Two Different models with the some of same properties cause problems in Swift

Question

i have two different models with slightly different properties in my project. But when i use them without default values in one of the model, it gives error Type 'Instructions' does not conform to protocol 'Decodable' if i just remove = "" from the property summary inside Instructions model. Why this happens and how to overcome? Because in this way, even if i get data from API, it doesn't overwrite the default value.

INSTRUCTIONS MODEL

struct Instructions: Codable, Hashable, Equatable {
    
    let vegetarian: Bool = false
    let vegan: Bool = false
    let glutenFree: Bool = false
    let dairyFree: Bool = false
    let veryHealthy: Bool = false
    let cheap: Bool = false
    let veryPopular: Bool = false
    let sustainable: Bool = false
    let lowFodmap: Bool = false
    let weightWatcherSmartPoints: Int = 0
    let gaps: String = ""
    let preparationMinutes: Int = 0
    let cookingMinutes: Int = 0
    let aggregateLikes: Int = 0
    let healthScore: Int = 0
    let creditsText: String = ""
    let license: String = ""
    let sourceName: String = ""
    let pricePerServing: Double = 0
    let extendedIngredients: [ExtendedIngredient]
    let id: Int
    let title: String
    let readyInMinutes: Int = 0
    let servings: Int = 0
    let sourceUrl: String = ""
    let image: String
    let imageType: String
    let summary: String = ""
    let cuisines: [String] = []
    let dishTypes: [String] = []
    let diets: [String] = []
    let occasions: [String] = []
    let winePairing: WinePairing?
    let instructions: String = ""
    let analyzedInstructions: [AnalyzedInstructions]
    let originalId: Int? = 0
    let spoonacularScore: Double = 0
    let spoonacularSourceUrl: String = ""
    
    enum CodingKeys: String, CodingKey {
        case id, title, image, imageType, winePairing, analyzedInstructions, extendedIngredients
    }
}

struct ExtendedIngredient: Codable, Hashable, Equatable {
    let id: Int
    let aisle: String
    let image: String
    let consistency: String
    let name: String
    let nameClean: String
    let original: String
    let originalName: String
    let amount: Double
    let unit: String
    let meta: [String]
    let measures: Measures
}

struct Measures: Codable, Hashable, Equatable {
    let us: Measure
    let metric: Measure
}

struct Measure: Codable, Hashable, Equatable {
    let amount: Double
    let unitShort: String
    let unitLong: String
}

struct WinePairing: Codable, Hashable, Equatable {
    let pairedWines: [String]
    let pairingText: String
    let productMatches: [ProductMatch]
}

struct ProductMatch: Codable, Hashable, Equatable {
}

struct AnalyzedInstructions: Codable, Hashable, Equatable {
    let name: String
    let steps: [Steps]
}

struct Steps: Codable, Hashable, Equatable {
    let number: Int
    let step: String
    let ingredients: [Ingredients]
    let equipment: [Equipments]
    let length: Lengths?
}

struct Ingredients: Codable, Hashable, Equatable {
    let id: Int
    let name: String
    let localizedName: String
    let image: String
}

struct Equipments: Codable, Hashable, Equatable {
    let id: Int
    let name: String
    let localizedName: String
    let image: String
}

struct Lengths: Codable, Hashable, Equatable {
    let number: Int
    let unit: String
}

RECIPE MODEL

// MARK: - Welcome
struct RecipeResults: Codable {
    let results: [Recipe]
    let offset, number, totalResults: Int
}

// MARK: - Result
struct Recipe: Codable, Hashable, Equatable {
    let vegetarian, vegan, glutenFree, dairyFree: Bool
    let veryHealthy, cheap, veryPopular, sustainable: Bool
    let lowFodmap: Bool
    let weightWatcherSmartPoints: Int
    let gaps: String
    let preparationMinutes, cookingMinutes, aggregateLikes, healthScore: Int
    let creditsText, sourceName: String
    let pricePerServing: Double
    let id: Int
    let title: String
    let readyInMinutes, servings: Int
    let sourceURL: String
    let image: String
    let imageType, summary: String
    let dishTypes, diets: [String]
    let analyzedInstructions: [AnalyzedInstruction]

    enum CodingKeys: String, CodingKey {
        case vegetarian, vegan, glutenFree, dairyFree, veryHealthy, cheap, veryPopular, sustainable, lowFodmap, weightWatcherSmartPoints, gaps, preparationMinutes, cookingMinutes, aggregateLikes, healthScore, creditsText, sourceName, pricePerServing, id, title, readyInMinutes, servings
        case sourceURL = "sourceUrl"
        case image, imageType, summary, dishTypes, diets, analyzedInstructions
    }
}

// MARK: - AnalyzedInstruction
struct AnalyzedInstruction: Codable, Hashable, Equatable {
    let name: String
    let steps: [Step]
}

// MARK: - Step
struct Step: Codable, Hashable, Equatable {
    let number: Int
    let step: String
    let ingredients, equipment: [Ent]
    let length: Length?
}

// MARK: - Ent
struct Ent: Codable, Hashable, Equatable {
    let id: Int
    let name, localizedName, image: String
    let temperature: Length?
}

// MARK: - Length
struct Length: Codable, Hashable, Equatable {
    let number: Int
    let unit: String
}

Answer 1

You are using custom coding keys for properties in InstructionsModel. In order to conform to to Codable protocol you need to define all properties and their custom keys, or if your property names are the same as JSON keys, just remove that enum.

enum CodingKeys: String, CodingKey {
    case id, title, image, imageType, winePairing, analyzedInstructions, extendedIngredients
}