Make it possible to run firestore tests against emulator (#488)

* Desktop and Android works with env variable and extra

* Format and remove GTEST_FILTER for now

* Add deletelocalref

* Feedback.

* More tweaks.

Author: wu-hui

firestore/integration_test_internal/AndroidManifest.xml

@@ -16,7 +16,7 @@
 */
 -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-          package="com.google.firebase.cpp.database.testapp"
+          package="com.google.firebase.cpp.firestore.testapp"
           android:versionCode="1"
           android:versionName="1.0">
   <uses-permission android:name="android.permission.INTERNET" />

firestore/integration_test_internal/src/firestore_integration_test.cc

@@ -20,32 +20,35 @@ namespace {
 // non-default app to avoid data ending up in the cache before tests run.
 static const char* kBootstrapAppName = "bootstrap";
 
-// Set Firestore up to use Firestore Emulator if it can be found.
+// Set Firestore up to use Firestore Emulator via USE_FIRESTORE_EMULATOR
 void LocateEmulator(Firestore* db) {
-  // iOS and Android pass emulator address differently, iOS writes it to a
-  // temp file, but there is no equivalent to `/tmp/` for Android, so it
-  // uses an environment variable instead.
-  // TODO(wuandy): See if we can use environment variable for iOS as well?
-  std::ifstream ifs("/tmp/emulator_address");
-  std::stringstream buffer;
-  buffer << ifs.rdbuf();
-  std::string address;
-  if (ifs.good()) {
-    address = buffer.str();
-  } else if (std::getenv("FIRESTORE_EMULATOR_HOST")) {
-    address = std::getenv("FIRESTORE_EMULATOR_HOST");
+  // Use emulator as long as this env variable is set, regardless its value.
+  if (std::getenv("USE_FIRESTORE_EMULATOR") == nullptr) {
+    LogDebug("Using Firestore Prod for testing.");
+    return;
   }
 
-#if !defined(__ANDROID__)
-  absl::StripAsciiWhitespace(&address);
-#endif  // !defined(__ANDROID__)
-  if (!address.empty()) {
-    auto settings = db->settings();
-    settings.set_host(address);
-    // Emulator does not support ssl yet.
-    settings.set_ssl_enabled(false);
-    db->set_settings(settings);
-  }
+#if defined(__ANDROID__)
+  // Special IP to access the hosting OS from Android Emulator.
+  std::string local_host = "10.0.2.2";
+#else
+  std::string local_host = "localhost";
+#endif  // defined(__ANDROID__)
+
+  // Use FIRESTORE_EMULATOR_PORT if it is set to non empty string,
+  // otherwise use the default port.
+  std::string port = std::getenv("FIRESTORE_EMULATOR_PORT")
+                         ? std::getenv("FIRESTORE_EMULATOR_PORT")
+                         : "8080";
+  std::string address =
+      port.empty() ? (local_host + ":8080") : (local_host + ":" + port);
+
+  LogInfo("Using Firestore Emulator (%s) for testing.", address.c_str());
+  auto settings = db->settings();
+  settings.set_host(address);
+  // Emulator does not support ssl yet.
+  settings.set_ssl_enabled(false);
+  db->set_settings(settings);
 }
 
 }  // namespace

testing/sample_framework/src/android/android_app_framework.cc

@@ -478,6 +478,43 @@ std::string ReadTextInput(const char* title, const char* message,
   return g_text_entry_field_data->ReadText(title, message, placeholder);
 }
 
+void SetEnvironmentVariableFromStringExtra(JNIEnv* env, const char* extra_name,
+                                           jobject intent) {
+  jclass intent_class = env->GetObjectClass(intent);
+  jmethodID get_string_extra = env->GetMethodID(
+      intent_class, "getStringExtra", "(Ljava/lang/String;)Ljava/lang/String;");
+  env->DeleteLocalRef(intent_class);
+
+  jstring extra_name_jstring = env->NewStringUTF(extra_name);
+  jstring extra_value_jstring = (jstring)env->CallObjectMethod(
+      intent, get_string_extra, extra_name_jstring);
+  env->DeleteLocalRef(extra_name_jstring);
+
+  if (extra_value_jstring != nullptr) {
+    const char* extra_value =
+        env->GetStringUTFChars(extra_value_jstring, nullptr);
+    setenv(extra_name, extra_value, /*overwrite=*/1);
+    env->ReleaseStringUTFChars(extra_value_jstring, extra_value);
+    env->DeleteLocalRef(extra_value_jstring);
+  }
+}
+
+void SetExtrasAsEnvironmentVariables() {
+  JNIEnv* env = app_framework::GetJniEnv();
+  jobject activity = app_framework::GetActivity();
+
+  jclass activity_class = env->GetObjectClass(activity);
+  jmethodID get_intent = env->GetMethodID(activity_class, "getIntent",
+                                          "()Landroid/content/Intent;");
+  env->DeleteLocalRef(activity_class);
+
+  jobject intent = env->CallObjectMethod(activity, get_intent);
+  SetEnvironmentVariableFromStringExtra(env, "USE_FIRESTORE_EMULATOR", intent);
+  SetEnvironmentVariableFromStringExtra(env, "FIRESTORE_EMULATOR_PORT", intent);
+
+  env->DeleteLocalRef(intent);
+}
+
 }  // namespace app_framework
 
 // Execute common_main(), flush pending events and finish the activity.
@@ -520,6 +557,8 @@ extern "C" void android_main(struct android_app* state) {
   pthread_create(&thread, nullptr, app_framework::stdout_logger,
                  reinterpret_cast<void*>(filedes));
 
+  app_framework::SetExtrasAsEnvironmentVariables();
+
   // Execute cross platform entry point.
   // Copy the app name into a non-const array, as googletest requires that
   // main() take non-const char* argv[] so it can modify the arguments.