diff --git a/src/php/ext/grpc/call.c b/src/php/ext/grpc/call.c
index 7ba14a38d8e3877589c4c796812bef7c9d12a840..4b4336666cba088d40ccb916c667f9ab818bfe01 100644
--- a/src/php/ext/grpc/call.c
+++ b/src/php/ext/grpc/call.c
@@ -125,15 +125,9 @@ zval *grpc_parse_metadata_array(grpc_metadata_array *metadata_array) {
     memcpy(str_val, elem->value, elem->value_length);
     if (zend_hash_find(array_hash, str_key, key_len, (void **)data) ==
         SUCCESS) {
-      if (Z_TYPE_P(*data) != IS_ARRAY) {
-        zend_throw_exception(zend_exception_get_default(),
-                             "Metadata hash somehow contains wrong types.",
-                             1 TSRMLS_CC);
-          efree(str_key);
-          efree(str_val);
-          return NULL;
-      }
-      add_next_index_stringl(*data, str_val, elem->value_length, false);
+      zend_throw_exception(zend_exception_get_default(),
+                           "Metadata hash somehow contains wrong types.",
+                           1 TSRMLS_CC);
     } else {
       MAKE_STD_ZVAL(inner_array);
       array_init(inner_array);
diff --git a/src/php/ext/grpc/channel.c b/src/php/ext/grpc/channel.c
index 60c94412dce6d66c06af79c84316212f096956e6..97e8cc1a63d925ee15bd62e91a344575d335500d 100644
--- a/src/php/ext/grpc/channel.c
+++ b/src/php/ext/grpc/channel.c
@@ -148,37 +148,33 @@ PHP_METHOD(Channel, __construct) {
                          "Channel expects a string and an array", 1 TSRMLS_CC);
     return;
   }
-  if (args_array == NULL) {
-    channel->wrapped = grpc_insecure_channel_create(target, NULL, NULL);
-  } else {
-    array_hash = Z_ARRVAL_P(args_array);
-    if (zend_hash_find(array_hash, "credentials", sizeof("credentials"),
-                       (void **)&creds_obj) == SUCCESS) {
-      if (Z_TYPE_P(*creds_obj) == IS_NULL) {
-        creds = NULL;
-        zend_hash_del(array_hash, "credentials", 12);
-      } else if (zend_get_class_entry(*creds_obj TSRMLS_CC) !=
-          grpc_ce_channel_credentials) {
-        zend_throw_exception(spl_ce_InvalidArgumentException,
-                             "credentials must be a ChannelCredentials object",
-                             1 TSRMLS_CC);
-        return;
-      } else {
-        creds = (wrapped_grpc_channel_credentials *)zend_object_store_get_object(
-            *creds_obj TSRMLS_CC);
-        zend_hash_del(array_hash, "credentials", 12);
-      }
-    }
-    php_grpc_read_args_array(args_array, &args);
-    if (creds == NULL) {
-      channel->wrapped = grpc_insecure_channel_create(target, &args, NULL);
+  array_hash = Z_ARRVAL_P(args_array);
+  if (zend_hash_find(array_hash, "credentials", sizeof("credentials"),
+                     (void **)&creds_obj) == SUCCESS) {
+    if (Z_TYPE_P(*creds_obj) == IS_NULL) {
+      creds = NULL;
+      zend_hash_del(array_hash, "credentials", 12);
+    } else if (zend_get_class_entry(*creds_obj TSRMLS_CC) !=
+        grpc_ce_channel_credentials) {
+      zend_throw_exception(spl_ce_InvalidArgumentException,
+                           "credentials must be a ChannelCredentials object",
+                           1 TSRMLS_CC);
+      return;
     } else {
-      gpr_log(GPR_DEBUG, "Initialized secure channel");
-      channel->wrapped =
-          grpc_secure_channel_create(creds->wrapped, target, &args, NULL);
+      creds = (wrapped_grpc_channel_credentials *)zend_object_store_get_object(
+          *creds_obj TSRMLS_CC);
+      zend_hash_del(array_hash, "credentials", 12);
     }
-    efree(args.args);
   }
+  php_grpc_read_args_array(args_array, &args);
+  if (creds == NULL) {
+    channel->wrapped = grpc_insecure_channel_create(target, &args, NULL);
+  } else {
+    gpr_log(GPR_DEBUG, "Initialized secure channel");
+    channel->wrapped =
+        grpc_secure_channel_create(creds->wrapped, target, &args, NULL);
+  }
+  efree(args.args);
 }
 
 /**
diff --git a/src/php/tests/unit_tests/CallCredentials3Test.php b/src/php/tests/unit_tests/CallCredentials3Test.php
new file mode 100644
index 0000000000000000000000000000000000000000..6d98815d16c35ea4f8bbfa52aed99e61f68d0081
--- /dev/null
+++ b/src/php/tests/unit_tests/CallCredentials3Test.php
@@ -0,0 +1,136 @@
+<?php
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+class CallCredentials3Test extends PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        $this->credentials = Grpc\ChannelCredentials::createSsl(
+            file_get_contents(dirname(__FILE__).'/../data/ca.pem'));
+        $server_credentials = Grpc\ServerCredentials::createSsl(
