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

pkg/unittest/lib/src/spread_args_helper.dart

-part of unittest;
-
-const _PLACE_HOLDER = const _ArgPlaceHolder();
-
-/// Used to track unused positional args.
-class _ArgPlaceHolder {
-  const _ArgPlaceHolder();
-}
-
-/// Simulates spread arguments using named arguments.
-class _SpreadArgsHelper {
-  final Function callback;
-  final int minExpectedCalls;
-  final int maxExpectedCalls;
-  final Function isDone;
-  final String id;
-  final String reason;
-  int actualCalls = 0;
-  final TestCase testCase;
-  bool complete;
-
-  _SpreadArgsHelper(Function callback, int minExpected, int maxExpected,
-      String id, String reason, {bool isDone()})
-      : this.callback = callback,
-        minExpectedCalls = minExpected,
-        maxExpectedCalls = (maxExpected == 0 && minExpected > 0)
-            ? minExpected
-            : maxExpected,
-        this.isDone = isDone,
-        this.reason = reason == null ? '' : '\n$reason',
-        this.testCase = currentTestCase,
-        this.id = _makeCallbackId(id, callback) {
-    ensureInitialized();
-    if (testCase == null) {
-      throw new StateError("No valid test. Did you forget to run your test "
-          "inside a call to test()?");
-    }
-
-    if (isDone != null || minExpected > 0) {
-      testCase._callbackFunctionsOutstanding++;
-      complete = false;
-    } else {
-      complete = true;
-    }
-  }
-
-  static String _makeCallbackId(String id, Function callback) {
-    // Try to create a reasonable id.
-    if (id != null) {
-      return "$id ";
-    } else {
-      // If the callback is not an anonymous closure, try to get the
-      // name.
-      var fname = callback.toString();
-      var prefix = "Function '";
-      var pos = fname.indexOf(prefix);
-      if (pos > 0) {
-        pos += prefix.length;
-        var epos = fname.indexOf("'", pos);
-        if (epos > 0) {
-          return "${fname.substring(pos, epos)} ";
-        }
-      }
-    }
-    return '';
-  }
-
-  bool shouldCallBack() {
-    ++actualCalls;
-    if (testCase.isComplete) {
-      // Don't run if the test is done. We don't throw here as this is not
-      // the current test, but we do mark the old test as having an error
-      // if it previously passed.
-      if (testCase.result == PASS) {
-        testCase._error(
-            'Callback ${id}called ($actualCalls) after test case '
-            '${testCase.description} has already been marked as '
-            '${testCase.result}.$reason');
-      }
-      return false;
-    } else if (maxExpectedCalls >= 0 && actualCalls > maxExpectedCalls) {
-      throw new TestFailure('Callback ${id}called more times than expected '
-                            '($maxExpectedCalls).$reason');
-    }
-    return true;
-  }
-
-  void after() {
-    if (!complete) {
-      if (minExpectedCalls > 0 && actualCalls < minExpectedCalls) return;
-      if (isDone != null && !isDone()) return;
-
-      // Mark this callback as complete and remove it from the testcase
-      // oustanding callback count; if that hits zero the testcase is done.
-      complete = true;
-      testCase._markCallbackComplete();
-    }
-  }
-
-  /// Returns a function that has as many required + positional arguments as
-  /// [callback] (up to a total of 6).
-  ///
-  /// Optional positional arguments are supported by using const place-holders
-  Function get func {
-    if (callback is _Func6) return _max6;
-    if (callback is _Func5) return _max5;
-    if (callback is _Func4) return _max4;
-    if (callback is _Func3) return _max3;
-    if (callback is _Func2) return _max2;
-    if (callback is _Func1) return _max1;
-    if (callback is _Func0) return _max0;
-
-    throw new ArgumentError(
-        'The callback argument has more than 6 required arguments');
-  }
-
-  /// This indirection is critical. It ensures the returned function has an
-  /// argument count of zero.
-  _max0() => _max6();
-
-  _max1([a0 = _PLACE_HOLDER]) => _max6(a0);
-
-  _max2([a0 = _PLACE_HOLDER, a1 = _PLACE_HOLDER]) => _max6(a0, a1);
-
-  _max3([a0 = _PLACE_HOLDER, a1 = _PLACE_HOLDER, a2 = _PLACE_HOLDER]) =>
-      _max6(a0, a1, a2);
-
-  _max4([a0 = _PLACE_HOLDER, a1 = _PLACE_HOLDER, a2 = _PLACE_HOLDER,
-      a3 = _PLACE_HOLDER]) => _max6(a0, a1, a2, a3);
-
-  _max5([a0 = _PLACE_HOLDER, a1 = _PLACE_HOLDER, a2 = _PLACE_HOLDER,
-      a3 = _PLACE_HOLDER, a4 = _PLACE_HOLDER]) => _max6(a0, a1, a2, a3, a4);
-
-  _max6([a0 = _PLACE_HOLDER, a1 = _PLACE_HOLDER, a2 = _PLACE_HOLDER,
-      a3 = _PLACE_HOLDER, a4 = _PLACE_HOLDER, a5 = _PLACE_HOLDER]) {
-    var args = [a0, a1, a2, a3, a4, a5];
-    args.removeWhere((a) => a == _PLACE_HOLDER);
-
-    return _guardAsync(
-        () {
-          if (shouldCallBack()) {
-            return Function.apply(callback, args);
-          }
-        },
-        after, testCase);
-  }
-
-  _guardAsync(Function tryBody, Function finallyBody, TestCase testCase) {
-    assert(testCase != null);
-    try {
-      return tryBody();
-    } catch (e, trace) {
-      _registerException(testCase, e, trace);
-    } finally {
-      if (finallyBody != null) finallyBody();
-    }
-  }
-}
-
-typedef _Func0();
-typedef _Func1(a);
-typedef _Func2(a, b);
-typedef _Func3(a, b, c);
-typedef _Func4(a, b, c, d);
-typedef _Func5(a, b, c, d, e);
-typedef _Func6(a, b, c, d, e, f);