Add the new build-stack-trace.js file

DominicKramer · DominicKramer · commit 93a897c0fecf · 2017-06-06T15:04:52.000-07:00
diff --git a/packages/error-reporting/src/build-stack-trace.js b/packages/error-reporting/src/build-stack-trace.js
@@ -0,0 +1,25 @@
+/**
+ * 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';
+
+function buildStackTrace(message) {
+  var fauxError = new Error('');
+  var fullStack = fauxError.stack.split('\n');
+  return (message ? message + '\n' : '') + fullStack.slice(2).join('\n');
+}
+
+module.exports = buildStackTrace;
diff --git a/packages/error-reporting/src/error-router.js b/packages/error-reporting/src/error-router.js
@@ -21,6 +21,7 @@ var isObject = is.object;
 var isString = is.string;
 var isNumber = is.number;
 var isFunction = is.function;
+var buildStackTrace = require('./build-stack-trace.js');
 
 /**
  * The Error handler router is responsible for taking an object of some type and
@@ -137,16 +138,7 @@ function populateFromObject(ob, errorMessage) {
  * @returns {Undefined} - does not return anything
  */
 function populateFromString(ob, errorMessage) {
-  var fauxError = new Error();
-  var fullStack = fauxError.stack.split('\n');
-  var cleanedStack = fullStack.slice(0, 1).concat(fullStack.slice(4));
-  var errChecked = '';
-
-  // Replace the generic error message with the user-provided string
-  cleanedStack[0] = ob;
-  errChecked = cleanedStack.join('\n');
-
-  errorMessage.setMessage(errChecked);
+  errorMessage.setMessage(buildStackTrace(ob));
 }
 
 /**
@@ -161,14 +153,8 @@ function populateFromString(ob, errorMessage) {
  * @returns {Undefined} - does not return anything
  */
 function populateFromNumber(ob, errorMessage) {
-  var fauxError = new Error();
-  var errChecked = fauxError.stack;
-
-  if (isNumber(ob) && isFunction(ob.toString)) {
-    errChecked = ob.toString();
-  }
-
-  errorMessage.setMessage(errChecked);
+  var message = isNumber(ob) && isFunction(ob.toString) ? ob.toString() : '';
+  errorMessage.setMessage(buildStackTrace(message));
 }
 
 /**
@@ -184,9 +170,7 @@ function populateFromNumber(ob, errorMessage) {
  * @returns {Undefined} - does not return anything
  */
 function populateFromUnknown(ob, errorMessage) {
-  var fauxError = new Error();
-
-  errorMessage.setMessage(fauxError.stack);
+  errorMessage.setMessage(buildStackTrace());
 }
 
 module.exports = errorHandlerRouter;
diff --git a/packages/error-reporting/src/interfaces/message-builder.js b/packages/error-reporting/src/interfaces/message-builder.js
@@ -16,6 +16,7 @@
 
 'use strict';
 var ErrorMessage = require('../classes/error-message.js');
+var buildStackTrace = require('../build-stack-trace.js');
 
 /**
  * The handler setup function serves to produce a bound instance of the
@@ -44,9 +45,7 @@ function handlerSetup(config) {
     //       error is used instead of the stack trace where the error is
     //       reported to be consistent with the behavior of reporting a
     //       an error when reporting an actual Node.js Error object.
-    var fauxError = new Error('');
-    var fullStack = fauxError.stack.split('\n');
-    var cleanedStack = fullStack.slice(2).join('\n');
+    var cleanedStack = buildStackTrace();
 
     var em = new ErrorMessage().setServiceContext(
                          config.getServiceContext().service,
diff --git a/packages/error-reporting/test/unit/build-stack-trace.js b/packages/error-reporting/test/unit/build-stack-trace.js
@@ -0,0 +1,60 @@
+/**
+ * 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';
+
+var assert = require('assert');
+var buildStackTrace = require('../../src/build-stack-trace.js');
+
+describe('build-stack-trace', function() {
+  it('Should not have a message attached if none is given', function() {
+    assert(buildStackTrace().startsWith('    at'));
+    assert(!buildStackTrace(undefined).startsWith('undefined'));
+    assert(!buildStackTrace(null).startsWith('null'));
+  });
+
+  it('Should attach a message if given', function() {
+    assert(buildStackTrace('Some Message').startsWith('Some Message\n'));
+  });
+
+  it('Should not contain error-reporting specific frames', function() {
+    var internalFileName = 'build-stack-trace';
+    var stackTrace = buildStackTrace();
+    var firstIndex = stackTrace.indexOf(internalFileName);
+    var lastIndex = stackTrace.lastIndexOf(internalFileName);
+    // This file, named 'build-stack-trace.js', tests the
+    // 'build-stack-trace.js' file.  The stack trace should not contain
+    // information about the 'build-stack-trace.js' file that is being
+    // tested.  Thus the stack trace should only contain the string
+    // 'build-stack-trace' one time, which corresponds to this test file
+    // and not the 'build-stack-trace.js' file being tested.
+    assert.strictEqual(firstIndex, lastIndex);
+  });
+
+  it('Should return the stack trace', function() {
+    (function functionA() {
+      (function functionB() {
+        (function functionC() {
+          var stackTrace = buildStackTrace();
+          assert(stackTrace);
+          assert.notStrictEqual(stackTrace.indexOf('functionA'), -1);
+          assert.notStrictEqual(stackTrace.indexOf('functionB'), -1);
+          assert.notStrictEqual(stackTrace.indexOf('functionC'), -1);
+        })();
+      })();
+    })();
+  });
+});
