Propagate accumulated unknowns in unary evaluation.

PiperOrigin-RevId: 955923584

Author: stanleyycheung

runtime/src/main/java/dev/cel/runtime/planner/BUILD.bazel

@@ -446,6 +446,7 @@ java_library(
         ":planned_interpretable",
         "//common/ast",
         "//common/values",
+        "//runtime:accumulated_unknowns",
         "//runtime:evaluation_exception",
         "//runtime:interpretable",
         "//runtime:resolved_overload",

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

@@ -19,6 +19,7 @@
 
 import dev.cel.common.ast.CelExpr;
 import dev.cel.common.values.CelValueConverter;
+import dev.cel.runtime.AccumulatedUnknowns;
 import dev.cel.runtime.CelEvaluationException;
 import dev.cel.runtime.CelResolvedOverload;
 import dev.cel.runtime.GlobalResolver;
@@ -36,6 +37,12 @@ Object evalInternal(GlobalResolver resolver, ExecutionFrame frame) throws CelEva
         resolvedOverload.isStrict()
             ? evalStrictly(arg, resolver, frame)
             : evalNonstrictly(arg, resolver, frame);
+
+    AccumulatedUnknowns unknowns = AccumulatedUnknowns.maybeMerge(null, argVal);
+    if (unknowns != null) {
+      return unknowns;
+    }
+
     return EvalHelpers.dispatch(functionName, resolvedOverload, celValueConverter, argVal);
   }
 

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

@@ -977,6 +977,27 @@ public void plan_partialEval_withWildcardQualification() throws Exception {
                 ImmutableSet.of(2L, 5L, 7L)));
   }
 
+  @Test
+  public void plan_unaryFunction_withUnknownArg() throws Exception {
+    CelCompiler compiler =
+        CelCompilerFactory.standardCelCompilerBuilder()
+            .addVar("unk", SimpleType.INT)
+            .addFunctionDeclarations(
+                newFunctionDeclaration(
+                    "neg", newGlobalOverload("neg_int", SimpleType.INT, SimpleType.INT)))
+            .build();
+    CelAbstractSyntaxTree ast = compile(compiler, "neg(unk)");
+
+    Program program = PLANNER.plan(ast);
+
+    CelUnknownSet result =
+        (CelUnknownSet) program.eval(PartialVars.of(CelAttributePattern.create("unk")));
+
+    assertThat(result)
+        .isEqualTo(
+            CelUnknownSet.create(ImmutableSet.of(CelAttribute.create("unk")), ImmutableSet.of(2L)));
+  }
+
   @Test
   public void localShadowIdentifier_inSelect() throws Exception {
     CelCompiler celCompiler =