Introduce CEL Policy Conformance Test Runner for Java

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

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+load("@rules_java//java:defs.bzl", "java_library")
+load(":cel_policy_conformance_test.bzl", "cel_policy_conformance_test_java")
+
+package(
+    default_applicable_licenses = ["//:license"],
+    default_testonly = True,
+)
+
+java_library(
+    name = "run",
+    srcs = glob(["*.java"]),
+    deps = [
+        "//:auto_value",
+        "//bundle:cel",
+        "//testing/testrunner:cel_expression_source",
+        "//testing/testrunner:cel_test_context",
+        "//testing/testrunner:cel_test_suite",
+        "//testing/testrunner:cel_test_suite_text_proto_parser",
+        "//testing/testrunner:cel_test_suite_yaml_parser",
+        "//testing/testrunner:test_runner_library",
+        "@maven//:com_google_guava_guava",
+        "@maven//:com_google_protobuf_protobuf_java",
+        "@maven//:junit_junit",
+    ],
+)

conformance/src/test/java/dev/cel/conformance/policy/PolicyConformanceTest.java

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+// Copyright 2026 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.conformance.policy;
+
+import com.google.protobuf.ListValue;
+import com.google.protobuf.Struct;
+import com.google.protobuf.Value;
+import dev.cel.bundle.Cel;
+import dev.cel.bundle.CelFactory;
+import dev.cel.testing.testrunner.CelExpressionSource;
+import dev.cel.testing.testrunner.CelTestContext;
+import dev.cel.testing.testrunner.CelTestSuite.CelTestSection.CelTestCase;
+import dev.cel.testing.testrunner.TestRunnerLibrary;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.runners.model.Statement;
+
+/** Statement representing a single CEL policy conformance test case. */
+public final class PolicyConformanceTest extends Statement {
+
+  private static final Cel CEL = CelFactory.standardCelBuilder().build();
+
+  private final String name;
+  private final CelTestCase testCase;
+  private final String dirPath;
+
+  public PolicyConformanceTest(String name, CelTestCase testCase, String dirPath) {
+    this.name = name;
+    this.testCase = testCase;
+    this.dirPath = dirPath;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  @Override
+  public void evaluate() throws Throwable {
+    String policyFile = Paths.get(dirPath, "policy.yaml").toString();
+
+    CelTestContext.Builder contextBuilder =
+        CelTestContext.newBuilder()
+            .setCelExpression(CelExpressionSource.fromSource(policyFile))
+            .setCel(CEL)
+            .addMessageTypes(
+                Struct.getDescriptor(), Value.getDescriptor(), ListValue.getDescriptor());
+
+    Path yamlConfigPath = Paths.get(dirPath, "config.yaml");
+    Path textprotoConfigPath = Paths.get(dirPath, "config.textproto");
+
+    if (Files.exists(yamlConfigPath)) {
+      contextBuilder.setConfigFile(yamlConfigPath.toString());
+    } else if (Files.exists(textprotoConfigPath)) {
+      contextBuilder.setConfigFile(textprotoConfigPath.toString());
+    }
+
+    TestRunnerLibrary.runTest(testCase, contextBuilder.build());
+  }
+}

conformance/src/test/java/dev/cel/conformance/policy/PolicyConformanceTestRunner.java

