Reverting 12485 and 12480 just for the sake of mocking,

pkg/unittest/mock.dart

 // Copyright (c) 2012, 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.
 
 /**
  * The error formatter for mocking is a bit different from the default one
  * for unit testing; instead of the third argument being a 'reason'
  * it is instead a [signature] describing the method signature filter
  * that was used to select the logs that were verified.
  */
@@ skipping 20 matching lines @@
   }
   void failMatch(actual, Matcher matcher, String reason,
                  MatchState matchState, bool verbose) {
     proxy.fail(_mockingErrorFormatter(actual, matcher, reason,
         matchState, verbose));
   }
 }
 
 _MockFailureHandler _mockFailureHandler = null;
 
+/**
+ * [_noArg] is a sentinel value representing no argument.
+ */
+const _noArg = const _Sentinel();
+
 /** The ways in which a call to a mock method can be handled. */
 class Action {
   /** Do nothing (void method) */
   static const IGNORE = const Action._('IGNORE');
 
   /** Return a supplied value. */
   static const RETURN = const Action._('RETURN');
 
   /** Throw a supplied value. */
   static const THROW = const Action._('THROW');
@@ skipping 30 matching lines @@
 class CallMatcher {
   Matcher nameFilter;
   List<Matcher> argMatchers;
 
   /**
    * Constructor for [CallMatcher]. [name] can be null to
    * match anything, or a literal [String], a predicate [Function],
    * or a [Matcher]. The various arguments can be scalar values or
    * [Matcher]s.
    */
-  CallMatcher([name, arg0, arg1, arg2, arg3, arg4,
-               arg5, arg6, arg7, arg8, arg9]) {
-    nameFilter = name != null ? wrapMatcher(name) : anything;
+  CallMatcher([name,
+              arg0 = _noArg,
+              arg1 = _noArg,
+              arg2 = _noArg,
+              arg3 = _noArg,
+              arg4 = _noArg,
+              arg5 = _noArg,
+              arg6 = _noArg,
+              arg7 = _noArg,
+              arg8 = _noArg,
+              arg9 = _noArg]) {
+    if (name == null) {
+      nameFilter = anything;
+    } else {
+      nameFilter = wrapMatcher(name);
+    }
     argMatchers = new List<Matcher>();
-    if (!?arg0) return;
+    if (arg0 === _noArg) return;
     argMatchers.add(wrapMatcher(arg0));
-    if (!?arg1) return;
+    if (arg1 === _noArg) return;
     argMatchers.add(wrapMatcher(arg1));
-    if (!?arg2) return;
+    if (arg2 === _noArg) return;
     argMatchers.add(wrapMatcher(arg2));
-    if (!?arg3) return;
+    if (arg3 === _noArg) return;
     argMatchers.add(wrapMatcher(arg3));
-    if (!?arg4) return;
+    if (arg4 === _noArg) return;
     argMatchers.add(wrapMatcher(arg4));
-    if (!?arg5) return;
+    if (arg5 === _noArg) return;
     argMatchers.add(wrapMatcher(arg5));
-    if (!?arg6) return;
+    if (arg6 === _noArg) return;
     argMatchers.add(wrapMatcher(arg6));
-    if (!?arg7) return;
+    if (arg7 === _noArg) return;
     argMatchers.add(wrapMatcher(arg7));
-    if (!?arg8) return;
+    if (arg8 === _noArg) return;
     argMatchers.add(wrapMatcher(arg8));
-    if (!?arg9) return;
+    if (arg9 === _noArg) return;
     argMatchers.add(wrapMatcher(arg9));
   }
 
   /**
    * We keep our behavior specifications in a Map, which is keyed
    * by the [CallMatcher]. To make the keys unique and to get a
    * descriptive value for the [CallMatcher] we have this override
    * of [toString()].
    */
   String toString() {
@@ skipping 33 matching lines @@
     }
     return true;
   }
 }
 
