json - Unable to bridge NSNumber to Float Swift 3.3

Question

After an Xcode update I encountered a weird problem. In my application, when I get a response from an API, I parse it manually and map it to my model. There are a lot of places in my code where I cast a JSON value to Float with null coalescing like below:

randomVariable = jsonDict["jsonKey"] as? Float ?? 0

It used to work fine but after the update, it would always default to 0. In order to determine the cause, I tried force casting it to Float like below

randomVariable = jsonDict["jsonKey"] as! Float

This resulted in the following error

Unable to bridge NSNumber to Float

Upon further investigation, I found out that Xcode is using Swift 3.3 (previously, it was using Swift 3.2). The solutions I found on StackOverflow revolve around casting it to NSNumber instead of Float. As I mentioned above, I have similar lines of code spread across my app. I was wondering if there is a way to fix this issue. Maybe using an extension of some sort?

Answer 1

As you have found, you may need to cast it first to NSNumber.

Something like this:

randomVariable = (jsonDict["jsonKey"] as? NSNumber)?.floatValue ?? 0

Maybe regex replacement would help you update your code.

Pattern: jsonDict[([^]]*)] as? Float

Replace with: (jsonDict[$1] as? NSNumber)?.floatValue