feat: Update to OPA v1.2.0 (#373)

Regorus now defaults to rego v1. `import rego.v1` is no longer needed.
Additionally, `future` keywords are automatically imported.

See
https://www.openpolicyagent.org/docs/latest/v0-upgrade/#changes-to-rego-in-opa-v10
to understand the differences between rego v1 and v0.

BREAKING CHANGE:

v0 style policies will error out by default. To enable v0 behavior, call engine.set_rego_v0(true) before
loading policies.

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

bindings/java/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "regorus-java"
-version = "0.2.2"
+version = "0.3.0"
 edition = "2021"
 repository = "https://github.com/microsoft/regorus/bindings/java"
 description = "Java bindings for Regorus - a fast, lightweight Rego interpreter written in Rust"

bindings/java/Test.java

@@ -4,39 +4,45 @@
 import com.microsoft.regorus.Engine;
 
 public class Test {
+
     public static void main(String[] args) {
         try (Engine engine = new Engine()) {
             String pkg = engine.addPolicy(
-                "hello.rego",
-                "package test\nx=1\nmessage = concat(\", \", [input.message, data.message])"
+                    "hello.rego",
+                    "package test\nx=1\nmessage = concat(\", \", [input.message, data.message])"
             );
-	    System.out.println("Loaded package " + pkg);
+            System.out.println("Loaded package " + pkg);
 
-	    
             engine.addDataJson("{\"message\":\"World!\"}");
             engine.setInputJson("{\"message\":\"Hello\"}");
 
-	    // Evaluate query.
-	    String resJson = engine.evalQuery("data.test.message");
+            // Evaluate query.
+            String resJson = engine.evalQuery("data.test.message");
             System.out.println(resJson);
 
-	    // Enable coverage.
-	    engine.setEnableCoverage(true);
+            // Enable coverage.
+            engine.setEnableCoverage(true);
 
-	    // Evaluate rule.
-	    String valueJson = engine.evalRule("data.test.message");
+            // Evaluate rule.
+            String valueJson = engine.evalRule("data.test.message");
             System.out.println(valueJson);
 
-	    String coverageJson = engine.getCoverageReport();
-	    System.out.println(coverageJson);
+            String coverageJson = engine.getCoverageReport();
+            System.out.println(coverageJson);
 
-	    System.out.println(engine.getCoverageReportPretty());
+            System.out.println(engine.getCoverageReportPretty());
 
-	    String packagesJson = engine.getPackages();
-	    System.out.println(packagesJson);
+            String packagesJson = engine.getPackages();
+            System.out.println(packagesJson);
 
-	    String policiesJson = engine.getPolicies();
-	    System.out.println(policiesJson);
+            String policiesJson = engine.getPolicies();
+            System.out.println(policiesJson);
+
+            engine.setRegoV0(true);
+            engine.addPolicy(
+                    "world.rego",
+                    "package world\nx { true }"
+            );
         }
     }
 }

bindings/java/src/lib.rs

@@ -28,6 +28,20 @@ pub extern "system" fn Java_com_microsoft_regorus_Engine_nativeClone(
     Box::into_raw(Box::new(c)) as jlong
 }
 
+#[no_mangle]
+pub extern "system" fn Java_com_microsoft_regorus_Engine_nativeSetRegoV0(
+    env: JNIEnv,
+    _class: JClass,
+    engine_ptr: jlong,
+    enable: bool,
+) {
+    let _ = throw_err(env, |_env| {
+        let engine = unsafe { &mut *(engine_ptr as *mut Engine) };
+        engine.set_rego_v0(enable);
+        Ok(())
+    });
+}
+
 #[no_mangle]
 pub extern "system" fn Java_com_microsoft_regorus_Engine_nativeAddPolicy(
     env: JNIEnv,

bindings/java/src/main/java/com/microsoft/regorus/Engine.java

@@ -8,10 +8,8 @@ package com.microsoft.regorus;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
-import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
-import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Regorus Engine.
@@ -23,6 +21,7 @@ public class Engine implements AutoCloseable, Cloneable {
     // if you update the native API.
     private static native long nativeNewEngine();
     private static native long nativeClone(long enginePtr);
+    private static native void nativeSetRegoV0(long enginePtr, boolean enable);
     private static native String nativeAddPolicy(long enginePtr, String path, String rego);
     private static native String nativeAddPolicyFromFile(long enginePtr, String path);
     private static native String nativeGetPackages(long enginePtr);
@@ -55,7 +54,7 @@ public class Engine implements AutoCloseable, Cloneable {
 
     
     Engine(long ptr) {
-	enginePtr = ptr;
+        enginePtr = ptr;
     }
 
     /**
@@ -65,6 +64,16 @@ public class Engine implements AutoCloseable, Cloneable {
 	return new Engine(nativeClone(enginePtr));
     }
     
+     /**
+     * Enable/disable Rego v0.
+     * 
+     * @param enable Whether to enable v0 or not.
+     * 
+     */
+    public void setRegoV0(boolean enable) {
+        nativeSetRegoV0(enginePtr, enable);
+    }
+
     /**
      * Adds an inline Rego policy.
      *