1 files changed, 8 insertions, 3 deletions
diff --git a/src/config.ts b/src/config.ts
index 937499923..af618a27f 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -24,6 +24,10 @@ function validateConfig(config: any): void {
       throw new Error(`[astro config] ${key}: ${JSON.stringify(config[key])}\n  Expected boolean, received ${type(config[key])}.`);
     }
   }
+
+  if(config.devOptions?.port !== 'number') {
+    throw new Error(`[astro config] devOptions.port: Expected number, received ${type(config.devOptions?.port)}`)
+  }
 }
 
 /** Set default config values */
@@ -34,7 +38,8 @@ function configDefaults(userConfig?: any): any {
   if (!config.astroRoot) config.astroRoot = './astro';
   if (!config.dist) config.dist = './_site';
   if (!config.public) config.public = './public';
-
+  if (!config.devOptions) config.devOptions = {};
+  if (!config.devOptions.port) config.devOptions.port = 3000;
   if (typeof config.sitemap === 'undefined') config.sitemap = true;
 
   return config;
@@ -53,13 +58,13 @@ function normalizeConfig(userConfig: any, root: string): AstroConfig {
 }
 
 /** Attempt to load an `astro.config.mjs` file */
-export async function loadConfig(rawRoot: string | undefined): Promise<AstroConfig> {
+export async function loadConfig(rawRoot: string | undefined, configFileName = 'astro.config.mjs'): Promise<AstroConfig> {
   if (typeof rawRoot === 'undefined') {
     rawRoot = process.cwd();
   }
 
   const root = pathResolve(rawRoot);
-  const astroConfigPath = pathJoin(root, 'astro.config.mjs');
+  const astroConfigPath = pathJoin(root, configFileName);
 
   // load
   let config: any;