Add tests for derived SystemMetrics

test/lib/data/SystemMetrics.js

@@ -0,0 +1,22 @@
+"use strict";
+const assert = require("assert").strict;
+
+const lib = require("@clusterio/lib");
+const { SystemMetrics } = lib;
+
+
+describe("lib/data/ModPack", function() {
+	describe("class SystemMetrics", function() {
+		it("correctly calculates derived metrics", function() {
+			const metrics = new SystemMetrics("controller", [0.5, 0.25, 0, 1], 1024, 768, 2048, 512, 0, false);
+			assert.equal(metrics.cpuCapacity, 4);
+			assert.equal(metrics.cpuUsed, 1.75);
+			assert.equal(metrics.cpuAvailable, 2.25);
+			assert.equal(metrics.cpuRatio, 0.4375);
+			assert.equal(metrics.memoryUsed, 256);
+			assert.equal(metrics.memoryRatio, 0.25);
+			assert.equal(metrics.diskUsed, 1536);
+			assert.equal(metrics.diskRatio, 0.75);
+		});
+	});
+});