feat: add --open to deno serve to open server in browser

cli/args/flags.rs

@@ -343,6 +343,7 @@ pub struct ServeFlags {
   pub port: u16,
   pub host: String,
   pub worker_count: Option<usize>,
+  pub open_site: bool,
 }
 
 impl ServeFlags {
@@ -354,6 +355,7 @@ impl ServeFlags {
       port,
       host: host.to_owned(),
       worker_count: None,
+      open_site: false,
     }
   }
 }
@@ -2787,7 +2789,7 @@ fn serve_subcommand() -> Command {
         .long("host")
         .help("The TCP address to serve on, defaulting to 0.0.0.0 (all interfaces)")
         .value_parser(serve_host_validator),
-    )
+    ).arg(Arg::new("open_site").long("open").help("Open the browser on the address that the server is running on.").action(ArgAction::SetTrue))
     .arg(
       parallel_arg("multiple server workers", false)
     )
@@ -4732,7 +4734,7 @@ fn serve_parse(
   let host = matches
     .remove_one::<String>("host")
     .unwrap_or_else(|| "0.0.0.0".to_owned());
-
+  let open_site = matches.remove_one::<bool>("open_site").unwrap_or(false);
   let worker_count = parallel_arg_parse(matches, false).map(|v| v.get());
 
   runtime_args_parse(flags, matches, true, true);
@@ -4775,6 +4777,7 @@ fn serve_parse(
     port,
     host,
     worker_count,
+    open_site,
   });
 
   Ok(())

cli/tools/serve.rs

@@ -50,6 +50,27 @@ pub async fn serve(
   )?);
   let worker_factory = factory.create_cli_main_worker_factory().await?;
 
+  if serve_flags.open_site {
+    let host: String;
+    if serve_flags.host == "0.0.0.0" || serve_flags.host == "127.0.0.1" {
+      host = "http://127.0.0.1".to_string();
+    } else if serve_flags.host == "localhost" {
+      host = "http://localhost".to_string();
+    } else {
+      host = format!("https://{}", serve_flags.host);
+    }
+    let port = serve_flags.port;
+    let browser_tab_open_result = open::that_detached(format!("{host}:{port}"));
+    if browser_tab_open_result.is_ok() {
+      log::info!(
+        "{}: Opened the browser on the address that the server is running on",
+        crate::colors::green("deno serve")
+      );
+    } else {
+      log::info!("{}: Couldn't open the browser on the address that the server is running on", crate::colors::red("deno serve"));
+    }
+  }
+
   do_serve(
     worker_factory,
     main_module,

tests/specs/serve/open_browser_tab/__test__.jsonc

@@ -0,0 +1,5 @@
+{
+  "args": "serve --open main.ts",
+  "output": "main.out",
+  "tempDir": true
+}

tests/specs/serve/open_browser_tab/main.out

@@ -0,0 +1,2 @@
+deno serve: Opened the browser on the address that the server is running on
+deno serve: Listening on http://localhost:8000/

tests/specs/serve/open_browser_tab/main.ts

@@ -0,0 +1,5 @@
+export default {
+  async fetch() {
+    return new Response("Hello world!");
+  },
+};