Teach dart_package to understand the packages/ subdirectory

third_party/dart-packages/unittest/unittest/src/expected_function.dart

-// Copyright (c) 2015, 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.expected_function;
-
-import '../unittest.dart';
-
-import 'internal_test_case.dart';
-
-/// An object used to detect unpassed arguments.
-const _PLACEHOLDER = const Object();
-
-// Functions used to check how many arguments a callback takes.
-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);
-
-typedef bool _IsDoneCallback();
-
-/// A wrapper for a function that ensures that it's called the appropriate
-/// number of times.
-///
-/// The containing test won't be considered to have completed successfully until
-/// this function has been called the appropriate number of times.
-///
-/// The wrapper function is accessible via [func]. It supports up to six
-/// optional and/or required positional arguments, but no named arguments.
-class ExpectedFunction {
-  /// The wrapped callback.
-  final Function _callback;
-
-  /// The minimum number of calls that are expected to be made to the function.
-  ///
-  /// If fewer calls than this are made, the test will fail.
-  final int _minExpectedCalls;
-
-  /// The maximum number of calls that are expected to be made to the function.
-  ///
-  /// If more calls than this are made, the test will fail.
-  final int _maxExpectedCalls;
-
-  /// A callback that should return whether the function is not expected to have
-  /// any more calls.
-  ///
-  /// This will be called after every time the function is run. The test case
-  /// won't be allowed to terminate until it returns `true`.
-  ///
-  /// This may be `null`. If so, the function is considered to be done after
-  /// it's been run once.
-  final _IsDoneCallback _isDone;
-
-  /// A descriptive name for the function.
-  final String _id;
-
-  /// An optional description of why the function is expected to be called.
-  ///
-  /// If not passed, this will be an empty string.
-  final String _reason;
-
-  /// The number of times the function has been called.
-  int _actualCalls = 0;
-
-  /// The test case in which this function was wrapped.
-  final InternalTestCase _testCase;
-
-  /// Whether this function has been called the requisite number of times.
-  bool _complete;
-
-  /// Wraps [callback] in a function that asserts that it's called at least
-  /// [minExpected] times and no more than [maxExpected] times.
-  ///
-  /// If passed, [id] is used as a descriptive name fo the function and [reason]
-  /// as a reason it's expected to be called. If [isDone] is passed, the test
-  /// won't be allowed to complete until it returns `true`.
-  ExpectedFunction(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$reason',
-        this._testCase = currentTestCase as InternalTestCase,
-        this._id = _makeCallbackId(id, callback) {
-    ensureInitialized();
-    if (_testCase == null) {
-      throw new StateError("No valid test. Did you forget to run your test "
-          "inside a call to test()?");
-    }
-
-    if (isDone != null || minExpected > 0) {
-      _testCase.callbackFunctionsOutstanding++;
-      _complete = false;
-    } else {
-      _complete = true;
-    }
-  }
-
-  /// Tries to find a reasonable name for [callback].
-  ///
-  /// If [id] is passed, uses that. Otherwise, tries to determine a name from
-  /// calling `toString`. If no name can be found, returns the empty string.
-  static String _makeCallbackId(String id, Function callback) {
-    if (id != null) return "$id ";
-
-    // If the callback is not an anonymous closure, try to get the
-    // name.
-    var toString = callback.toString();
-    var prefix = "Function '";
-    var start = toString.indexOf(prefix);
-    if (start == -1) return '';
-
-    start += prefix.length;
-    var end = toString.indexOf("'", start);
-    if (end == -1) return '';
-    return "${toString.substring(start, end)} ";
-  }
-
-  /// Returns a function that has the same number of positional arguments as the
-  /// wrapped function (up to a total of 6).
-  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 wrapped function 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 = _PLACEHOLDER]) => _max6(a0);
-
-  _max2([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER]) => _max6(a0, a1);
-
-  _max3([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER, a2 = _PLACEHOLDER]) =>
-      _max6(a0, a1, a2);
-
-  _max4([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER, a2 = _PLACEHOLDER,
-      a3 = _PLACEHOLDER]) => _max6(a0, a1, a2, a3);
-
-  _max5([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER, a2 = _PLACEHOLDER,
-      a3 = _PLACEHOLDER, a4 = _PLACEHOLDER]) => _max6(a0, a1, a2, a3, a4);
-
-  _max6([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER, a2 = _PLACEHOLDER,
-      a3 = _PLACEHOLDER, a4 = _PLACEHOLDER, a5 = _PLACEHOLDER]) =>
-      _run([a0, a1, a2, a3, a4, a5].where((a) => a != _PLACEHOLDER));
-
-  /// Runs the wrapped function with [args] and returns its return value.
-  ///
-  /// This will pass any errors on to [_testCase] and return `null`.
-  _run(Iterable args) {
-    try {
-      _actualCalls++;
-      if (_testCase.isComplete) {
-        // Don't run the callback 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 '
-              '${_testCase.description} had already been marked as '
-              '${_testCase.result}.$_reason');
-        }
-        return null;
-      } else if (_maxExpectedCalls >= 0 && _actualCalls > _maxExpectedCalls) {
-        throw new TestFailure('Callback ${_id}called more times than expected '
-                              '($_maxExpectedCalls).$_reason');
-      }
-
-      return Function.apply(_callback, args.toList());
-    } catch (error, stackTrace) {
-      _testCase.registerException(error, stackTrace);
-      return null;
-    } finally {
-      _afterRun();
-    }
-  }
-
-  /// After each time the function is run, check to see if it's complete.
-  void _afterRun() {
-    if (_complete) return;
-    if (_minExpectedCalls > 0 && _actualCalls < _minExpectedCalls) return;
-    if (_isDone != null && !_isDone()) return;
-
-    // Mark this callback as complete and remove it from the test case's
-    // oustanding callback count; if that hits zero the test is done.
-    _complete = true;
-    _testCase.markCallbackComplete();
-  }
-}