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+// Copyright 2026 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.conformance.policy;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.base.Splitter;
+import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.Files;
+import com.google.protobuf.ListValue;
+import com.google.protobuf.Struct;
+import com.google.protobuf.TypeRegistry;
+import com.google.protobuf.Value;
+import dev.cel.testing.testrunner.CelTestSuite;
+import dev.cel.testing.testrunner.CelTestSuite.CelTestSection;
+import dev.cel.testing.testrunner.CelTestSuite.CelTestSection.CelTestCase;
+import dev.cel.testing.testrunner.CelTestSuiteTextProtoParser;
+import dev.cel.testing.testrunner.CelTestSuiteYamlParser;
+import java.io.File;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.runner.Description;
+import org.junit.runner.notification.RunNotifier;
+import org.junit.runners.ParentRunner;
+import org.junit.runners.model.InitializationError;
+
+/** Custom JUnit runner for CEL policy conformance tests. */
+public final class PolicyConformanceTestRunner extends ParentRunner<PolicyConformanceTest> {
+
+  private static final Splitter SPLITTER = Splitter.on(",").omitEmptyStrings();
+  private static final String TESTS_YAML_FILE_NAME = "tests.yaml";
+  private static final String TESTS_TEXTPROTO_FILE_NAME = "tests.textproto";
+  private static final TypeRegistry TYPE_REGISTRY =
+      TypeRegistry.newBuilder()
+          .add(Struct.getDescriptor())
+          .add(Value.getDescriptor())
+          .add(ListValue.getDescriptor())
+          .build();
+
+  private static final String TEST_DIRS_PROP =
+      System.getProperty("dev.cel.policy.conformance.tests");
+  private static final String TESTDATA_DIR =
+      System.getProperty("dev.cel.policy.conformance.testdata_dir", "testdata");
+  private static final String SKIP_TESTS_PROP =
+      System.getProperty("dev.cel.policy.conformance.skip_tests");
+
+  private static final ImmutableList<String> TESTS_TO_SKIP =
+      Strings.isNullOrEmpty(SKIP_TESTS_PROP)
+          ? ImmutableList.of()
+          : ImmutableList.copyOf(SPLITTER.splitToList(SKIP_TESTS_PROP));
+
+  private static final ImmutableList<String> TEST_DIRS =
+      Strings.isNullOrEmpty(TEST_DIRS_PROP)
+          ? discoverTestDirs(TESTDATA_DIR)
+          : ImmutableList.copyOf(SPLITTER.splitToList(TEST_DIRS_PROP));
+
+  private static ImmutableList<String> discoverTestDirs(String testdataDir) {
+    File dir = new File(testdataDir);
+    if (!dir.exists() || !dir.isDirectory()) {
+      return ImmutableList.of();
+    }
+    String[] directories = dir.list((current, name) -> new File(current, name).isDirectory());
+    if (directories == null) {
+      return ImmutableList.of();
+    }
+    Arrays.sort(directories);
+    return ImmutableList.copyOf(directories);
+  }
+
+  private final ImmutableList<PolicyConformanceTest> tests;
+
+  private ImmutableList<PolicyConformanceTest> loadTests() {
+    if (TEST_DIRS.isEmpty()) {
+      return ImmutableList.of();
+    }
+
+    ImmutableList.Builder<PolicyConformanceTest> testsBuilder = ImmutableList.builder();
+
+    for (String dir : TEST_DIRS) {
+      String fullDirPath = TESTDATA_DIR + "/" + dir;
+      try {
+        ImmutableList<CelTestSuiteContext> suites = readTestSuites(fullDirPath);
+        for (CelTestSuiteContext namedSuite : suites) {
+          for (CelTestSection section : namedSuite.testSuite().sections()) {
+            for (CelTestCase testCase : section.tests()) {
+              String baseName = String.format("%s/%s/%s", dir, section.name(), testCase.name());
+              String displayName = baseName + namedSuite.formatSuffix();
+              if (!shouldSkipTest(baseName, TESTS_TO_SKIP)) {
+                testsBuilder.add(new PolicyConformanceTest(displayName, testCase, fullDirPath));
+              }
+            }
+          }
+        }
+      } catch (Exception e) {
+        throw new RuntimeException("Failed to load test suite in " + fullDirPath, e);
+      }
+    }
+    return testsBuilder.build();
+  }
+
+  private static boolean shouldSkipTest(String name, List<String> testsToSkip) {
+    for (String testToSkip : testsToSkip) {
+      if (name.startsWith(testToSkip)) {
+        String consumedName = name.substring(testToSkip.length());
+        if (consumedName.isEmpty() || consumedName.startsWith("/")) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
+  private static ImmutableList<CelTestSuiteContext> readTestSuites(String dirPath)
+      throws Exception {
+    File dir = new File(dirPath);
+    File yamlFile = new File(dir, TESTS_YAML_FILE_NAME);
+    File textprotoFile = new File(dir, TESTS_TEXTPROTO_FILE_NAME);
+
+    boolean bothExist = yamlFile.exists() && textprotoFile.exists();
+    ImmutableList.Builder<CelTestSuiteContext> suitesBuilder = ImmutableList.builder();
+
+    if (yamlFile.exists()) {
+      suitesBuilder.add(
+          CelTestSuiteContext.create(
+              CelTestSuiteYamlParser.newInstance()
+                  .parse(Files.asCharSource(yamlFile, UTF_8).read()),
+              bothExist ? " (yaml)" : ""));
+    }
+    if (textprotoFile.exists()) {
+      suitesBuilder.add(
+          CelTestSuiteContext.create(
+              CelTestSuiteTextProtoParser.newInstance()
+                  .parse(Files.asCharSource(textprotoFile, UTF_8).read(), TYPE_REGISTRY),
+              bothExist ? " (textproto)" : ""));
+    }
+
+    ImmutableList<CelTestSuiteContext> suites = suitesBuilder.build();
+    if (suites.isEmpty()) {
+      throw new IllegalArgumentException(
+          String.format(
+              "No %s or %s found in %s", TESTS_YAML_FILE_NAME, TESTS_TEXTPROTO_FILE_NAME, dirPath));
+    }
+    return suites;
+  }
+
+  @Override
+  protected ImmutableList<PolicyConformanceTest> getChildren() {
+    return tests;
+  }
+
+  @Override
+  protected Description describeChild(PolicyConformanceTest child) {
+    return Description.createTestDescription(getTestClass().getJavaClass(), child.getName());
+  }
+
+  @Override
+  protected void runChild(PolicyConformanceTest child, RunNotifier notifier) {
+    runLeaf(child, describeChild(child), notifier);
+  }
+
+  public PolicyConformanceTestRunner(Class<?> clazz) throws InitializationError {
+    super(clazz);
+    this.tests = loadTests();
+  }
+
+  @AutoValue
+  abstract static class CelTestSuiteContext {
+    abstract CelTestSuite testSuite();
+
+    abstract String formatSuffix();
+
+    static CelTestSuiteContext create(CelTestSuite testSuite, String formatSuffix) {
+      return new AutoValue_PolicyConformanceTestRunner_CelTestSuiteContext(testSuite, formatSuffix);
+    }
+  }
+}

