Use package:stack_trace in unittest.

pkg/unittest/lib/src/test_case.dart

Index: pkg/unittest/lib/src/test_case.dart
diff --git a/pkg/unittest/lib/src/test_case.dart b/pkg/unittest/lib/src/test_case.dart
index 67b791efb96a55144daa64e7f899667c36660b52..cffe3b7c98b4d52e1adba229e7df6b99daa57ad2 100644
--- a/pkg/unittest/lib/src/test_case.dart
+++ b/pkg/unittest/lib/src/test_case.dart
@@ -41,9 +41,9 @@ class TestCase {
    */
   String get result => _result;
 
-  String _stackTrace;
+  Trace _stackTrace;
   /** Stack trace associated with this test, or [null] if it succeeded. */
-  String get stackTrace => _stackTrace;
+  Trace get stackTrace => _stackTrace;
 
   /** The group (or groups) under which this test is running. */
   final String currentGroup;
@@ -82,11 +82,9 @@ class TestCase {
     var f = testFunction();
     --_callbackFunctionsOutstanding;
     if (f is Future) {
-      return f.then((_) => _finishTest())
-        .catchError((error) {
-          var stack = getAttachedStackTrace(error);
-          _registerException(this, error, stack);
-        });
+      return f.then((_) => _finishTest()).catchError((error) {
+        _registerException(this, error, getAttachedStackTrace(error));
+      });
     } else {
       _finishTest();
       return null;
@@ -113,18 +111,17 @@ class TestCase {
     _doneTeardown = false;
     var rtn = setUp == null ? null : setUp();
     if (rtn is Future) {
-      rtn.then((_) => _runTest())
-         .catchError((e) {
-          _prepTest();
-          // Calling error() will result in the tearDown being done.
-          // One could debate whether tearDown should be done after
-          // a failed setUp. There is no right answer, but doing it
-          // seems to be the more conservative approach, because
-          // unittest will not stop at a test failure.
-          var stack = getAttachedStackTrace(e);
-          if (stack == null) stack = '';
-          error("$description: Test setup failed: $e", "$stack");
-        });
+      rtn.then((_) => _runTest()).catchError((e) {
+        _prepTest();
+        // Calling error() will result in the tearDown being done.
+        // One could debate whether tearDown should be done after
+        // a failed setUp. There is no right answer, but doing it
+        // seems to be the more conservative approach, because
+        // unittest will not stop at a test failure.
+        error(
+            "$description: Test setup failed: $e",
+            getAttachedStackTrace(e));
+      });
     } else {
       var f = _runTest();
       if (f != null) {
@@ -147,9 +144,9 @@ class TestCase {
 
   // Set the results, notify the config, and return true if this
   // is the first time the result is being set.
-  void _setResult(String testResult, String messageText, String stack) {
+  void _setResult(String testResult, String messageText, stack) {
     _message = messageText;
-    _stackTrace = _formatStack(stack);
+    _stackTrace = _getTrace(stack);
     if (result == null) {
       _result = testResult;
       _config.onTestResult(this);
@@ -159,9 +156,7 @@ class TestCase {
     }
   }
 
-  void _complete(String testResult,
-                [String messageText = '',
-                 String stack = '']) {
+  void _complete(String testResult, [String messageText = '', stack]) {
     if (runningTime == null) {
       // The startTime can be `null` if an error happened during setup. In this
       // case we simply report a running time of 0.
@@ -199,8 +194,7 @@ class TestCase {
     _complete(PASS);
   }
 
-  void fail(String messageText, [String stack = '']) {
-    assert(stack != null);
+  void fail(String messageText, [stack]) {
     if (result != null) {
       String newMessage = (result == PASS)
           ? 'Test failed after initially passing: $messageText'
@@ -212,8 +206,7 @@ class TestCase {
     }
   }
 
-  void error(String messageText, [String stack = '']) {
-    assert(stack != null);
+  void error(String messageText, [stack]) {
     _complete(ERROR, messageText, stack);
   }