feat: Calculate VAT using useFeeBreakdown(), not via Calculate co…

…mponent
theopensystemslab · Dec 5, 2024 · c926c05 · c926c05
1 parent dbd4569
commit c926c05
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Showing 5 changed files with 54 additions and 26 deletions.
diff --git a/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/FeeBreakdown.tsx b/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/FeeBreakdown.tsx
@@ -26,7 +26,7 @@ const BoldTableRow = styled(TableRow)(() => ({
   },
 }));
 
-const VAT_RATE = 0.2;
+export const VAT_RATE = 0.2;
 
 const DESCRIPTION =
   "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.";

diff --git a/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/types.ts b/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/types.ts
@@ -12,7 +12,7 @@ export interface FeeBreakdown {
 export interface PassportFeeFields {
   "application.fee.calculated": number;
   "application.fee.payable": number;
-  "application.fee.payable.vat": number;
+  "application.fee.payable.includesVAT": boolean;
   "application.fee.reduction.alternative": boolean;
   "application.fee.reduction.parishCouncil": boolean;
   "application.fee.reduction.sports": boolean;

diff --git a/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/useFeeBreakdown.test.ts b/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/useFeeBreakdown.test.ts
@@ -20,7 +20,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": 1000,
         "application.fee.payable": 800,
-        "application.fee.payable.vat": 160,
+        "application.fee.payable.includesVAT": ["true"],
         "some.other.fields": ["abc", "xyz"],
       };
 
@@ -33,7 +33,7 @@ describe("useFeeBreakdown() hook", () => {
           applicationFee: 1000,
           total: 800,
           reduction: 200,
-          vat: 160,
+          vat: 166.67,
         },
         exemptions: [],
         reductions: [],
@@ -44,7 +44,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": [1000],
         "application.fee.payable": [800],
-        "application.fee.payable.vat": [160],
+        "application.fee.payable.includesVAT": ["true"],
         "some.other.fields": ["abc", "xyz"],
       };
 
@@ -57,7 +57,7 @@ describe("useFeeBreakdown() hook", () => {
           applicationFee: 1000,
           total: 800,
           reduction: 200,
-          vat: 160,
+          vat: 166.67,
         },
         exemptions: [],
         reductions: [],
@@ -68,7 +68,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": 1000,
         "application.fee.payable": 800,
-        "application.fee.payable.vat": 160,
+        "application.fee.payable.includesVAT": ["true"],
         "application.fee.reduction.alternative": ["true"],
         "application.fee.reduction.parishCouncil": ["true"],
         "some.other.fields": ["abc", "xyz"],
@@ -88,7 +88,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": 1000,
         "application.fee.payable": 800,
-        "application.fee.payable.vat": 160,
+        "application.fee.payable.includesVAT": ["true"],
         "application.fee.reduction.alternative": ["false"],
         "application.fee.reduction.parishCouncil": ["false"],
         "some.other.fields": ["abc", "xyz"],
@@ -105,7 +105,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": 1000,
         "application.fee.payable": 800,
-        "application.fee.payable.vat": 160,
+        "application.fee.payable.includesVAT": ["true"],
         "application.fee.reduction.alternative": ["true"],
         "application.fee.reduction.parishCouncil": ["false"],
         "application.fee.reduction.someReason": ["true"],
@@ -128,7 +128,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": 1000,
         "application.fee.payable": 800,
-        "application.fee.payable.vat": 160,
+        "application.fee.payable.includesVAT": ["true"],
         "application.fee.exemption.disability": ["true"],
         "application.fee.exemption.resubmission": ["true"],
         "some.other.fields": ["abc", "xyz"],
@@ -148,7 +148,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": 1000,
         "application.fee.payable": 800,
-        "application.fee.payable.vat": 160,
+        "application.fee.payable.includesVAT": ["true"],
         "application.fee.exemption.disability": ["false"],
         "application.fee.exemption.resubmission": ["false"],
         "some.other.fields": ["abc", "xyz"],
@@ -165,7 +165,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": 1000,
         "application.fee.payable": 800,
-        "application.fee.payable.vat": 160,
+        "application.fee.payable.includesVAT": ["true"],
         "application.fee.exemption.disability": ["false"],
         "application.fee.exemption.resubmission": ["false"],
         "application.fee.exemption.someReason": ["true"],
@@ -180,10 +180,10 @@ describe("useFeeBreakdown() hook", () => {
 
       const result = useFeeBreakdown();
 
-      expect(result?.exemption).toEqual(
+      expect(result?.exemptions).toEqual(
         expect.not.arrayContaining(["someReason"])
       );
-      expect(result?.exemption).toEqual(
+      expect(result?.exemptions).toEqual(
         expect.not.arrayContaining(["someOtherReason"])
       );
     });
@@ -205,7 +205,7 @@ describe("useFeeBreakdown() hook", () => {
     it("returns undefined for partial data", () => {
       const mockPassportData = {
         "application.fee.calculated": [1000],
-        "application.fee.payable.vat": [160],
+        "application.fee.payable.includesVAT": ["true"],
         "some.other.fields": ["abc", "xyz"],
       };
 
