feat: Run callbacks before native crash reports (#379)

* Added support for modifying all reports (including native crash
reports) prior to delivery.
* Added new functionality to convert an Error cached on disk back
into an Error object, which is then added to reports. The new 
callbacks are run on the resulting report object just prior to 
delivery.

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 ## TBD
 
+### Enhancements
+
+* Add a callback to allow modifying reports immediately prior to delivery,
+  including fatal crashes from native C/C++ code. For more information, see the
+  [callback reference](https://docs.bugsnag.com/platforms/android/sdk/customizing-error-reports).
+  [#379](https://github.com/bugsnag/bugsnag-android/pull/379)
+
 ### Bug fixes
 
 * [NDK] Improve stack trace quality for signals raised on ARM32 devices

features/before_send.feature

@@ -0,0 +1,49 @@
+Feature: Run callbacks before reports delivered
+
+    Scenario: Change report before native crash report delivered
+        When I run "NativeBeforeSendScenario"
+        And I configure the app to run in the "non-crashy" state
+        And I relaunch the app
+        Then I should receive a request
+        And the request payload contains a completed native report
+        And the exception "errorClass" equals "SIGSEGV"
+        And the exception "message" equals "Segmentation violation (invalid memory reference)"
+        And the event "context" equals "!important"
+        And the exception "type" equals "c"
+        And the event "severity" equals "error"
+        And the event "unhandled" is true
+
+    Scenario: Change report before JVM crash report delivered
+        When I run "BeforeSendScenario"
+        And I configure the app to run in the "non-crashy" state
+        And I relaunch the app
+        Then I should receive a request
+        And the request payload contains a completed native report
+        And the exception "errorClass" equals "java.lang.RuntimeException"
+        And the exception "message" equals "Ruh-roh"
+        And the event "context" equals "UNSET"
+        And the exception "type" equals "android"
+        And the event "severity" equals "error"
+        And the event "unhandled" is true
+
+    Scenario: Change report before native notify() report delivered
+        When I run "NativeNotifyBeforeSendScenario"
+        Then I should receive a request
+        And the request is a valid for the error reporting API
+        And the exception "errorClass" equals "Ad-hoc"
+        And the exception "message" equals "Auto-generated issue"
+        And the event "context" equals "hello"
+        And the exception "type" equals "c"
+        And the event "severity" equals "info"
+        And the event "unhandled" is false
+
+    Scenario: Change report before notify() report delivered
+        When I run "NotifyBeforeSendScenario"
+        Then I should receive a request
+        And the request is a valid for the error reporting API
+        And the exception "errorClass" equals "java.lang.Exception"
+        And the exception "message" equals "Registration failure"
+        And the event "context" equals "RESET"
+        And the exception "type" equals "android"
+        And the event "severity" equals "error"
+        And the event "unhandled" is false

features/fixtures/mazerunner/src/main/cpp/bugsnags.cpp

@@ -44,6 +44,13 @@ Java_com_bugsnag_android_mazerunner_scenarios_CXXExtraordinaryLongStringScenario
   return 12062 / value;
 }
 
+JNIEXPORT void JNICALL
+Java_com_bugsnag_android_mazerunner_scenarios_NativeNotifyBeforeSendScenario_activate(JNIEnv *env,
+                                                                         jobject instance) {
+  bugsnag_notify_env(env, (char *)"Ad-hoc",
+                     (char *)"Auto-generated issue", BSG_SEVERITY_INFO);
+}
+
 JNIEXPORT void JNICALL
 Java_com_bugsnag_android_mazerunner_scenarios_CXXNotifyScenario_activate(JNIEnv *env,
                                                                          jobject instance) {

features/fixtures/mazerunner/src/main/cpp/entrypoint.cpp

@@ -188,6 +188,12 @@ Java_com_bugsnag_android_mazerunner_scenarios_CXXWriteReadOnlyMemoryScenario_cra
     printf("This one here: %d\n", crash_write_read_only_mem(42));
 }
 
+JNIEXPORT void JNICALL
+Java_com_bugsnag_android_mazerunner_scenarios_NativeBeforeSendScenario_crash(JNIEnv *env,
+                                                                             jobject instance) {
+    printf("This one here: %s\n", crash_improper_cast(39));
+}
+
 JNIEXPORT void JNICALL
 Java_com_bugsnag_android_mazerunner_scenarios_CXXImproperTypecastScenario_crash(JNIEnv *env,
                                                                                 jobject instance) {

features/fixtures/mazerunner/src/main/java/com/bugsnag/android/mazerunner/scenarios/BeforeSendScenario.java

@@ -0,0 +1,36 @@
+package com.bugsnag.android.mazerunner.scenarios;
+
+import com.bugsnag.android.Bugsnag;
+import com.bugsnag.android.BeforeSend;
+import com.bugsnag.android.Configuration;
+import com.bugsnag.android.Report;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+
+
+public class BeforeSendScenario extends Scenario {
+
+    public BeforeSendScenario(@NonNull Configuration config, @NonNull Context context) {
+        super(config, context);
+        config.setAutoCaptureSessions(false);
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                report.getError().setContext("UNSET");
+
+                return true;
+            }
+        });
+    }
+
+    @Override
+    public void run() {
+        super.run();
+        String metadata = getEventMetaData();
+        if (metadata != null && metadata.equals("non-crashy")) {
+            return;
+        }
+        throw new RuntimeException("Ruh-roh");
+    }
+}

features/fixtures/mazerunner/src/main/java/com/bugsnag/android/mazerunner/scenarios/NativeBeforeSendScenario.java

