Update the "encoders" extension to be compatible with CelEnvironmentExporter

PiperOrigin-RevId: 786894924

Author: dmitriplotnikov

bundle/src/main/java/dev/cel/bundle/CelEnvironmentExporter.java

@@ -114,6 +114,7 @@ public abstract static class Builder {
     public Builder addStandardExtensions(CelOptions options) {
       addExtensionLibraries(
           CelExtensions.getExtensionLibrary("bindings", options),
+          CelExtensions.getExtensionLibrary("encoders", options),
           CelExtensions.getExtensionLibrary("math", options),
           CelExtensions.getExtensionLibrary("lists", options));
       // TODO: add support for remaining standard extensions

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

@@ -154,6 +154,7 @@ java_library(
         "//common:compiler_common",
         "//common/types",
         "//compiler:compiler_builder",
+        "//extensions:extension_library",
         "//runtime",
         "//runtime:function_binding",
         "@maven//:com_google_errorprone_error_prone_annotations",

extensions/src/main/java/dev/cel/extensions/CelEncoderExtensions.java

@@ -14,6 +14,8 @@
 
 package dev.cel.extensions;
 
+import static com.google.common.collect.ImmutableSet.toImmutableSet;
+
 import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.annotations.Immutable;
 import com.google.protobuf.ByteString;
@@ -31,7 +33,9 @@
 
 /** Internal implementation of Encoder Extensions. */
 @Immutable
-public class CelEncoderExtensions implements CelCompilerLibrary, CelRuntimeLibrary {
+public class CelEncoderExtensions
+    implements CelCompilerLibrary, CelRuntimeLibrary, CelExtensionLibrary.FeatureSet {
+
   private static final Encoder BASE64_ENCODER = Base64.getEncoder();
 
   private static final Decoder BASE64_DECODER = Base64.getDecoder();
@@ -74,6 +78,35 @@ String getFunction() {
     }
   }
 
+  private static final CelExtensionLibrary<CelEncoderExtensions> LIBRARY =
+      new CelExtensionLibrary<CelEncoderExtensions>() {
+        private final CelEncoderExtensions version0 = new CelEncoderExtensions();
+
+        @Override
+        public String name() {
+          return "encoders";
+        }
+
+        @Override
+        public ImmutableSet<CelEncoderExtensions> versions() {
+          return ImmutableSet.of(version0);
+        }
+      };
+
+  static CelExtensionLibrary<CelEncoderExtensions> library() {
+    return LIBRARY;
+  }
+
+  @Override
+  public int version() {
+    return 0;
+  }
+
+  @Override
+  public ImmutableSet<CelFunctionDecl> functions() {
+    return functions.stream().map(f -> f.functionDecl).collect(toImmutableSet());
+  }
+
   @Override
   public void setCheckerOptions(CelCheckerBuilder checkerBuilder) {
     functions.forEach(function -> checkerBuilder.addFunctionDeclarations(function.functionDecl));

extensions/src/main/java/dev/cel/extensions/CelExtensionLibrary.java

@@ -57,10 +57,14 @@ interface FeatureSet {
     int version();
 
     /** Returns the set of function declarations defined by this extension library. */
-    ImmutableSet<CelFunctionDecl> functions();
+    default ImmutableSet<CelFunctionDecl> functions() {
+      return ImmutableSet.of();
+    }
 
     /** Returns the set of macros defined by this extension library. */
-    ImmutableSet<CelMacro> macros();
+    default ImmutableSet<CelMacro> macros() {
+      return ImmutableSet.of();
+    }
 
     // TODO - Add a method for variables.
   }

extensions/src/main/java/dev/cel/extensions/CelExtensions.java

@@ -305,6 +305,8 @@ public static CelExtensionLibrary<? extends CelExtensionLibrary.FeatureSet> getE
     switch (name) {
       case "bindings":
         return CelBindingsExtensions.library();
+      case "encoders":
+        return CelEncoderExtensions.library();
       case "math":
         return CelMathExtensions.library(options);
       case "lists":

extensions/src/test/java/dev/cel/extensions/CelEncoderExtensionsTest.java

@@ -22,6 +22,8 @@
 import com.google.protobuf.ByteString;
 import com.google.testing.junit.testparameterinjector.TestParameterInjector;
 import dev.cel.common.CelAbstractSyntaxTree;
+import dev.cel.common.CelFunctionDecl;
+import dev.cel.common.CelOptions;
 import dev.cel.common.CelValidationException;
 import dev.cel.common.types.SimpleType;
 import dev.cel.compiler.CelCompiler;
@@ -43,6 +45,17 @@ public class CelEncoderExtensionsTest {
   private static final CelRuntime CEL_RUNTIME =
       CelRuntimeFactory.standardCelRuntimeBuilder().addLibraries(CelExtensions.encoders()).build();
 
+  @Test
+  public void library() {
+    CelExtensionLibrary<?> library =
+        CelExtensions.getExtensionLibrary("encoders", CelOptions.DEFAULT);
+    assertThat(library.name()).isEqualTo("encoders");
+    assertThat(library.latest().version()).isEqualTo(0);
+    assertThat(library.version(0).functions().stream().map(CelFunctionDecl::name))
+        .containsExactly("base64.decode", "base64.encode");
+    assertThat(library.version(0).macros()).isEmpty();
+  }
+
   @Test
   public void encode_success() throws Exception {
     String encodedBytes =