+            null,
+            file_get_contents(dirname(__FILE__).'/../data/server1.key'),
+            file_get_contents(dirname(__FILE__).'/../data/server1.pem'));
+        $this->server = new Grpc\Server();
+        $this->port = $this->server->addSecureHttp2Port('0.0.0.0:0',
+                                              $server_credentials);
+        $this->server->start();
+        $this->host_override = 'foo.test.google.fr';
+        $this->channel = new Grpc\Channel(
+            'localhost:'.$this->port,
+            [
+            'grpc.ssl_target_name_override' => $this->host_override,
+            'grpc.default_authority' => $this->host_override,
+            'credentials' => $this->credentials,
+            ]
+        );
+    }
+
+    public function tearDown()
+    {
+        unset($this->channel);
+        unset($this->server);
+    }
+
+    public function callbackFunc($context)
+    {
+        $this->assertTrue(is_string($context->service_url));
+        $this->assertTrue(is_string($context->method_name));
+
+        return ['k1' => ['v1'], 'k2' => ['v2']];
+    }
+
+    public function testCreateFromPlugin()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $status_text = 'xyz';
+        $call = new Grpc\Call($this->channel,
+                              '/abc/dummy_method',
+                              $deadline,
+                              $this->host_override);
+
+        $call_credentials = Grpc\CallCredentials::createFromPlugin(
+            [$this, 'callbackFunc']);
+        $call->setCredentials($call_credentials);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_close);
+
+        $event = $this->server->requestCall();
+
+        $this->assertTrue(is_array($event->metadata));
+        $metadata = $event->metadata;
+        $this->assertTrue(array_key_exists('k1', $metadata));
+        $this->assertTrue(array_key_exists('k2', $metadata));
+        $this->assertSame($metadata['k1'], ['v1']);
+        $this->assertSame($metadata['k2'], ['v2']);
+
+        $this->assertSame('/abc/dummy_method', $event->method);
+        $server_call = $event->call;
+
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => Grpc\STATUS_OK,
+                'details' => $status_text,
+            ],
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_status);
+        $this->assertFalse($event->cancelled);
+
+        $event = $call->startBatch([
+            Grpc\OP_RECV_INITIAL_METADATA => true,
+            Grpc\OP_RECV_STATUS_ON_CLIENT => true,
+        ]);
+
+        $this->assertSame([], $event->metadata);
+        $status = $event->status;
+        $this->assertSame([], $status->metadata);
+        $this->assertSame(Grpc\STATUS_OK, $status->code);
+        $this->assertSame($status_text, $status->details);
+
+        unset($call);
+        unset($server_call);
+    }
+
+}
diff --git a/src/php/tests/unit_tests/CallCredentialsTest.php b/src/php/tests/unit_tests/CallCredentialsTest.php
index 0918412781614ab4c662e2c21976dde12acad83d..5fec06cd13395a48785e7cf6bcb8d5bccdf712bb 100644
--- a/src/php/tests/unit_tests/CallCredentialsTest.php
+++ b/src/php/tests/unit_tests/CallCredentialsTest.php
@@ -36,13 +36,13 @@ class CallCredentialsTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
-        $credentials = Grpc\ChannelCredentials::createSsl(
+        $this->credentials = Grpc\ChannelCredentials::createSsl(
             file_get_contents(dirname(__FILE__).'/../data/ca.pem'));
-        $call_credentials = Grpc\CallCredentials::createFromPlugin(
-            array($this, 'callbackFunc'));
-        $credentials = Grpc\ChannelCredentials::createComposite(
-            $credentials,
-            $call_credentials
+        $this->call_credentials = Grpc\CallCredentials::createFromPlugin(
+            [$this, 'callbackFunc']);
+        $this->credentials = Grpc\ChannelCredentials::createComposite(
+            $this->credentials,
+            $this->call_credentials
         );
         $server_credentials = Grpc\ServerCredentials::createSsl(
             null,
@@ -58,7 +58,7 @@ class CallCredentialsTest extends PHPUnit_Framework_TestCase
             [
             'grpc.ssl_target_name_override' => $this->host_override,
             'grpc.default_authority' => $this->host_override,
-            'credentials' => $credentials,
+            'credentials' => $this->credentials,
             ]
         );
     }
@@ -134,4 +134,41 @@ class CallCredentialsTest extends PHPUnit_Framework_TestCase
         unset($call);
         unset($server_call);
