chore: Setup linting on project (#41)

* chore: Setup linting rules

* fix: Linting issues

* fix: Outstanding linting fixes

* chore: Tidy up eslint

* chore: Run prettier after rebase

* fix: Add back `socialRentTotalEarning`
- Please see https://github.com/theopensystemslab/fairhold-dashboard/pull/41\#discussion_r1701743583

.eslintrc.json

@@ -1,3 +1,13 @@
 {
-  "extends": ["next/core-web-vitals", "prettier"]
+  "extends": [
+    "next/core-web-vitals",
+    "prettier",
+    "plugin:@typescript-eslint/recommended"
+  ],
+  "parser": "@typescript-eslint/parser",
+  "plugins": ["@typescript-eslint"],
+  "parserOptions": {
+    "ecmaVersion": "latest",
+    "sourceType": "module"
+  }
 }

app/api/route.ts

@@ -103,7 +103,7 @@ export async function POST(req: Request) {
 
     // Calculate the total price    if (!pricesPaid) throw Error("Prices fetching failed");
     const totalPrice = pricesPaid.reduce(
-      (total: number, item: any) => total + item.price,
+      (total, item) => total + item.price,
       0
     );
     console.log("totalPrice:", totalPrice);
@@ -216,11 +216,12 @@ export async function POST(req: Request) {
       if (socialRentEarningRes.length === 1) {
         socialRentAverageEarning = socialRentEarningRes[0].earningsperweek;
       } else if (socialRentEarningRes.length > 1) {
-        const socialRentTotalEarning = socialRentEarningRes.reduce(
-          (sum, item) => sum + item.earningsperweek,
-          0
-        );
-        socialRentAverageEarning = totalRent / socialRentEarningRes.length;
+          const socialRentTotalEarning = socialRentEarningRes.reduce(
+            (sum, item) => sum + item.earningsperweek,
+            0
+          );
+        socialRentAverageEarning =
+          socialRentTotalEarning / socialRentEarningRes.length;
       }
       console.log("socialRentAverageEarning: ", socialRentAverageEarning);
 

app/components/graphs/LifetimeCombinedChart.tsx

@@ -5,8 +5,6 @@ import {
   Chart,
   ChartData,
   ChartDataset,
-  ChartOptions,
-  ChartTypeRegistry,
   PointElement,
   BarElement,
   BarController,

app/components/graphs/TotalPaymentBarChart.tsx

@@ -8,8 +8,6 @@ import {
   BarController,
   CategoryScale,
   LinearScale,
-  Tooltip,
-  Legend,
 } from "chart.js";
 
 Chart.register(BarElement, BarController, CategoryScale, LinearScale);

app/components/ui/CalculatorInput.tsx

@@ -1,6 +1,5 @@
 "use client";
-import { trueDependencies } from "mathjs";
-import React, { useState } from "react";
+import React, { FormEvent, useState } from "react";
 import calculateFairhold from "@/app/models/testClasses";
 import { Household } from "@/app/models/Household";
 import Dashboard from "./Dashboard";
@@ -22,7 +21,7 @@ const CalculatorInput = () => {
   const [houseAge, setHouseAge] = useState(""); // variables associated to the house age
 
   // fucntion that defines what happens after submitting the form
-  async function handleSubmit(e: any) {
+  async function handleSubmit(e: FormEvent<HTMLFormElement>) {
     e.preventDefault(); // pr event the default of the form
     const formData = new FormData(e.currentTarget); // get the data in the form, e.g postcode, house size etc
     const data = Object.fromEntries(formData.entries());

app/models/Mortgage.ts

@@ -83,7 +83,7 @@ export class Mortgage {
     let remainingBalance =
       this.totalMortgageCost - this.monthlyPayment * MONTHS_PER_YEAR;
 
-    let yearlyPaymentBreakdown: MortgageBreakdown = [
+    const yearlyPaymentBreakdown: MortgageBreakdown = [
       {
         yearlyPayment: yearlyPayment,
         cumulativePaid: cumulativePaid,

app/models/Property.ts

@@ -20,7 +20,7 @@ type PropertyParams = Pick<
 
 export const HOUSE_TYPES = ["D", "S", "T", "F"] as const;
 
