Add new SROC Billing Period service

app/controllers/test/supplementary.controller.js

@@ -1,7 +1,7 @@
 'use strict'
 
-const FindRegionService = require('../../services/test/find_region.service')
-const SupplementaryService = require('../../services/test/supplementary.service.js')
+const FindRegionService = require('../../services/supplementary_billing/find_region.service')
+const SupplementaryService = require('../../services/supplementary_billing/supplementary.service.js')
 
 class SupplementaryController {
   static async index (request, h) {

app/services/supplementary_billing/billing_period.service.js

@@ -0,0 +1,58 @@
+'use strict'
+
+/**
+ * @module BillingPeriodService
+ */
+
+class BillingPeriodService {
+  /**
+   * Returns the billing periods needed when generating a supplementary bill run
+   *
+   * **IMPORANT!** This service currently only handles SROC billing periods and only the 'current year'
+   *
+   * Using the current date at the time the service is called, it calculates the billing periods to use. We permit
+   * changes to charge versions to be retroactively applied up to 5 years. So, a bill run generated in 2022 would need
+   * to consider every financial year back to 2017.
+   *
+   * The exception to that is the change in charge scheme that happened in 2022, when we moved from ALCS (or PRESROC) to
+   * SROC. Changes prior to 2022 would only apply to a ALCS bill run and vice versa.
+   *
+   * @returns {Object[]} an array of billing periods each containing a `startDate` and `endDate`.
+   */
+  static go () {
+    const currentDate = this._currentDate()
+    const currentYear = currentDate.getFullYear()
+
+    // 01-APR to 31-MAR
+    const financialPeriod = {
+      start: { day: 1, month: 3 },
+      end: { day: 31, month: 2 }
+    }
+
+    let startYear
+    let endYear
+
+    // IMPORANT! getMonth returns an integer (0-11). So, January is represented as 0 and December as 11. This is why
+    // financialPeriod.end.month is 2 rather than 3, even though we mean March
+    if (currentDate.getMonth() <= financialPeriod.end.month) {
+      // For example, if currentDate was 2022-02-15 it would fall in financial year 2021-04-01 to 2022-03-31
+      startYear = currentYear - 1
+      endYear = currentYear
+    } else {
+      // For example, if currentDate was 2022-06-15 it would fall in financial year 2022-04-01 to 2023-03-31
+      startYear = currentYear
+      endYear = currentYear + 1
+    }
+
+    return [{
+      startDate: new Date(startYear, financialPeriod.start.month, financialPeriod.start.day),
+      endDate: new Date(endYear, financialPeriod.end.month, financialPeriod.end.day)
+    }]
+  }
+
+  static _currentDate () {
+    return new Date()
+  }
+}
+
+module.exports = BillingPeriodService

app/services/test/supplementary.service.js → app/services/supplementary_billing/fetch_charge_versions.service.js

@@ -1,24 +1,20 @@
 'use strict'
 
 /**
- * @module SupplementaryService
+ * @module FetchChargeVersionsService
+ *
  */
 
 const { db } = require('../../../db/db')
 
-/**
- * @module SupplementaryService
- */
-
-class SupplementaryService {
+class FetchChargeVersionsService {
   static async go (regionId) {
-    const chargeVersions = await this._fetchChargeVersions(regionId)
-    const response = { chargeVersions }
+    const chargeVersions = await this._fetch(regionId)
 
-    return response
+    return chargeVersions
   }
 
-  static async _fetchChargeVersions (regionId) {
+  static async _fetch (regionId) {
     const chargeVersions = db
       .select('chargeVersionId', 'licences.licenceRef')
       .from('water.charge_versions')
@@ -36,4 +32,4 @@ class SupplementaryService {
   }
 }
 
-module.exports = SupplementaryService
+module.exports = FetchChargeVersionsService

app/services/supplementary_billing/supplementary.service.js

@@ -0,0 +1,20 @@
+'use strict'
+
+/**
+ * @module SupplementaryService
+ */
+
+const FetchChargeVersionsService = require('./fetch_charge_versions.service.js')
+const BillingPeriodService = require('./billing_period.service')
+
+class SupplementaryService {
+  static async go (regionId) {
+    const chargeVersions = await FetchChargeVersionsService.go(regionId)
+    const financialYears = BillingPeriodService.go()
+    const response = { chargeVersions, financialYears }
+
+    return response
+  }
+}
+
+module.exports = SupplementaryService

test/controllers/test/supplementary.controller.test.js

@@ -12,8 +12,8 @@ const { expect } = Code
 const LicenceHelper = require('../../support/helpers/licence.helper.js')
 
