1. Reference: In Refactoring: Improved Design of Existing Code (2nd Edition), build the test system – the writing of the sample code to be tested:https://www.shuijingwanwq.com/2023/01/28/7368/. The problem now is that multiple classes exist in the same file. Decided to split, each class forms a separate file.
2. Create a new class file /modules/producer.js, and migrate the class definition to the file
class Producer {
constructor(aProvince, data) {
this._province = aProvince;
this._cost = data.cost;
this._name = data.name;
this._production = data.production || 0;
}
get name() {
return this._name;
}
get cost() {
return this._cost;
}
set cost(arg) {
this._cost = parseInt(arg);
}
get production() {
return this._production;
}
set production(amountStr) {
const amount = parseInt(amountStr);
const newProduction = Number.isNaN(amount) ? 0 : amount;
this._province.totalProduction += newProduction - this._production;
this._production = newProduction;
}
}
export {Producer};
3. Create a new class file /modules/province.js, and migrate the class definition to the file. Import class Producer
import {Producer} from './producer.js';
class Province {
constructor(doc) {
this._name = doc.name;
this._producers = [];
this._totalProduction = 0;
this._demand = doc.demand;
this._price = doc.price;
doc.producers.forEach(d => this.addProducer(new Producer(this, d)));
}
addProducer(arg) {
this._producers.push(arg);
this._totalProduction += arg.production;
}
get name() {
return this._name;
}
get producers() {
return this._producers.slice();
}
get totalProduction() {
return this._totalProduction;
}
set totalProduction(arg) {
this._totalProduction = arg;
}
get demand() {
return this._demand;
}
set demand(arg) {
this._demand = parseInt(arg);
}
get price() {
return this._price;
}
set price(arg) {
this._price = parseInt(arg);
}
get shortfall() {
return this._demand - this.totalProduction;
}
get profit() {
return this.demandValue - this.demandCost;
}
get demandCost() {
let remainingDemand = this.demand;
let result = 0;
this.producers
.sort((a, b) => a.cost - b.cost)
.forEach(p => {
const contribution = Math.min(remainingDemand, p.production);
remainingDemand -= contribution;
result += contribution * p.cost;
});
return result;
}
get demandValue() {
return this.satisfiedDemand * this.price;
}
get satisfiedDemand() {
return Math.min(this._demand, this.totalProduction);
}
}
export {Province};
4. Edit /productionplan.js, delete the code related to the two classes, and then import the class province
import {Province} from './modules/province.js';
function sampleProvinceData() {
return {
name: "Asia",
producers: [{name: "Byzantium", cost: 10, production: 9}, {
name: "Attalia",
cost: 12,
production: 10
}, {name: "Sinope", cost: 10, production: 6},],
demand: 30,
price: 20
};
}
const asia = new Province(sampleProvinceData());
console.log(asia.shortfall);
5. Run the code again (it is recommended to force the browser to refresh), the output in the console is unchanged, which is in line with expectations. as shown in Figure 1
6. The final code structure is shown below. as shown in Figure 2
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