exception handling, overloading, global scope (#7)

* add try catch to jni

* bug fix for exception handler

* make get operator return nullable value

* add ability to do things in global scope to get away from memory management

* bug fix and more unit tests

* add comments

* add support for overloading methods

* optimize thread to avoid deadlock

* add global memory table and unit tests for it

* handle null property in json object

---------

Co-authored-by: Wenxi Zeng <wzeng@twilio.com>

Author: wenxi-zeng

substrata-kotlin/src/androidTest/java/com/segment/analytics/substrata/kotlin/EngineTests.kt

@@ -2,7 +2,10 @@ package com.segment.analytics.substrata.kotlin
 
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import junit.framework.Assert.*
+import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
 import org.junit.After
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -60,6 +63,12 @@ class EngineTests {
             assertEquals("123", bridge.getString("string"))
             assertEquals(123, bridge.getInt("int"))
             assertEquals(false, bridge.getBoolean("bool"))
+
+            val ret = evaluate("""
+                let v = DataBridge["int"]
+                v
+            """.trimIndent())
+            assertEquals(123, ret)
         }
         assertNull(exception)
     }
@@ -456,6 +465,140 @@ class EngineTests {
         assertNull(exception)
     }
 
+    @Test
+    fun testCallWithJsonElement() {
+        val message = "This came from a LivePlugin"
+        val script = """
+            class MyTest {
+                track(event) {
+                    event.context.livePluginMessage = "$message";
+                    const mcvid = DataBridge["mcvid"]
+                    if (mcvid) {
+                        event.context.mcvid = mcvid;
+                    }
+                    return event
+                }
+            }
+            let myTest = new MyTest()
+            myTest
+        """.trimIndent()
+        val json = """
+            {"properties":{"version":1,"build":1,"from_background":false},"event":"Application Opened","type":"track","messageId":"2132f014-a8fe-41b6-b714-0226db39e0d3","anonymousId":"a7bffc58-991e-4a2d-98a7-2a04abb3ea93","integrations":{},"context":{"library":{"name":"analytics-kotlin","version":"1.15.0"},"instanceId":"49f19161-6d56-4024-b23d-7f32d6ab9982","app":{"name":"analytics-kotlin-live","version":1,"namespace":"com.segment.analytics.liveplugins.app","build":1},"device":{"id":"87bc73d4e4ca1608da083975d36421aef0411dff765c9766b9bfaf266b7c1586","manufacturer":"Google","model":"sdk_gphone64_arm64","name":"emu64a","type":"android"},"os":{"name":"Android","version":14},"screen":{"density":2.75,"height":2154,"width":1080},"network":{},"locale":"en-US","userAgent":"Dalvik/2.1.0 (Linux; U; Android 14; sdk_gphone64_arm64 Build/UE1A.230829.036.A1)","timezone":"America/Chicago"},"userId":"","_metadata":{"bundled":[],"unbundled":[],"bundledIds":[]},"timestamp":"2024-04-25T16:40:55.994Z"}
+        """.trimIndent()
+        val content = Json.parseToJsonElement(json)
+
+        scope.sync {
+            val ret = evaluate(script)
+            assert(ret is JSObject)
+            val res: Any = call(ret as JSObject, "track", JsonElementConverter.write(content, context))
+            assert(res is JSObject)
+            val jsonObject = JsonElementConverter.read(res)
+            assertNotNull(jsonObject)
+            assertEquals(message, jsonObject.jsonObject["context"]?.jsonObject?.get("livePluginMessage")?.jsonPrimitive?.content)
+        }
+        assertNull(exception)
+    }
+
+    @Test
+    fun testOverloads() {
+        class MyTest {
+            fun track() = 0
+
+            fun track(str: String) = str
+
+            fun track(i: Int, str: String) = "$i and $str"
+        }
+
+        scope.sync {
+            export("MyTest", MyTest::class)
+            val ret = evaluate("let myTest = new MyTest(); myTest")
+            assert(ret is JSObject)
+            val jsObject = ret as JSObject
+            assertEquals(0, call(jsObject, "track"))
+            assertEquals("testtest", call(jsObject, "track", "testtest"))
+            assertEquals("0 and testtest", call(jsObject, "track", 0, "testtest"))
+        }
+        assertNull(exception)
+    }
+
+    @Test
+    fun testNestedScopes() {
+        scope.sync {
+            val l1 = scope.await {
+                val l2 = scope.await {
+                    scope.sync {
+                        Thread.sleep(500L)
+                    }
+                    1
+                }
+
+                (l2 ?: 0) + 1
+            }
+
+            assertEquals(2, l1)
+        }
+        assertNull(exception)
+    }
+
+    @Test
+    fun testNestedScopesInCallback() {
+        class MyTest {
+            var engine: JSScope? = null
+
+            fun track() {
+                engine?.sync {
+                    println("callback")
+                }
+            }
+        }
+        val myTest = MyTest()
+        myTest.engine = scope
+
+        scope.sync {
+            export(myTest, "MyTest", "myTest")
+            call("myTest", "track")
+        }
+        assertNull(exception)
+    }
+
+    @Test
+    fun testGlobalScopeDoesPersist() {
+        var ret: JSObject? = null
+        scope.sync {
+            ret = scope.await(global = true) {
+                val jsObject = context.newObject()
+                jsObject["a"] = 1
+                jsObject
+            }
+        }
+        assertNotNull(ret)
+        assert(ret is JSObject)
+
+        scope.sync {
+            val a = (ret as JSObject)["a"]
+            assertEquals(1, a)
+        }
+
+        assertNull(exception)
+    }
+
+    @Test
+    fun testException() {
+        class MyJSClass {
+            fun test(): Int {
+                throw Exception("something wrong")
+            }
+        }
+        scope.sync {
+            export( "MyJSClass", MyJSClass::class)
+            evaluate("""
+                let o = MyJSClass()
+                o.test()
+            """)
+        }
+        assertNotNull(exception)
+    }
+
     @Test
     fun testAwait() {
         val ret = scope.await {

