test: fix flaky test-child-process-spawnsync-input

test/parallel/test-child-process-spawnsync-input.js

@@ -87,15 +87,3 @@ ret = spawnSync(process.execPath, args, { encoding: 'utf8' });
 checkSpawnSyncRet(ret);
 assert.strictEqual(ret.stdout, msgOut + '\n');
 assert.strictEqual(ret.stderr, msgErr + '\n');
-
-options = {
-  maxBuffer: 1
-};
-
-ret = spawnSync(process.execPath, args, options);
-
-assert.ok(ret.error, 'maxBuffer should error');
-assert.strictEqual(ret.error.errno, 'ENOBUFS');
-// we can have buffers larger than maxBuffer because underneath we alloc 64k
-// that matches our read sizes
-assert.deepEqual(ret.stdout, msgOutBuf);

test/parallel/test-child-process-spawnsync-maxbuf.js

@@ -0,0 +1,27 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+const spawnSync = require('child_process').spawnSync;
+
+const msgOut = 'this is stdout';
+
+// this is actually not os.EOL?
+const msgOutBuf = new Buffer(msgOut + '\n');
+
+const args = [
+  '-e',
+  `console.log("${msgOut}");`
+];
+
+const options = {
+  maxBuffer: 1
+};
+
+const ret = spawnSync(process.execPath, args, options);
+
+assert.ok(ret.error, 'maxBuffer should error');
+assert.strictEqual(ret.error.errno, 'ENOBUFS');
+// we can have buffers larger than maxBuffer because underneath we alloc 64k
+// that matches our read sizes
+assert.deepEqual(ret.stdout, msgOutBuf);