JSON2Codable

JSON2Codable is a simple command-line tool that reads a JSON document from stdin and prints out a new Codable-conforming Swift struct that matches the structure of the JSON document.

Example

$ cat colors.json
{
"colors": [
{
"color": "red",
"category": "hue",
"type": "primary",
"code": {
"rgba": [255,0,0,1],
"hex": "#FF0"
}
},
{
"color": "blue",
"category": "hue",
"type": "primary",
"code": {
"rgba": [0,0,255,1],
"hex": "#00F"
}
}
]
}
$ cat colors.json | json2codable
struct NewType: Codable {
let colors: [Color]
struct Color: Codable {
let category: String
let code: Code
struct Code: Codable {
let hex: String
let rgba: [Int]
}
let color: String
let type: String
}
}

Known issues

• Heterogeneous types in arrays are currently not supported (e.g [123, "string"]) unless the types can be "merged", for example Int can be promoted to Double and any type can become an Optional if a null is present in the array.
• If the root type of the JSON document is an array, it is unwrapped until a dictionary is found. That dictionary forms the new root type of the final Swift struct. JSON documents with an array root type are expected to be decoded to a Swift type wrapped in an array (e.g. JSONDecoder().decode([SomeType].self, from: jsonData))