Add node tests

test/node/expect.js

@@ -0,0 +1,36 @@
+import expect from 'expect.js';
+
+/**
+ * Assert value is within some tolerance of a number.
+ * @param {number} n Number.
+ * @param {number} tol Tolerance.
+ * @return {expect.Assertion} The assertion.
+ */
+expect.Assertion.prototype.roughlyEqual = function (n, tol) {
+  this.assert(
+    Math.abs(this.obj - n) <= tol,
+    function () {
+      return (
+        'expected ' +
+        expect.stringify(this.obj) +
+        ' to be within ' +
+        tol +
+        ' of ' +
+        n
+      );
+    },
+    function () {
+      return (
+        'expected ' +
+        expect.stringify(this.obj) +
+        ' not to be within ' +
+        tol +
+        ' of ' +
+        n
+      );
+    }
+  );
+  return this;
+};
+
+export default expect;