[Draft] Agentic Policy Compiler

.bazelversion

@@ -0,0 +1 @@
+8.5.0

policy/src/main/java/dev/cel/policy/CelPolicy.java

@@ -27,6 +27,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -77,8 +78,7 @@ public abstract static class Builder {
 
     public abstract Builder setPolicySource(CelPolicySource policySource);
 
-    // This should stay package-private to encourage add/set methods to be used instead.
-    abstract ImmutableMap.Builder<String, Object> metadataBuilder();
+    private final HashMap<String, Object> metadata = new HashMap<>();
 
     public abstract Builder setMetadata(ImmutableMap<String, Object> value);
 
@@ -90,6 +90,10 @@ public List<Import> imports() {
       return Collections.unmodifiableList(importList);
     }
 
+    public Map<String, Object> metadata() {
+      return Collections.unmodifiableMap(metadata);
+    }
+
     @CanIgnoreReturnValue
     public Builder addImport(Import value) {
       importList.add(value);
@@ -104,13 +108,13 @@ public Builder addImports(Collection<Import> values) {
 
     @CanIgnoreReturnValue
     public Builder putMetadata(String key, Object value) {
-      metadataBuilder().put(key, value);
+      metadata.put(key, value);
       return this;
     }
 
     @CanIgnoreReturnValue
     public Builder putMetadata(Map<String, Object> map) {
-      metadataBuilder().putAll(map);
+      metadata.putAll(map);
       return this;
     }
 

policy/src/main/java/dev/cel/policy/testing/BUILD.bazel

@@ -0,0 +1,29 @@
+load("@rules_java//java:defs.bzl", "java_library")
+
+package(
+    default_applicable_licenses = ["//:license"],
+    default_visibility = [
+        "//policy/testing:__pkg__",
+    ],
+)
+
+java_library(
+    name = "policy_test_suite_helper",
+    testonly = True,
+    srcs = [
+        "PolicyTestSuiteHelper.java",
+    ],
+    deps = [
+        "//bundle:cel",
+        "//common:cel_ast",
+        "//common:compiler_common",
+        "//common/formats:value_string",
+        "//policy",
+        "//policy:parser",
+        "//policy:parser_builder",
+        "//policy:policy_parser_context",
+        "//runtime:evaluation_exception",
+        "@maven//:com_google_guava_guava",
+        "@maven//:org_yaml_snakeyaml",
+    ],
+)

policy/src/main/java/dev/cel/policy/testing/PolicyTestSuiteHelper.java

@@ -0,0 +1,192 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dev.cel.policy.testing;
+
+import static com.google.common.base.Strings.isNullOrEmpty;
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Ascii;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.io.Resources;
+import dev.cel.bundle.Cel;
+import dev.cel.common.CelAbstractSyntaxTree;
+import dev.cel.common.CelValidationException;
+import dev.cel.runtime.CelEvaluationException;
+import java.io.IOException;
+import java.net.URL;
+import java.util.List;
+import java.util.Map;
+import org.yaml.snakeyaml.LoaderOptions;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.constructor.Constructor;
+
+/**
+ * Helper to assist with policy testing.
+ *
+ **/
+public final class PolicyTestSuiteHelper {
+
+  /**
+   * TODO
+   */
+  public static PolicyTestSuite readTestSuite(String path) throws IOException {
+    Yaml yaml = new Yaml(new Constructor(PolicyTestSuite.class, new LoaderOptions()));
+    String testContent = readFile(path);
+
+    return yaml.load(testContent);
+  }
+
+  /**
+   * TODO
+   * @param yamlPath
+   * @return
+   * @throws IOException
+   */
+  public static String readFromYaml(String yamlPath) throws IOException {
+    return readFile(yamlPath);
+  }
+
+  /**
+   * TestSuite describes a set of tests divided by section.
+   *
+   * <p>Visibility must be public for YAML deserialization to work. This is effectively
+   * package-private since the outer class is.
+   */
+  @VisibleForTesting
+  public static final class PolicyTestSuite {
+    private String description;
+    private List<PolicyTestSection> section;
+
+    public void setDescription(String description) {
+      this.description = description;
+    }
+
+    public void setSection(List<PolicyTestSection> section) {
+      this.section = section;
+    }
+
+    public String getDescription() {
+      return description;
+    }
+
+    public List<PolicyTestSection> getSection() {
+      return section;
+    }
+
+    @VisibleForTesting
+    public static final class PolicyTestSection {
+      private String name;
+      private List<PolicyTestCase> tests;
+
+      public void setName(String name) {
+        this.name = name;
+      }
+
+      public void setTests(List<PolicyTestCase> tests) {
+        this.tests = tests;
+      }
+
+      public String getName() {
+        return name;
+      }
+
+      public List<PolicyTestCase> getTests() {
+        return tests;
+      }
+
+      @VisibleForTesting
+      public static final class PolicyTestCase {
+        private String name;
+        private Map<String, PolicyTestInput> input;
+        private String output;
+
+        public void setName(String name) {
+          this.name = name;
+        }
+
+        public void setInput(Map<String, PolicyTestInput> input) {
+          this.input = input;
+        }
+
+        public void setOutput(String output) {
+          this.output = output;
+        }
+
+        public String getName() {
+          return name;
+        }
+
+        public Map<String, PolicyTestInput> getInput() {
+          return input;
+        }
+
+        public String getOutput() {
+          return output;
+        }
+
+        @VisibleForTesting
+        public static final class PolicyTestInput {
+          private Object value;
+          private String expr;
+
+          public Object getValue() {
+            return value;
+          }
+
+          public void setValue(Object value) {
+            this.value = value;
+          }
+
+          public String getExpr() {
+            return expr;
+          }
+
+          public void setExpr(String expr) {
+            this.expr = expr;
+          }
+        }
+
+        public ImmutableMap<String, Object> toInputMap(Cel cel)
+            throws CelValidationException, CelEvaluationException {
+          ImmutableMap.Builder<String, Object> inputBuilder = ImmutableMap.builderWithExpectedSize(
+              input.size());
+          for (Map.Entry<String, PolicyTestInput> entry : input.entrySet()) {
+            String exprInput = entry.getValue().getExpr();
+            if (isNullOrEmpty(exprInput)) {
+              inputBuilder.put(entry.getKey(), entry.getValue().getValue());
+            } else {
+              CelAbstractSyntaxTree exprInputAst = cel.compile(exprInput).getAst();
+              inputBuilder.put(entry.getKey(), cel.createProgram(exprInputAst).eval());
+            }
+          }
+
+          return inputBuilder.buildOrThrow();
+        }
+      }
+    }
+  }
+
+
+  private static URL getResource(String path) {
+    return Resources.getResource(Ascii.toLowerCase(path));
+  }
+
+  private static String readFile(String path) throws IOException {
+    return Resources.toString(getResource(path), UTF_8);
+  }
+
+  private PolicyTestSuiteHelper() {}
+}

