feat: `deno init --serve` (#24897)

This commit adds "--serve" flag to "deno init" subcommand,
that provides a template for quick starting a project using
"deno serve".

---------

Co-authored-by: Asher Gomez <ashersaupingomez@gmail.com>

2 files changed, 127 insertions, 7 deletions

diff --git a/cli/args/flags.rs b/cli/args/flags.rs
index 1053e8f3f..e28ce549b 100644
--- a/cli/args/flags.rs
+++ b/cli/args/flags.rs
@@ -214,6 +214,7 @@ impl FmtFlags {
 pub struct InitFlags {
   pub dir: Option<String>,
   pub lib: bool,
+  pub serve: bool,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -2121,6 +2122,14 @@ fn init_subcommand() -> Command {
             .required(false)
             .action(ArgAction::SetTrue),
         )
+        .arg(
+          Arg::new("serve")
+            .long("serve")
+            .long_help("Generate an example project for `deno serve`")
+            .conflicts_with("lib")
+            .required(false)
+            .action(ArgAction::SetTrue),
+        )
     })
 }
 
@@ -4174,6 +4183,7 @@ fn init_parse(flags: &mut Flags, matches: &mut ArgMatches) {
   flags.subcommand = DenoSubcommand::Init(InitFlags {
     dir: matches.remove_one::<String>("dir"),
     lib: matches.get_flag("lib"),
+    serve: matches.get_flag("serve"),
   });
 }
 
@@ -10026,7 +10036,8 @@ mod tests {
       Flags {
         subcommand: DenoSubcommand::Init(InitFlags {
           dir: None,
-          lib: false
+          lib: false,
+          serve: false,
         }),
         ..Flags::default()
       }
@@ -10038,7 +10049,8 @@ mod tests {
       Flags {
         subcommand: DenoSubcommand::Init(InitFlags {
           dir: Some(String::from("foo")),
-          lib: false
+          lib: false,
+          serve: false,
         }),
         ..Flags::default()
       }
@@ -10050,7 +10062,8 @@ mod tests {
       Flags {
         subcommand: DenoSubcommand::Init(InitFlags {
           dir: None,
-          lib: false
+          lib: false,
+          serve: false,
         }),
         log_level: Some(Level::Error),
         ..Flags::default()
@@ -10063,7 +10076,21 @@ mod tests {
       Flags {
         subcommand: DenoSubcommand::Init(InitFlags {
           dir: None,
-          lib: true
+          lib: true,
+          serve: false,
+        }),
+        ..Flags::default()
+      }
+    );
+
+    let r = flags_from_vec(svec!["deno", "init", "--serve"]);
+    assert_eq!(
+      r.unwrap(),
+      Flags {
+        subcommand: DenoSubcommand::Init(InitFlags {
+          dir: None,
+          lib: false,
+          serve: true,
         }),
         ..Flags::default()
       }
@@ -10075,7 +10102,8 @@ mod tests {
       Flags {
         subcommand: DenoSubcommand::Init(InitFlags {
           dir: Some(String::from("foo")),
-          lib: true
+          lib: true,
+          serve: false,
         }),
         ..Flags::default()
       }
diff --git a/cli/tools/init/mod.rs b/cli/tools/init/mod.rs
index c62d93289..6d442198e 100644
--- a/cli/tools/init/mod.rs
+++ b/cli/tools/init/mod.rs
@@ -20,7 +20,87 @@ pub fn init_project(init_flags: InitFlags) -> Result<(), AnyError> {
     cwd
   };
 
-  if init_flags.lib {
+  if init_flags.serve {
+    create_file(
+      &dir,
+      "main.ts",
+      r#"import { type Route, route, serveDir } from "@std/http";
+
+const routes: Route[] = [
+  {
+    pattern: new URLPattern({ pathname: "/" }),
+    handler: () => new Response("Home page"),
+  },
+  {
+    pattern: new URLPattern({ pathname: "/users/:id" }),
+    handler: (_req, _info, params) => new Response(params?.pathname.groups.id),
+  },
+  {
+    pattern: new URLPattern({ pathname: "/static/*" }),
+    handler: (req) => serveDir(req, { urlRoot: "./" }),
+  },
+];
+
+function defaultHandler(_req: Request) {
+  return new Response("Not found", { status: 404 });
+}
+
+const handler = route(routes, defaultHandler);
+
+export default {
+  fetch(req) {
+    return handler(req);
+  },
+} satisfies Deno.ServeDefaultExport;
+ 
+"#,
+    )?;
+    create_file(
+      &dir,
+      "main_test.ts",
+      r#"import { assertEquals } from "@std/assert";
+import server from "./main.ts";
+
+Deno.test(async function serverFetch() {
+  const req = new Request("https://deno.land");
+  const res = await server.fetch(req);
+  assertEquals(await res.text(), "Home page");
+});
+
+Deno.test(async function serverFetchNotFound() {
+  const req = new Request("https://deno.land/404");
+  const res = await server.fetch(req);
+  assertEquals(res.status, 404);
+});
+
+Deno.test(async function serverFetchUsers() {
+  const req = new Request("https://deno.land/users/123");
+  const res = await server.fetch(req);
+  assertEquals(await res.text(), "123");
+});
+
+Deno.test(async function serverFetchStatic() {
+  const req = new Request("https://deno.land/static/main.ts");
+  const res = await server.fetch(req);
+  assertEquals(res.headers.get("content-type"), "text/plain;charset=UTF-8");
+});
+"#,
+    )?;
+
+    create_json_file(
+      &dir,
+      "deno.json",
+      &json!({
+        "tasks": {
+          "dev": "deno serve --watch -R main.ts",
+        },
+        "imports": {
+          "@std/assert": "jsr:@std/assert@1",
+          "@std/http": "jsr:@std/http@1",
+        }
+      }),
+    )?;
+  } else if init_flags.lib {
     // Extract the directory name to use as the project name
     let project_name = dir
       .file_name()
@@ -111,7 +191,19 @@ Deno.test(function addTest() {
     info!("  cd {}", dir);
     info!("");
   }
-  if init_flags.lib {
+  if init_flags.serve {
+    info!("  {}", colors::gray("# Run the server"));
+    info!("  deno serve -R main.ts");
+    info!("");
+    info!(
+      "  {}",
+      colors::gray("# Run the server and watch for file changes")
+    );
+    info!("  deno task dev");
+    info!("");
+    info!("  {}", colors::gray("# Run the tests"));
+    info!("  deno -R test");
+  } else if init_flags.lib {
     info!("  {}", colors::gray("# Run the tests"));
     info!("  deno test");
     info!("");