Add documentation link in discovery files

Author: kaldebert

endpoints-framework/src/main/java/com/google/api/server/spi/discovery/DiscoveryGenerator.java

@@ -154,6 +154,9 @@ private RestDescription writeApi(ApiKey apiKey, Iterable<ApiConfig> apiConfigs,
       if (config.getTitle() != null) {
         doc.setTitle(config.getTitle());
       }
+      if (config.getDocumentationLink() != null) {
+        doc.setDocumentationLink(config.getDocumentationLink());
+      }
       if (config.getNamespaceConfig() != null) {
         ApiNamespaceConfig namespaceConfig = config.getNamespaceConfig();
         if (!Strings.isEmptyOrWhitespace(namespaceConfig.getOwnerName())) {
@@ -392,7 +395,8 @@ private DirectoryList generateDirectory(Map<ApiKey, RestDescription> discoveryDo
           .setName(doc.getName())
           .setPreferred(preferred.contains(entry.getKey()))
           .setTitle(doc.getTitle())
-          .setVersion(doc.getVersion()));
+          .setVersion(doc.getVersion())
+          .setDocumentationLink(doc.getDocumentationLink()));
     }
     return directory.setItems(items);
   }

endpoints-framework/src/test/resources/com/google/api/server/spi/discovery/foo_endpoint.json

@@ -13,6 +13,7 @@
   "batchPath": "batch",
   "description": "Just Foo Things",
   "discoveryVersion": "v1",
+  "documentationLink": "https://example.com",
   "icons": {
     "x16": "https://www.gstatic.com/images/branding/product/1x/googleg_16dp.png",
     "x32": "https://www.gstatic.com/images/branding/product/1x/googleg_32dp.png"

endpoints-framework/src/test/resources/com/google/api/server/spi/discovery/foo_endpoint_default_context.json

@@ -13,6 +13,7 @@
   "batchPath": "batch",
   "description": "Just Foo Things",
   "discoveryVersion": "v1",
+  "documentationLink": "https://example.com",
   "icons": {
     "x16": "https://www.gstatic.com/images/branding/product/1x/googleg_16dp.png",
     "x32": "https://www.gstatic.com/images/branding/product/1x/googleg_32dp.png"

endpoints-framework/src/test/resources/com/google/api/server/spi/discovery/foo_endpoint_localhost.json

@@ -13,6 +13,7 @@
   "batchPath": "batch",
   "description": "Just Foo Things",
   "discoveryVersion": "v1",
+  "documentationLink": "https://example.com",
   "icons": {
     "x16": "https://www.gstatic.com/images/branding/product/1x/googleg_16dp.png",
     "x32": "https://www.gstatic.com/images/branding/product/1x/googleg_32dp.png"

test-utils/src/main/java/com/google/api/server/spi/testing/FooEndpoint.java

@@ -27,7 +27,8 @@
     version = "v1",
     audiences = {"audience"},
     title = "The Foo API",
-    description = "Just Foo Things")
+    description = "Just Foo Things",
+    documentationLink = "https://example.com")
 public class FooEndpoint {
   @ApiMethod(name = "foo.create", description = "create desc", path = "foos/{id}",
       httpMethod = HttpMethod.PUT)