diff --git a/src/node/cli.ts b/src/node/cli.ts
index 5a0e4473..2469bedb 100644
--- a/src/node/cli.ts
+++ b/src/node/cli.ts
@@ -244,7 +244,7 @@ export const optionDescriptions = (): string[] => {
 export const parse = (
   argv: string[],
   opts?: {
-    configFile: string
+    configFile?: string
   },
 ): Args => {
   const error = (msg: string): Error => {
@@ -521,7 +521,19 @@ export async function readConfigFile(configPath?: string): Promise<ConfigArgs> {
   }
 
   const configFile = await fs.readFile(configPath)
-  const config = yaml.safeLoad(configFile.toString(), {
+  return parseConfigFile(configFile.toString(), configPath)
+}
+
+/**
+ * parseConfigFile parses configFile into ConfigArgs.
+ * configPath is used as the filename in error messages
+ */
+export function parseConfigFile(configFile: string, configPath: string): ConfigArgs {
+  if (configFile == "") {
+    return  { _: [], config: configPath }
+  }
+
+  const config = yaml.safeLoad(configFile, {
     filename: configPath,
   })
   if (!config || typeof config === "string") {
diff --git a/test/httpserver.ts b/test/httpserver.ts
index dc88da3d..570adf13 100644
--- a/test/httpserver.ts
+++ b/test/httpserver.ts
@@ -3,9 +3,17 @@ import * as nodeFetch from "node-fetch"
 import * as util from "../src/common/util"
 import { ensureAddress } from "../src/node/app"
 
+// Perhaps an abstraction similar to this should be used in app.ts as well.
 export class HttpServer {
   private hs = http.createServer()
 
+  public constructor(hs?: http.Server) {
+    // See usage in test/integration.ts
+    if (hs) {
+      this.hs = hs
+    }
+  }
+
   /**
    * listen starts the server on a random localhost port.
    * Use close to cleanup when done.
@@ -53,4 +61,12 @@ export class HttpServer {
   public fetch(requestPath: string, opts?: nodeFetch.RequestInit): Promise<nodeFetch.Response> {
     return nodeFetch.default(`${ensureAddress(this.hs)}${requestPath}`, opts)
   }
+
+  public port(): number {
+    const addr = this.hs.address()
+    if (addr && typeof addr == "object") {
+      return addr.port
+    }
+    throw new Error("server not listening or listening on unix socket")
+  }
 }
diff --git a/test/integration.ts b/test/integration.ts
new file mode 100644
index 00000000..a4cc7586
--- /dev/null
+++ b/test/integration.ts
@@ -0,0 +1,16 @@
+import { createApp } from "../src/node/app"
+import { register } from "../src/node/routes"
+import { parse, setDefaults, parseConfigFile, DefaultedArgs } from  "../src/node/cli"
+import * as httpserver from "./httpserver"
+import * as express from "express"
+
+export async function setup(argv: string[], configFile?: string): Promise<[express.Application, express.Application, httpserver.HttpServer, DefaultedArgs]> {
+  const cliArgs = parse(argv)
+  let configArgs = parseConfigFile(configFile || "", "test/integration.ts")
+  const args = await setDefaults(cliArgs, configArgs)
+
+  const [app, wsApp, server] = await createApp(args)
+  await register(app, wsApp, server, args)
+
+  return [app, wsApp, new httpserver.HttpServer(server), args]
+}