[Author: dmaclach]

Add utility code to make it faster, easier and more robust to spin runloops during tests.

R=thomasvl
DELTA=186  (140 added, 19 deleted, 27 changed)

2 files changed, 148 insertions, 29 deletions

diff --git a/UnitTesting/GTMUnitTestingUtilities.h b/UnitTesting/GTMUnitTestingUtilities.h
index 128a4c4..d47c1ec 100644
--- a/UnitTesting/GTMUnitTestingUtilities.h
+++ b/UnitTesting/GTMUnitTestingUtilities.h
@@ -19,6 +19,33 @@
 #import <Foundation/Foundation.h>
 #import <objc/objc.h>
 
+// Many tests need to spin the runloop and wait for an event to happen. This is
+// often done by calling:
+// NSDate* next = [NSDate dateWithTimeIntervalSinceNow:resolution];
+// [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode
+//                          beforeDate:next];
+// where |resolution| is a guess at how long it will take for the event to 
+// happen. There are two major problems with this approach:
+// a) By guessing we force the test to take at least |resolution| time.
+// b) It makes for flaky tests in that sometimes this guess isn't good, and the 
+//    test takes slightly longer than |resolution| time causing the test to post
+//    a possibly false-negative failure.
+// To make timing callback tests easier use this class and the 
+// GTMUnitTestingAdditions additions to NSRunLoop and NSApplication.
+// Your call would look something like this:
+// id<GTMUnitTestingRunLoopContext> context = [self getMeAContext];
+// [[NSRunLoop currentRunLoop] gtm_runUpToSixtySecondsWithContext:context];
+// Then in some callback method within your test you would call
+// [context setShouldStop:YES];
+// Internally gtm_runUpToSixtySecondsWithContext will poll the runloop really
+// quickly to keep test times down to a minimum, but will stop after a good time
+// interval (in this case 60 seconds) for failures.
+@protocol GTMUnitTestingRunLoopContext
+// Return YES if the NSRunLoop (or equivalent) that this context applies to
+// should stop as soon as possible.
+- (BOOL)shouldStop;
+@end
+
 // Collection of utilities for unit testing
 @interface GTMUnitTestingUtilities : NSObject
 
@@ -76,16 +103,52 @@
 + (void)postTypeCharacterEvent:(CGCharCode)keyChar 
                      modifiers:(UInt32)cocoaModifiers;
 
-// Runs the event loop in NSDefaultRunLoopMode until date. Can be useful for
-// testing user interface responses in a controlled timed event loop. For most
-// uses using:
-// [[NSRunLoop currentRunLoop] runUntilDate:date]
-// will do. The only reason you would want to use this is if you were 
-// using the postKeyEvent:character:modifiers to send events and wanted to
-// receive user input.
-//  Arguments:
-//    date - end of execution time
-+ (void)runUntilDate:(NSDate*)date;
+@end
 
+// An implementation of the GTMUnitTestingRunLoopContext that is a simple
+// BOOL flag. See GTMUnitTestingRunLoopContext documentation.
+@interface GTMUnitTestingBooleanRunLoopContext : NSObject <GTMUnitTestingRunLoopContext> {
+ @private
+  BOOL shouldStop_;
+}
++ (id)context;
+- (BOOL)shouldStop;
+- (void)setShouldStop:(BOOL)stop;
 @end
 
+// Some category methods to simplify spinning the runloops in such a way as
+// to make tests less flaky, but have them complete as fast as possible.
+@interface NSRunLoop (GTMUnitTestingAdditions)
+// Will spin the runloop in mode until date in mode until the runloop returns
+// because all sources have been removed or the current date is greater than
+// |date| or [context shouldStop] returns YES.
+// Return YES if the runloop was stopped because [context shouldStop] returned
+// YES.
+- (BOOL)gtm_runUntilDate:(NSDate *)date
+                    mode:(NSString *)mode
+                 context:(id<GTMUnitTestingRunLoopContext>)context;
+
+// Calls -gtm_runUntilDate:mode:context: with mode set to NSDefaultRunLoopMode.
+- (BOOL)gtm_runUntilDate:(NSDate *)date 
+                 context:(id<GTMUnitTestingRunLoopContext>)context;
+
+// Calls -gtm_runUntilDate:mode:context: with mode set to NSDefaultRunLoopMode,
+// and the timeout date set to 60 seconds.
+- (BOOL)gtm_runUpToSixtySecondsWithContext:(id<GTMUnitTestingRunLoopContext>)context;
+
+@end
+
+// Some category methods to simplify spinning the runloops in such a way as
+// to make tests less flaky, but have them complete as fast as possible.
+@interface NSApplication (GTMUnitTestingAdditions)
+// Has NSApplication call nextEventMatchingMask repeatedly until 
+// [context shouldStop] returns YES or it returns nil because the current date 
+// is greater than |date|.
+// Return YES if the runloop was stopped because [context shouldStop] returned
+// YES.
+- (BOOL)gtm_runUntilDate:(NSDate *)date 
+                 context:(id<GTMUnitTestingRunLoopContext>)context;
+
+// Calls -gtm_runUntilDate:context: with the timeout date set to 60 seconds.
+- (BOOL)gtm_runUpToSixtySecondsWithContext:(id<GTMUnitTestingRunLoopContext>)context;
+@end
diff --git a/UnitTesting/GTMUnitTestingUtilities.m b/UnitTesting/GTMUnitTestingUtilities.m
index 5ce4219..2bd7b88 100644
--- a/UnitTesting/GTMUnitTestingUtilities.m
+++ b/UnitTesting/GTMUnitTestingUtilities.m
@@ -168,25 +168,6 @@ CantWorkWithScreenSaver:
   [self postKeyEvent:NSKeyUp character:keyChar modifiers:cocoaModifiers];
 }
 
