Allow adding a custom server to validate against

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+- Add `--add-server` to add a custom server when using `--validate-server`.
+  This allows quickly adding a custom domain or base path that will properly
+  validate.
 - Add `--header` (short `-H`) option to specify a custom header when fetching
   the API document. This allows you to pass custom auth info.
 - Add `readOnly` and `writeOnly` support to the example generator.

apisprout.go

@@ -114,6 +114,7 @@ func main() {
 	addParameter(flags, "watch", "w", false, "Reload when input file changes")
 	addParameter(flags, "disable-cors", "", false, "Disable CORS headers")
 	addParameter(flags, "header", "H", "", "Add a custom header when fetching API")
+	addParameter(flags, "add-server", "", "", "Add a new valid server URL, use with --validate-server")
 
 	// Run the app!
 	root.Execute()
@@ -292,6 +293,14 @@ func load(uri string, data []byte) (swagger *openapi3.Swagger, router *openapi3f
 		if err = addLocalServers(swagger); err != nil {
 			return
 		}
+
+		if cs := viper.GetString("add-server"); cs != "" {
+			swagger.Servers = append(swagger.Servers, &openapi3.Server{
+				URL:         cs,
+				Description: "Custom server from command line param",
+				Variables:   make(map[string]*openapi3.ServerVariable),
+			})
+		}
 	}
 
 	// Create a new router using the OpenAPI document's declared paths.