@@ -0,0 +1,43 @@
+package com.bugsnag.android.mazerunner.scenarios;
+
+import com.bugsnag.android.Bugsnag;
+import com.bugsnag.android.BeforeSend;
+import com.bugsnag.android.Configuration;
+import com.bugsnag.android.Report;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+
+
+public class NativeBeforeSendScenario extends Scenario {
+
+    static {
+        System.loadLibrary("bugsnag-ndk");
+        System.loadLibrary("entrypoint");
+    }
+
+    public native void crash();
+
+    public NativeBeforeSendScenario(@NonNull Configuration config, @NonNull Context context) {
+        super(config, context);
+        config.setAutoCaptureSessions(false);
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                report.getError().setContext("!important");
+
+                return true;
+            }
+        });
+    }
+
+    @Override
+    public void run() {
+        super.run();
+        String metadata = getEventMetaData();
+        if (metadata != null && metadata.equals("non-crashy")) {
+            return;
+        }
+        crash();
+    }
+}

features/fixtures/mazerunner/src/main/java/com/bugsnag/android/mazerunner/scenarios/NativeNotifyBeforeSendScenario.java

@@ -0,0 +1,39 @@
+package com.bugsnag.android.mazerunner.scenarios;
+
+import com.bugsnag.android.Bugsnag;
+import com.bugsnag.android.BeforeSend;
+import com.bugsnag.android.Configuration;
+import com.bugsnag.android.Report;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+
+
+public class NativeNotifyBeforeSendScenario extends Scenario {
+
+    static {
+        System.loadLibrary("bugsnag-ndk");
+        System.loadLibrary("entrypoint");
+    }
+
+    public native void activate();
+
+    public NativeNotifyBeforeSendScenario(@NonNull Configuration config, @NonNull Context context) {
+        super(config, context);
+        config.setAutoCaptureSessions(false);
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                report.getError().setContext("hello");
+
+                return true;
+            }
+        });
+    }
+
+    @Override
+    public void run() {
+        super.run();
+        activate();
+    }
+}

features/fixtures/mazerunner/src/main/java/com/bugsnag/android/mazerunner/scenarios/NotifyBeforeSendScenario.java

@@ -0,0 +1,34 @@
+package com.bugsnag.android.mazerunner.scenarios;
+
+import com.bugsnag.android.Bugsnag;
+import com.bugsnag.android.BeforeSend;
+import com.bugsnag.android.Configuration;
+import com.bugsnag.android.Report;
+import com.bugsnag.android.Severity;
+
+import android.content.Context;
+import android.support.annotation.NonNull;
+
+
+public class NotifyBeforeSendScenario extends Scenario {
+
+    public NotifyBeforeSendScenario(@NonNull Configuration config, @NonNull Context context) {
+        super(config, context);
+        config.setAutoCaptureSessions(false);
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                report.getError().setContext("RESET");
+                report.getError().setSeverity(Severity.ERROR);
+
+                return true;
+            }
+        });
+    }
+
+    @Override
+    public void run() {
+        super.run();
+        Bugsnag.notify(new Exception("Registration failure"));
+    }
+}

sdk/src/androidTest/java/com/bugsnag/android/BeforeSendTest.java

@@ -0,0 +1,114 @@
+package com.bugsnag.android;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import android.support.test.InstrumentationRegistry;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class BeforeSendTest {
+
+    private Client client;
+    private Configuration config;
+    private Report lastReport;
+    private String result = "";
+
+    /**
+     * Configures a client
+     */
+    @Before
+    public void setUp() throws Exception {
+        result = "";
+        config = new Configuration("key");
+        config.setDelivery(new Delivery() {
+            @Override
+            public void deliver(SessionTrackingPayload payload,
+                                Configuration config)
+                throws DeliveryFailureException {}
+
+            @Override
+            public void deliver(Report report,
+                                Configuration config)
+                throws DeliveryFailureException {
+                lastReport = report;
+            }
+        });
+        client = new Client(InstrumentationRegistry.getContext(), config);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        lastReport = null;
+        Async.cancelTasks();
+    }
+
+    @Test
+    public void testCallbackOrderPreserved() {
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                result = result + "a";
+                return true;
+            }
+        });
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                result = result + "b";
+                return true;
+            }
+        });
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                result = result + "c";
+                return true;
+            }
+        });
+        client.notifyBlocking(new Exception("womp womp"));
+        assertEquals("abc", result);
+        assertNotNull(lastReport);
+    }
+
+    @Test
+    public void testCancelReport() {
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                result = result + "a";
+                return true;
+            }
+        });
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                result = result + "b";
+                return false;
+            }
+        });
+        client.notifyBlocking(new Exception("womp womp"));
+        assertEquals("ab", result);
+        assertNull(lastReport);
+    }
+
+    @Test
+    public void testAlterReport() {
+        config.beforeSend(new BeforeSend() {
+            @Override
+            public boolean run(Report report) {
+                report.getError().setGroupingHash("123");
+                return true;
+            }
+        });
+        client.notifyBlocking(new Exception("womp womp"));
+        assertEquals("123", lastReport.getError().getGroupingHash());
+    }
+}