_FOUND:
+        throw CelAttributeNotFoundException.forMissingAttributes(missingAttributes);
+      case FIELD_NOT_FOUND:
+        throw CelAttributeNotFoundException.forFieldResolution(missingAttributes);
+    }
+
+    throw new IllegalArgumentException("Unexpected kind: " + kind);
   }
 
   @Override
   public Attribute addQualifier(Qualifier qualifier) {
     throw new UnsupportedOperationException("Unsupported operation");
   }
 
-  static MissingAttribute newMissingAttribute(String... attributeNames) {
-    return newMissingAttribute(ImmutableSet.copyOf(attributeNames));
+  static MissingAttribute newMissingAttribute(ImmutableSet<String> attributeNames) {
+    return new MissingAttribute(attributeNames, Kind.ATTRIBUTE_NOT_FOUND);
   }
 
-  static MissingAttribute newMissingAttribute(ImmutableSet<String> attributeNames) {
-    return new MissingAttribute(attributeNames);
+  static MissingAttribute newMissingField(String... attributeNames) {
+    return newMissingField(ImmutableSet.copyOf(attributeNames));
   }
 
-  private MissingAttribute(ImmutableSet<String> missingAttributes) {
+  static MissingAttribute newMissingField(ImmutableSet<String> attributeNames) {
+    return new MissingAttribute(attributeNames, Kind.FIELD_NOT_FOUND);
+  }
+
+  private MissingAttribute(ImmutableSet<String> missingAttributes, Kind kind) {
     this.missingAttributes = missingAttributes;
+    this.kind = kind;
+  }
+
+  private enum Kind {
+    ATTRIBUTE_NOT_FOUND,
+    FIELD_NOT_FOUND
   }
 }

runtime/src/main/java/dev/cel/runtime/planner/PresenceTestQualifier.java

@@ -14,7 +14,7 @@
 
 package dev.cel.runtime.planner;
 
-import static dev.cel.runtime.planner.MissingAttribute.newMissingAttribute;
+import static dev.cel.runtime.planner.MissingAttribute.newMissingField;
 
 import dev.cel.common.values.SelectableValue;
 import java.util.Map;
@@ -40,7 +40,7 @@ public Object qualify(Object obj) {
       return map.containsKey(value);
     }
 
-    return newMissingAttribute(value.toString());
+    return newMissingField(value.toString());
   }
 
   static PresenceTestQualifier create(Object value) {

runtime/src/test/java/dev/cel/runtime/planner/ProgramPlannerTest.java

@@ -300,6 +300,15 @@ public void planIdent_typeLiteral(@TestParameter TypeLiteralTestCase testCase) t
     assertThat(result).isEqualTo(testCase.type);
   }
 
+  @Test
+  public void plan_ident_missingAttribute_throws() throws Exception {
+    CelAbstractSyntaxTree ast = compile("int_var");
+    Program program = PLANNER.plan(ast);
+
+    CelEvaluationException e = assertThrows(CelEvaluationException.class, program::eval);
+    assertThat(e).hasMessageThat().contains("evaluation error at <input>:0: No such attribute(s)");
+  }
+
   @Test
   public void plan_ident_withContainer() throws Exception {
     CelAbstractSyntaxTree ast = compile("abbr.ident");
@@ -713,14 +722,13 @@ public void plan_select_onMapVariable() throws Exception {
   public void plan_select_mapVarInputMissing_throws() throws Exception {
     CelAbstractSyntaxTree ast = compile("map_var.foo");
     Program program = PLANNER.plan(ast);
-    String errorMessage = "evaluation error at <input>:7: Error resolving ";
+    String errorMessage = "evaluation error at <input>:7: No such attribute(s): ";
     if (isParseOnly) {
       errorMessage +=
-          "fields 'cel.expr.conformance.proto3.map_var, cel.expr.conformance.map_var,"
-              + " cel.expr.map_var, cel.map_var, map_var'";
-    } else {
-      errorMessage += "field 'map_var'";
+          "cel.expr.conformance.proto3.map_var, cel.expr.conformance.map_var, cel.expr.map_var,"
+              + " cel.map_var, ";
     }
+    errorMessage += "map_var";
 
     CelEvaluationException e =
         assertThrows(CelEvaluationException.class, () -> program.eval(ImmutableMap.of()));