Add expectAsyncX and expectAsyncUntilX methods, and deprecate the old methods.

lib/src/frontend/expect_async.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.
 
 import 'dart:async';
 
 import '../backend/invoker.dart';
 import 'expect.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 T Func0<T>();
+typedef T Func1<T, A>(A a);
+typedef T Func2<T, A, B>(A a, B b);
+typedef T Func3<T, A, B, C>(A a, B b, C c);
+typedef T Func4<T, A, B, C, D>(A a, B b, C c, D d);
+typedef T Func5<T, A, B, C, D, E>(A a, B b, C c, D d, E e);
+typedef T Func6<T, A, B, C, D, E, F>(A a, B b, C c, D d, E e, F 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 {
+class _ExpectedFunction<T> {
   /// 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.
   ///
@@ skipping 33 matching lines @@
   /// 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,
+        _maxExpectedCalls =
+            (maxExpected == 0 && minExpected > 0) ? minExpected : maxExpected,

[nweiz, 2016/11/21 22:08:02]

Nit: Please don't include unrelated whitespace diffs.

[floitsch, 2016/11/22 14:14:27]

I tried, but writing multiline function signatures without invoking the dart
formatter turned out to be too difficult.

I undid this change (and will do the same for any other I can see).

         this._isDone = isDone,
         this._reason = reason == null ? '' : '\n$reason',
         this._zone = Zone.current,
         this._id = _makeCallbackId(id, callback) {
     if (_invoker == null) {
       throw new StateError("[expectAsync] was called outside of a test.");
     } else if (maxExpected > 0 && minExpected > maxExpected) {
       throw new ArgumentError("max ($maxExpected) may not be less than count "
           "($minExpected).");
     }
@@ skipping 22 matching lines @@
 
     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;
+    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;
 
     _invoker.removeOutstandingCallback();
     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();
+  T _max0() => _max6();

[nweiz, 2016/11/21 22:08:02]

Since these are being accessed outside the class now, make them public.

[floitsch, 2016/11/22 14:14:27]

Done.

 
-  _max1([a0 = _PLACEHOLDER]) => _max6(a0);
+  T _max1([a0 = _PLACEHOLDER]) => _max6(a0);
 
-  _max2([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER]) => _max6(a0, a1);
+  T _max2([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER]) => _max6(a0, a1);
 
-  _max3([a0 = _PLACEHOLDER, a1 = _PLACEHOLDER, a2 = _PLACEHOLDER]) =>
+  T _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);
+  T _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);
+  T _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]) =>
+  T _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.
-  _run(Iterable args) {
+  T _run(Iterable args) {
     // Note that in the old test, this returned `null` if it encountered an
     // error, where now it just re-throws that error because Zone machinery will
     // pass it to the invoker anyway.
     try {
       _actualCalls++;
       if (_invoker.liveTest.state.shouldBeDone) {
         throw 'Callback ${_id}called ($_actualCalls) after test case '
-              '${_invoker.liveTest.test.name} had already completed.$_reason';
+            '${_invoker.liveTest.test.name} had already completed.$_reason';
       } else if (_maxExpectedCalls >= 0 && _actualCalls > _maxExpectedCalls) {
         throw new TestFailure('Callback ${_id}called more times than expected '
-                              '($_maxExpectedCalls).$_reason');
+            '($_maxExpectedCalls).$_reason');
       }
 
-      return Function.apply(_callback, args.toList());
+      return Function.apply(_callback, args.toList()) as T;
     } catch (error, stackTrace) {
       _zone.handleUncaughtError(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;
     _invoker.removeOutstandingCallback();
   }
 }
 
 /// Indicate that [callback] is expected to be called [count] number of times
 /// (by default 1).

[nweiz, 2016/11/21 22:08:02]

Remove the old documentation.

[floitsch, 2016/11/22 14:14:27]

Done.

