PoC for java records (JEP 395)

languages/java/oso/pom.xml

@@ -12,7 +12,7 @@
 
   <groupId>com.osohq</groupId>
   <artifactId>oso</artifactId>
-  <!-- oso_version --><version>0.26.4</version>
+  <!-- oso_version --><version>0.26.5-SNAPSHOT</version>
 
   <distributionManagement>
     <snapshotRepository>
@@ -38,8 +38,8 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <maven.compiler.source>1.8</maven.compiler.source>
-    <maven.compiler.target>1.8</maven.compiler.target>
+    <maven.compiler.source>17</maven.compiler.source>
+    <maven.compiler.target>17</maven.compiler.target>
   </properties>
 
   <dependencies>

languages/java/oso/src/main/java/com/osohq/oso/Query.java

@@ -114,13 +114,7 @@ private void handleCall(
           }
           result = method.invoke(instance, args.get().toArray());
         } else {
-          // Look for a field with the given name.
-          try {
-            Field field = cls.getField(attrName);
-            result = field.get(instance);
-          } catch (NoSuchFieldException f) {
-            throw new Exceptions.InvalidAttributeError(cls.getName(), attrName);
-          }
+          result = getFromFieldOrRecordAccessor(attrName, instance, cls);
         }
         String term = host.toPolarTerm(result).toString();
         ffiQuery.callResult(callId, term);
@@ -141,6 +135,22 @@ private void handleCall(
     }
   }
 
+  private Object getFromFieldOrRecordAccessor(String attrName, Object instance, Class<?> cls) throws IllegalAccessException {
+    // Look for a field with the given name.
+    try {
+      Field field = cls.getField(attrName);
+      return field.get(instance);
+    } catch (NoSuchFieldException ignored) {
+    }
+    // Assume record so try the no args accessor method instead.
+    try {
+      Method method = cls.getMethod(attrName);
+      return method.invoke(instance);
+    } catch (NoSuchMethodException | InvocationTargetException e) {
+      throw new Exceptions.InvalidAttributeError(cls.getName(), attrName);
+    }
+  }
+
   /** Helper for `NextExternal` query events */
   private void handleNextExternal(long callId, JSONObject iterable) throws Exceptions.OsoException {
     if (!calls.containsKey(callId)) {

languages/java/oso/src/test/java/com/osohq/oso/OsoJavaRecordTest.java

@@ -0,0 +1,155 @@
+package com.osohq.oso;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.net.URL;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class OsoJavaRecordTest {
+  protected Oso o;
+
+  public record User(String name) {
+    public List<Company> companies() {
+      return List.of(new Company(1));
+    }
+  }
+
+  public record Widget(int id) {
+  }
+
+  public record Company(int id) {
+
+    public String role(User a) {
+      if (a.name.equals("president")) {
+        return "admin";
+      }
+
+      return "guest";
+    }
+  }
+
+  @BeforeEach
+  public void setUp() throws Exception {
+    try {
+      URL testOso = getClass().getClassLoader().getResource("test_oso.polar");
+
+      o = new Oso();
+      o.registerClass(User.class, "User");
+      o.registerClass(Widget.class, "Widget");
+      o.registerClass(Company.class, "Company");
+
+      o.loadFile(testOso.getPath());
+    } catch (Exception e) {
+      throw new Error(e);
+    }
+  }
+
+  @Test
+  public void testIsAllowed() throws Exception {
+    User guest = new User("guest");
+    Widget resource1 = new Widget(1);
+    assertTrue(o.isAllowed(guest, "get", resource1));
+
+    User president = new User("president");
+    Company company = new Company(1);
+    assertTrue(o.isAllowed(president, "create", company));
+  }
+
+  @Test
+  public void testFail() throws Exception {
+    User guest = new User("guest");
+    Widget widget = new Widget(1);
+    assertFalse(o.isAllowed(guest, "not_allowed", widget));
+  }
+
+  @Test
+  public void testInstanceFromExternalCall() throws Exception {
+    Company company = new Company(1);
+    User guest = new User("guest");
+    assertTrue(o.isAllowed(guest, "frob", company));
+
+    // if the guest user can do it, then the dict should
+    // create an instance of the user and be allowed
+    HashMap<String, String> userMap = new HashMap<String, String>();
+    userMap.put("username", "guest");
+    assertTrue(o.isAllowed(userMap, "frob", company));
+  }
+
+  @Test
+  public void testAllowModel() throws Exception {
+    User auditor = new User("auditor");
+
+    assertTrue(o.isAllowed(auditor, "list", Company.class));
+    assertFalse(o.isAllowed(auditor, "list", Widget.class));
+  }
+
+  @Test
+  public void testGetAllowedActions() throws Exception {
+
+    Oso o = new Oso();
+    o.registerClass(User.class, "User");
+    o.registerClass(Widget.class, "Widget");
+
+    o.loadStr(
+        "allow(_actor: User{name: \"sally\"}, action, _resource: Widget{id: 1})"
+            + " if action in [\"CREATE\", \"READ\"];");
+
+    User actor = new User("sally");
+    Widget widget = new Widget(1);
+    HashSet<Object> actions = o.getAllowedActions(actor, widget);
+
+    assertEquals(actions.size(), 2);
+    assertTrue(actions.contains("CREATE"));
+    assertTrue(actions.contains("READ"));
+
+    o.clearRules();
+
+    o.loadStr(
+        "allow(_actor: User{name: \"fred\"}, action, _resource: Widget{id: 2})"
+            + " if action in [1, 2, 3, 4];");
+
+    User actor2 = new User("fred");
+    Widget widget2 = new Widget(2);
+    HashSet<Object> actions2 = o.getAllowedActions(actor2, widget2);
+
+    assertEquals(actions2.size(), 4);
+    assertTrue(actions2.contains(1));
+    assertTrue(actions2.contains(2));
+    assertTrue(actions2.contains(3));
+    assertTrue(actions2.contains(4));
+
+    User actor3 = new User("doug");
+    Widget widget3 = new Widget(4);
+    assertTrue(o.getAllowedActions(actor3, widget3).isEmpty());
+  }
+
+  @Test
+  public void testGetAllowedActionsWildcard() throws Exception {
+    Oso o = new Oso();
+
+    o.registerClass(User.class, "User");
+    o.registerClass(Widget.class, "Widget");
+
+    o.loadStr("allow(_actor: User{name: \"John\"}, _action, _resource: Widget{id: 1});");
+
+    User actor = new User("John");
+    Widget widget = new Widget(1);
+
+    assertEquals(Set.of("*"), o.getAllowedActions(actor, widget, true));
+    assertThrows(Exceptions.OsoException.class, () -> o.getAllowedActions(actor, widget, false));
+  }
+
+  @Test
+  public void testNotEqualOperator() {
+    Oso oso = new Oso();
+    oso.registerClass(User.class, "User");
+    oso.loadStr("allow(actor: User, _action, _resource) if actor != nil;");
+    assertFalse(oso.isAllowed(null, "foo", "foo"));
+  }
+}