Make TypeFunction subsettable in CelLiteRuntime and resolve struct types via CelTypeProvider in TypeResolver

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

@@ -244,6 +244,7 @@ java_library(
         ":type_resolver",
         "//common/annotations",
         "//common/types",
+        "//common/types:default_type_provider",
         "//common/types:type_providers",
         "//common/values",
         "@maven//:com_google_errorprone_error_prone_annotations",
@@ -665,6 +666,7 @@ java_library(
         "//runtime/standard:string",
         "//runtime/standard:subtract",
         "//runtime/standard:timestamp",
+        "//runtime/standard:type",
         "//runtime/standard:uint",
         "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_guava_guava",
@@ -723,6 +725,7 @@ cel_android_library(
         "//runtime/standard:string_android",
         "//runtime/standard:subtract_android",
         "//runtime/standard:timestamp_android",
+        "//runtime/standard:type_android",
         "//runtime/standard:uint_android",
         "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_guava_guava",

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

@@ -189,17 +189,24 @@ public CelLiteRuntime build() {
         }
       }
 
+      CelTypeProvider celTypeProvider = DefaultTypeProvider.getInstance();
+      if (this.celTypeProvider != null) {
+        celTypeProvider =
+            new CelTypeProvider.CombinedCelTypeProvider(celTypeProvider, this.celTypeProvider);
+      }
+
       ImmutableMap.Builder<String, CelFunctionBinding> functionBindingsBuilder =
           ImmutableMap.builder();
 
       ImmutableSet<CelStandardFunction> standardFunctions = standardFunctionBuilder.build();
-      if (!standardFunctions.isEmpty()) {
-        for (CelStandardFunction standardFunction : standardFunctions) {
-          ImmutableSet<CelFunctionBinding> standardFunctionBinding =
-              standardFunction.newFunctionBindings(celOptions, runtimeEquality);
-          for (CelFunctionBinding func : standardFunctionBinding) {
-            functionBindingsBuilder.put(func.getOverloadId(), func);
-          }
+      for (CelStandardFunction standardFunction : standardFunctions) {
+        for (CelFunctionBinding func :
+            standardFunction.newFunctionBindings(
+                celOptions,
+                runtimeEquality,
+                celTypeProvider,
+                celValueProvider.celValueConverter())) {
+          functionBindingsBuilder.put(func.getOverloadId(), func);
         }
       }
 
@@ -222,12 +229,6 @@ public CelLiteRuntime build() {
                     func.getDefinition());
               });
 
-      CelTypeProvider celTypeProvider = DefaultTypeProvider.getInstance();
-      if (this.celTypeProvider != null) {
-        celTypeProvider =
-            new CelTypeProvider.CombinedCelTypeProvider(celTypeProvider, this.celTypeProvider);
-      }
-
       ProgramPlanner planner =
           ProgramPlanner.newPlanner(
               celTypeProvider,

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

@@ -105,6 +105,7 @@
 import dev.cel.runtime.standard.SubtractOperator.SubtractOverload;
 import dev.cel.runtime.standard.TimestampFunction;
 import dev.cel.runtime.standard.TimestampFunction.TimestampOverload;
+import dev.cel.runtime.standard.TypeFunction;
 import dev.cel.runtime.standard.UintFunction;
 import dev.cel.runtime.standard.UintFunction.UintOverload;
 import java.util.Collection;
@@ -186,6 +187,7 @@ public final class CelStandardFunctions {
           StringFunction.create(),
           SubtractOperator.create(),
           TimestampFunction.create(),
+          TypeFunction.create(),
           UintFunction.create(),
           NotStrictlyFalseFunction.create());
 

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

@@ -21,6 +21,7 @@
 import dev.cel.common.annotations.Internal;
 import dev.cel.common.types.CelType;
 import dev.cel.common.types.CelTypeProvider;
+import dev.cel.common.types.DefaultTypeProvider;
 import dev.cel.common.types.StructTypeReference;
 import dev.cel.common.types.TypeType;
 import dev.cel.common.values.CelValueConverter;
@@ -89,7 +90,8 @@ public TypeType resolveObjectType(Object obj, CelType typeCheckedType) {
 
   private DescriptorTypeResolver(
       @Nullable CelTypeProvider typeProvider, CelValueConverter celValueConverter) {
-    super(celValueConverter);
+    super(
+        typeProvider != null ? typeProvider : DefaultTypeProvider.getInstance(), celValueConverter);
     this.typeProvider = typeProvider;
   }
 }

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

@@ -28,6 +28,7 @@
 import com.google.protobuf.Timestamp;
 import dev.cel.common.annotations.Internal;
 import dev.cel.common.types.CelType;
+import dev.cel.common.types.CelTypeProvider;
 import dev.cel.common.types.ListType;
 import dev.cel.common.types.MapType;
 import dev.cel.common.types.OptionalType;
@@ -55,10 +56,12 @@
 @Internal
 public class TypeResolver {
 
+  private final CelTypeProvider celTypeProvider;
   private final CelValueConverter celValueConverter;
 