-type HouseType = (typeof HOUSE_TYPES)[number];
+export type HouseType = (typeof HOUSE_TYPES)[number];
 
 export class Property {
   postcode: string;
@@ -91,7 +91,6 @@ export class Property {
   }
 
   private calculateBedWeightedAveragePrice() {
-    const beds = BED_WEIGHTS_AND_CAPS.numberOfBedrooms;
     const bedWeights = BED_WEIGHTS_AND_CAPS.weight;
     let bedWeight;
 

app/models/tenure/FairholdLandPurchase.test.ts

@@ -1,32 +1,10 @@
 import { Fairhold } from "../Fairhold";
 import { DEFAULT_FORECAST_PARAMETERS } from "../ForecastParameters";
-import { Property } from "../Property";
 import { FairholdLandPurchase } from "./FairholdLandPurchase";
-import { MarketPurchase } from "./MarketPurchase";
 
 let tenureFairholdLandPurchase: FairholdLandPurchase;
 
 beforeEach(() => {
-  let property = new Property({
-    postcode: "WV8 1HG",
-    houseType: "T",
-    numberOfBedrooms: 2,
-    age: 10,
-    size: 88,
-    newBuildPricePerMetre: 2120,
-    averageMarketPrice: 218091.58,
-    itl3: "TLG24",
-  });
-
-  let tenureMarketPurchase = new MarketPurchase({
-    incomeYearly: 45816,
-    averagePrice: 218091.58,
-    newBuildPrice: 186560,
-    depreciatedBuildPrice: 110717.45,
-    landPrice: 31531.579,
-    ...DEFAULT_FORECAST_PARAMETERS,
-  });
-
   tenureFairholdLandPurchase = new FairholdLandPurchase({
     //incomeYearly: 45816,
     //averagePrice: 218091.58,

app/models/tenure/FairholdLandPurchase.ts

@@ -61,7 +61,7 @@ export class FairholdLandPurchase {
     let landMortgagePaymentYearlyIterative =
       landMortgagePaymentYearly[0].yearlyPayment;
 
-    let lifetime: Lifetime = [
+    const lifetime: Lifetime = [
       {
         maintenanceCost: maintenanceCostIterative,
         landMortgagePaymentYearly: landMortgagePaymentYearlyIterative,

app/models/tenure/FairholdLandRent.test.ts

@@ -1,33 +1,10 @@
 import { Fairhold } from "../Fairhold";
 import { DEFAULT_FORECAST_PARAMETERS } from "../ForecastParameters";
-import { Property } from "../Property";
 import { FairholdLandRent } from "./FairholdLandRent";
-import { MarketRent } from "./MarketRent";
 
 let tenureFairholdLandRent: FairholdLandRent;
 
 beforeEach(() => {
-  let property = new Property({
-    postcode: "WV8 1HG",
-    houseType: "T",
-    numberOfBedrooms: 2,
-    age: 10,
-    size: 88,
-    newBuildPricePerMetre: 2120,
-    averageMarketPrice: 218091.58,
-    itl3: "TLG24",
-  });
-
-  let tenureMarketRent = new MarketRent({
-    averageRentYearly: 20000,
-    incomeYearly: 45816,
-    averagePrice: 218091.58,
-    newBuildPrice: 186560,
-    depreciatedBuildPrice: 110717.45,
-    landPrice: 31531.579,
-    ...DEFAULT_FORECAST_PARAMETERS,
-  });
-
   tenureFairholdLandRent = new FairholdLandRent({
     averageRentYearly: 20000,
     incomeYearly: 45816,

app/models/tenure/FairholdLandRent.ts

@@ -85,11 +85,11 @@ export class FairholdLandRent {
     let averageRentYearlyIterative = averageRentYearly;
     let averageRentLandYearlyIterative =
       averageRentYearlyIterative * landToTotalRatioIterative;
-    let affordabilityIterative = averageRentYearlyIterative / incomeIterative;
+    const affordabilityIterative = averageRentYearlyIterative / incomeIterative;
     let maintenanceCostIterative =
       maintenanceCostPercentage * newBuildPriceIterative;
 
