diff --git a/test/unit/io_cloud.js b/test/unit/io_cloud.js
new file mode 100644
index 000000000..d7f2c7843
--- /dev/null
+++ b/test/unit/io_cloud.js
@@ -0,0 +1,84 @@
+const test = require('tap').test;
+const Cloud = require('../../src/io/cloud');
+const Target = require('../../src/engine/target');
+const Variable = require('../../src/engine/variable');
+
+test('spec', t => {
+    const cloud = new Cloud();
+
+    t.type(cloud, 'object');
+    t.type(cloud.postData, 'function');
+    t.type(cloud.requestUpdateVariable, 'function');
+    t.type(cloud.updateCloudVariable, 'function');
+    t.type(cloud.setProvider, 'function');
+    t.type(cloud.setStage, 'function');
+    t.type(cloud.clear, 'function');
+    t.end();
+});
+
+test('stage and provider are null initially', t => {
+    const cloud = new Cloud();
+
+    t.strictEquals(cloud.provider, null);
+    t.strictEquals(cloud.stage, null);
+    t.end();
+});
+
+test('setProvider sets the provider', t => {
+    const cloud = new Cloud();
+
+    const provider = {
+        foo: 'a fake provider'
+    };
+
+    cloud.setProvider(provider);
+    t.strictEquals(cloud.provider, provider);
+
+    t.end();
+});
+
+test('postData updates the variable', t => {
+    const stage = new Target();
+    const fooVar = new Variable(
+        'a fake var id',
+        'foo',
+        Variable.SCALAR_TYPE,
+        true /* isCloud */
+    );
+    stage.variables[fooVar.id] = fooVar;
+
+    t.strictEquals(fooVar.value, 0);
+
+    const cloud = new Cloud();
+    cloud.setStage(stage);
+    cloud.postData({varUpdate: {
+        name: 'foo',
+        value: 3
+    }});
+    t.strictEquals(fooVar.value, 3);
+    t.end();
+});
+
+test('requestUpdateVariable calls provider\'s updateVariable function', t => {
+    let updateVariableCalled = false;
+    let mockVarName = '';
+    let mockVarValue = '';
+    const mockUpdateVariable = (name, value) => {
+        updateVariableCalled = true;
+        mockVarName = name;
+        mockVarValue = value;
+        return;
+    };
+
+    const provider = {
+        updateVariable: mockUpdateVariable
+    };
+
+    const cloud = new Cloud();
+    cloud.setProvider(provider);
+    cloud.requestUpdateVariable('foo', 3);
+    t.equals(updateVariableCalled, true);
+    t.strictEquals(mockVarName, 'foo');
+    t.strictEquals(mockVarValue, 3);
+    t.end();
+});