3 files changed, 60 insertions, 20 deletions

diff --git a/std/http/file_server.ts b/std/http/file_server.ts
index 84ca45692..7614c3ab2 100755
--- a/std/http/file_server.ts
+++ b/std/http/file_server.ts
@@ -34,10 +34,7 @@ interface FileServerArgs {
 const encoder = new TextEncoder();
 
 const serverArgs = parse(args) as FileServerArgs;
-
-const CORSEnabled = serverArgs.cors ? true : false;
 const target = posix.resolve(serverArgs._[0] ?? "");
-const addr = `0.0.0.0:${serverArgs.port ?? serverArgs.p ?? 4507}`;
 
 const MEDIA_TYPES: Record<string, string> = {
   ".md": "text/markdown",
@@ -60,23 +57,6 @@ function contentType(path: string): string | undefined {
   return MEDIA_TYPES[extname(path)];
 }
 
-if (serverArgs.h ?? serverArgs.help) {
-  console.log(`Deno File Server
-  Serves a local directory in HTTP.
-
-INSTALL:
-  deno install --allow-net --allow-read https://deno.land/std/http/file_server.ts
-
-USAGE:
-  file_server [path] [options]
-
-OPTIONS:
-  -h, --help          Prints help information
-  -p, --port <PORT>   Set port
-  --cors              Enable CORS via the "Access-Control-Allow-Origin" header`);
-  exit();
-}
-
 function modeToString(isDir: boolean, maybeMode: number | null): string {
   const modeMap = ["---", "--x", "-w-", "-wx", "r--", "r-x", "rw-", "rwx"];
 
@@ -319,6 +299,26 @@ function html(strings: TemplateStringsArray, ...values: unknown[]): string {
 }
 
 function main(): void {
+  const CORSEnabled = serverArgs.cors ? true : false;
+  const addr = `0.0.0.0:${serverArgs.port ?? serverArgs.p ?? 4507}`;
+
+  if (serverArgs.h ?? serverArgs.help) {
+    console.log(`Deno File Server
+    Serves a local directory in HTTP.
+  
+  INSTALL:
+    deno install --allow-net --allow-read https://deno.land/std/http/file_server.ts
+  
+  USAGE:
+    file_server [path] [options]
+  
+  OPTIONS:
+    -h, --help          Prints help information
+    -p, --port <PORT>   Set port
+    --cors              Enable CORS via the "Access-Control-Allow-Origin" header`);
+    exit();
+  }
+
   listenAndServe(
     addr,
     async (req): Promise<void> => {
diff --git a/std/http/file_server_test.ts b/std/http/file_server_test.ts
index 97c07c250..dbbaf81ff 100644
--- a/std/http/file_server_test.ts
+++ b/std/http/file_server_test.ts
@@ -38,6 +38,24 @@ async function startFileServer({
   assert(s !== null && s.includes("server listening"));
 }
 
+async function startFileServerAsLibrary({}: FileServerCfg = {}): Promise<void> {
+  fileServer = await Deno.run({
+    cmd: [
+      Deno.execPath(),
+      "run",
+      "--allow-read",
+      "--allow-net",
+      "http/testdata/file_server_as_library.ts",
+    ],
+    stdout: "piped",
+    stderr: "null",
+  });
+  assert(fileServer.stdout != null);
+  const r = new TextProtoReader(new BufReader(fileServer.stdout));
+  const s = await r.readLine();
+  assert(s !== null && s.includes("Server running..."));
+}
+
 async function killFileServer(): Promise<void> {
   fileServer.close();
   // Process.close() kills the file server process. However this termination
@@ -166,3 +184,13 @@ test("contentType", async () => {
   assertEquals(contentType, "text/html");
   (response.body as Deno.File).close();
 });
+
+test("file_server running as library", async function (): Promise<void> {
+  await startFileServerAsLibrary();
+  try {
+    const res = await fetch("http://localhost:8000");
+    assertEquals(res.status, 200);
+  } finally {
+    await killFileServer();
+  }
+});
diff --git a/std/http/testdata/file_server_as_library.ts b/std/http/testdata/file_server_as_library.ts
new file mode 100644
index 000000000..ab5fdcaab
--- /dev/null
+++ b/std/http/testdata/file_server_as_library.ts
@@ -0,0 +1,12 @@
+import { serve } from "../server.ts";
+import { serveFile } from "../file_server.ts";
+
+const server = serve({ port: 8000 });
+
+console.log('Server running...');
+
+for await (const req of server) {
+  serveFile(req, './http/testdata/hello.html').then(response => {
+    req.respond(response);
+  });
+}
\ No newline at end of file