Add minimal test coverage and docs for mouse module

test/unit/io_mouse.js

@@ -0,0 +1,49 @@
+var test = require('tap').test;
+var Mouse = require('../../src/io/mouse');
+var Runtime = require('../../src/engine/runtime');
+
+test('spec', function (t) {
+    var rt = new Runtime();
+    var m = new Mouse(rt);
+
+    t.type(m, 'object');
+    t.type(m.postData, 'function');
+    t.type(m.getX, 'function');
+    t.type(m.getY, 'function');
+    t.type(m.getIsDown, 'function');
+    t.end();
+});
+
+test('mouseUp', function (t) {
+    var rt = new Runtime();
+    var m = new Mouse(rt);
+
+    m.postData({
+        x: 1,
+        y: 10,
+        isDown: false,
+        canvasWidth: 480,
+        canvasHeight: 360
+    });
+    t.strictEquals(m.getX(), -239);
+    t.strictEquals(m.getY(), 170);
+    t.strictEquals(m.getIsDown(), false);
+    t.end();
+});
+
+test('mouseDown', function (t) {
+    var rt = new Runtime();
+    var m = new Mouse(rt);
+
+    m.postData({
+        x: 10,
+        y: 100,
+        isDown: true,
+        canvasWidth: 480,
+        canvasHeight: 360
+    });
+    t.strictEquals(m.getX(), -230);
+    t.strictEquals(m.getY(), 80);
+    t.strictEquals(m.getIsDown(), true);
+    t.end();
+});