-  static TypeResolver create(CelValueConverter celValueConverter) {
-    return new TypeResolver(celValueConverter);
+  public static TypeResolver create(
+      CelTypeProvider celTypeProvider, CelValueConverter celValueConverter) {
+    return new TypeResolver(celTypeProvider, celValueConverter);
   }
 
   // Sentinel runtime value representing the special "type" ident. This ensures following to be
@@ -121,11 +124,7 @@ TypeType adaptType(CelType typeCheckedType) {
     }
   }
 
-  Optional<TypeType> resolveWellKnownObjectType(Object obj) {
-    return findWellKnownObjectType(obj);
-  }
-
-  private static Optional<TypeType> findWellKnownObjectType(Object obj) {
+  static Optional<TypeType> resolveWellKnownObjectType(Object obj) {
     if (obj instanceof TypeType) {
       return Optional.of(RUNTIME_TYPE_TYPE);
     }
@@ -157,7 +156,7 @@ private static Optional<TypeType> findWellKnownObjectType(Object obj) {
    */
   public static String resolveTypeName(Object obj) {
     checkNotNull(obj);
-    Optional<TypeType> resolvedType = findWellKnownObjectType(obj);
+    Optional<TypeType> resolvedType = resolveWellKnownObjectType(obj);
     if (!resolvedType.isPresent()) {
       resolvedType = resolveExtendableObjectType(obj.getClass());
     }
@@ -195,11 +194,10 @@ public TypeType resolveObjectType(Object obj, CelType typeCheckedType) {
       return wellKnownTypeType.get();
     }
 
-    if (celValueConverter != null) {
-      Object celVal = celValueConverter.toRuntimeValue(obj);
-      if (celVal instanceof CelValue) {
-        return TypeType.create(((CelValue) celVal).celType());
-      }
+    Object celVal = celValueConverter.toRuntimeValue(obj);
+    if (celVal instanceof CelValue) {
+      CelType celType = ((CelValue) celVal).celType();
+      return TypeType.create(celTypeProvider.findType(celType.name()).orElse(celType));
     }
 
     if (obj instanceof MessageLiteOrBuilder) {
@@ -234,7 +232,8 @@ private static CelType adaptStructType(StructType typeOfType) {
     return newTypeOfType;
   }
 
-  protected TypeResolver(CelValueConverter celValueConverter) {
+  TypeResolver(CelTypeProvider celTypeProvider, CelValueConverter celValueConverter) {
+    this.celTypeProvider = checkNotNull(celTypeProvider);
     this.celValueConverter = checkNotNull(celValueConverter);
   }
 }

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

@@ -17,6 +17,8 @@ java_library(
     deps = [
         ":standard_overload",
         "//common:options",
+        "//common/types:type_providers",
+        "//common/values",
         "//runtime:function_binding",
         "//runtime:runtime_equality",
         "@maven//:com_google_errorprone_error_prone_annotations",
@@ -32,6 +34,8 @@ cel_android_library(
     deps = [
         ":standard_overload_android",
         "//common:options",
+        "//common/types:type_providers_android",
+        "//common/values:values_android",
         "//runtime:function_binding_android",
         "//runtime:runtime_equality_android",
         "@maven//:com_google_errorprone_error_prone_annotations",
@@ -1407,10 +1411,14 @@ java_library(
         ":standard_overload",
         "//common:options",
         "//common/types",
+        "//common/types:type_providers",
+        "//common/values",
         "//runtime:function_binding",
         "//runtime:runtime_equality",
         "//runtime:type_resolver",
+        "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_guava_guava",
+        "@maven//:org_jspecify_jspecify",
     ],
 )
 
@@ -1423,10 +1431,14 @@ cel_android_library(
         ":standard_function_android",
         ":standard_overload_android",
         "//common:options",
+        "//common/types:type_providers_android",
         "//common/types:types_android",
+        "//common/values:values_android",
         "//runtime:function_binding_android",
         "//runtime:runtime_equality_android",
         "//runtime:type_resolver_android",
+        "@maven//:com_google_errorprone_error_prone_annotations",
+        "@maven//:org_jspecify_jspecify",
         "@maven_android//:com_google_guava_guava",
     ],
 )

runtime/src/main/java/dev/cel/runtime/standard/CelStandardFunction.java

@@ -21,6 +21,8 @@
 import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.annotations.Immutable;
 import dev.cel.common.CelOptions;
+import dev.cel.common.types.CelTypeProvider;
+import dev.cel.common.values.CelValueConverter;
 import dev.cel.runtime.CelFunctionBinding;
 import dev.cel.runtime.RuntimeEquality;
 
@@ -43,6 +45,14 @@ public ImmutableSet<CelFunctionBinding> newFunctionBindings(
     return CelFunctionBinding.fromOverloads(name, overloadBindings);
   }
 