-    let fairholdRentLandIterative = new Fairhold({
+    const fairholdRentLandIterative = new Fairhold({
       affordability: affordabilityIterative,
       landPriceOrRent: averageRentLandYearlyIterative / MONTHS_PER_YEAR,
     }).discountedLandPriceOrRent;
@@ -100,7 +100,7 @@ export class FairholdLandRent {
     let houseMortgagePaymentYearlyIterative =
       houseMortgagePaymentYearly[0].yearlyPayment; // find the first year
 
-    let lifetime: Lifetime = [
+    const lifetime: Lifetime = [
       {
         maintenanceCost: maintenanceCostIterative,
         fairholdRentLand: fairholdRentLandIterative,
@@ -125,9 +125,10 @@ export class FairholdLandRent {
       averageRentLandYearlyIterative =
         averageRentYearlyIterative * landToTotalRatioIterative;
 
-      let affordabilityIterative = averageRentYearlyIterative / incomeIterative;
+      const affordabilityIterative =
+        averageRentYearlyIterative / incomeIterative;
 
-      let fairholdRentLandIterative = new Fairhold({
+      const fairholdRentLandIterative = new Fairhold({
         affordability: affordabilityIterative,
         landPriceOrRent: averageRentLandYearlyIterative,
       }).discountedLandPriceOrRent;

app/models/tenure/MarketPurchase.test.ts

@@ -1,10 +1,9 @@
-import { Property } from "../Property";
 import { MarketPurchase } from "./MarketPurchase";
 
 let tenureMarketPurchase: MarketPurchase;
 
 beforeEach(() => {
-  let forecastParameters = {
+  const forecastParameters = {
     maintenanceCostPercentage: 0.0125, // percentage maintenance cost
     incomeGrowthPerYear: 0.04, // 4% income growth per year
     constructionPriceGrowthPerYear: 0.025, // 2.5%
@@ -14,17 +13,6 @@ beforeEach(() => {
     affordabilityThresholdIncomePercentage: 0.35, // percentage of imcome to afford rent or purchase
   };
 
-  let property = new Property({
-    postcode: "WV8 1HG",
-    houseType: "T",
-    numberOfBedrooms: 2,
-    age: 10,
-    size: 88,
-    newBuildPricePerMetre: 2120,
-    averageMarketPrice: 218091.58,
-    itl3: "TLG24",
-  });
-
   tenureMarketPurchase = new MarketPurchase({
     incomeYearly: 45816,
     averagePrice: 218091.58,

app/models/tenure/MarketPurchase.ts

@@ -58,12 +58,12 @@ export class MarketPurchase {
     const houseMortgagePaymentYearly =
       this.houseMortgage.yearlyPaymentBreakdown;
     const landMortgagePaymentYearly = this.landMortgage.yearlyPaymentBreakdown;
-    
+
     // Find the first year
     let houseMortgagePaymentYearlyIterative =
       houseMortgagePaymentYearly[0].yearlyPayment;
     let landMortgagePaymentYearlyIterative =
-      landMortgagePaymentYearly[0].yearlyPayment; 
+      landMortgagePaymentYearly[0].yearlyPayment;
 
     const lifetime: Lifetime = [
       {

app/models/tenure/MarketRent.test.ts

@@ -1,10 +1,9 @@
-import { Property } from "../Property";
 import { MarketRent } from "./MarketRent";
 
 let tenureMarketRent: MarketRent;
 
 beforeEach(() => {
-  let forecastParameters = {
+  const forecastParameters = {
     maintenanceCostPercentage: 0.0125, // percentage maintenance cost
     incomeGrowthPerYear: 0.04, // 4% income growth per year
     constructionPriceGrowthPerYear: 0.025, // 2.5%
@@ -14,17 +13,6 @@ beforeEach(() => {
     affordabilityThresholdIncomePercentage: 0.35, // percentage of imcome to afford rent or purchase
   };
 