substrata-kotlin/src/androidTest/java/com/segment/analytics/substrata/kotlin/TypesTests.kt

@@ -1,6 +1,7 @@
 package com.segment.analytics.substrata.kotlin
 
 import androidx.test.ext.junit.runners.AndroidJUnit4
+import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.add
 import kotlinx.serialization.json.boolean
 import kotlinx.serialization.json.buildJsonArray
@@ -190,4 +191,19 @@ class TypesTests {
         assertEquals("testtesttest", nestedArr[2].jsonPrimitive.content)
         assertEquals(3.3, nestedArr[3].jsonPrimitive.double, 0.01)
     }
+
+    @Test
+    fun testJsonElementConverter() {
+        val json = """
+            {"properties":{"version":1,"test": null, "build":1,"from_background":false},"event":"Application Opened","type":"track","messageId":"2132f014-a8fe-41b6-b714-0226db39e0d3","anonymousId":"a7bffc58-991e-4a2d-98a7-2a04abb3ea93","integrations":{},"context":{"library":{"name":"analytics-kotlin","version":"1.15.0"},"instanceId":"49f19161-6d56-4024-b23d-7f32d6ab9982","app":{"name":"analytics-kotlin-live","version":1,"namespace":"com.segment.analytics.liveplugins.app","build":1},"device":{"id":"87bc73d4e4ca1608da083975d36421aef0411dff765c9766b9bfaf266b7c1586","manufacturer":"Google","model":"sdk_gphone64_arm64","name":"emu64a","type":"android"},"os":{"name":"Android","version":14},"screen":{"density":2.75,"height":2154,"width":1080},"network":{},"locale":"en-US","userAgent":"Dalvik/2.1.0 (Linux; U; Android 14; sdk_gphone64_arm64 Build/UE1A.230829.036.A1)","timezone":"America/Chicago","livePluginMessage":"This came from a LivePlugin"},"userId":"","_metadata":{"bundled":[],"unbundled":[],"bundledIds":[]},"timestamp":"2024-04-25T16:40:55.994Z"}
+        """.trimIndent()
+        val content = Json.parseToJsonElement(json)
+
+        context.memScope {
+            val jsObject = JsonElementConverter.write(content, this)
+            assert(jsObject is JSObject)
+            val jsonObject = JsonElementConverter.read(jsObject)
+            assertNotNull(jsonObject)
+        }
+    }
 }

substrata-kotlin/src/main/cpp/java_helper.cpp

@@ -1,20 +1,29 @@
 #include <stdio.h>
+#include <string>
+#include <iostream>
 
 #include "java_helper.h"
 
-#define MAX_MSG_SIZE 1024
 
-jint throw_exception(JNIEnv *env, const char *exception_name, const char *message, ...) {
-    char formatted_message[MAX_MSG_SIZE];
-    va_list va_args;
-    va_start(va_args, message);
-    vsnprintf(formatted_message, MAX_MSG_SIZE, message, va_args);
-    va_end(va_args);
+void swallow_cpp_exception_and_throw_java(JNIEnv * env) {
+    try {
+        throw;
+    } catch(const ThrownJavaException&) {
+        //already reported to Java, ignore
+    } catch(const std::bad_alloc& rhs) {
+        //translate OOM C++ exception to a Java exception
+        NewJavaException(env, "java/lang/OutOfMemoryError", rhs.what());
+    } catch(const std::ios_base::failure& rhs) { //sample translation
+        //translate IO C++ exception to a Java exception
+        NewJavaException(env, "java/io/IOException", rhs.what());
 
