error-reporting: Fix report() silently failing

packages/error-reporting/src/build-stack-trace.js

@@ -0,0 +1,42 @@
+/**
+ * Copyright 2017 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+
+const SRC_ROOT = __dirname;
+
+/**
+ * Constructs a string representation of the stack trace at the point where
+ * this function was invoked.  Note that the stack trace will not include any
+ * references to frames specific to this error-reporting library itself.
+ * @param {String?} message - The message that should appear as the first line
+ *   of the stack trace.  This value defaults to the empty string.
+ * @returns {String} - A string representation of the stack trace at the point
+ *   where this method was invoked.
+ */
+function buildStackTrace(message) {
+  var target = {};
+  // Build a stack trace without the frames associated with `buildStackTrace`.
+  // The stack is located at `target.stack`.
+  Error.captureStackTrace(target, buildStackTrace);
+  var prefix = message ? message + '\n' : '';
+  return prefix + target.stack.split('\n').slice(1).filter(function(line) {
+    // Filter out all frames that are specific to the error-reporting library
+    return !line || line.indexOf(SRC_ROOT) === -1;
+  }).join('\n');
+}
+
+module.exports = buildStackTrace;