Assert allowed CelOptions during CelLiteRuntime environment construction

runtime/src/main/java/dev/cel/runtime/LiteRuntimeImpl.java

@@ -68,8 +68,42 @@ public CelLiteRuntimeBuilder addFunctionBindings(Iterable<CelFunctionBinding> bi
       return this;
     }
 
+    /** Throws if an unsupported flag in CelOptions is toggled. */
+    private static void assertAllowedCelOptions(CelOptions celOptions) {
+      String prefix = "Misconfigured CelOptions: ";
+      if (!celOptions.enableCelValue()) {
+        throw new IllegalArgumentException(prefix + "enableCelValue must be enabled.");
+      }
+      if (!celOptions.enableUnsignedLongs()) {
+        throw new IllegalArgumentException(prefix + "enableUnsignedLongs cannot be disabled.");
+      }
+      if (!celOptions.unwrapWellKnownTypesOnFunctionDispatch()) {
+        throw new IllegalArgumentException(
+            prefix + "unwrapWellKnownTypesOnFunctionDispatch cannot be disabled.");
+      }
+      if (!celOptions.enableStringConcatenation()) {
+        throw new IllegalArgumentException(
+            prefix
+                + "enableStringConcatenation cannot be disabled. Subset the environment instead"
+                + " using setStandardFunctions method.");
+      }
+      if (!celOptions.enableStringConversion()) {
+        throw new IllegalArgumentException(
+            prefix
+                + "enableStringConversion cannot be disabled. Subset the environment instead using"
+                + " setStandardFunctions method.");
+      }
+      if (!celOptions.enableListConcatenation()) {
+        throw new IllegalArgumentException(
+            prefix
+                + "enableListConcatenation cannot be disabled. Subset the environment instead using"
+                + " setStandardFunctions method.");
+      }
+    }
+
     @Override
     public CelLiteRuntime build() {
+      assertAllowedCelOptions(celOptions);
       ImmutableMap.Builder<String, CelFunctionBinding> functionBindingsBuilder =
           ImmutableMap.builder();
       if (celStandardFunctions != null) {

runtime/src/test/java/dev/cel/runtime/BUILD.bazel

@@ -160,6 +160,7 @@ cel_android_local_test(
         "//:java_truth",
         "//common:cel_ast_android",
         "//common:cel_source_android",
+        "//common:options",
         "//common:proto_ast_android",
         "//common/ast:ast_android",
         "//common/types:types_android",

runtime/src/test/java/dev/cel/runtime/CelLiteRuntimeTest.java

@@ -23,8 +23,10 @@
 import com.google.common.primitives.UnsignedLong;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.ExtensionRegistryLite;
+import com.google.testing.junit.testparameterinjector.TestParameter;
 import com.google.testing.junit.testparameterinjector.TestParameterInjector;
 import dev.cel.common.CelAbstractSyntaxTree;
+import dev.cel.common.CelOptions;
 import dev.cel.common.CelProtoAbstractSyntaxTree;
 import dev.cel.common.CelSource;
 import dev.cel.common.ast.CelConstant;
@@ -63,6 +65,14 @@ public void programConstruction() throws Exception {
     assertThat(program).isNotNull();
   }
 
+  @Test
+  public void setCelOptions_unallowedOptionsSet_throws(@TestParameter CelOptionsTestCase testCase) {
+    assertThrows(
+        IllegalArgumentException.class,
+        () ->
+            CelLiteRuntimeFactory.newLiteRuntimeBuilder().setOptions(testCase.celOptions).build());
+  }
+
   @Test
   public void standardEnvironment_disabledByDefault() throws Exception {
     CelLiteRuntime runtime = CelLiteRuntimeFactory.newLiteRuntimeBuilder().build();
@@ -187,4 +197,24 @@ private static CelAbstractSyntaxTree readCheckedExpr(String compiledCelTarget) t
         CheckedExpr.parseFrom(checkedExprBytes, ExtensionRegistryLite.getEmptyRegistry());
     return CelProtoAbstractSyntaxTree.fromCheckedExpr(checkedExpr).getAst();
   }
+
+  private enum CelOptionsTestCase {
+    CEL_VALUE_DISABLED(newBaseTestOptions().enableCelValue(false).build()),
+    UNSIGNED_LONG_DISABLED(newBaseTestOptions().enableUnsignedLongs(false).build()),
+    UNWRAP_WKT_DISABLED(newBaseTestOptions().unwrapWellKnownTypesOnFunctionDispatch(false).build()),
+    STRING_CONCAT_DISABLED(newBaseTestOptions().enableStringConcatenation(false).build()),
+    STRING_CONVERSION_DISABLED(newBaseTestOptions().enableStringConversion(false).build()),
+    LIST_CONCATENATION_DISABLED(newBaseTestOptions().enableListConcatenation(false).build()),
+    ;
+
+    private final CelOptions celOptions;
+
+    private static CelOptions.Builder newBaseTestOptions() {
+      return CelOptions.current().enableCelValue(true);
+    }
+
+    CelOptionsTestCase(CelOptions celOptions) {
+      this.celOptions = celOptions;
+    }
+  }
 }