[Help] Mapping a single element when an array is expected about freddy

[mdmathias]

One way to handle this is to make use of the error JSON.Error.valueNotConvertible that Freddy provides. Below, data could be whatever you pull down from your server API. The Resident type comes from Freddy's test suite.

func getDataThatMaybeIsArrayOrDictionary() {
//        let data = [ ["name": "Matt", "age": 33, "hasPet": false, "rent": 1000.0],
//                                 ["name": "Drew", "age": 34, "hasPet": true, "rent": 1234.5] ] as JSON
    let data = ["name": "Pat", "age": 40, "hasPet": false, "rent": 111.11] as JSON
        
    do {
        let residents = try data.decodedArray(type: Resident.self)
        print("It's an array: \(residents)")
    } catch let JSON.Error.valueNotConvertible(value, type) where type == Array<JSON>.self {
        do {
            let pat = try value.decode(type: Resident.self)
            print("It's a dictionary: \(pat)")
        } catch {
            // Handle error
        }
    } catch {
        // Handle error
    }
}

The nested do/catch is not ideal. You could do something like this instead if dealing with an optional makes sense:

func getDataThatMaybeIsArrayOrDictionary() {
//        let data = [ ["name": "Matt", "age": 33, "hasPet": false, "rent": 1000.0],
//                                 ["name": "Drew", "age": 34, "hasPet": true, "rent": 1234.5] ] as JSON
    let data = ["name": "Pat", "age": 40, "hasPet": false, "rent": 111.11] as JSON
        
    do {
        let residents = try data.decodedArray(type: Resident.self)
        print("It's an array: \(residents)")
    } catch let JSON.Error.valueNotConvertible(value, type) where type == Array<JSON>.self {
-        do {
-            let pat = try value.decode(type: Resident.self)
-            print("It's a dictionary: \(pat)")
-        } catch {
-            // Handle error
-        }
+       guard let pat = try? value.decode(type: Resident.self) else { return }
+       print("It's a dictionary: \(pat)")
    } catch {
        // Handle error
    }
}

[edasque]

thank you, I'll try that.