conformance/src/test/java/dev/cel/conformance/policy/PolicyConformanceTests.java

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+// Copyright 2026 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.conformance.policy;
+
+import org.junit.runner.RunWith;
+
+/** Main test class for CEL policy conformance tests. */
+@RunWith(PolicyConformanceTestRunner.class)
+public class PolicyConformanceTests {}

conformance/src/test/java/dev/cel/conformance/policy/cel_policy_conformance_test.bzl

@@ -0,0 +1,50 @@
+# Copyright 2026 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.
+
+"""Macro to run CEL policy conformance tests."""
+
+load("@rules_java//java:defs.bzl", "java_test")
+
+def cel_policy_conformance_test_java(
+        name,
+        testdata,
+        test_cases = [],
+        skip_tests = [],
+        **kwargs):
+    """Macro to run CEL policy conformance tests for Java.
+
+    Args:
+        name: The name of the test target.
+        testdata: Testdata filegroup target.
+        test_cases: (optional) List of test case names (directory names) to run.
+        skip_tests: (optional) List of test case names (directory names) to skip.
+        **kwargs: Other standard Bazel target attributes.
+    """
+
+    lbl = native.package_relative_label(testdata)
+    testdata_dir = lbl.package + "/" + lbl.name
+
+    java_test(
+        name = name,
+        jvm_flags = [
+            "-Ddev.cel.policy.conformance.tests=" + ",".join(test_cases),
+            "-Ddev.cel.policy.conformance.testdata_dir=" + testdata_dir,
+            "-Ddev.cel.policy.conformance.skip_tests=" + ",".join(skip_tests),
+        ],
+        data = [testdata],
+        size = "small",
+        test_class = "dev.cel.conformance.policy.PolicyConformanceTests",
+        runtime_deps = [Label(":run")],
+        **kwargs
+    )