ColCh · February 24, 2017 13:25 · Feb 24, 2017
diff --git a/app.js b/app.js
@@ -0,0 +1,5 @@
+// WARNING: SIDE-EFFECTS. ONLY FOR PROD VERSION
+if (!__DEV__) {
+  require('./utils/log.js');
+}
+// SIDE-EFFECTS END
diff --git a/log.js b/log.js
@@ -0,0 +1,78 @@
+/**
+ * log wrapper around crashlytics and RN log
+ */
+
+
+import { Platform } from 'react-native';
+
+import { Crashlytics } from 'react-native-fabric';
+
+
+function convertToString(arg) {
+  return typeof arg === 'object' ? JSON.stringify(arg) : `${arg}`;
+}
+
+
+['error', 'warn', 'log'].forEach((methodName) => {
+  const origMethod = console[methodName];
+  console[methodName] = (...args) => {
+    if (args.length > 1) {
+      console.warn(`react-native-fabric supports only 1 (one) argument to method and have passed <${args.length}> arguments. Replace this line by "console.trace()" to see stack trace`);
+    }
+    if (args.some(arg => typeof arg !== 'string')) {
+      console.warn(`It seems that some argument type is not <string> on <${JSON.stringify(args)}>. Converting it to string.`);
+    }
+    const message = convertToString(args.shift());
+    if (Platform.OS === 'android') {
+      // console.log calls to device log on ios
+      // but on android, it's needed to call Crashlytics log
+      Crashlytics.log(message);
+    }
+    origMethod.call(console, message);
+  };
+  console[methodName].name = `decoratedConsole_${methodName}`;
+});
+
+
+// Copypasted from
+// https://github.com/bugsnag/bugsnag-react-native/blob/754008743c17d39f6c6d2bc1a0078e7e1bc3ac96/lib/Bugsnag.js#L36
+/*eslint-disable*/
+handleUncaughtErrors = () => {
+  console.log('App is handling uncaught errors');
+  if (ErrorUtils) {
+    const previousHandler = ErrorUtils.getGlobalHandler();
+
+    ErrorUtils.setGlobalHandler((error, isFatal) => {
+      console.log(`Handle error. Is fatal? <${isFatal}>`);
+      error.message = `ErrorUtils: handled ${isFatal ? 'fatal':'non-fatal'} error: ${error.message}`;
+      if (isFatal) {
+        Crashlytics.recordError(error);
+      } else {
+        Crashlytics.logException(error);
+      }
+      if (previousHandler) {
+        previousHandler(error, isFatal);
+      }
+    });
+  }
+}
+handlePromiseRejections = () => {
+  console.log('App is handling promise rejections');
+  const tracking = require('promise/setimmediate/rejection-tracking');
+  tracking.enable({
+    allRejections: true,
+    onUnhandled: function(id, error) {
+      console.log('Handle promise rejection');
+      error.message = `handlePromiseRejections: handled promise rejection: ${error.message}`;
+      Crashlytics.recordError(error);
+    },
+    onHandled: function() {}
+  });
+}
+
+handleUncaughtErrors();
+handlePromiseRejections();
+/*eslint-enable*/
+
+
+console.log('App is running decorated console methods');