-// Runs the event loop in NSDefaultRunLoopMode until date. Can be useful for
-// testing user interface responses in a controlled timed event loop. For most
-// uses using:
-// [[NSRunLoop currentRunLoop] runUntilDate:date]
-// will do. The only reason you would want to use this is if you were 
-// using the postKeyEvent:character:modifiers to send events and wanted to
-// receive user input.
-//  Arguments:
-//    date - end of execution time
-+ (void)runUntilDate:(NSDate*)date {
-  NSEvent *event;
-  while ((event = [NSApp nextEventMatchingMask:NSAnyEventMask 
-                                     untilDate:date 
-                                        inMode:NSDefaultRunLoopMode 
-                                       dequeue:YES])) {
-    [NSApp sendEvent:event];
-  }
-}
-
 @end
 
 BOOL GTMAreCMProfilesEqual(CMProfileRef a, CMProfileRef b) {
@@ -333,3 +314,78 @@ static CGKeyCode GTMKeyCodeForCharCode(CGCharCode charCode) {
   return outCode;
 }
 
+@implementation GTMUnitTestingBooleanRunLoopContext
+
++ (id)context {
+  return [[[GTMUnitTestingBooleanRunLoopContext alloc] init] autorelease];
+}
+
+- (BOOL)shouldStop {
+  return shouldStop_;
+}
+
+- (void)setShouldStop:(BOOL)stop {
+  shouldStop_ = stop;
+}
+
+@end
+
+@implementation NSRunLoop (GTMUnitTestingAdditions)
+
+- (BOOL)gtm_runUpToSixtySecondsWithContext:(id<GTMUnitTestingRunLoopContext>)context {
+  return [self gtm_runUntilDate:[NSDate dateWithTimeIntervalSinceNow:60]
+                        context:context];
+}
+
+- (BOOL)gtm_runUntilDate:(NSDate *)date 
+                 context:(id<GTMUnitTestingRunLoopContext>)context {
+  return [self gtm_runUntilDate:date mode:NSDefaultRunLoopMode context:context];
+}
+
+- (BOOL)gtm_runUntilDate:(NSDate *)date
+                    mode:(NSString *)mode
+                 context:(id<GTMUnitTestingRunLoopContext>)context {
+  BOOL contextShouldStop = NO;
+  NSRunLoop *rl = [NSRunLoop currentRunLoop];
+  while (1) {
+    contextShouldStop = [context shouldStop];
+    if (contextShouldStop) break;
+    NSDate* next = [[NSDate alloc] initWithTimeIntervalSinceNow:0.01];
+    if (!([rl runMode:mode beforeDate:next])) break;
+    if ([next compare:date] == NSOrderedDescending) break;
+    [next release];
+  }
+  return contextShouldStop;
+}
+
+@end
+
+@implementation NSApplication (GTMUnitTestingAdditions)
+
+- (BOOL)gtm_runUntilDate:(NSDate *)date 
+                 context:(id<GTMUnitTestingRunLoopContext>)context {
+  BOOL contextShouldStop = NO;
+  while (1) {
+    contextShouldStop = [context shouldStop];
+    if (contextShouldStop) break;
+    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+    NSEvent *event = [NSApp nextEventMatchingMask:NSAnyEventMask 
+                                         untilDate:date 
+                                            inMode:NSDefaultRunLoopMode 
+                                           dequeue:YES];
+    if (!event) {
+      [pool drain];
+      break;
+    }
+    [NSApp sendEvent:event];
+    [pool drain];
+  }
+  return contextShouldStop;
+}
+
+- (BOOL)gtm_runUpToSixtySecondsWithContext:(id<GTMUnitTestingRunLoopContext>)context {
+  return [self gtm_runUntilDate:[NSDate dateWithTimeIntervalSinceNow:60]
+                        context:context];
+}
+
+@end