Define Your Data Model

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Chapter 5 of 10 at Apple Developer > Jump Right In is Define Your Data Model.

Download the answer at the end of this chapter whenever you like.

No you don't need to be them any time soon

Yea, they really do tell you to read and understand all of the voluminous "FoodTrackerTests.swift" file, even though they then tell you to delete most of what you just deciphered.

So you might rather delete what you're going to delete, then go back and understand just what remains.

<= Learning Objectives
<= Create a Data Model
<= Test Your Data

Always the pieces, sometimes the whole

Yea there's a glaring tupo of an entire example missing at <<< Your unit test class should look like this: >>>. In place of the example, they give you only its first line. Oh well. What they meant to say is, in order to demo your first test failure, your code should look like this:

import XCTest
@testable import FoodTracker

class FoodTrackerTests: XCTestCase {
    
    //MARK: Meal Class Tests
    
    func testMealInitializationSucceeds() {
        
        let zeroRatingMeal = Meal.init(name: "Zero", photo: nil, rating: 0)
        XCTAssertNotNil(zeroRatingMeal)
        
        let positiveRatingMeal = Meal.init(name: "Positive", photo: nil, rating: 5)
        XCTAssertNotNil(positiveRatingMeal)
    }
    
    func testMealInitializationFails() {
        
        let negativeRatingMeal = Meal.init(name: "Negative", photo: nil, rating: -1)
        XCTAssertNil(negativeRatingMeal)
        
        let largeRatingMeal = Meal.init(name: "Large", photo: nil, rating: 6)
        XCTAssertNil(largeRatingMeal)
        
        let emptyStringMeal = Meal.init(name: "", photo: nil, rating: 0)
        XCTAssertNil(emptyStringMeal)
    }
}

<= Test Your Data

Simulate an iPhone to fail your first test

Yes, testing your code as they suggest will trigger Xcode to open up a simulated iPhone, if you have quit Xcode and relaunched it since you last needed to run a simulated iPhone.

This launch will be as slow as it always is, first negotiating your admin privilege to do such a thing, and then taking time for the simulated iPhone to boot. But they will eventually get around to testing the code of your Data Model.

<= Test Your Data

Download and compare and commit

The download is 05_DefineYourDataModel. Your Commit Message can be "Define Your Data Model". 

<= Wrapping Up

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