Improve C4 object leak check in tests (#3479)

* Created a utitlity function for interval wating and checking using runlopp spinning to avoid main thread block warning.

* Increased the timeout period from 2 seconds to 8 seconds.

* Made a constant variable for disabing MultipeerReplicatorTest.

Author: pasin

Objective-C/Tests/CBLTestCase.h

@@ -218,6 +218,11 @@ extern const NSTimeInterval kExpTimeout;
  */
 - (XCTestExpectation*) allowOverfillExpectationWithDescription:(NSString *)description;
 
+/** A utility function for waiting for the condition or timeout, spinning the run loop without blocking. */
+- (BOOL) waitWithTimeout: (NSTimeInterval)timeout
+                interval: (NSTimeInterval)interval
+                   until: (BOOL (^)(void))condition;
+
 @end
 
 NS_ASSUME_NONNULL_END

Objective-C/Tests/CBLTestCase.m

@@ -36,10 +36,6 @@ @implementation CBLTestCase
 
 @synthesize db=_db, otherDB=_otherDB, disableObjectLeakCheck=_disableObjectLeakCheck;
 
-// TODO: Remove https://issues.couchbase.com/browse/CBL-3206
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wdeprecated-declarations"
-
 - (XCTestExpectation*) allowOverfillExpectationWithDescription:(NSString *)description {
     XCTestExpectation* e = [super expectationWithDescription: description];
     e.assertForOverFulfill = false;
@@ -75,15 +71,12 @@ - (void) tearDown {
 
     if (!_disableObjectLeakCheck) {
         // Wait a little while for objects to be cleaned up:
-        int leaks = 0;
-        for (int i = 0; i < 20; i++) {
-            leaks = c4_getObjectCount() - _c4ObjectCount;
-            if (leaks == 0)
-                break;
-            else
-                [NSThread sleepForTimeInterval: 0.1];
-        }
-        if (leaks) {
+        __block int leaks = 0;
+        BOOL success = [self waitWithTimeout: 8 interval: 0.5 until: ^BOOL{
+            leaks = c4_getObjectCount() - self->_c4ObjectCount;
+            return leaks == 0;
+        }];
+        if (!success) {
             fprintf(stderr, "**** LITECORE OBJECTS STILL NOT FREED: ****\n");
             c4_dumpInstances();
             XCTFail("%d LiteCore objects have not been freed (see above)", leaks);
@@ -483,6 +476,18 @@ - (NSString*) getRickAndMortyJSON {
     return [self stringFromResource: @"rick_morty" ofType: @"json"];
 }
 
-#pragma clang diagnostic pop
+- (BOOL) waitWithTimeout: (NSTimeInterval)timeout
+                interval: (NSTimeInterval)interval
+                   until: (BOOL (^)(void))condition {
+    NSDate *deadline = [NSDate dateWithTimeIntervalSinceNow: timeout];
+    while ([deadline timeIntervalSinceNow] > 0) {
+        if (condition()) {
+            return YES;
+        }
+        [[NSRunLoop currentRunLoop] runMode: NSDefaultRunLoopMode
+                                 beforeDate: [NSDate dateWithTimeIntervalSinceNow: interval]];
+    }
+    return condition();
+}
 
 @end

Objective-C/Tests/MultipeerReplicatorTest.m

@@ -16,6 +16,9 @@
 #define kTestMaxIdentity 10
 #define kTestIdentityCommonName @"CBLMultipeerReplTest"
 
+// Disable as cannot be run on the build VM (Got POSIX Error 50, Network is down)
+#define kDisableMultipeerTests YES
+
 typedef NSMutableDictionary<CBLPeerID*, CBLPeerReplicatorStatus*> CBLPeerReplicatorStatusMap;
 
 typedef CBLDocument * _Nullable (^MultipeerConflictResolverBlock)(CBLPeerID*, CBLConflict*);
@@ -67,6 +70,9 @@ - (void) setUp {
 
     XCTSkipUnless(self.isExecutionAllowed);
 
+    // Disabled by testConfigurationValidation, ensure to re-enable the leak check:
+    self.disableObjectLeakCheck = NO;
+    
     [self cleanupIdentities];
     [self openOtherDB];
 
@@ -90,8 +96,7 @@ - (BOOL) isExecutionAllowed {
     // See FAQ-12 : https://developer.apple.com/forums/thread/663858)
     return NO;
 #else
-    // Disable as cannot be run on the build VM (Got POSIX Error 50, Network is down)
-    return self.keyChainAccessAllowed && false;
+    return kDisableMultipeerTests ? NO : self.keyChainAccessAllowed;
 #endif
 }
 

Swift/Tests/MultipeerReplicatorTest.swift

@@ -34,6 +34,9 @@ class MultipeerReplicatorTest: CBLTestCase {
         }
     }
 
+    // Disable as cannot be run on the build VM (Got POSIX Error 50, Network is down)
+    let kDisableMultipeerReplicatorTest = true
+    
     let kTestKeyUsages: KeyUsages = [.clientAuth, .serverAuth]
 
     let kTestPeerGroupID = "CBLMultipeerReplTestGroup"
@@ -59,8 +62,7 @@ class MultipeerReplicatorTest: CBLTestCase {
         // See FAQ-12: https://developer.apple.com/forums/thread/663858
         return false
 #else
-        // Disable as cannot be run on the build VM (Got POSIX Error 50, Network is down)
-        return keyChainAccessAllowed && false
+        return kDisableMultipeerReplicatorTest ? false : keyChainAccessAllowed;
 #endif
     }