 ///
+/// This function is deprecated. Use [expectAsync0], [expectAsync1],

[nweiz, 2016/11/21 22:08:02]

"is deprecated because it doesn't work well with strong mode."

[floitsch, 2016/11/22 14:14:27]

Done.

+/// [expectAsync2], [expectAsync3], [expectAsync4], [expectAsync5], or
+/// [expectAsync6] instead.
+///
 /// The test framework will wait for the callback to run the [count] times
 /// before it considers the current test to be complete. [callback] may take up
 /// to six optional or required positional arguments; named arguments are not
 /// supported.
 ///
 /// [max] can be used to specify an upper bound on the number of calls; if this
 /// is exceeded the test will fail. If [max] is `0` (the default), the callback
 /// is expected to be called exactly [count] times. If [max] is `-1`, the
 /// callback is allowed to be called any number of times greater than [count].
 ///
 /// Both [id] and [reason] are optional and provide extra information about the
 /// callback when debugging. [id] should be the name of the callback, while
 /// [reason] should be the reason the callback is expected to be called.
+@deprecated

[nweiz, 2016/11/21 22:08:02]

Use @Deprecated and mention that it will be removed in 0.13.0.

[floitsch, 2016/11/22 14:14:27]

Done.

 Function expectAsync(Function callback,
-        {int count: 1, int max: 0, String id, String reason}) {
+    {int count: 1, int max: 0, String id, String reason}) {
   if (Invoker.current == null) {
     throw new StateError("expectAsync() may only be called within a test.");
   }
 
   return new _ExpectedFunction(callback, count, max, id: id, reason: reason)
       .func;
 }
 
+/// Indicate that [callback] is expected to be called [count] number of times
+/// (by default 1).
+///
+/// The test framework will wait for the callback to run the [count] times
+/// before it considers the current test to be complete.
+///
+/// [max] can be used to specify an upper bound on the number of calls; if this
+/// is exceeded the test will fail. If [max] is `0` (the default), the callback
+/// is expected to be called exactly [count] times. If [max] is `-1`, the
+/// callback is allowed to be called any number of times greater than [count].
+///
+/// Both [id] and [reason] are optional and provide extra information about the
+/// callback when debugging. [id] should be the name of the callback, while
+/// [reason] should be the reason the callback is expected to be called.

[nweiz, 2016/11/21 22:08:03]

Add a paragraph describing the difference between the various expectAsyncN
methods. Maybe:

"This takes a callback with zero arguments. See also [expectAsync1],
[expectAsync2], [expectAsync3], [expectAsync4], [expectAsync5], or
[expectAsync6] for callbacks with different numbers of arguments."

[floitsch, 2016/11/22 14:14:27]

Done.

+Func0<dynamic/*=T*/ > expectAsync0/*<T>*/(dynamic/*=T*/ callback(),

[nweiz, 2016/11/21 22:08:02]

Nit: "<dynamic/*=T*/>"

[floitsch, 2016/11/22 14:14:27]

I don't understand.
If it's the spacing: I used the dartformatter.

+    {int count: 1, int max: 0, String id, String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError("expectAsync() may only be called within a test.");

[nweiz, 2016/11/21 22:08:02]

"expectAsync0()"

[floitsch, 2016/11/22 14:14:27]

Done.

+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, count, max,
+          id: id, reason: reason)
+      ._max0;
+}
+
+/// See [expectAsync0].

[nweiz, 2016/11/21 22:08:02]

I'd prefer to copy the docs from [expectAsync0] rather than just refer to them.
I'm willing to make maintenance a little more annoying in exchange for saving
users a click.

[floitsch, 2016/11/22 14:14:27]

Done.

