fix endpoint path removal (#1795)

.changes/nextrelease/changelog_endpoint_path.json

@@ -0,0 +1,7 @@
+[
+    {
+        "type": "bugfix",
+        "category": "Api",
+        "description": "Preserve path on custom endpoints"
+    }
+]

src/Api/Serializer/RestSerializer.php

@@ -212,6 +212,12 @@ function (array $matches) use ($varspecs) {
             $relative .= strpos($relative, '?') ? "&{$append}" : "?$append";
         }
 
+        // If endpoint has path, remove leading '/' to preserve URI resolution.
+        $path = $this->endpoint->getPath();
+        if ($path && $relative[0] === '/') {
+            $relative = substr($relative, 1);
+        }
+
         // Expand path place holders using Amazon's slightly different URI
         // template syntax.
         return UriResolver::resolve($this->endpoint, new Uri($relative));

tests/Api/Serializer/RestJsonSerializerTest.php

@@ -86,6 +86,14 @@ private function getRequest($commandName, $input)
         return $j($command);
     }
 
+    private function getPathEndpointRequest($commandName, $input)
+    {
+        $service = $this->getTestService();
+        $command = new Command($commandName, $input);
+        $j = new RestJsonSerializer($service, 'http://foo.com/bar');
+        return $j($command);
+    }
+
     public function testPreparesRequestsWithContentType()
     {
         $request = $this->getRequest('foo', ['baz' => 'bar']);
@@ -98,6 +106,18 @@ public function testPreparesRequestsWithContentType()
         );
     }
 
+    public function testPreparesRequestsWithEndpointWithPath()
+    {
+        $request = $this->getPathEndpointRequest('foo', ['baz' => 'bar']);
+        $this->assertEquals('POST', $request->getMethod());
+        $this->assertEquals('http://foo.com/bar', (string) $request->getUri());
+        $this->assertEquals('{"baz":"bar"}', (string) $request->getBody());
+        $this->assertEquals(
+            'application/json',
+            $request->getHeaderLine('Content-Type')
+        );
+    }
+
     public function testPreparesRequestsWithBlobButNoForcedContentType()
     {
         $request = $this->getRequest('bar', ['baz' => 'bar']);