Remove race-condition in file_server tests (denoland/deno_std#125)

Original: https://github.com/denoland/deno_std/commit/e28c9a407951f10d952993ff6a7b248ca11243e1

examples/test.ts

@@ -13,7 +13,8 @@ test(function t2() {
 /** A more complicated test that runs a subprocess. */
 test(async function catSmoke() {
   const p = run({
-    args: ["deno", "examples/cat.ts", "README.md"]
+    args: ["deno", "examples/cat.ts", "README.md"],
+    stdout: "piped"
   });
   const s = await p.status();
   assertEqual(s.code, 0);

http/file_server_test.ts

-import { readFile } from "deno";
+import { readFile, run } from "deno";
 
 import { test, assert, assertEqual } from "../testing/mod.ts";
+import { BufReader } from "../io/bufio.ts";
+import { TextProtoReader } from "../textproto/mod.ts";
 
-// Promise to completeResolve when all tests completes
-let completeResolve;
-export const completePromise = new Promise(res => (completeResolve = res));
-let completedTestCount = 0;
-
-function maybeCompleteTests() {
-  completedTestCount++;
-  // Change this when adding more tests
-  if (completedTestCount === 3) {
-    completeResolve();
-  }
+let fileServer;
+async function startFileServer() {
+  fileServer = run({
+    args: ["deno", "--allow-net", "http/file_server.ts", ".", "--cors"],
+    stdout: "piped"
+  });
+  // Once fileServer is ready it will write to its stdout.
+  const r = new TextProtoReader(new BufReader(fileServer.stdout));
+  const [s, err] = await r.readLine();
+  assert(err == null);
+  assert(s.includes("server listening"));
+}
+function killFileServer() {
+  fileServer.close();
+  fileServer.stdout.close();
 }
 
-export function runTests(serverReadyPromise: Promise<any>) {
-  test(async function serveFile() {
-    await serverReadyPromise;
+test(async function serveFile() {
+  await startFileServer();
+  try {
     const res = await fetch("http://localhost:4500/azure-pipelines.yml");
     assert(res.headers.has("access-control-allow-origin"));
     assert(res.headers.has("access-control-allow-headers"));
@@ -27,25 +33,32 @@ export function runTests(serverReadyPromise: Promise<any>) {
       await readFile("./azure-pipelines.yml")
     );
     assertEqual(downloadedFile, localFile);
-    maybeCompleteTests();
-  });
+  } finally {
+    killFileServer();
+  }
+});
 
-  test(async function serveDirectory() {
-    await serverReadyPromise;
+test(async function serveDirectory() {
+  await startFileServer();
+  try {
     const res = await fetch("http://localhost:4500/");
     assert(res.headers.has("access-control-allow-origin"));
     assert(res.headers.has("access-control-allow-headers"));
     const page = await res.text();
     assert(page.includes("azure-pipelines.yml"));
-    maybeCompleteTests();
-  });
+  } finally {
+    killFileServer();
+  }
+});
 
-  test(async function serveFallback() {
-    await serverReadyPromise;
+test(async function serveFallback() {
+  await startFileServer();
+  try {
     const res = await fetch("http://localhost:4500/badfile.txt");
     assert(res.headers.has("access-control-allow-origin"));
     assert(res.headers.has("access-control-allow-headers"));
     assertEqual(res.status, 404);
-    maybeCompleteTests();
-  });
-}
+  } finally {
+    killFileServer();
+  }
+});

http/http.ts

@@ -2,7 +2,7 @@ import { listen, Conn, toAsyncIterator, Reader, copy } from "deno";
 import { BufReader, BufState, BufWriter } from "../io/bufio.ts";
 import { TextProtoReader } from "../textproto/mod.ts";
 import { STATUS_TEXT } from "./http_status.ts";
-import { assert } from "../io/util.ts";
+import { assert } from "../testing/mod.ts";
 
 interface Deferred {
   promise: Promise<{}>;

io/bufio.ts

@@ -4,7 +4,8 @@
 // license that can be found in the LICENSE file.
 
 import { Reader, ReadResult, Writer } from "deno";
-import { assert, charCode, copyBytes } from "./util.ts";
+import { charCode, copyBytes } from "./util.ts";
+import { assert } from "../testing/mod.ts";
 
 const DEFAULT_BUF_SIZE = 4096;
 const MIN_BUF_SIZE = 16;

io/util.ts

 import { Buffer, Reader } from "deno";
 
-export function assert(cond: boolean, msg = "assert") {
-  if (!cond) {
-    throw Error(msg);
-  }
-}
-
 // `off` is the offset into `dst` where it will at which to begin writing values
 // from `src`.
 // Returns the number of bytes copied.

test.ts

 #!/usr/bin/env deno --allow-run --allow-net --allow-write
-import { run } from "deno";
-
 import "colors/test.ts";
 import "datetime/test.ts";
 import "examples/test.ts";
@@ -16,21 +14,12 @@ import "fs/path/relative_test.ts";
 import "fs/path/resolve_test.ts";
 import "fs/path/zero_length_strings_test.ts";
 import "io/bufio_test.ts";
+import "io/ioutil_test.ts";
 import "http/http_test.ts";
+import "http/file_server_test.ts";
 import "log/test.ts";
 import "media_types/test.ts";
 import "testing/test.ts";
 import "textproto/test.ts";
+import "ws/sha1_test.ts";
 import "ws/test.ts";
-
-import { runTests, completePromise } from "http/file_server_test.ts";
-
-const fileServer = run({
-  args: ["deno", "--allow-net", "http/file_server.ts", ".", "--cors"]
-});
-
-runTests(new Promise(res => setTimeout(res, 5000)));
-(async () => {
-  await completePromise;
-  fileServer.close();
-})();