-  let property = new Property({
-    postcode: "WV8 1HG",
-    houseType: "T",
-    numberOfBedrooms: 2,
-    age: 10,
-    size: 88,
-    newBuildPricePerMetre: 2120,
-    averageMarketPrice: 218091.58,
-    itl3: "TLG24",
-  });
-
   tenureMarketRent = new MarketRent({
     averageRentYearly: 20000,
     incomeYearly: 45816,

app/models/tenure/MarketRent.ts

@@ -83,7 +83,7 @@ export class MarketRent {
     let averageRentHouseYearlyIterative =
       averageRentYearlyIterative - averageRentLandYearlyIterative;
 
-    let lifetime: Lifetime = [
+    const lifetime: Lifetime = [
       {
         averageRentLandYearly: averageRentLandYearlyIterative,
         averageRentHouseYearly: averageRentHouseYearlyIterative,

app/models/tenure/SocialRent.test.ts

@@ -1,31 +1,9 @@
-import { Property } from "../Property";
 import { SocialRent, SocialRentAdjustments } from "./SocialRent";
 
 let tenureSocialRent: SocialRent;
 
 beforeEach(() => {
-  let forecastParameters = {
-    maintenanceCostPercentage: 0.0125, // percentage maintenance cost
-    incomeGrowthPerYear: 0.04, // 4% income growth per year
-    constructionPriceGrowthPerYear: 0.025, // 2.5%
-    rentGrowthPerYear: 0.03, // 3%
-    propertyPriceGrowthPerYear: 0.05, // 5%
-    yearsForecast: 40, // 40 years
-    affordabilityThresholdIncomePercentage: 0.35, // percentage of imcome to afford rent or purchase
-  };
-
-  let property = new Property({
-    postcode: "WV8 1HG",
-    houseType: "T",
-    numberOfBedrooms: 2,
-    age: 10,
-    size: 88,
-    newBuildPricePerMetre: 2120,
-    averageMarketPrice: 218091.58,
-    itl3: "TLG24",
-  });
-
-  let socialRentAdjustments: SocialRentAdjustments = [
+  const socialRentAdjustments: SocialRentAdjustments = [
     {
       inflation: 3.3,
       total: 4.3,

app/models/testClasses.ts

@@ -1,9 +1,30 @@
 import { DEFAULT_FORECAST_PARAMETERS } from "./ForecastParameters";
 import { Household } from "./Household";
-import { Property } from "./Property";
+import { HouseType, Property } from "./Property";
+import { MONTHS_PER_YEAR } from "./constants";
+import { SocialRentAdjustments } from "./tenure/SocialRent";
 
-function calculateFairhold(responseData: any) {
-  if (!responseData.buildPrice || responseData.buildPrice.length === 0) {
+// TODO: Share type with backend
+export interface ResponseData {
+  postcode: string;
+  houseType: HouseType;
+  houseBedrooms: number;
+  buildPrice: number;
+  houseAge: number;
+  houseSize: number;
+  newBuildPricePerMetre: number;
+  averagePrice: number;
+  itl3: string;
+  gdhi: number;
+  averageRentMonthly: number;
+  socialRentAverageEarning: number;
+  socialRentAdjustments: SocialRentAdjustments;
+  hpi: number;
+  gasBillYearly: number;
+}
+
+function calculateFairhold(responseData: ResponseData) {
+  if (!responseData.buildPrice) {
     throw new Error("buildPrice data is missing or empty");
   }
   if (!responseData.itl3 || responseData.itl3.length === 0) {
@@ -25,7 +46,7 @@ function calculateFairhold(responseData: any) {
   // define the household object
   const household = new Household({
     incomePerPersonYearly: responseData.gdhi,
-    averageRentYearly: responseData.averageRentMonthly * 12,
+    averageRentYearly: responseData.averageRentMonthly * MONTHS_PER_YEAR,
     socialRentAverageEarning: responseData.socialRentAverageEarning,
     socialRentAdjustments: responseData.socialRentAdjustments,
     housePriceIndex: responseData.hpi,