--- /dev/null
+++ libmalloc/libmalloc-646.0.13/tests/xctests/nano_common_tests.m
@@ -0,0 +1,91 @@
+#import "internal.h"
+
+#if CONFIG_NANOZONE
+
+#import <XCTest/XCTest.h>
+
+// from nano_malloc_common.c
+extern nano_version_t
+_nano_common_init_pick_mode(const char *envp[], const char *apple[], const char *bootargs, bool space_efficient_enabled);
+
+// Test stubs
+bool malloc_space_efficient_enabled;
+unsigned int phys_ncpus;
+
+@interface nano_common_tests : XCTestCase {
+@private
+
+}
+@end
+
+@implementation nano_common_tests
+
+- (nano_version_t)pickModeWithEnv:(const char *)env
+							apple:(const char *)apple
+						  bootarg:(const char *)bootarg
+				  space_efficient:(bool)space_efficient_enabled {
+	// Create the null terminated array
+	const char *envp[] = { env, NULL};
+	const char *applep[] = { apple, NULL};
+
+	return _nano_common_init_pick_mode(envp, applep, bootarg, space_efficient_enabled);
+}
+
+- (void)testNanoEnabledIfBootargForcedOn {
+	XCTAssertEqual([self pickModeWithEnv:NULL apple:NULL bootarg:"nanov2_mode=forced" space_efficient:false], NANO_V2);
+}
+
+- (void)testNanoEnabledIfBootargConditionalAndNotSpaceEfficient {
+	XCTAssertEqual([self pickModeWithEnv:NULL apple:NULL bootarg:"nanov2_mode=conditional" space_efficient:false], NANO_V2);
+}
+
+- (void)testNanoDisabledIfBootargConditionalAndSpaceEfficient {
+	XCTAssertEqual([self pickModeWithEnv:NULL apple:NULL bootarg:"nanov2_mode=conditional" space_efficient:true], NANO_NONE);
+}
+
+- (void)testNanoEnvironmentEnableOverridesConditionalSpaceEfficient {
+	const char *environments[] = {
+		"MallocNanoZone=1",
+		"MallocNanoZone=v1",
+		"MallocNanoZone=V1",
+		"MallocNanoZone=v2",
+		"MallocNanoZone=V2",
+	};
+	for (size_t i = 0; i < countof(environments); i++) {
+		XCTAssertEqual([self pickModeWithEnv:environments[i] apple:NULL bootarg:"nanov2_mode=conditional" space_efficient:true], NANO_V2);
+	}
+}
+
+- (void)testNanoEnvironmentDisableOverridesConditionalSpaceEfficient {
+	XCTAssertEqual([self pickModeWithEnv:"MallocNanoZone=0" apple:NULL bootarg:"nanov2_mode=conditional" space_efficient:false], NANO_NONE);
+}
+
+- (void)testNanoEnvironmentDisableOverridesApple {
+	XCTAssertEqual([self pickModeWithEnv:"MallocNanoZone=0" apple:"MallocNanoZone=1" bootarg:"nanov2_mode=enabled" space_efficient:false], NANO_NONE);
+}
+
+- (void)testNanoEnabledIfAppleEnabled {
+	// Need to set boot-arg for platforms with the default of conditional
+	XCTAssertEqual([self pickModeWithEnv:NULL apple:"MallocNanoZone=1" bootarg:"nanov2_mode=enabled" space_efficient:true], NANO_V2);
+}
+
+#if MALLOC_TARGET_IOS || TARGET_OS_DRIVERKIT
+// NANOV2_DEFAULT_MODE == NANO_ENABLED
+
+- (void)testDefaultNotSpaceEfficient {
+	XCTAssertEqual([self pickModeWithEnv:NULL apple:NULL bootarg:"" space_efficient:false], NANO_NONE);
+}
+
+#else // MALLOC_TARGET_IOS || TARGET_OS_DRIVERKIT
+// NANOV2_DEFAULT_MODE == NANO_CONDITIONAL
+
+- (void)testDefaultNotSpaceEfficient {
+	XCTAssertEqual([self pickModeWithEnv:NULL apple:NULL bootarg:"" space_efficient:false], NANO_V2);
+}
+
+#endif // MALLOC_TARGET_IOS || TARGET_OS_DRIVERKIT
+
+@end
+
+
+#endif // CONFIG_NANOZONE