feat: support requesting numeric enum rest encoding

src/RequestBuilder.php

@@ -92,6 +92,7 @@ public function build($path, Message $message, array $headers = [])
             );
         }
 
+        $numericEnums = isset($this->restConfig['numericEnums']) && $this->restConfig['numericEnums'];
         $methodConfig = $this->restConfig['interfaces'][$interface][$method] + [
             'placeholders' => [],
             'body' => null,
@@ -107,6 +108,12 @@ public function build($path, Message $message, array $headers = [])
                 // We found a valid uriTemplate - now build and return the Request
 
                 list($body, $queryParams) = $this->constructBodyAndQueryParameters($message, $config);
+
+                // Request enum fields be encoded as numbers rather than strings.
+                if ($numericEnums) {
+                    $queryParams['$alt'] = "json;enum-encoding=int";
+                }
+
                 $uri = $this->buildUri($pathTemplate, $queryParams);
 
                 return new Request(

tests/Tests/Unit/RequestBuilderTest.php

@@ -45,6 +45,10 @@ public function setUp()
             'www.example.com',
             __DIR__ . '/testdata/test_service_rest_client_config.php'
         );
+        $this->numericEnumsBuilder = new RequestBuilder(
+            'www.example.com',
+            __DIR__ . '/testdata/test_numeric_enums_rest_client_config.php'
+        );
     }
 
     public function testMethodWithUrlPlaceholder()
@@ -378,6 +382,20 @@ public function testMethodWithOneOfInQueryString()
         $this->assertSame('some-value', $query['field1']);
     }
 
+    public function testMethodWithNumericEnumsQueryParam()
+    {
+        $message = (new MockRequestBody())
+            ->setName('')
+            ->setNumber(0);
+
+        $request = $this->numericEnumsBuilder->build(self::SERVICE_NAME . '/MethodWithNumericEnumsQueryParam', $message);
+        $query = Query::parse($request->getUri()->getQuery());
+
+        $this->assertSame('', $query['name']);
+        $this->assertEquals(0, $query['number']);
+        $this->assertEquals('json;enum-encoding=int', $query['$alt']);
+    }
+
     /**
      * @expectedException \Google\ApiCore\ValidationException
      * @expectedExceptionMessage Could not map bindings for test.interface.v1.api/MethodWithAdditionalBindings to any Uri template.

tests/Tests/Unit/testdata/test_numeric_enums_rest_client_config.php

@@ -0,0 +1,17 @@
+<?php
+
+return [
+    'numericEnums' => true,
+    'interfaces' => [
+        'test.interface.v1.api' => [
+            'MethodWithNumericEnumsQueryParam' => [
+                'method' => 'get',
+                'uriTemplate' => '/v1/fixedurl',
+                'queryParams' => [
+                    'name',
+                    'number'
+                ]
+            ]
+        ],
+    ],
+];