adds PolicySet to JSON conversion

CedarJava/src/main/java/com/cedarpolicy/model/policy/PolicySet.java

@@ -16,8 +16,10 @@
 
 package com.cedarpolicy.model.policy;
 
+import static com.cedarpolicy.CedarJson.objectWriter;
 import com.cedarpolicy.loader.LibraryLoader;
 import com.cedarpolicy.model.exception.InternalException;
+import com.fasterxml.jackson.core.JsonProcessingException;
 
 import java.util.Collections;
 import java.util.List;
@@ -87,22 +89,33 @@ public Map<String, String> getTemplates() {
 
     /**
      * Gets number of static policies in the Policy Set.
-     * 
+     *
      * @return number of static policies, returns 0 if policies set is null
      */
     public int getNumPolicies() {
         return policies != null ? policies.size() : 0;
-    } 
+    }
 
     /**
      * Gets number of templates in the Policy Set.
-     * 
+     *
      * @return number of templates, returns 0 if templates set is null
      */
     public int getNumTemplates() {
         return templates != null ? templates.size() : 0;
     }
 
+    /**
+      * Converts the PolicySet object to a Cedar JSON string representation.
+      *
+      * @return Cedar JSON string representation of the PolicySet
+      * @throws InternalException if there is an error during JSON conversion in the Rust native code
+      * @throws JsonProcessingException if there is an error serializing the object to JSON
+      */
+      public String toJson() throws InternalException, JsonProcessingException {
+        return policySetToJson(objectWriter().writeValueAsString(this));
+    }
+
     /**
      * Parse multiple policies and templates from a file into a PolicySet.
      * @param filePath the path to the file containing the policies
@@ -130,4 +143,5 @@ public static PolicySet parsePolicies(String policiesString) throws InternalExce
     }
 
     private static native PolicySet parsePoliciesJni(String policiesStr) throws InternalException, NullPointerException;
+    private static native String policySetToJson(String policySetStr) throws InternalException, NullPointerException;
 }

CedarJava/src/test/java/com/cedarpolicy/PolicySetTests.java

@@ -23,18 +23,22 @@
 
 import java.io.IOException;
 import java.nio.file.Path;
+import com.fasterxml.jackson.core.JsonProcessingException;
 
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static com.cedarpolicy.TestUtil.buildValidPolicySet;
+import static com.cedarpolicy.TestUtil.buildInvalidPolicySet;
 
 public class PolicySetTests {
     private static final String TEST_RESOURCES_DIR = "src/test/resources/";
 
     @Test
     public void parsePoliciesTests() throws InternalException, IOException {
-        PolicySet policySet = PolicySet.parsePolicies(Path.of(TEST_RESOURCES_DIR + "policies.cedar"));
-        for (Policy p: policySet.policies) {
+        PolicySet policySet =
+                PolicySet.parsePolicies(Path.of(TEST_RESOURCES_DIR + "policies.cedar"));
+        for (Policy p : policySet.policies) {
             assertNotNull(p.policySrc);
         }
         // Make sure the policy IDs are unique as Policies are made
@@ -46,13 +50,14 @@ public void parsePoliciesTests() throws InternalException, IOException {
     @Test
     public void parsePoliciesStringTests() throws InternalException {
         PolicySet policySet = PolicySet.parsePolicies("permit(principal, action, resource);");
-        PolicySet policySet2 = PolicySet.parsePolicies("permit(principal, action, resource) when { principal has x && principal.x == 5};");
-        for (Policy p: policySet.policies) {
+        PolicySet policySet2 = PolicySet.parsePolicies(
+                "permit(principal, action, resource) when { principal has x && principal.x == 5};");
+        for (Policy p : policySet.policies) {
             assertNotNull(p.policySrc);
         }
         assertEquals(1, policySet.policies.size());
         assertEquals(0, policySet.templates.size());
-        for (Policy p: policySet2.policies) {
+        for (Policy p : policySet2.policies) {
             assertNotNull(p.policySrc);
         }
         assertEquals(1, policySet2.policies.size());
@@ -61,13 +66,14 @@ public void parsePoliciesStringTests() throws InternalException {
 
     @Test
     public void parseTemplatesTests() throws InternalException, IOException {
-        PolicySet policySet = PolicySet.parsePolicies(Path.of(TEST_RESOURCES_DIR + "template.cedar"));
-        for (Policy p: policySet.policies) {
+        PolicySet policySet =
+                PolicySet.parsePolicies(Path.of(TEST_RESOURCES_DIR + "template.cedar"));
+        for (Policy p : policySet.policies) {
             assertNotNull(p.policySrc);
         }
         assertEquals(2, policySet.policies.size());
 
-        for (Policy p: policySet.templates) {
+        for (Policy p : policySet.templates) {
             assertNotNull(p.policySrc);
         }
         assertEquals(1, policySet.templates.size());
@@ -96,8 +102,33 @@ public void getNumTests() throws InternalException, IOException {
         assertEquals(0, emptyPolicySet.getNumTemplates());
 