-    jclass exception_class = env->FindClass(exception_name);
-    if (exception_class == NULL) {
-        return -1;
-    }
+        //TRANSLATE ANY OTHER C++ EXCEPTIONS TO JAVA EXCEPTIONS HERE
 
-    return env->ThrowNew(exception_class, formatted_message);
-}
+    } catch(const std::exception& e) {
+        //translate unknown C++ exception to a Java exception
+        NewJavaException(env, "java/lang/Error", e.what());
+    } catch(...) {
+        //translate unknown C++ exception to a Java exception
+        NewJavaException(env, "java/lang/Error", "Unknown exception type");
+    }
+}

substrata-kotlin/src/main/cpp/java_helper.h

@@ -1,48 +1,50 @@
 //
-// Created by Wenxi Zeng on 3/1/24.
+// See the original post here: https://stackoverflow.com/a/12014833/8296631
 //
 
 #ifndef SUBSTRATA_KOTLIN_JAVA_HELPER_H
 #define SUBSTRATA_KOTLIN_JAVA_HELPER_H
 
 #include <jni.h>
+#include <string>
+#include <stdexcept>
 
-#define CLASS_NAME_ILLEGAL_STATE_EXCEPTION "java/lang/IllegalStateException"
-
-#define THROW_EXCEPTION(ENV, EXCEPTION_NAME, ...)                               \
-    do {                                                                        \
-        throw_exception((ENV), (EXCEPTION_NAME), __VA_ARGS__);                  \
-        return;                                                                 \
-    } while (0)
-#define THROW_EXCEPTION_RET(ENV, EXCEPTION_NAME, ...)                           \
-    do {                                                                        \
-        throw_exception((ENV), (EXCEPTION_NAME), __VA_ARGS__);                  \
-        return 0;                                                               \
-    } while (0)
 #define MSG_OOM "Out of memory"
-#define MSG_NULL_JS_RUNTIME "Null JSRuntime"
-#define MSG_NULL_JS_CONTEXT "Null JSContext"
-#define MSG_NULL_JS_VALUE "Null JSValue"
-#define THROW_ILLEGAL_STATE_EXCEPTION(ENV, ...)                                 \
-    THROW_EXCEPTION(ENV, CLASS_NAME_ILLEGAL_STATE_EXCEPTION, __VA_ARGS__)
-#define THROW_ILLEGAL_STATE_EXCEPTION_RET(ENV, ...)                             \
-    THROW_EXCEPTION_RET(ENV, CLASS_NAME_ILLEGAL_STATE_EXCEPTION, __VA_ARGS__)
-#define CHECK_NULL(ENV, POINTER, MESSAGE)                                       \
-    do {                                                                        \
-        if ((POINTER) == NULL) {                                                \
-            THROW_ILLEGAL_STATE_EXCEPTION((ENV), (MESSAGE));                    \
-        }                                                                       \
-    } while (0)
-#define CHECK_NULL_RET(ENV, POINTER, MESSAGE)                                   \
-    do {                                                                        \
-        if ((POINTER) == NULL) {                                                \
-            THROW_ILLEGAL_STATE_EXCEPTION_RET((ENV), (MESSAGE));                \
-        }                                                                       \
-    } while (0)
-
-#define MAX_MSG_SIZE 1024
-
-jint throw_exception(JNIEnv *env, const char *exception_name, const char *message, ...);
+#define CLASS_NAME_ILLEGAL_STATE_EXCEPTION "java/lang/IllegalStateException"
 
+struct ThrownJavaException : std::exception {
+    ThrownJavaException(const std::string& message) : m_message(message) {}
+    ThrownJavaException() : m_message("") {}
+
+    // Override the what() method to provide a description of the exception
+    const char* what() const noexcept override {
+        return m_message.c_str();
+    }
+
+private:
+    std::string m_message;
+};
+
+//used to throw a new Java exception. use full paths like:
+//"java/lang/NoSuchFieldException"
+//"java/lang/NullPointerException"
+//"java/security/InvalidParameterException"
+struct NewJavaException : public ThrownJavaException{
+    NewJavaException(JNIEnv * env, const char* type, const char* message="")
+            :ThrownJavaException(type+std::string(" ")+message)
+    {
+        jclass newExcCls = env->FindClass(type);
+        if (newExcCls != NULL)
+            env->ThrowNew(newExcCls, message);
+        //if it is null, a NoClassDefFoundError was already thrown
+    }
+};
+
+inline void assert_no_exception(JNIEnv * env) {
+    if (env->ExceptionCheck()==JNI_TRUE)
+        throw ThrownJavaException("assert_no_exception");
+}
+
+void swallow_cpp_exception_and_throw_java(JNIEnv * env);
 
 #endif //SUBSTRATA_KOTLIN_JAVA_HELPER_H