     }
+
+    public function callbackFunc2($context)
+    {
+        return [];
+    }
+
+    public function testCreateComposite()
+    {
+        $call_credentials2 = Grpc\CallCredentials::createFromPlugin(
+            [$this, 'callbackFunc2']);
+        $call_credentials3 = Grpc\CallCredentials::createComposite(
+            $this->call_credentials,
+            $call_credentials2
+        );
+        $this->assertSame('Grpc\CallCredentials', get_class($call_credentials3));
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testCreateFromPluginInvalidParam()
+    {
+        $call_credentials = Grpc\CallCredentials::createFromPlugin(
+            'callbackFunc'
+        );
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testCreateCompositeInvalidParam()
+    {
+        $call_credentials3 = Grpc\CallCredentials::createComposite(
+            $this->call_credentials,
+            $this->credentials
+        );
+    }
 }
diff --git a/src/php/tests/unit_tests/CallTest.php b/src/php/tests/unit_tests/CallTest.php
index 3b697b50c3bc84415acbe18c173a85d68911306a..1170a440fa98490cb0b55ec890cd85630371598d 100755
--- a/src/php/tests/unit_tests/CallTest.php
+++ b/src/php/tests/unit_tests/CallTest.php
@@ -91,4 +91,32 @@ class CallTest extends PHPUnit_Framework_TestCase
     {
         $this->assertTrue(is_string($this->call->getPeer()));
     }
+
+    public function testCancel()
+    {
+      $this->assertNull($this->call->cancel());
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidMetadataKey()
+    {
+        $batch = [
+            'invalid' => ['key1' => 'value1'],
+        ];
+        $result = $this->call->startBatch($batch);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidMetadataInnerValue()
+    {
+        $batch = [
+            Grpc\OP_SEND_INITIAL_METADATA => ['key1' => 'value1'],
+        ];
+        $result = $this->call->startBatch($batch);
+    }
+
 }
diff --git a/src/php/tests/unit_tests/ChannelCredentialsTest.php b/src/php/tests/unit_tests/ChannelCredentialsTest.php
new file mode 100644
index 0000000000000000000000000000000000000000..1a42d69428b60120847103ed3b8a6a75041ebea1
--- /dev/null
+++ b/src/php/tests/unit_tests/ChannelCredentialsTest.php
@@ -0,0 +1,73 @@
+<?php
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+class ChanellCredentialsTest extends PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+    }
+
+    public function tearDown()
+    {
+    }
+
+    public function testCreateDefault()
+    {
+        $channel_credentials = Grpc\ChannelCredentials::createDefault();
+        $this->assertSame('Grpc\ChannelCredentials', get_class($channel_credentials));
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidCreateSsl()
+    {
+        $channel_credentials = Grpc\ChannelCredentials::createSsl([]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidCreateComposite()
+    {
+        $channel_credentials = Grpc\ChannelCredentials::createComposite(
+            'something', 'something');
+    }
+
+    public function testCreateInsecure()
+    {
+        $channel_credentials = Grpc\ChannelCredentials::createInsecure();
+        $this->assertNull($channel_credentials);
+    }
+}
\ No newline at end of file
diff --git a/src/php/tests/unit_tests/ChannelTest.php b/src/php/tests/unit_tests/ChannelTest.php
new file mode 100644
index 0000000000000000000000000000000000000000..b6eac3109a8d63bf4ba5b5c6fa2bd387c96efe15
--- /dev/null
+++ b/src/php/tests/unit_tests/ChannelTest.php
@@ -0,0 +1,82 @@
+<?php
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+class ChannelTest extends PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+    }
+
+    public function tearDown()
+    {
+    }
+
+    public function testInsecureCredentials()
+    {
+        $this->channel = new Grpc\Channel(
+            'localhost:0',
+            [
+                'credentials' => Grpc\ChannelCredentials::createInsecure(),
+            ]
+        );
+        $this->assertSame('Grpc\Channel', get_class($this->channel));
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidCredentials()
+    {
+        $this->channel = new Grpc\Channel(
+            'localhost:0',
+            [
+                'credentials' => new Grpc\Timeval(100),
+            ]
+        );
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidOptionsArray()
+    {
+        $this->channel = new Grpc\Channel(
+            'localhost:0',
+            [
+                'abc' => [],
+            ]
+        );
+    }
+
+}
\ No newline at end of file
