From 676be6632c113b61d95e9a0897c4810d63e479b2 Mon Sep 17 00:00:00 2001
From: Bert Belder <bertbelder@gmail.com>
Date: Thu, 14 May 2020 06:49:45 +0200
Subject: [PATCH] Fix flakiness in std file_server tests (#5306)

Fixes: #5275
---
 std/http/file_server_test.ts | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/std/http/file_server_test.ts b/std/http/file_server_test.ts
index 07c8618c11..2ff1149064 100644
--- a/std/http/file_server_test.ts
+++ b/std/http/file_server_test.ts
@@ -28,9 +28,16 @@ async function startFileServer(): Promise<void> {
   assert(s !== null && s.includes("server listening"));
 }
 
-function killFileServer(): void {
+async function killFileServer(): Promise<void> {
   fileServer.close();
-  fileServer.stdout?.close();
+  // Process.close() kills the file server process. However this termination
+  // happens asynchronously, and since we've just closed the process resource,
+  // we can't use `await fileServer.status()` to wait for the process to have
+  // exited. As a workaround, wait for its stdout to close instead.
+  // TODO(piscisaureus): when `Process.kill()` is stable and works on Windows,
+  // switch to calling `kill()` followed by `await fileServer.status()`.
+  await Deno.readAll(fileServer.stdout!);
+  fileServer.stdout!.close();
 }
 
 test("file_server serveFile", async (): Promise<void> => {
@@ -46,7 +53,7 @@ test("file_server serveFile", async (): Promise<void> => {
     );
     assertEquals(downloadedFile, localFile);
   } finally {
-    killFileServer();
+    await killFileServer();
   }
 });
 
@@ -68,7 +75,7 @@ test("serveDirectory", async function (): Promise<void> {
       assert(/<td class="mode">(\s)*\(unknown mode\)(\s)*<\/td>/.test(page));
     assert(page.includes(`<a href="/README.md">README.md</a>`));
   } finally {
-    killFileServer();
+    await killFileServer();
   }
 });
 
@@ -81,7 +88,7 @@ test("serveFallback", async function (): Promise<void> {
     assertEquals(res.status, 404);
     const _ = await res.text();
   } finally {
-    killFileServer();
+    await killFileServer();
   }
 });
 
@@ -99,7 +106,7 @@ test("serveWithUnorthodoxFilename", async function (): Promise<void> {
     assertEquals(res.status, 200);
     _ = await res.text();
   } finally {
-    killFileServer();
+    await killFileServer();
   }
 });