+  public ImmutableSet<CelFunctionBinding> newFunctionBindings(
+      CelOptions celOptions,
+      RuntimeEquality runtimeEquality,
+      CelTypeProvider celTypeProvider,
+      CelValueConverter celValueConverter) {
+    return newFunctionBindings(celOptions, runtimeEquality);
+  }
+
   CelStandardFunction(String name, ImmutableSet<CelStandardOverload> overloads) {
     checkArgument(!Strings.isNullOrEmpty(name), "Function name must be provided.");
     checkArgument(!overloads.isEmpty(), "At least 1 overload must be provided.");

runtime/src/main/java/dev/cel/runtime/standard/TypeFunction.java

@@ -14,27 +14,42 @@
 
 package dev.cel.runtime.standard;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.annotations.Immutable;
 import dev.cel.common.CelOptions;
+import dev.cel.common.types.CelTypeProvider;
 import dev.cel.common.types.SimpleType;
 import dev.cel.common.types.TypeType;
+import dev.cel.common.values.CelValueConverter;
 import dev.cel.runtime.CelFunctionBinding;
 import dev.cel.runtime.RuntimeEquality;
 import dev.cel.runtime.TypeResolver;
+import java.util.Arrays;
+import org.jspecify.annotations.Nullable;
 
-/**
- * Standard function for the {@code type} function.
- *
- * <p>The {@code type} function returns the CEL type of its argument. It accepts a
- * {@link TypeResolver} so that different runtimes can supply the appropriate resolver (e.g. a
- * descriptor-based resolver for full proto, or a base resolver for lite proto).
- */
+/** Standard function for the {@code type} function. */
+@Immutable
 public final class TypeFunction extends CelStandardFunction {
+  private static final TypeFunction ALL_OVERLOADS = create(TypeOverload.values());
+
+  private final @Nullable TypeResolver typeResolver;
+
+  public static TypeFunction create() {
+    return ALL_OVERLOADS;
+  }
 
-  private final TypeResolver typeResolver;
+  public static TypeFunction create(TypeFunction.TypeOverload... overloads) {
+    return create(Arrays.asList(overloads));
+  }
+
+  public static TypeFunction create(Iterable<TypeFunction.TypeOverload> overloads) {
+    return new TypeFunction(ImmutableSet.copyOf(overloads), /* typeResolver= */ null);
+  }
 
   public static TypeFunction create(TypeResolver typeResolver) {
-    return new TypeFunction(typeResolver);
+    return new TypeFunction(ImmutableSet.copyOf(TypeOverload.values()), checkNotNull(typeResolver));
   }
 
   /** Overloads for the standard {@code type} function. */
@@ -48,24 +63,38 @@ public CelFunctionBinding newFunctionBinding(
       // TypeResolver instance.
       // TODO: Instantiate from CelStandardFunctions.
       throw new UnsupportedOperationException(
-          "TypeOverload bindings must be created through TypeFunction.create(TypeResolver)");
+          "TypeOverload bindings must be created through TypeFunction");
     }
   }
 
   @Override
   public ImmutableSet<CelFunctionBinding> newFunctionBindings(
       CelOptions celOptions, RuntimeEquality runtimeEquality) {
+    return newFunctionBindings(checkNotNull(typeResolver));
+  }
+
+  @Override
+  public ImmutableSet<CelFunctionBinding> newFunctionBindings(
+      CelOptions celOptions,
+      RuntimeEquality runtimeEquality,
+      CelTypeProvider celTypeProvider,
+      CelValueConverter celValueConverter) {
+    return newFunctionBindings(TypeResolver.create(celTypeProvider, celValueConverter));
+  }
+
+  private static ImmutableSet<CelFunctionBinding> newFunctionBindings(TypeResolver typeResolver) {
     CelFunctionBinding binding =
         CelFunctionBinding.from(
             "type",
             Object.class,
             arg -> typeResolver.resolveObjectType(arg, TypeType.create(SimpleType.DYN)));
 
-    return CelFunctionBinding.fromOverloads("type", ImmutableSet.of(binding));
+    return CelFunctionBinding.fromOverloads("type", binding);
   }
 
-  private TypeFunction(TypeResolver typeResolver) {
-    super("type", ImmutableSet.copyOf(TypeOverload.values()));
+  private TypeFunction(
+      ImmutableSet<CelStandardOverload> overloads, @Nullable TypeResolver typeResolver) {
+    super("type", overloads);
     this.typeResolver = typeResolver;
   }
 }

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

@@ -58,6 +58,7 @@ java_library(
         "//common/internal:well_known_proto",
         "//common/types",
         "//common/types:cel_v1alpha1_types",
+        "//common/types:default_type_provider",
         "//common/types:message_type_provider",
         "//common/values",
         "//common/values:cel_byte_string",
@@ -101,9 +102,11 @@ java_library(
         "//runtime:unknown_attributes",
         "//runtime:unknown_options",
         "//runtime/standard:add",
+        "//runtime/standard:equals",
         "//runtime/standard:not_strictly_false",
         "//runtime/standard:standard_overload",
         "//runtime/standard:subtract",
+        "//runtime/standard:type",
         "//testing:cel_runtime_flavor",
         "//testing/protos:message_with_enum_cel_java_proto",
         "//testing/protos:message_with_enum_java_proto",