diff --git a/src/php/tests/unit_tests/EndToEndTest.php b/src/php/tests/unit_tests/EndToEndTest.php
index 5a38262451bec477021d19c1fe54079bf29d7ae5..3fa92c950bacea663e32a4a1f3aaed0f2be209de 100755
--- a/src/php/tests/unit_tests/EndToEndTest.php
+++ b/src/php/tests/unit_tests/EndToEndTest.php
@@ -201,6 +201,318 @@ class EndToEndTest extends PHPUnit_Framework_TestCase
         unset($server_call);
     }
 
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidClientMessageArray()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => 'invalid',
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidClientMessageString()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => 0],
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidClientMessageFlags()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => 'abc',
+                                     'flags' => 'invalid'],
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidServerStatusMetadata()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => $req_text],
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_close);
+        $this->assertTrue($event->send_message);
+
+        $event = $this->server->requestCall();
+        $this->assertSame('dummy_method', $event->method);
+        $server_call = $event->call;
+
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_MESSAGE => ['message' => $reply_text],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => 'invalid',
+                'code' => Grpc\STATUS_OK,
+                'details' => $status_text,
+            ],
+            Grpc\OP_RECV_MESSAGE => true,
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidServerStatusCode()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => $req_text],
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_close);
+        $this->assertTrue($event->send_message);
+
+        $event = $this->server->requestCall();
+        $this->assertSame('dummy_method', $event->method);
+        $server_call = $event->call;
+
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_MESSAGE => ['message' => $reply_text],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => 'invalid',
+                'details' => $status_text,
+            ],
+            Grpc\OP_RECV_MESSAGE => true,
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testMissingServerStatusCode()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => $req_text],
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_close);
+        $this->assertTrue($event->send_message);
+
+        $event = $this->server->requestCall();
+        $this->assertSame('dummy_method', $event->method);
+        $server_call = $event->call;
+
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_MESSAGE => ['message' => $reply_text],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'details' => $status_text,
+            ],
+            Grpc\OP_RECV_MESSAGE => true,
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidServerStatusDetails()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => $req_text],
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_close);
+        $this->assertTrue($event->send_message);
+
+        $event = $this->server->requestCall();
+        $this->assertSame('dummy_method', $event->method);
+        $server_call = $event->call;
+
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_MESSAGE => ['message' => $reply_text],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => Grpc\STATUS_OK,
+                'details' => 0,
+            ],
+            Grpc\OP_RECV_MESSAGE => true,
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testMissingServerStatusDetails()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => $req_text],
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_close);
+        $this->assertTrue($event->send_message);
+
+        $event = $this->server->requestCall();
+        $this->assertSame('dummy_method', $event->method);
+        $server_call = $event->call;
+
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_MESSAGE => ['message' => $reply_text],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => Grpc\STATUS_OK,
+            ],
+            Grpc\OP_RECV_MESSAGE => true,
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidStartBatchKey()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            9999999 => [],
+        ]);
+    }
+
+    /**
+     * @expectedException LogicException
+     */
+    public function testInvalidStartBatch()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $req_text = 'client_server_full_request_response';
