diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/GDLLogWriter.h b/GoogleDataLogger/GoogleDataLogger/Classes/GDLLogWriter.h
index 96c1abd63b9..99f386826f1 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/GDLLogWriter.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/GDLLogWriter.h
@@ -20,6 +20,8 @@
 
 @protocol GDLLogTransformer;
 
+NS_ASSUME_NONNULL_BEGIN
+
 /** Manages the writing and log-time transforming of logs. */
 @interface GDLLogWriter : NSObject
 
@@ -38,3 +40,5 @@
     afterApplyingTransformers:(nullable NSArray<id<GDLLogTransformer>> *)logTransformers;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogStorage_Private.h b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogStorage_Private.h
index 24b90ad4183..0697f466bd6 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogStorage_Private.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogStorage_Private.h
@@ -18,6 +18,8 @@
 
 @class GDLUploadCoordinator;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface GDLLogStorage ()
 
 /** The queue on which all storage work will occur. */
@@ -34,3 +36,5 @@
 @property(nonatomic) GDLUploadCoordinator *uploader;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogWriter_Private.h b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogWriter_Private.h
index 83627959553..11f143633d5 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogWriter_Private.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogWriter_Private.h
@@ -18,6 +18,8 @@
 
 @class GDLLogStorage;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface GDLLogWriter ()
 
 /** The queue on which all work will occur. */
@@ -27,3 +29,5 @@
 @property(nonatomic) GDLLogStorage *storageInstance;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogger_Private.h b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogger_Private.h
index 277434c8e31..48c2fb25291 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogger_Private.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLLogger_Private.h
@@ -18,6 +18,8 @@
 
 @class GDLLogWriter;
 
+NS_ASSUME_NONNULL_BEGIN
+
 @interface GDLLogger ()
 
 /** The log mapping identifier that a GDLLogBackend will use to map the extension to proto. */
@@ -33,3 +35,5 @@
 @property(nonatomic) GDLLogWriter *logWriterInstance;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLRegistrar_Private.h b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLRegistrar_Private.h
index b4d4d19b75c..2eaa1c502e2 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLRegistrar_Private.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/Private/GDLRegistrar_Private.h
@@ -18,6 +18,8 @@
 
 @interface GDLRegistrar ()
 
+NS_ASSUME_NONNULL_BEGIN
+
 /** The concurrent queue on which all registration occurs. */
 @property(nonatomic, readonly) dispatch_queue_t registrarQueue;
 
@@ -30,3 +32,5 @@
     NSMutableDictionary<NSNumber *, id<GDLLogPrioritizer>> *logTargetToPrioritizer;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogPrioritizer.h b/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogPrioritizer.h
index 1cb547479ad..cdb2f7fe26e 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogPrioritizer.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogPrioritizer.h
@@ -18,6 +18,8 @@
 
 @class GDLLogEvent;
 
+NS_ASSUME_NONNULL_BEGIN
+
 /** This protocol defines the common interface of a log prioritization. Log prioritizers are
  * stateful objects that prioritize logs upon insertion into storage and remain prepared to return a
  * set of log filenames to the storage system.
@@ -45,3 +47,5 @@
 - (NSSet<NSNumber *> *)logsForNextUpload;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogProto.h b/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogProto.h
index 2f424bd0b9c..dfe4d2d549a 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogProto.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogProto.h
@@ -16,6 +16,8 @@
 
 #import <Foundation/Foundation.h>
 
+NS_ASSUME_NONNULL_BEGIN
+
 /** This protocol defines the common interface that log protos should implement regardless of the
  * underlying transport technology (protobuf, nanopb, etc).
  */
@@ -28,3 +30,5 @@
 - (NSData *)protoBytes;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogTransformer.h b/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogTransformer.h
index c8e072e8d0e..d426e07895d 100644
--- a/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogTransformer.h
+++ b/GoogleDataLogger/GoogleDataLogger/Classes/Public/GDLLogTransformer.h
@@ -18,6 +18,8 @@
 
 @class GDLLogEvent;
 
+NS_ASSUME_NONNULL_BEGIN
+
 /** Defines the API that log transformers must adopt. */
 @protocol GDLLogTransformer <NSObject>
 
@@ -32,3 +34,5 @@
 - (GDLLogEvent *)transform:(GDLLogEvent *)logEvent;
 
