added expect-relations helper and used it to test get-cart

integration-tests/api/helpers/expect-relations.js

@@ -0,0 +1,20 @@
+const { expect } = require("@jest/globals")
+
+export function expectRelations(expected, actual){
+    expected.forEach(a => expectRelations_(a, actual))
+}
+
+function expectRelations_(expected, actual){
+    const items = expected.split(".");
+    let data_ = actual;
+
+    for(const i in items){
+        data_ = data_[items[i]];
+        
+        if(data_ instanceof Array && data_.length > 0) {
+            data_ = data_[0];
+        } 
+    
+        expect(data_).toBeDefined();
+    }
+}