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

@@ -33,6 +33,7 @@ java_library(
         "//policy:policy_parser_context",
         "//policy:source",
         "//policy:validation_exception",
+        "//policy/testing:policy_test_suite_helper",
         "//runtime",
         "//runtime:function_binding",
         "//runtime:late_function_binding",

policy/src/test/java/dev/cel/policy/CelPolicyCompilerImplTest.java

@@ -14,9 +14,8 @@
 
 package dev.cel.policy;
 
-import static com.google.common.base.Strings.isNullOrEmpty;
 import static com.google.common.truth.Truth.assertThat;
-import static dev.cel.policy.PolicyTestHelper.readFromYaml;
+import static dev.cel.policy.testing.PolicyTestSuiteHelper.readFromYaml;
 import static org.junit.Assert.assertThrows;
 
 import com.google.common.collect.ImmutableList;
@@ -38,17 +37,15 @@
 import dev.cel.parser.CelStandardMacro;
 import dev.cel.parser.CelUnparserFactory;
 import dev.cel.policy.PolicyTestHelper.K8sTagHandler;
-import dev.cel.policy.PolicyTestHelper.PolicyTestSuite;
-import dev.cel.policy.PolicyTestHelper.PolicyTestSuite.PolicyTestSection;
-import dev.cel.policy.PolicyTestHelper.PolicyTestSuite.PolicyTestSection.PolicyTestCase;
-import dev.cel.policy.PolicyTestHelper.PolicyTestSuite.PolicyTestSection.PolicyTestCase.PolicyTestInput;
 import dev.cel.policy.PolicyTestHelper.TestYamlPolicy;
+import dev.cel.policy.testing.PolicyTestSuiteHelper.PolicyTestSuite;
+import dev.cel.policy.testing.PolicyTestSuiteHelper.PolicyTestSuite.PolicyTestSection;
+import dev.cel.policy.testing.PolicyTestSuiteHelper.PolicyTestSuite.PolicyTestSection.PolicyTestCase;
 import dev.cel.runtime.CelFunctionBinding;
 import dev.cel.runtime.CelLateFunctionBindings;
 import dev.cel.testing.testdata.SingleFileProto.SingleFile;
 import dev.cel.testing.testdata.proto3.StandaloneGlobalEnum;
 import java.io.IOException;
-import java.util.Map;
 import java.util.Optional;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -215,17 +212,8 @@ public void evaluateYamlPolicy_withCanonicalTestData(
     // Compile then evaluate the policy
     CelAbstractSyntaxTree compiledPolicyAst =
         CelPolicyCompilerFactory.newPolicyCompiler(cel).build().compile(policy);
-    ImmutableMap.Builder<String, Object> inputBuilder = ImmutableMap.builder();
-    for (Map.Entry<String, PolicyTestInput> entry : testData.testCase.getInput().entrySet()) {
-      String exprInput = entry.getValue().getExpr();
-      if (isNullOrEmpty(exprInput)) {
-        inputBuilder.put(entry.getKey(), entry.getValue().getValue());
-      } else {
-        CelAbstractSyntaxTree exprInputAst = cel.compile(exprInput).getAst();
-        inputBuilder.put(entry.getKey(), cel.createProgram(exprInputAst).eval());
-      }
-    }
-    Object evalResult = cel.createProgram(compiledPolicyAst).eval(inputBuilder.buildOrThrow());
+    ImmutableMap<String, Object> inputMap = testData.testCase.toInputMap(cel);
+    Object evalResult = cel.createProgram(compiledPolicyAst).eval(inputMap);
 
     // Assert
     // Note that policies may either produce an optional or a non-optional result,