         // Non-empty policy set
-        PolicySet policySet = PolicySet.parsePolicies(Path.of(TEST_RESOURCES_DIR + "template.cedar"));
+        PolicySet policySet =
+                PolicySet.parsePolicies(Path.of(TEST_RESOURCES_DIR + "template.cedar"));
         assertEquals(2, policySet.getNumPolicies());
         assertEquals(1, policySet.getNumTemplates());
     }
+
+    @Test
+    public void policySetToJsonTests()
+            throws JsonProcessingException, IOException, InternalException {
+        // Tests valid PolicySet
+        PolicySet validPolicySet = buildValidPolicySet();
+        String validJson =
+                "{\"templates\":{\"t0\":{\"effect\":\"permit\",\"principal\":{\"op\":\"==\",\"slot\":\"?principal\"},"
+                        + "\"action\":{\"op\":\"==\",\"entity\":{\"type\":\"Action\",\"id\":\"View_Photo\"}},"
+                        + "\"resource\":{\"op\":\"in\",\"entity\":{\"type\":\"Album\",\"id\":\"Vacation\"}},\"conditions\":[]}},"
+                        + "\"staticPolicies\":{\"p1\":{\"effect\":\"permit\",\"principal\":{\"op\":\"==\","
+                        + "\"entity\":{\"type\":\"User\",\"id\":\"Bob\"}},"
+                        + "\"action\":{\"op\":\"==\",\"entity\":{\"type\":\"Action\",\"id\":\"View_Photo\"}},"
+                        + "\"resource\":{\"op\":\"in\",\"entity\":{\"type\":\"Album\",\"id\":\"Vacation\"}},\"conditions\":[]}},"
+                        + "\"templateLinks\":[{\"templateId\":\"t0\",\"newId\":\"tl0\",\"values\":{\"?principal\":"
+                        + "{\"__entity\":{\"type\":\"User\",\"id\":\"Alice\"}}}}]}";
+        assertEquals(validJson, validPolicySet.toJson());
+
+        // Tests invalid PolicySet
+        PolicySet invalidPolicySet = buildInvalidPolicySet();
+        assertThrows(InternalException.class, () -> {
+            invalidPolicySet.toJson();
+        });
+    }
 }

CedarJava/src/test/java/com/cedarpolicy/TestUtil.java

@@ -18,11 +18,21 @@
 
 import com.cedarpolicy.model.schema.Schema;
 import com.cedarpolicy.model.schema.Schema.JsonOrCedar;
+import com.cedarpolicy.model.policy.TemplateLink;
+import com.cedarpolicy.model.policy.PolicySet;
+import com.cedarpolicy.model.policy.LinkValue;
+import com.cedarpolicy.model.policy.Policy;
+import com.cedarpolicy.model.entity.Entity;
+import com.cedarpolicy.value.EntityTypeName;
 
+import java.util.HashSet;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Optional;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Set;
 
 /** Utils to help with tests. */
 public final class TestUtil {
@@ -45,4 +55,57 @@ public static Schema loadSchemaResource(String schemaFile) {
             throw new RuntimeException("Failed to load test schema file " + schemaFile, e);
         }
     }
+
+    public static PolicySet buildValidPolicySet() {
+        EntityTypeName principalType = EntityTypeName.parse("User").get();
+        Set<Policy> policies = new HashSet<>();
+        Set<Policy> templates = new HashSet<>();
+        ArrayList<TemplateLink> templateLinks = new ArrayList<TemplateLink>();
+        ArrayList<LinkValue> linkValueList = new ArrayList<>();
+
+        String fullPolicy =
+                "permit(principal == User::\"Bob\", action == Action::\"View_Photo\", resource in Album::\"Vacation\");";
+        Policy newPolicy = new Policy(fullPolicy, "p1");
+        policies.add(newPolicy);
+
+        String template = "permit(principal == ?principal, action == Action::\"View_Photo\", resource in Album::\"Vacation\");";
+        Policy policyTemplate = new Policy(template, "t0");
+        templates.add(policyTemplate);
+
+        Entity principal = new Entity(principalType.of("Alice"), new HashMap<>(), new HashSet<>());
+        LinkValue principalLinkValue = new LinkValue("?principal", principal.getEUID());
+        linkValueList.add(principalLinkValue);
+
+        TemplateLink templateLink = new TemplateLink("t0", "tl0", linkValueList);
+        templateLinks.add(templateLink);
+
+        return new PolicySet(policies, templates, templateLinks);
+    }
+
+    public static PolicySet buildInvalidPolicySet() {
+        EntityTypeName principalType = EntityTypeName.parse("User").get();
+        Set<Policy> policies = new HashSet<>();
+        Set<Policy> templates = new HashSet<>();
+        ArrayList<TemplateLink> templateLinks = new ArrayList<TemplateLink>();
+        ArrayList<LinkValue> linkValueList = new ArrayList<>();
+
+        String fullPolicy =
+                "permit(prinipal == User::\"Bob\", action == Action::\"View_Photo\", resource in Album::\"Vacation\");";
+        Policy newPolicy = new Policy(fullPolicy, "p1");
+        policies.add(newPolicy);
+
+        String template = "permit(principal, action == Action::\"View_Photo\", resource in Album::\"Vacation\");";
+        Policy policyTemplate = new Policy(template, "t0");
+        templates.add(policyTemplate);
+
+        Entity principal = new Entity(principalType.of("Alice"), new HashMap<>(), new HashSet<>());
+        LinkValue principalLinkValue = new LinkValue("?principal", principal.getEUID());
+        linkValueList.add(principalLinkValue);
+
+        TemplateLink templateLink = new TemplateLink("t0", "tl0", linkValueList);
+        templateLinks.add(templateLink);
+
+        return new PolicySet(policies, templates, templateLinks);
+    }
+
 }