Re-apply "Remove unittest and matcher from the repo."

pkg/unittest/lib/src/utils.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library unittest.utils;
-
-import 'package:stack_trace/stack_trace.dart';
-
-/// Indent each line in [str] by two spaces.
-String indent(String str) =>
-  str.replaceAll(new RegExp("^", multiLine: true), "  ");
-
-/// A pair of values.
-class Pair<E, F> {
-  final E first;
-  final F last;
-
-  Pair(this.first, this.last);
-
-  String toString() => '($first, $last)';
-
-  bool operator ==(other) {
-    if (other is! Pair) return false;
-    return other.first == first && other.last == last;
-  }
-
-  int get hashCode => first.hashCode ^ last.hashCode;
-}
-
-/// Returns a Trace object from a StackTrace object or a String, or the
-/// unchanged input if formatStacks is false;
-Trace getTrace(stack, bool formatStacks, bool filterStacks) {
-  Trace trace;
-  if (stack == null || !formatStacks) return null;
-  if (stack is String) {
-    trace = new Trace.parse(stack);
-  } else if (stack is StackTrace) {
-    trace = new Trace.from(stack);
-  } else {
-    throw new Exception('Invalid stack type ${stack.runtimeType} for $stack.');
-  }
-
-  if (!filterStacks) return trace;
-
-  // Format the stack trace by removing everything above TestCase._runTest,
-  // which is usually going to be irrelevant. Also fold together unittest and
-  // core library calls so only the function the user called is visible.
-  return new Trace(trace.frames.takeWhile((frame) {
-    return frame.package != 'unittest' || frame.member != 'TestCase._runTest';
-  })).terse.foldFrames((frame) => frame.package == 'unittest' || frame.isCore);
-}