+Func1<dynamic/*=T*/, dynamic/*=A*/ > expectAsync1/*<T, A>*/(
+    dynamic/*=T*/ callback(dynamic/*=A*/ a),
+    {int count: 1,
+    int max: 0,
+    String id,
+    String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError("expectAsync() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, count, max,
+          id: id, reason: reason)
+      ._max1;
+}
+
+/// See [expectAsync0].
+Func2<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/ > expectAsync2/*<T, A, B>*/(
+    dynamic/*=T*/ callback(dynamic/*=A*/ a, dynamic/*=B*/ b),
+    {int count: 1,
+    int max: 0,
+    String id,
+    String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError("expectAsync() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, count, max,
+          id: id, reason: reason)
+      ._max2;
+}
+
+/// See [expectAsync0].
+Func3<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/ >
+    expectAsync3/*<T, A, B, C>*/(
+        dynamic/*=T*/ callback(
+            dynamic/*=A*/ a, dynamic/*=B*/ b, dynamic/*=C*/ c),
+        {int count: 1,
+        int max: 0,
+        String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError("expectAsync() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, count, max,
+          id: id, reason: reason)
+      ._max3;
+}
+
+/// See [expectAsync0].
+Func4<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/,
+        dynamic/*=D*/ >
+    expectAsync4/*<T, A, B, C, D>*/(
+        dynamic/*=T*/ callback(
+            dynamic/*=A*/ a, dynamic/*=B*/ b, dynamic/*=C*/ c, dynamic/*=D*/ d),
+        {int count: 1,
+        int max: 0,
+        String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError("expectAsync() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, count, max,
+          id: id, reason: reason)
+      ._max4;
+}
+
+/// See [expectAsync0].
+Func5<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/,
+        dynamic/*=D*/, dynamic/*=E*/ >
+    expectAsync5/*<T, A, B, C, D, E>*/(
+        dynamic/*=T*/ callback(dynamic/*=A*/ a, dynamic/*=B*/ b,
+            dynamic/*=C*/ c, dynamic/*=D*/ d, dynamic/*=E*/ e),
+        {int count: 1,
+        int max: 0,
+        String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError("expectAsync() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, count, max,
+          id: id, reason: reason)
+      ._max5;
+}
+
+/// See [expectAsync0].
+Func6<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/,
+        dynamic/*=D*/, dynamic/*=E*/, dynamic/*=F*/ >
+    expectAsync6/*<T, A, B, C, D, E, F>*/(
+        dynamic/*=T*/ callback(dynamic/*=A*/ a, dynamic/*=B*/ b,
+            dynamic/*=C*/ c, dynamic/*=D*/ d, dynamic/*=E*/ e, dynamic/*=F*/ f),
+        {int count: 1,
+        int max: 0,
+        String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError("expectAsync() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, count, max,
+          id: id, reason: reason)
+      ._max6;
+}
+
 /// Indicate that [callback] is expected to be called until [isDone] returns
 /// true.
 ///
+/// Deprecated. Use [expectAsyncUntil0], [expectAsyncUntil1],
+/// [expectAsyncUntil2], [expectAsyncUntil3], [expectAsyncUntil4],
+/// [expectAsyncUntil5], or [expectAsyncUntil6] instead.
+///
 /// [isDone] is called after each time the function is run. Only when it returns
 /// true will the callback be considered complete. [callback] may take up to six
 /// optional or required positional arguments; named arguments are not
 /// supported.
 ///
 /// Both [id] and [reason] are optional and provide extra information about the
 /// callback when debugging. [id] should be the name of the callback, while
 /// [reason] should be the reason the callback is expected to be called.
+@deprecated
 Function expectAsyncUntil(Function callback, bool isDone(),
     {String id, String reason}) {
   if (Invoker.current == null) {
     throw new StateError(
         "expectAsyncUntil() may only be called within a test.");
   }
 
