some android lint ref.

sentry-android-core/src/main/java/io/sentry/android/core/DefaultAndroidEventProcessor.java

@@ -23,8 +23,8 @@
 import java.util.*;
 
 public class DefaultAndroidEventProcessor implements EventProcessor {
-  Context context;
-  SentryOptions options;
+  final Context context;
+  final SentryOptions options;
 
   // it could also be a parameter and get from Sentry.init(...)
   private static final Date appStartTime = DateUtils.getCurrentDateTime();

sentry-core/src/main/java/io/sentry/core/DiagnosticLogger.java

@@ -5,8 +5,8 @@
 
 /** Sentry SDK internal diagnostic logger. */
 public class DiagnosticLogger implements ILogger {
-  private SentryOptions options;
-  private ILogger logger;
+  private final SentryOptions options;
+  private final ILogger logger;
 
   /**
    * Creates a new instance of DiagnosticLogger with the wrapped ILogger.

sentry-core/src/main/java/io/sentry/core/EnvelopeReader.java

@@ -27,7 +27,7 @@ SentryEnvelopeItemHeader.class, new SentryEnvelopeItemHeaderAdapter())
 
   public @Nullable SentryEnvelope read(InputStream stream) throws IOException {
     byte[] buffer = new byte[1024];
-    int currentLength = 0;
+    int currentLength;
     int streamOffset = 0;
     // Offset of the line break defining the end of the envelope header
     int envelopeEndHeaderOffset = -1;

sentry-core/src/main/java/io/sentry/core/Hub.java

@@ -1,5 +1,7 @@
 package io.sentry.core;
 
+import static io.sentry.core.ILogger.log;
+
 import io.sentry.core.protocol.SentryId;
 import io.sentry.core.util.Nullable;
 import java.util.Deque;
@@ -40,8 +42,7 @@ private Hub(SentryOptions options, @Nullable StackItem rootStackItem) {
   static StackItem createRootStackItem(SentryOptions options) {
     Scope scope = new Scope();
     ISentryClient client = new SentryClient(options);
-    StackItem item = new StackItem(client, scope);
-    return item;
+    return new StackItem(client, scope);
   }
 
   @Override
@@ -53,16 +54,26 @@ public boolean isEnabled() {
   public SentryId captureEvent(SentryEvent event) {
     SentryId sentryId;
     StackItem item = stack.peek();
-    sentryId = item.client.captureEvent(event, item.scope);
-    this.lastEventId = sentryId;
+    if (item != null) {
+      sentryId = item.client.captureEvent(event, item.scope);
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when captureEvent");
+      sentryId = SentryId.EMPTY_ID;
+    }
+    this.lastEventId = event.getEventId();
     return sentryId;
   }
 
   @Override
   public SentryId captureMessage(String message) {
     SentryId sentryId;
     StackItem item = stack.peek();
-    sentryId = item.client.captureMessage(message, item.scope);
+    if (item != null) {
+      sentryId = item.client.captureMessage(message, item.scope);
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when captureMessage");
+      sentryId = SentryId.EMPTY_ID;
+    }
     this.lastEventId = sentryId;
     return sentryId;
   }
@@ -71,7 +82,12 @@ public SentryId captureMessage(String message) {
   public SentryId captureException(Throwable throwable) {
     SentryId sentryId;
     StackItem item = stack.peek();
-    sentryId = item.client.captureException(throwable, item.scope);
+    if (item != null) {
+      sentryId = item.client.captureException(throwable, item.scope);
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when captureException");
+      sentryId = SentryId.EMPTY_ID;
+    }
     this.lastEventId = sentryId;
     return sentryId;
   }
@@ -80,14 +96,22 @@ public SentryId captureException(Throwable throwable) {
   public void close() {
     // Close the top-most client
     StackItem item = stack.peek();
-    item.client.close();
+    if (item != null) {
+      item.client.close();
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when closing Hub");
+    }
     isEnabled = false;
   }
 
   @Override
   public void addBreadcrumb(Breadcrumb breadcrumb) {
     StackItem item = stack.peek();
-    item.scope.addBreadcrumb(breadcrumb);
+    if (item != null) {
+      item.scope.addBreadcrumb(breadcrumb);
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when addBreadcrumb");
+    }
   }
 
   @Override
@@ -98,9 +122,24 @@ public SentryId getLastEventId() {
   @Override
   public void pushScope() {
     StackItem item = stack.peek();
-    Scope clone = item.scope.clone();
-    StackItem newItem = new StackItem(item.client, clone);
-    stack.push(newItem);
+    if (item != null) {
+      Scope clone = null;
+      try {
+        clone = item.scope.clone();
+      } catch (CloneNotSupportedException e) {
+        log(
+            options.getLogger(),
+            SentryLevel.ERROR,
+            "An error has occurred when cloning a Scope",
+            e);
+      }
+      if (clone != null) {
+        StackItem newItem = new StackItem(item.client, clone);
+        stack.push(newItem);
+      }
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when pushScope");
+    }
   }
 
