tests: share http server between tests (#3336)

Re-enable flaky tests

cli/test_util.rs

@@ -8,11 +8,13 @@ use std::path::PathBuf;
 use std::process::Child;
 use std::process::Command;
 use std::process::Stdio;
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
 use std::sync::Mutex;
-use std::sync::MutexGuard;
 
 lazy_static! {
-  static ref GUARD: Mutex<()> = Mutex::new(());
+  static ref SERVER: Mutex<Option<Child>> = Mutex::new(None);
+  static ref SERVER_COUNT: AtomicUsize = AtomicUsize::new(0);
 }
 
 pub fn root_path() -> PathBuf {
@@ -35,32 +37,37 @@ pub fn deno_exe_path() -> PathBuf {
   p
 }
 
-pub struct HttpServerGuard<'a> {
-  #[allow(dead_code)]
-  g: MutexGuard<'a, ()>,
-  child: Child,
-}
+pub struct HttpServerGuard {}
 
-impl<'a> Drop for HttpServerGuard<'a> {
+impl Drop for HttpServerGuard {
   fn drop(&mut self) {
-    match self.child.try_wait() {
-      Ok(None) => {
-        self.child.kill().expect("failed to kill http_server.py");
-      }
-      Ok(Some(status)) => {
-        panic!("http_server.py exited unexpectedly {}", status)
-      }
-      Err(e) => panic!("http_server.py err {}", e),
+    let count = SERVER_COUNT.fetch_sub(1, Ordering::Relaxed);
+    // If no more tests hold guard we can kill the server
+    if count == 1 {
+      kill_http_server();
     }
   }
 }
 
-/// Starts tools/http_server.py when the returned guard is dropped, the server
-/// will be killed.
-pub fn http_server<'a>() -> HttpServerGuard<'a> {
-  // TODO(ry) Allow tests to use the http server in parallel.
-  let g = GUARD.lock().unwrap();
+fn kill_http_server() {
+  let mut server_guard = SERVER.lock().unwrap();
+  let mut child = server_guard
+    .take()
+    .expect("Trying to kill server but already killed");
+  match child.try_wait() {
+    Ok(None) => {
+      child.kill().expect("failed to kill http_server.py");
+    }
+    Ok(Some(status)) => panic!("http_server.py exited unexpectedly {}", status),
+    Err(e) => panic!("http_server.py err {}", e),
+  };
+}
 
+pub fn http_server() -> HttpServerGuard {
+  SERVER_COUNT.fetch_add(1, Ordering::Relaxed);
+  {
+    let mut server_guard = SERVER.lock().unwrap();
+    if server_guard.is_none() {
       println!("tools/http_server.py starting...");
       let mut child = Command::new("python")
         .current_dir(root_path())
@@ -74,6 +81,8 @@ pub fn http_server<'a>() -> HttpServerGuard<'a> {
       let mut lines = BufReader::new(stdout).lines();
       let line = lines.next().unwrap().unwrap();
       assert!(line.starts_with("ready"));
-
-  HttpServerGuard { child, g }
+      server_guard.replace(child);
+    }
+  }
+  HttpServerGuard {}
 }

cli/tests/integration_tests.rs

@@ -156,13 +156,11 @@ itest!(_018_async_catch {
   output: "018_async_catch.ts.out",
 });
 
-/* TODO(ry) Re-enable this test. It is flaky and only fails occasionally.
 itest!(_019_media_types {
   args: "run --reload 019_media_types.ts",
   output: "019_media_types.ts.out",
   http_server: true,
 });
-*/
 
 itest!(_020_json_modules {
   args: "run --reload 020_json_modules.ts",
@@ -174,13 +172,11 @@ itest!(_021_mjs_modules {
   output: "021_mjs_modules.ts.out",
 });
 
-/* TODO(ry) Re-enable this test. It is flaky and only fails occasionally.
 itest!(_022_info_flag_script {
   args: "info http://127.0.0.1:4545/cli/tests/019_media_types.ts",
   output: "022_info_flag_script.out",
   http_server: true,
 });
-*/
 
 itest!(_023_no_ext_with_headers {
   args: "run --reload 023_no_ext_with_headers",
@@ -335,21 +331,17 @@ itest!(_047_jsx {
   output: "047_jsx_test.jsx.out",
 });
 
-/* TODO(ry) Re-enable this test. It is flaky and only fails occasionally.
 itest!(_048_media_types_jsx {
   args: "run  --reload 048_media_types_jsx.ts",
   output: "048_media_types_jsx.ts.out",
   http_server: true,
 });
-*/
 
-/* TODO(ry) Re-enable this test. It is flaky and only fails occasionally.
 itest!(_049_info_flag_script_jsx {
   args: "info http://127.0.0.1:4545/cli/tests/048_media_types_jsx.ts",
   output: "049_info_flag_script_jsx.out",
   http_server: true,
 });
-*/
 
 itest!(_050_more_jsons {
   args: "run --reload 050_more_jsons.ts",
@@ -362,13 +354,11 @@ itest!(lock_check_ok {
   http_server: true,
 });
 
-/* TODO(ry) Re-enable this test. It is flaky and only fails occasionally.
 itest!(lock_check_ok2 {
   args: "run 019_media_types.ts --lock=lock_check_ok2.json",
   output: "019_media_types.ts.out",
   http_server: true,
 });
-*/
 
 itest!(lock_check_err {
   args: "run --lock=lock_check_err.json http://127.0.0.1:4545/cli/tests/003_relative_import.ts",
@@ -378,7 +368,6 @@ itest!(lock_check_err {
   http_server: true,
 });
 
-/* TODO(ry) Re-enable this test. It is flaky and only fails occasionally.
 itest!(lock_check_err2 {
   args: "run 019_media_types.ts --lock=lock_check_err2.json",
   output: "lock_check_err2.out",
@@ -386,7 +375,6 @@ itest!(lock_check_err2 {
   exit_code: 10,
   http_server: true,
 });
-*/
 
 itest!(async_error {
   exit_code: 1,