Why is FileManager so unforgiving?

This is more of a reminder for me as to how to do simple things.

Apple keeps modifying the FileManager API, but doesn’t actually make it obvious as to how to do simple things.  I have Data that I want to save somewhere.  You think it would be as easy as getting a path, then writing it.  Nope.

So here’s a recipe to show how to simply write some data somewhere, overwriting as you do it:

func testSerialization() {
        do {
            let data = try NSKeyedArchiver.archivedData(withRootObject: self.dates, requiringSecureCoding: false)
            let url = writeLocation()  // currently just the caches directory / SomeFolder / SomeFilename.dta
            let fm = FileManager.default
            if fm.fileExists(atPath: url.path) {
                try fm.removeItem(at: url)
            }
            let folder = url.deletingLastPathComponent()
            try fm.createDirectory(at: folder, withIntermediateDirectories: true, attributes: nil)
            let success = fm.createFile(atPath: url.path, contents: data, attributes: nil)

            XCTAssertTrue(success, "Should have written the file!")
            XCTAssertTrue(fm.fileExists(atPath: url.path), "Should have written something here")

        } catch let error {
            XCTFail("Failed with error: \(error.localizedDescription)")
        }
    }

 

Level Up: Test-Driven Development

Until very recently, I’m used to being that hired gun who parachutes in, kills all the work tickets, asks the important questions about the product, makes an app work as desired on a tight deadline to a reasonable level of quality given the constraints, then is out again, all for a reasonably good sum of money. It’s exhausting because these companies often have no established procedures.  So in addition to being Lone Wolf: Kicker of Asses, I’m training junior developers so they can assist me without slowing me down too much, I’m creating an Adhoc QA Department (what is severity, what is reproducibility, how to write bug reports, what is a end-user test suite so you know how to regression test, and why you should use a ticketing system instead of just popping by my desk to effectively pull the plug on whatever 50 things I had in my head), I’m having to interpret incomplete designs, pull the assets out of the Design tools (Zeplin, Sketch, sometimes Photoshop) because many designers don’t know what exactly you need anyway, poke holes and/or fill in the gaps with the UX, and of course manage upwards. Oh yeah, and also do “Agile Waterfall” development, which is borne out of companies who only really do Waterfall but want to be “hip” to the new trends and demand we do Agile (with no scrum master or really anyone who knows how to lead that effectively). So then your time is further taken up with meetings and pushing work tickets around that actually don’t really encapsulate the work you actually need to do, but managers need you to do that so they can generate reports with some data that is meant to impress other people who really have no idea what’s going on anyway, and actually just increased levels of trust in your hires and “we’re good” would be equally effective/ineffective. (Ah, perhaps they don’t know how to make the right hires or can’t get them if they did.) In all of that, I have to “get ‘er done” because the deadline doesn’t change and surprise! All of your dependencies (Design, Backend API) also have the same deadline.

Yikes. A day in the life.  That above would be the worst day in the life.  It’s rarely all of those things.

So I’m grateful for my current freelance contract. It’s the first contract really in years where I felt I’m working in a proper software development company. The management overhead seems low, but the organization is not impacted. They have a process here that works. (I think it’s just because I hit the jackpot and they just placed a priority on the members of the team; personable yet very competent. Ultimately it’s a team who cares about what they do, and making sure there’s a nice team vibe. It also helps that they have corporate backing and therefore have a generous timeframe and budget it would seem.)

“Take the time you need to do a good job.” This is very much the culture here. For one of the first times in my career, I’ve been really exposed  to an office environment where you’re given time to think, and time to write a lot of tests while you develop. You can ask for specifications and those exist and are fixed. There are 2 other iOS devs here to bounce ideas off of, and of course to do code reviews with. It is so extremely satisfying when you get to refactor your original approach into ever more concise code that is more robust and less error prone. Time where you can write the API docs and the Unit Tests to basically freeze the specification. Normally there just isn’t enough time, given all the other tasks that Lone Wolf has, AND the product design always seems to be a moving target.

In short, it feels like I finally have the time and space to level up. Unit Tests are especially awesome when you work in teams and I’m glad for the opportunity to work in this environment for a while so I can establish some good habits and really reach a new plateau in my journey as a software developer.

Core Data Migrations – Woes…

So thankfully I won’t go into a misogynistic blog post a la frustrated Mark Zuckerberg in the movie “The Social Network”, but sometimes you just need to blog to let your technical frustrations out!

I’m doing some complicated Core Data migrations where the lightweight ones won’t work.  I’m migrating from one Core Data model to a completely different one, and I’m trying to map those properties over.

I’ve already discovered a wealth of information either through google, trial and error, and a bit of both, which I will share once I’ve got the entire migration code running.

I just have to say here however… I think it’s probably best to avoid these Xcode tools like a mapping model.  Because they’re buggy as hell.  For example, if you define a mapping model and provide source and destination models, but then change either of those source or destination models, the Mapping Model will no longer work, and even if you re-select the source and destination, it doesn’t matter:  You’ve just killed your Mapping Model.  Is there any info about this?  No.  Just “could not find a suitable mapping model”.

Ugh.

I’ve been trying to debug something for 3 HOURS because all you get is an EXC_BAD_ACCESS crash, and ZERO information as to what it’s all about, and NSZombies do nothing.

So I’m sitting here, taking shots into the dark and hope I discover something.

I question whether I should just give up on TOOLS, which are supposed to make your life easier, and just write the whole heavyweight migration in code.  If I had started on that 3 hours ago, I’d probably be done.  My data model is like 8 entity types.

Is it just me or is the quality of Apple’s tools getting worse?  It’s like they produce stuff that’s 80% good.  But it’s a tool chain, so 0.8 * 0.8 = 0.64.  So you see where this is going…