 @end
+
+NS_ASSUME_NONNULL_END
diff --git a/GoogleDataLogger/GoogleDataLogger/DependencyWrappers/GDLConsoleLogger.h b/GoogleDataLogger/GoogleDataLogger/DependencyWrappers/GDLConsoleLogger.h
index 98fa197d305..154da49f856 100644
--- a/GoogleDataLogger/GoogleDataLogger/DependencyWrappers/GDLConsoleLogger.h
+++ b/GoogleDataLogger/GoogleDataLogger/DependencyWrappers/GDLConsoleLogger.h
@@ -50,14 +50,14 @@ typedef NS_ENUM(NSInteger, GDLMessageCode) {
 };
 
 /** */
-FOUNDATION_EXTERN NSString *GDLMessageCodeEnumToString(GDLMessageCode code);
+FOUNDATION_EXTERN NSString *_Nonnull GDLMessageCodeEnumToString(GDLMessageCode code);
 
 /** Logs the warningMessage string to the console at the warning level.
  *
  * @param warningMessageFormat The format string to log to the console.
  */
 FOUNDATION_EXTERN void GDLLogWarning(GDLMessageCode messageCode,
-                                     NSString *warningMessageFormat,
+                                     NSString *_Nonnull warningMessageFormat,
                                      ...) NS_FORMAT_FUNCTION(2, 3);
 
 // A define to wrap GULLogWarning with slightly more convenient usage.
diff --git a/GoogleDataLogger/Tests/Unit/GDLClockTest.m b/GoogleDataLogger/Tests/Unit/GDLClockTest.m
index e16e59d93e0..583843dac90 100644
--- a/GoogleDataLogger/Tests/Unit/GDLClockTest.m
+++ b/GoogleDataLogger/Tests/Unit/GDLClockTest.m
@@ -48,6 +48,7 @@ - (void)testSupportsSecureEncoding {
   XCTAssertTrue([GDLClock supportsSecureCoding]);
 }
 
+/** Tests encoding and decoding a clock using a keyed archiver. */
 - (void)testEncoding {
   GDLClock *clock = [GDLClock snapshot];
   NSData *clockData = [NSKeyedArchiver archivedDataWithRootObject:clock];
@@ -56,6 +57,7 @@ - (void)testEncoding {
   XCTAssertEqualObjects(clock, unarchivedClock);
 }
 
+/** Tests creating a clock that represents a future time. */
 - (void)testClockSnapshotInTheFuture {
   GDLClock *clock1 = [GDLClock snapshot];
   GDLClock *clock2 = [GDLClock clockSnapshotInTheFuture:1];
diff --git a/GoogleDataLogger/Tests/Unit/GDLLogWriterTest.m b/GoogleDataLogger/Tests/Unit/GDLLogWriterTest.m
index 2e173d4d987..e5081d29b56 100644
--- a/GoogleDataLogger/Tests/Unit/GDLLogWriterTest.m
+++ b/GoogleDataLogger/Tests/Unit/GDLLogWriterTest.m
@@ -124,10 +124,4 @@ - (void)testWriteLogWithBadTransformer {
   [self waitForExpectations:@[ errorExpectation ] timeout:5.0];
 }
 
-/** Tests that writing a nil log throws. */
-- (void)testWritingANilLogThrows {
-  GDLLogWriter *writer = [GDLLogWriter sharedInstance];
-  XCTAssertThrows([writer writeLog:nil afterApplyingTransformers:nil]);
-}
-
 @end
diff --git a/GoogleDataLogger/Tests/Unit/GDLRegistrarTest.m b/GoogleDataLogger/Tests/Unit/GDLRegistrarTest.m
index ace2b313d41..68a0dea3d77 100644
--- a/GoogleDataLogger/Tests/Unit/GDLRegistrarTest.m
+++ b/GoogleDataLogger/Tests/Unit/GDLRegistrarTest.m
@@ -31,6 +31,7 @@ @interface GDLRegistrarTest : GDLTestCase
 @implementation GDLRegistrarTest
 
 - (void)setUp {
+  [super setUp];
   _logTarget = 23;
 }
 
diff --git a/GoogleDataLogger/generate_project.sh b/GoogleDataLogger/generate_project.sh
index 01873fe30a9..8672ba70f62 100755
--- a/GoogleDataLogger/generate_project.sh
+++ b/GoogleDataLogger/generate_project.sh
@@ -18,8 +18,4 @@
 # From https://stackoverflow.com/questions/59895/getting-the-source-directory-of-a-bash-script-from-within
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"
 
-# Remove the old generated project
-echo "Removing $DIR/gen"
-rm -rf "$DIR/gen/"
-
-pod gen "$DIR/../GoogleDataLogger.podspec" --auto-open --gen-directory="$DIR/gen"
+pod gen "$DIR/../GoogleDataLogger.podspec" --auto-open --gen-directory="$DIR/gen" --clean