changing ChannelCredentials::createInsecure() to return grpc_insecure_credentials_create() instead of NULL

src/php/ext/grpc/channel_credentials.c

@@ -233,12 +233,15 @@ PHP_METHOD(ChannelCredentials, createComposite) {
  * @return null
  */
 PHP_METHOD(ChannelCredentials, createInsecure) {
-  RETURN_NULL();
+  grpc_channel_credentials* creds = grpc_insecure_credentials_create();
+  zval* creds_object = grpc_php_wrap_channel_credentials(
+      creds, strdup("INSECURE"), false TSRMLS_CC);
+  RETURN_DESTROY_ZVAL(creds_object);
 }
 
 /**
  * Create XDS channel credentials
- * @param ChannelCredentials|null $fallback_creds  The fallback credentials used
+ * @param ChannelCredentials $fallback_creds  The fallback credentials used
  * if the channel target does not have the 'xds:///' scheme or if the xDS
  * control plane does not provide information on how to fetch credentials
  * dynamically.
@@ -248,25 +251,20 @@ PHP_METHOD(ChannelCredentials, createXds) {
   grpc_channel_credentials* xds_creds = NULL;
   zval* fallback_creds = NULL;
   if (zend_parse_parameters_ex(0,  // ZEND_PARSE_PARAMS_QUIET,
-                               ZEND_NUM_ARGS() TSRMLS_CC, "O!", &fallback_creds,
+                               ZEND_NUM_ARGS() TSRMLS_CC, "O", &fallback_creds,
                                grpc_ce_channel_credentials) != SUCCESS) {
     zend_throw_exception(spl_ce_InvalidArgumentException,
                          "createXds expects a fallback credentials",
                          1 TSRMLS_CC);
     return;
   }
-  char* fallback_creds_hash_str = "";
-  if (!fallback_creds) {
-    grpc_channel_credentials* insecure_creds =
-        grpc_insecure_credentials_create();
-    xds_creds = grpc_xds_credentials_create(insecure_creds);
-  } else {
+
   wrapped_grpc_channel_credentials* wrapped_fallback_creds =
       PHP_GRPC_GET_WRAPPED_OBJECT(wrapped_grpc_channel_credentials,
                                   fallback_creds);
   xds_creds = grpc_xds_credentials_create(wrapped_fallback_creds->wrapped);
-    fallback_creds_hash_str = wrapped_fallback_creds->hashstr;
-  }
+  const char* fallback_creds_hash_str =
+      wrapped_fallback_creds->hashstr ? wrapped_fallback_creds->hashstr : "";
 
   // prefix "XDS:" as the hash of the xDS channel
   char* hash_str = malloc(strlen(fallback_creds_hash_str) + strlen("XDS:") + 1);

src/php/tests/unit_tests/ChannelCredentialsTest.php

@@ -43,7 +43,7 @@ class ChanellCredentialsTest extends \PHPUnit\Framework\TestCase
     public function testCreateInsecure()
     {
         $channel_credentials = Grpc\ChannelCredentials::createInsecure();
-        $this->assertNull($channel_credentials);
+        $this->assertNotNull($channel_credentials);
     }
 
     public function testDefaultRootsPem()

src/php/tests/unit_tests/ChannelTest.php

@@ -59,6 +59,16 @@ class ChannelTest extends \PHPUnit\Framework\TestCase
         $this->assertNotNull($xdsCreds);
     }
 
+    public function testCreateXdsWithNull() {
+        $this->expectException(\InvalidArgumentException::class);
+        $xdsCreds = \Grpc\ChannelCredentials::createXds(null);
+    }
+
+    public function testCreateXdsWithInvalidType() {
+        $this->expectException(\TypeError::class);
+        $xdsCreds = \Grpc\ChannelCredentials::createXds("invalid-type");
+    }
+
     public function testGetConnectivityState()
     {
         $this->channel = new Grpc\Channel('localhost:50001',