test: add test cases to assert certain behavior (#168)

This is in relation to the Edge implementation. Everything this PR does is to assert how we handle something today, so that we can rely on it not changing in the future.

src/test/create-context.test.ts

@@ -25,6 +25,29 @@ test('should move rest props to properties', () => {
     expect(context.properties?.tenantId).toBe('some-tenant');
 });
 
+test('when an extra property is both on the top-level and under properties, the properties-level wins', () => {
+    const context = createContext({
+        customProperty: 'top-level',
+        properties: {
+            customProperty: 'properties-level',
+        },
+    });
+
+    expect(context).not.toHaveProperty('customProperty');
+    expect(context.properties?.customProperty).toBe('properties-level');
+});
+
+test('If you specify top-level properties under properties, they do not get moved up', () => {
+    const context = createContext({
+        properties: {
+            appName: 'name',
+        },
+    });
+
+    expect(context.properties?.appName).toBe('name');
+    expect(context.appName).toBe(undefined);
+});
+
 test('should keep properties', () => {
     const context = createContext({
         userId: '123',

src/test/unleash-proxy.test.ts

@@ -338,6 +338,34 @@ test('Should remove "undefined" environment field from context', async () => {
     expect(client.queriedContexts[0]).not.toHaveProperty('environment');
 });
 
+test('Providing a string for `properties` yields a 400', async () => {
+    const toggles = [
+        {
+            name: 'test',
+            enabled: true,
+            impressionData: true,
+        },
+    ];
+    const client = new MockClient(toggles);
+
+    const proxySecrets = ['sdf'];
+    const app = createApp(
+        {
+            unleashUrl,
+            unleashApiToken,
+            proxySecrets,
+            environment: 'test',
+        },
+        client,
+    );
+    client.emit('ready');
+
+    await request(app)
+        .get('/proxy?userId=123&properties=string')
+        .set('Authorization', 'sdf')
+        .expect(400);
+});
+
 test('Should register metrics', () => {
     const toggles = [
         {