chore: add payments by product backend validation (#7077)

* chore: scaffold controller code

* chore: split into services

* chore: update typeguard to check for _id and name

* chore: validate product price

* chore: update error message for payment definition failure

* chore: add unit tests for isPaymentsProducts

* chore: add tests for payments service

* chore: remove stray comment

* chore: check entire product definition

* chore: convert mongoose doc to obj for comparison

* chore: refine testcases

---------

Co-authored-by: Ken <ken@open.gov.sg>

shared/types/form/__tests__/product.spec.ts

@@ -0,0 +1,126 @@
+import { ObjectId } from 'bson'
+import { isPaymentsProducts } from '../product'
+import { Product } from '../product'
+
+describe('Product validation', () => {
+  it('should return false if products is not an array', () => {
+    // Arrange
+    const mockProductNonArray = 'some thing'
+
+    // Assert
+    expect(isPaymentsProducts(mockProductNonArray)).toBe(false)
+  })
+
+  it('should return true if products is an empty array', () => {
+    // Arrange
+    const mockProductEmptyArray: Product[] = []
+
+    // Assert
+    expect(isPaymentsProducts(mockProductEmptyArray)).toBe(false)
+  })
+
+  it('should return false if product has invalid object id', () => {
+    // Arrange
+    const mockProductInvalidId: any = [
+      {
+        name: 'some name',
+        description: 'some description',
+        multi_qty: true,
+        min_qty: 1,
+        max_qty: 1,
+        amount_cents: 1,
+        _id: 'some id',
+      },
+    ]
+
+    // Assert
+    expect(isPaymentsProducts(mockProductInvalidId)).toBe(false)
+  })
+
+  it('should return false if product has no name', () => {
+    // Arrange
+    const mockProductWrongName = [
+      {
+        description: 'some description',
+        multi_qty: true,
+        min_qty: 1,
+        max_qty: 1,
+        amount_cents: 1,
+        _id: new ObjectId(),
+      },
+    ] as unknown as Product[]
+
+    // Assert
+    expect(isPaymentsProducts(mockProductWrongName)).toBe(false)
+  })
+
+  it('should return false if there are multiple products and at least one has no name', () => {
+    // Arrange
+    const mockMultipleProductOneNoName = [
+      {
+        description: 'some description',
+        multi_qty: true,
+        min_qty: 1,
+        max_qty: 1,
+        amount_cents: 1,
+        _id: new ObjectId(),
+      },
+      {
+        name: 'has name',
+        multi_qty: true,
+        min_qty: 1,
+        max_qty: 1,
+        amount_cents: 1,
+        _id: new ObjectId(),
+      },
+    ] as unknown as Product[]
+
+    // Assert
+    expect(isPaymentsProducts(mockMultipleProductOneNoName)).toBe(false)
+  })
+
+  it('should return true if product has valid object id and name', () => {
+    // Arrange
+    const mockProductsCorrectShape = [
+      {
+        name: 'some name',
+        description: 'some description',
+        multi_qty: true,
+        min_qty: 1,
+        max_qty: 1,
+        amount_cents: 1,
+        _id: new ObjectId(),
+      },
+    ] as unknown as Product[]
+
+    // Assert
+    expect(isPaymentsProducts(mockProductsCorrectShape)).toBe(true)
+  })
+
+  it('should return true if multiple products have valid object id and name', () => {
+    // Arrange
+    const mockProductsCorrectShapeMultiple = [
+      {
+        name: 'some name',
+        description: 'some description',
+        multi_qty: true,
+        min_qty: 1,
+        max_qty: 1,
+        amount_cents: 1,
+        _id: new ObjectId(),
+      },
+      {
+        name: 'another name',
+        description: 'another description',
+        multi_qty: true,
+        min_qty: 1,
+        max_qty: 1,
+        amount_cents: 1,
+        _id: new ObjectId(),
+      },
+    ] as unknown as Product[]
+
+    // Assert
+    expect(isPaymentsProducts(mockProductsCorrectShapeMultiple)).toBe(true)
+  })
+})

shared/types/form/product.ts

@@ -16,3 +16,23 @@ export type ProductItem = {
   selected: boolean
   quantity: number
 }
+
+// Typeguard for Product
+export const isPaymentsProducts = (
+  products: unknown,
+): products is Product[] => {
+  if (!Array.isArray(products)) {
+    return false
+  }
+  return (
+    products.length > 0 &&
+    products.every((product) => {
+      return (
+        product._id &&
+        String(product._id).match(/^[0-9a-fA-F]{24}$/) &&
+        product.name &&
+        typeof product.name === 'string'
+      )
+    })
+  )
+}