test: basic functionality of readUIntBE()

PR-URL: https://github.com/nodejs/node/pull/10417
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Italo A. Casas <me@italoacasas.com>
Reviewed-By: Julian Duque <julianduquej@gmail.com>

test/parallel/test-buffer-readuintbe.js

@@ -0,0 +1,24 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+// testing basic functionality of readUIntBE()
+
+const buf = Buffer.from([42, 84, 168, 127]);
+const result = buf.readUIntBE(2);
+
+assert.strictEqual(result, 84);
+
+assert.throws(
+  () => {
+    buf.readUIntBE(5);
+  },
+  /Index out of range/
+);
+
+assert.doesNotThrow(
+  () => {
+    buf.readUIntBE(5, 0, true);
+  },
+  'readUIntBE() should not throw if noAssert is true'
+);