test native <-> polyfill publish/subscribe

test/cross-communication.spec.js

@@ -0,0 +1,52 @@
+const test = require('tape');
+
+const { hasDiagnosticsChannel } = require('../checks');
+
+if (!hasDiagnosticsChannel()) {
+  test('cross-communication', t => {
+    t.comment(`The current version of Node.js, ${process.version}, does not include diagnostics_channel. Skipping test.`);
+    t.end();
+  });
+
+  return;
+}
+
+const polyfill = require('../dc-polyfill.js');
+const native = require('../dc-polyfill.js');
+
+test('subscribe in native, publish from polyfill', t => {
+  const native_ch = native.channel('foo');
+  const polyfill_ch = polyfill.channel('foo');
+
+  t.equal(native_ch.hasSubscribers, false, 'native ch should have no subscribers yet');
+  t.equal(polyfill_ch.hasSubscribers, false, 'polyfill ch should have no subscribers yet');
+
+  native.subscribe('foo', (msg) => {
+    t.equal(msg, 'bar');
+    t.end();
+  });
+
+  t.equal(native_ch.hasSubscribers, true, 'native ch should now have subscribers');
+  t.equal(polyfill_ch.hasSubscribers, true, 'polyfill ch should now have subscribers');
+
+  polyfill_ch.publish('bar');
+});
+
+test('subscribe in polyfill, publish from native', t => {
+  const native_ch = native.channel('foo2');
+  const polyfill_ch = polyfill.channel('foo2');
+
+  t.equal(native_ch.hasSubscribers, false, 'native ch should have no subscribers yet');
+  t.equal(polyfill_ch.hasSubscribers, false, 'polyfill ch should have no subscribers yet');
+
+  polyfill.subscribe('foo2', (msg) => {
+    t.equal(msg, 'bar');
+    t.end();
+  });
+
+  t.equal(native_ch.hasSubscribers, true, 'native ch should now have subscribers');
+  t.equal(polyfill_ch.hasSubscribers, true, 'polyfill ch should now have subscribers');
+
+  native_ch.publish('bar');
+});
+