+        $reply_text = 'reply:client_server_full_request_response';
+        $status_text = 'status:client_server_full_response_text';
+
+        $call = new Grpc\Call($this->channel,
+                              'dummy_method',
+                              $deadline);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+            Grpc\OP_SEND_MESSAGE => ['message' => $req_text],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => Grpc\STATUS_OK,
+                'details' => 'abc',
+            ],
+        ]);
+    }
+
     public function testGetTarget()
     {
         $this->assertTrue(is_string($this->channel->getTarget()));
@@ -255,4 +567,36 @@ class EndToEndTest extends PHPUnit_Framework_TestCase
         $new_state = $this->channel->getConnectivityState();
         $this->assertTrue($new_state == Grpc\CHANNEL_IDLE);
     }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testGetConnectivityStateInvalidParam()
+    {
+        $this->assertTrue($this->channel->getConnectivityState(
+            new Grpc\Timeval));
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testWatchConnectivityStateInvalidParam()
+    {
+        $this->assertTrue($this->channel->watchConnectivityState(
+            0, 1000));
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testChannelConstructorInvalidParam()
+    {
+        $this->channel = new Grpc\Channel('localhost:'.$this->port, NULL);
+    }
+
+    public function testClose()
+    {
+        $this->assertNull($this->channel->close());
+    }
+
 }
diff --git a/src/php/tests/unit_tests/ServerTest.php b/src/php/tests/unit_tests/ServerTest.php
new file mode 100644
index 0000000000000000000000000000000000000000..d18f9abe9bfe6a51689a2c7cab07f164fe500b95
--- /dev/null
+++ b/src/php/tests/unit_tests/ServerTest.php
@@ -0,0 +1,71 @@
+<?php
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+class ServerTest extends PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+    }
+
+    public function tearDown()
+    {
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidConstructor()
+    {
+        $server = new Grpc\Server('invalid_host');
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidAddHttp2Port()
+    {
+        $this->server = new Grpc\Server([]);
+        $this->port = $this->server->addHttp2Port(['0.0.0.0:0']);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testInvalidAddSecureHttp2Port()
+    {
+        $this->server = new Grpc\Server([]);
+        $this->port = $this->server->addSecureHttp2Port(['0.0.0.0:0']);
+    }
+
+}
\ No newline at end of file
diff --git a/src/php/tests/unit_tests/TimevalTest.php b/src/php/tests/unit_tests/TimevalTest.php
index 1d2a8d303e737f304fd57db6a0cf8bd44e936f93..43abba126ab1b24033eb8ada9f0b61e2ca3f2ea1 100755
--- a/src/php/tests/unit_tests/TimevalTest.php
+++ b/src/php/tests/unit_tests/TimevalTest.php
@@ -91,4 +91,69 @@ class TimevalTest extends PHPUnit_Framework_TestCase
         $back_to_now = $deadline->subtract($delta);
         $this->assertSame(0, Grpc\Timeval::compare($back_to_now, $now));
     }
+
+    public function testSimilar()
+    {
+      $a = Grpc\Timeval::now();
+      $delta = new Grpc\Timeval(1000);
+      $b = $a->add($delta);
+      $thresh = new Grpc\Timeval(1100);
+      $this->assertTrue(Grpc\Timeval::similar($a, $b, $thresh));
+      $thresh = new Grpc\Timeval(900);
+      $this->assertFalse(Grpc\Timeval::similar($a, $b, $thresh));
+    }
+
+    public function testSleepUntil()
+    {
+        $curr_microtime = microtime(true);
+        $now = Grpc\Timeval::now();
+        $delta = new Grpc\Timeval(1000);
+        $deadline = $now->add($delta);
+        $deadline->sleepUntil();
+        $done_microtime = microtime(true);
+        $this->assertTrue(($done_microtime - $curr_microtime) > 0.0009);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testConstructorInvalidParam()
+    {
+        $delta = new Grpc\Timeval('abc');
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testAddInvalidParam()
+    {
+        $a = Grpc\Timeval::now();
+        $a->add(1000);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testSubtractInvalidParam()
+    {
+        $a = Grpc\Timeval::now();
+        $a->subtract(1000);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testCompareInvalidParam()
+    {
+        $a = Grpc\Timeval::compare(1000, 1100);
+    }
+
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testSimilarInvalidParam()
+    {
+        $a = Grpc\Timeval::similar(1000, 1100, 1200);
+    }
+
 }