   @Override
@@ -118,7 +157,11 @@ public void withScope(ScopeCallback callback) {
     pushScope();
     try {
       StackItem item = stack.peek();
-      callback.run(item.scope);
+      if (item != null) {
+        callback.run(item.scope);
+      } else {
+        log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when withScope");
+      }
     } finally {
       popScope();
     }
@@ -127,19 +170,31 @@ public void withScope(ScopeCallback callback) {
   @Override
   public void configureScope(ScopeCallback callback) {
     StackItem item = stack.peek();
-    callback.run(item.scope);
+    if (item != null) {
+      callback.run(item.scope);
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when configureScope");
+    }
   }
 
   @Override
   public void bindClient(SentryClient client) {
     StackItem item = stack.peek();
-    item.client = client;
+    if (item != null) {
+      item.client = client != null ? client : NoOpSentryClient.getInstance();
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when bindClient");
+    }
   }
 
   @Override
   public void flush(long timeoutMills) {
     StackItem item = stack.peek();
-    item.client.flush(timeoutMills);
+    if (item != null) {
+      item.client.flush(timeoutMills);
+    } else {
+      log(options.getLogger(), SentryLevel.FATAL, "Stack peek was NULL when flush");
+    }
   }
 
   @Override

sentry-core/src/main/java/io/sentry/core/NoOpLogger.java

@@ -3,7 +3,7 @@
 /** No-op implementation of ILogger */
 class NoOpLogger implements ILogger {
 
-  private static NoOpLogger instance = new NoOpLogger();
+  private static final NoOpLogger instance = new NoOpLogger();
 
   public static NoOpLogger getInstance() {
     return instance;

sentry-core/src/main/java/io/sentry/core/Scope.java

@@ -76,8 +76,7 @@ public void setExtra(String key, String value) {
   }
 
   @Override
-  protected Scope clone() {
-    // TODO: clone me
-    return new Scope();
+  protected Scope clone() throws CloneNotSupportedException {
+    return (Scope) super.clone();
   }
 }

sentry-core/src/main/java/io/sentry/core/Sentry.java

@@ -8,7 +8,7 @@ public final class Sentry {
 
   private Sentry() {}
 
-  private static ThreadLocal<IHub> currentHub = new ThreadLocal<>();
+  private static final ThreadLocal<IHub> currentHub = new ThreadLocal<>();
 
   private static volatile IHub mainHub = NoOpHub.getInstance();
 

sentry-core/src/test/java/io/sentry/core/HubTest.kt

@@ -2,9 +2,40 @@ package io.sentry.core
 
 import com.nhaarman.mockitokotlin2.mock
 import com.nhaarman.mockitokotlin2.verify
+import io.sentry.core.protocol.User
 import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertNotSame
 
 class HubTest {
+
+    @Test
+    fun `when cloning Scope it returns the same values`() {
+        val scope = Scope()
+        scope.extra["test"] = "test"
+        val breadcrumb = Breadcrumb()
+        breadcrumb.message = "test"
+        scope.breadcrumbs.add(breadcrumb)
+        scope.level = SentryLevel.DEBUG
+        scope.transaction = "test"
+        scope.fingerprint.add("test")
+        scope.tags["test"] = "test"
+        val user = User()
+        user.email = "[email protected]"
+        scope.user = user
+
+        val clone = scope.clone()
+        assertNotNull(clone)
+        assertNotSame(scope, clone)
+        assertEquals("test", clone.extra["test"])
+        assertEquals("test", clone.breadcrumbs[0].message)
+        assertEquals("test", scope.transaction)
+        assertEquals("test", scope.fingerprint[0])
+        assertEquals("test", clone.tags["test"])
+        assertEquals("[email protected]", clone.user.email)
+    }
+
     @Test
     fun `when hub is initialized, integrations are registed`() {
         val integrationMock = mock<Integration>()

sentry-core/src/test/java/io/sentry/core/SentryEnvelopeTest.kt

@@ -4,15 +4,13 @@ import com.nhaarman.mockitokotlin2.any
 import com.nhaarman.mockitokotlin2.mock
 import com.nhaarman.mockitokotlin2.whenever
 import java.io.InputStream
-import java.nio.charset.Charset
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 import kotlin.test.assertNotNull
 import kotlin.test.assertNull
 
 class SentryEnvelopeTest {
-    private val UTF_8 = Charset.forName("UTF-8")
 
     @Test
     fun `deserialize sample envelope with event and two attachments`() {
@@ -46,7 +44,7 @@ class SentryEnvelopeTest {
     @Test
     fun `when envelope is empty, reader throws illegal argument`() {
         val envelopeReader = EnvelopeReader()
-        var stream = mock<InputStream>()
+        val stream = mock<InputStream>()
         whenever(stream.read(any())).thenReturn(-1)
         val exception = assertFailsWith<IllegalArgumentException> { envelopeReader.read(stream) }
         assertEquals("Empty stream.", exception.message)

sentry-core/src/test/java/io/sentry/core/transport/HttpTransportTest.kt

@@ -21,7 +21,7 @@ import kotlin.test.assertTrue
 class HttpTransportTest {
 
     private class Fixture {
-        var dsn = URI.create("http://key@localhost/proj").toURL()
+        val dsn: URL = URI.create("http://key@localhost/proj").toURL()
         val serializer = mock<ISerializer>()
         var proxy: Proxy? = null
         var requestUpdater = IConnectionConfigurator {}