Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/unittest/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);