added unit testing, and started implementing unit tests...phew

node_modules/@sinonjs/commons/lib/order-by-first-call.test.js

@@ -0,0 +1,52 @@
+"use strict";
+
+var assert = require("@sinonjs/referee-sinon").assert;
+var knuthShuffle = require("knuth-shuffle").knuthShuffle;
+var sinon = require("@sinonjs/referee-sinon").sinon;
+var orderByFirstCall = require("./order-by-first-call");
+
+describe("orderByFirstCall", function() {
+    it("should order an Array of spies by the callId of the first call, ascending", function() {
+        // create an array of spies
+        var spies = [
+            sinon.spy(),
+            sinon.spy(),
+            sinon.spy(),
+            sinon.spy(),
+            sinon.spy(),
+            sinon.spy()
+        ];
+
+        // call all the spies
+        spies.forEach(function(spy) {
+            spy();
+        });
+
+        // add a few uncalled spies
+        spies.push(sinon.spy());
+        spies.push(sinon.spy());
+
+        // randomise the order of the spies
+        knuthShuffle(spies);
+
+        var sortedSpies = orderByFirstCall(spies);
+
+        assert.equals(sortedSpies.length, spies.length);
+
+        var orderedByFirstCall = sortedSpies.every(function(spy, index) {
+            if (index + 1 === sortedSpies.length) {
+                return true;
+            }
+            var nextSpy = sortedSpies[index + 1];
+
+            // uncalled spies should be ordered first
+            if (!spy.called) {
+                return true;
+            }
+
+            return spy.calledImmediatelyBefore(nextSpy);
+        });
+
+        assert.isTrue(orderedByFirstCall);
+    });
+});