Better synchronization in @babel/cli interactive tests

packages/babel-cli/test/fixtures/babel/dir --out-dir --watch --verbose with external dependencies/executor.js

@@ -1,25 +1,47 @@
 const fs = require("fs");
+const assert = require("assert");
 
-// Wait for the initial build
-sleep(300);
+// For Node.js <= 10
+if (!assert.match) assert.match = (val, re) => assert(re.test(val));
 
-logFile("lib/index.js");
-logFile("lib/main.js");
+const run = (function* () {
+  let files = [yield, yield].sort();
+  assert.match(files[0], /src[\\/]index.js -> lib[\\/]index.js/);
+  assert.match(files[1], /src[\\/]main.js -> lib[\\/]main.js/);
+  assert.match(yield, /Successfully compiled 2 files with Babel \(\d+ms\)\./);
 
-fs.writeFileSync("./file.txt", "Updated!");
+  logFile("lib/index.js");
+  logFile("lib/main.js");
 
-// Wait for the new build
-sleep(300);
+  fs.writeFileSync("./file.txt", "Updated!");
 
-logFile("lib/index.js");
-logFile("lib/main.js");
+  files = [yield, yield].sort();
+  assert.match(files[0], /src[\\/]index.js -> lib[\\/]index.js/);
+  assert.match(files[1], /src[\\/]main.js -> lib[\\/]main.js/);
+  assert.match(yield, /Successfully compiled 2 files with Babel \(\d+ms\)\./);
+
+  logFile("lib/index.js");
+  logFile("lib/main.js");
+})();
+
+run.next();
+
+process.stdin.on("data", function listener(chunk) {
+  const str = String(chunk).trim();
+  if (!str) return;
+
+  console.log(str);
+
+  if (run.next(str).done) {
+    process.exit(0);
+  }
+});
 
 function logFile(file) {
   console.log("EXECUTOR", file, JSON.stringify(fs.readFileSync(file, "utf8")));
 }
 
-function sleep(ms) {
-  const arr = new Int32Array(new SharedArrayBuffer(4));
-  arr[0] = 0;
-  Atomics.wait(arr, 0, 0, ms);
-}
+setTimeout(() => {
+  console.error("EXECUTOR TIMEOUT");
+  process.exit(1);
+}, 5000);

packages/babel-cli/test/fixtures/babel/dir --out-dir --watch with external dependencies/executor.js

@@ -1,25 +1,41 @@
 const fs = require("fs");
+const assert = require("assert");
 
-// Wait for the initial build
-sleep(300);
+// For Node.js <= 10
+if (!assert.match) assert.match = (val, re) => assert(re.test(val));
 
-logFile("lib/index.js");
-logFile("lib/main.js");
+const run = function* () {
+  assert.match(yield, /Successfully compiled 2 files with Babel \(\d+ms\)\./);
 
-fs.writeFileSync("./file.txt", "Updated!");
+  logFile("lib/index.js");
+  logFile("lib/main.js");
 
-// Wait for the new build
-sleep(300);
+  fs.writeFileSync("./file.txt", "Updated!");
 
-logFile("lib/index.js");
-logFile("lib/main.js");
+  assert.match(yield, /Successfully compiled 2 files with Babel \(\d+ms\)\./);
+
+  logFile("lib/index.js");
+  logFile("lib/main.js");
+}();
+
+run.next();
+
+process.stdin.on("data", function listener(chunk) {
+  const str = String(chunk).trim();
+  if (!str) return;
+
+  console.log(str);
+
+  if (run.next(str).done) {
+    process.exit(0);
+  }
+});
 
 function logFile(file) {
   console.log("EXECUTOR", file, JSON.stringify(fs.readFileSync(file, "utf8")));
 }
 
-function sleep(ms) {
-  const arr = new Int32Array(new SharedArrayBuffer(4));
-  arr[0] = 0;
-  Atomics.wait(arr, 0, 0, ms);
-}
+setTimeout(() => {
+  console.error("EXECUTOR TIMEOUT");
+  process.exit(1);
+}, 5000);

packages/babel-cli/test/index.js

@@ -152,14 +152,6 @@ const buildTest = function (binName, testName, opts) {
     let stderr = "";
     let stdout = "";
 
-    spawn.stderr.on("data", function (chunk) {
-      stderr += chunk;
-    });
-
-    spawn.stdout.on("data", function (chunk) {
-      stdout += chunk;
-    });
-
     spawn.on("close", function () {
       let err;
 
@@ -182,22 +174,31 @@ const buildTest = function (binName, testName, opts) {
       spawn.stdin.end();
     }
 
-    if (opts.executor) {
-      const executor = child.spawn(process.execPath, [opts.executor], {
-        cwd: tmpLoc,
-      });
-
-      executor.stderr.on("data", function (chunk) {
+    const captureOutput = proc => {
+      proc.stderr.on("data", function (chunk) {
         stderr += chunk;
       });
 
-      executor.stdout.on("data", function (chunk) {
+      proc.stdout.on("data", function (chunk) {
         stdout += chunk;
       });
+    };
+
+    if (opts.executor) {
+      const executor = child.spawn(process.execPath, [opts.executor], {
+        cwd: tmpLoc,
+      });
+
+      spawn.stdout.pipe(executor.stdin);
+      spawn.stderr.pipe(executor.stdin);
 
       executor.on("close", function () {
         setTimeout(() => spawn.kill("SIGINT"), 250);
       });
+
+      captureOutput(executor);
+    } else {
+      captureOutput(spawn);
     }
   };
 };