This Sprint led to a frustrating conclusion. Our group essentially completed the offline storage service, which incidentally does much more than just store data, but came upon some sudden issues.
Because the service itself can also store, retrieve, delete, and update data while offline to an offline PouchDB database, that actually just uses IndexedDB on chrome, I floated the idea of renaming it to an offline database service instead. The idea was accepted, but currently renaming is an easy step that can be implemented after we get it working.
The main issue that has appeared is a confusing and somewhat baffling error that suddenly appeared. My team mate, Connor, had made a number of new tests for our service that were much more comprehensive than our previous simple ones. Using the tests we could see if the service worked, not just by the test results but by looking at the database itself in chromes dev tools to see the documents stored when the tests ran. The put and get commands added documents to our PouchDB database and would retrieve a JSON object from the database. However, starting this week, it simply stopped working.
I am still testing our service in isolation from the larger project, while using the same tslint.json to keep the format required the same, to avoid needless complications. Last week, running ng test to run the tests for our service through karma could no longer successfully launch. It would fail to open the browser consistently. Looking up the issue, I decided to reinstall the node modules director of my project. This ended up working, but ever since then, the methods in our service stopped succeeding.
The most baffling part is that there seems to be no feedback or explicit error at all. The commands to put and get documents and such are promises with a catch statement, so any errors should be caught and then logged. No errors are logged and yet the commands themselves also do not succeed. By viewing the database itself, it became apparent that no documents were being put into the database at all. Adding several console log statements throughout the methods to see which parts of it were executing showed that the entire put or get promise is being seemingly ignored. The promise has 3 different outcomes, it being resolves, being rejected, or an error happening. None of the options execute, which was very confusing.
This is still an ongoing issue with our service that once we fix should mean we are done. Frustratingly, this issue has shown up in my team mates projects as well, which means there must be something that happened that made it seem as if it was executing flawlessly earlier or we missed something. More research is required to fix this, it is a road block currently. I also discovered the command used for the ng2-amrs project is ‘npm run test’ instead of using angular cli’s test command ‘ng test’. This seems annoying as difference is that ‘npm run test’ seemingly has to be used every time tests need to be run, while ‘ng test’ can be used once and the tests will reload and be rerun whenever a code change happens.
I also did some more research into promises in pursuit of a fix to the issue in our project. I now understand the format of the then method much more comprehensively. And researching the PouchDB Api some more, I suggested some changes to the tests to make them much better at testing if the methods worked.
As long as we can fix our major issue right now, we can essentially finish our offline database and use is to complete the offline storage task of the project. Also, in my opinion, will somewhat easily allow us or another team to complete the offline form storage task.
Fu's Faulty Functions 