 /**
  * Returns a [CallMatcher] for the specified signature. [method] can be
  * null to match anything, or a literal [String], a predicate [Function],
  * or a [Matcher]. The various arguments can be scalar values or [Matcher]s.
  */
-CallMatcher callsTo([method, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9]) {
-  if (!?a0) return new CallMatcher(method);
-  if (!?a1) return new CallMatcher(method, a0);
-  if (!?a2) return new CallMatcher(method, a0, a1);
-  if (!?a3) return new CallMatcher(method, a0, a1, a2);
-  if (!?a4) return new CallMatcher(method, a0, a1, a2, a3);
-  if (!?a5) return new CallMatcher(method, a0, a1, a2, a3, a4);
-  if (!?a6) return new CallMatcher(method, a0, a1, a2, a3, a4, a5);
-  if (!?a7) return new CallMatcher(method, a0, a1, a2, a3, a4, a5, a6);
-  if (!?a8) return new CallMatcher(method, a0, a1, a2, a3, a4, a5, a6, a7);
-  if (!?a9) return new CallMatcher(method, a0, a1, a2, a3, a4, a5, a6, a7, a8);
-  return new CallMatcher(method, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9);
+CallMatcher callsTo([method,
+                     arg0 = _noArg,
+                     arg1 = _noArg,
+                     arg2 = _noArg,
+                     arg3 = _noArg,
+                     arg4 = _noArg,
+                     arg5 = _noArg,
+                     arg6 = _noArg,
+                     arg7 = _noArg,
+                     arg8 = _noArg,
+                     arg9 = _noArg]) {
+  return new CallMatcher(method, arg0, arg1, arg2, arg3, arg4,
+      arg5, arg6, arg7, arg8, arg9);
 }
 
 /**
  * A [Behavior] represents how a [Mock] will respond to one particular
  * type of method call.
  */
 class Behavior {
   CallMatcher matcher; // The method call matcher.
   List<Responder> actions; // The values to return/throw or proxies to call.
   bool logging = true;
@@ skipping 1208 matching lines @@
           Exception("Can't retrieve logs when logging was never enabled.");
     } else {
       return log.getMatches(name, logFilter, actionMatcher, destructive);
     }
   }
 
   /**
    * Useful shorthand method that creates a [CallMatcher] from its arguments
    * and then calls [getLogs].
    */
-  LogEntryList calls(method, [a0, a1, a2, a3, a4, a5, a6, a7, a8, a9]) {
-    if (!?a0) return getLogs(callsTo(method));
-    if (!?a1) return getLogs(callsTo(method, a0));
-    if (!?a2) return getLogs(callsTo(method, a0, a1));
-    if (!?a3) return getLogs(callsTo(method, a0, a1, a2));
-    if (!?a4) return getLogs(callsTo(method, a0, a1, a2, a3));
-    if (!?a5) return getLogs(callsTo(method, a0, a1, a2, a3, a4));
-    if (!?a6) return getLogs(callsTo(method, a0, a1, a2, a3, a4, a5));
-    if (!?a7) return getLogs(callsTo(method, a0, a1, a2, a3, a4, a5, a6));
-    if (!?a8) return getLogs(callsTo(method, a0, a1, a2, a3, a4, a5, a6, a7));
-    if (!?a9) {
-      return getLogs(callsTo(method, a0, a1, a2, a3, a4, a5, a6, a7, a8));
-    }
-    return getLogs(callsTo(method, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9));
-  }
+  LogEntryList calls(method,
+                      [arg0 = _noArg,
+                       arg1 = _noArg,
+                       arg2 = _noArg,
+                       arg3 = _noArg,
+                       arg4 = _noArg,
+                       arg5 = _noArg,
+                       arg6 = _noArg,
+                       arg7 = _noArg,
+                       arg8 = _noArg,
+                       arg9 = _noArg]) =>
+      getLogs(callsTo(method, arg0, arg1, arg2, arg3, arg4,
+          arg5, arg6, arg7, arg8, arg9));
 
   /** Clear the behaviors for the Mock. */
   void resetBehavior() => _behaviors.clear();
 
   /** Clear the logs for the Mock. */
   void clearLogs() {
     if (log != null) {
       if (name == null) { // This log is not shared.
         log.logs.clear();
       } else { // This log may be shared.
         log.logs = log.logs.filter((e) => e.mockName != name);
       }
     }
   }
 
   /** Clear both logs and behavior. */
   void reset() {
     resetBehavior();
     clearLogs();
   }
 }