@@ -220,7 +220,7 @@ describe("useFeeBreakdown() hook", () => {
       const mockPassportData = {
         "application.fee.calculated": "some string",
         "application.fee.payable": [800, 700],
-        "application.fee.payable.vat": false,
+        "application.fee.payable.includesVAT": false,
         "some.other.fields": ["abc", "xyz"],
       };
 

diff --git a/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/utils.test.ts b/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/utils.test.ts
@@ -22,7 +22,7 @@ describe("calculateReduction() helper function", () => {
     const input: PassportFeeFields = {
       "application.fee.calculated": 100,
       "application.fee.payable": 50,
-      "application.fee.payable.vat": 0,
+      "application.fee.payable.includesVAT": false,
       "application.fee.reduction.alternative": false,
       "application.fee.reduction.parishCouncil": false,
       "application.fee.reduction.sports": false,
@@ -38,7 +38,7 @@ describe("calculateReduction() helper function", () => {
     const input: PassportFeeFields = {
       "application.fee.calculated": 0,
       "application.fee.payable": 100,
-      "application.fee.payable.vat": 0,
+      "application.fee.payable.includesVAT": false,
       "application.fee.reduction.alternative": false,
       "application.fee.reduction.parishCouncil": false,
       "application.fee.reduction.sports": false,
@@ -56,7 +56,7 @@ describe("toFeeBreakdown() helper function", () => {
     const input: PassportFeeFields = {
       "application.fee.calculated": 100,
       "application.fee.payable": 50,
-      "application.fee.payable.vat": 10,
+      "application.fee.payable.includesVAT": true,
       "application.fee.reduction.alternative": false,
       "application.fee.reduction.parishCouncil": false,
       "application.fee.reduction.sports": false,
@@ -68,14 +68,13 @@ describe("toFeeBreakdown() helper function", () => {
 
     expect(amount.applicationFee).toEqual(input["application.fee.calculated"]);
     expect(amount.total).toEqual(input["application.fee.payable"]);
-    expect(amount.vat).toEqual(input["application.fee.payable.vat"]);
     expect(amount.reduction).toEqual(50);
   });
 
   it("sets applicationFee to payable amount if no calculated value is provided", () => {
     const input: PassportFeeFields = {
       "application.fee.calculated": 0,
-      "application.fee.payable.vat": 10,
+      "application.fee.payable.includesVAT": true,
       "application.fee.payable": 50,
       "application.fee.reduction.alternative": false,
       "application.fee.reduction.parishCouncil": false,
@@ -88,4 +87,21 @@ describe("toFeeBreakdown() helper function", () => {
 
     expect(amount.applicationFee).toEqual(input["application.fee.payable"]);
   });
+
+  it("correctly calculates the VAT", () => {
+    const input: PassportFeeFields = {
+      "application.fee.calculated": 100,
+      "application.fee.payable": 50,
+      "application.fee.payable.includesVAT": true,
+      "application.fee.reduction.alternative": false,
+      "application.fee.reduction.parishCouncil": false,
+      "application.fee.reduction.sports": false,
+      "application.fee.exemption.disability": false,
+      "application.fee.exemption.resubmission": false,
+    };
+
+    const { amount } = toFeeBreakdown(input);
+
+    expect(amount.vat).toEqual(16.67);
+  });
 });
diff --git a/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/utils.ts b/editor.planx.uk/src/@planx/components/Pay/Public/FeeBreakdown/utils.ts
@@ -1,5 +1,6 @@
 import { z } from "zod";
 
+import { VAT_RATE } from "./FeeBreakdown";
 import { FeeBreakdown, PassportFeeFields } from "./types";
 
 export const toNumber = (input: number | [number]) =>
@@ -29,6 +30,9 @@ const toBoolean = (val: ["true" | "false"]) => val[0] === "true";
     return granularKeys;
   };
 
+export const calculateApplicationFee = (data: PassportFeeFields) => 
+  data["application.fee.calculated"] || data["application.fee.payable"]
+
 /**
  * A "reduction" is the sum of the difference between calculated and payable
  */
@@ -37,16 +41,24 @@ export const calculateReduction = (data: PassportFeeFields) =>
     ? data["application.fee.calculated"] - data["application.fee.payable"]
     : 0;
 
+export const calculateVAT = (data: PassportFeeFields) => {
+  if (!data["application.fee.payable.includesVAT"]) return 0;
+
+  const fee = calculateApplicationFee(data);
+  const vat = (fee * VAT_RATE) / (1 + VAT_RATE);
+  const roundedVAT = Number(vat.toFixed(2));
+
+  return roundedVAT;
+};
+
 /**
  * Transform Passport data to a FeeBreakdown
  */
 export const toFeeBreakdown = (data: PassportFeeFields): FeeBreakdown => ({
   amount: {
-    applicationFee:
-      data["application.fee.calculated"] ||
-      data["application.fee.payable"],
+    applicationFee: calculateApplicationFee(data),
     total: data["application.fee.payable"],
-    vat: data["application.fee.payable.vat"],
+    vat: calculateVAT(data),
     reduction: calculateReduction(data),
   },
   reductions: getGranularKeys(data, "application.fee.reduction"),
@@ -70,7 +82,7 @@ export const createPassportSchema = () => {
     .object({
       "application.fee.calculated": feeSchema.optional().default(0),
       "application.fee.payable": feeSchema,
-      "application.fee.payable.vat": feeSchema.optional().default(0),
+      "application.fee.payable.includesVAT": booleanSchema,
       "application.fee.reduction.alternative": booleanSchema,
       "application.fee.reduction.parishCouncil": booleanSchema,
       "application.fee.reduction.sports": booleanSchema,