test: fix another flaky stringbytes test

Avoid depending on precise timing of when an object will be collected
by GC. This test was missed by #6039 as it happened to be in a
different directory than the rest.

Ref: https://github.com/nodejs/node/pull/6039
PR-URL: https://github.com/nodejs/node/pull/6073
Reviewed-By: Trott - Rich Trott <rtrott@gmail.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-at-max.js b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-at-max.js
new file mode 100644
index 0000000000..9903d6787a
--- /dev/null
+++ b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-at-max.js
@@ -0,0 +1,34 @@
+'use strict';
+
+const common = require('../../common');
+const binding = require('./build/Release/binding');
+const assert = require('assert');
+
+// v8 fails silently if string length > v8::String::kMaxLength
+// v8::String::kMaxLength defined in v8.h
+const kStringMaxLength = process.binding('buffer').kStringMaxLength;
+
+const skipMessage =
+  '1..0 # Skipped: intensive toString tests due to memory confinements';
+if (!common.enoughTestMem) {
+  console.log(skipMessage);
+  return;
+}
+
+try {
+  var buf = Buffer.allocUnsafe(kStringMaxLength);
+} catch (e) {
+  // If the exception is not due to memory confinement then rethrow it.
+  if (e.message !== 'Array buffer allocation failed') throw (e);
+  console.log(skipMessage);
+  return;
+}
+
+// Ensure we have enough memory available for future allocations to succeed.
+if (!binding.ensureAllocation(2 * kStringMaxLength)) {
+  console.log(skipMessage);
+  return;
+}
+
+const maxString = buf.toString('binary');
+assert.equal(maxString.length, kStringMaxLength);