   return new _ExpectedFunction(callback, 0, -1,
-      id: id, reason: reason, isDone: isDone).func;
+          id: id, reason: reason, isDone: isDone)
+      .func;
 }
+
+/// Indicate that [callback] is expected to be called until [isDone] returns
+/// true.
+///
+/// [isDone] is called after each time the function is run. Only when it returns
+/// true will the callback be considered complete.
+///
+/// Both [id] and [reason] are optional and provide extra information about the
+/// callback when debugging. [id] should be the name of the callback, while
+/// [reason] should be the reason the callback is expected to be called.
+Func0<dynamic/*=T*/ > expectAsyncUntil0/*<T>*/(
+    dynamic/*=T*/ callback(), bool isDone(),
+    {String id, String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError(
+        "expectAsyncUntil() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, 0, -1,
+          id: id, reason: reason, isDone: isDone)
+      ._max0;
+}
+
+/// See [expectAsyncUntil0].
+Func1<dynamic/*=T*/, dynamic/*=A*/ > expectAsyncUntil1/*<T, A>*/(
+    dynamic/*=T*/ callback(dynamic/*=A*/ a), bool isDone(),
+    {String id, String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError(
+        "expectAsyncUntil() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, 0, -1,
+          id: id, reason: reason, isDone: isDone)
+      ._max1;
+}
+
+/// See [expectAsyncUntil0].
+Func2<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/ >
+    expectAsyncUntil2/*<T, A, B>*/(
+        dynamic/*=T*/ callback(dynamic/*=A*/ a, dynamic/*=B*/ b), bool isDone(),
+        {String id, String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError(
+        "expectAsyncUntil() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, 0, -1,
+          id: id, reason: reason, isDone: isDone)
+      ._max2;
+}
+
+/// See [expectAsyncUntil0].
+Func3<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/ >
+    expectAsyncUntil3/*<T, A, B, C>*/(
+        dynamic/*=T*/ callback(
+            dynamic/*=A*/ a, dynamic/*=B*/ b, dynamic/*=C*/ c),
+        bool isDone(),
+        {String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError(
+        "expectAsyncUntil() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, 0, -1,
+          id: id, reason: reason, isDone: isDone)
+      ._max3;
+}
+
+/// See [expectAsyncUntil0].
+Func4<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/,
+        dynamic/*=D*/ >
+    expectAsyncUntil4/*<T, A, B, C, D>*/(
+        dynamic/*=T*/ callback(
+            dynamic/*=A*/ a, dynamic/*=B*/ b, dynamic/*=C*/ c, dynamic/*=D*/ d),
+        bool isDone(),
+        {String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError(
+        "expectAsyncUntil() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, 0, -1,
+          id: id, reason: reason, isDone: isDone)
+      ._max4;
+}
+
+/// See [expectAsyncUntil0].
+Func5<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/,
+        dynamic/*=D*/, dynamic/*=E*/ >
+    expectAsyncUntil5/*<T, A, B, C, D, E>*/(
+        dynamic/*=T*/ callback(dynamic/*=A*/ a, dynamic/*=B*/ b,
+            dynamic/*=C*/ c, dynamic/*=D*/ d, dynamic/*=E*/ e),
+        bool isDone(),
+        {String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError(
+        "expectAsyncUntil() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, 0, -1,
+          id: id, reason: reason, isDone: isDone)
+      ._max5;
+}
+
+/// See [expectAsyncUntil0].
+Func6<dynamic/*=T*/, dynamic/*=A*/, dynamic/*=B*/, dynamic/*=C*/,
+        dynamic/*=D*/, dynamic/*=E*/, dynamic/*=F*/ >
+    expectAsyncUntil6/*<T, A, B, C, D, E, F>*/(
+        dynamic/*=T*/ callback(dynamic/*=A*/ a, dynamic/*=B*/ b,
+            dynamic/*=C*/ c, dynamic/*=D*/ d, dynamic/*=E*/ e, dynamic/*=F*/ f),
+        bool isDone(),
+        {String id,
+        String reason}) {
+  if (Invoker.current == null) {
+    throw new StateError(
+        "expectAsyncUntil() may only be called within a test.");
+  }
+
+  return new _ExpectedFunction/*<T>*/(callback, 0, -1,
+          id: id, reason: reason, isDone: isDone)
+      ._max6;
+}