 // Things we need to stub
-const FindRegionService = require('../../../app/services/test/find_region.service')
-const SupplementaryService = require('../../../app/services/test/supplementary.service.js')
+const FindRegionService = require('../../../app/services/supplementary_billing/find_region.service')
+const SupplementaryService = require('../../../app/services/supplementary_billing/supplementary.service.js')
 
 // For running our service
 const { init } = require('../../../app/server')

test/services/supplementary_billing/billing_period.service.test.js

@@ -0,0 +1,83 @@
+'use strict'
+
+// Test framework dependencies
+const Lab = require('@hapi/lab')
+const Code = require('@hapi/code')
+const Sinon = require('sinon')
+
+const { describe, it, beforeEach, afterEach } = exports.lab = Lab.script()
+const { expect } = Code
+
+// Thing under test
+const BillingPeriodService = require('../../../app/services/supplementary_billing/billing_period.service')
+
+describe('BillingPeriod service', () => {
+  afterEach(() => {
+    Sinon.restore()
+  })
+
+  describe('when the date is in 2022 and falls within the 2022 financial year', () => {
+    const testDate = new Date('2022-04-01')
+    const expectedResult = {
+      startDate: new Date('2022-04-01'),
+      endDate: new Date('2023-03-31')
+    }
+
+    beforeEach(async () => {
+      Sinon.stub(BillingPeriodService, '_currentDate').returns(testDate)
+    })
+
+    it('returns the expected date range', () => {
+      const result = BillingPeriodService.go()
+
+      expect(result.length).to.equal(1)
+      expect(result[0]).to.equal(expectedResult)
+    })
+  })
+
+  describe('when the date is in 2023 and falls within the 2022 financial year', () => {
+    const testDate = new Date('2023-03-01')
+    const expectedResult = {
+      startDate: new Date('2022-04-01'),
+      endDate: new Date('2023-03-31')
+    }
+
+    beforeEach(async () => {
+      Sinon.stub(BillingPeriodService, '_currentDate').returns(testDate)
+    })
+
+    it('returns the expected date range', () => {
+      const result = BillingPeriodService.go()
+
+      expect(result.length).to.equal(1)
+      expect(result[0]).to.equal(expectedResult)
+    })
+  })
+
+  describe('when the date is in 2023 and falls within the 2023 financial year', () => {
+    const testDate = new Date('2023-10-10')
+    const expectedResult = {
+      startDate: new Date('2023-04-01'),
+      endDate: new Date('2024-03-31')
+    }
+
+    beforeEach(async () => {
+      Sinon.stub(BillingPeriodService, '_currentDate').returns(testDate)
+    })
+
+    it('returns the expected date range', () => {
+      const result = BillingPeriodService.go()
+
+      expect(result.length).to.equal(1)
+      expect(result[0]).to.equal(expectedResult)
+    })
+  })
+
+  describe('when the _currentDate function is not stubbed', () => {
+    it('returns a date range', () => {
+      const result = BillingPeriodService.go()
+
+      expect(result.length).to.equal(1)
+    })
+  })
+})

test/services/test/supplementary.service.test.js → test/services/supplementary_billing/fetch_charge_versions.service.test.js

@@ -13,9 +13,9 @@ const DatabaseHelper = require('../../support/helpers/database.helper.js')
 const LicenceHelper = require('../../support/helpers/licence.helper.js')
 
 // Thing under test
-const SupplementaryService = require('../../../app/services/test/supplementary.service.js')
+const FetchChargeVersionsService = require('../../../app/services/supplementary_billing/fetch_charge_versions.service.js')
 
-describe('Supplementary service', () => {
+describe('FetchChargeVersions service', () => {
   const { region_id: regionId } = LicenceHelper.defaults()
   let testRecords
 
@@ -41,10 +41,10 @@ describe('Supplementary service', () => {
     })
 
     it('returns only the current SROC charge versions that are applicable', async () => {
-      const result = await SupplementaryService.go(regionId)
+      const result = await FetchChargeVersionsService.go(regionId)
 
-      expect(result.chargeVersions.length).to.equal(1)
-      expect(result.chargeVersions[0].charge_version_id).to.equal(testRecords[0].charge_version_id)
+      expect(result.length).to.equal(1)
+      expect(result[0].charge_version_id).to.equal(testRecords[0].charge_version_id)
     })
   })
 
@@ -58,9 +58,9 @@ describe('Supplementary service', () => {
       })
 
       it('returns no applicable charge versions', async () => {
-        const result = await SupplementaryService.go(regionId)
+        const result = await FetchChargeVersionsService.go(regionId)
 
-        expect(result.chargeVersions.length).to.equal(0)
+        expect(result.length).to.equal(0)
       })
     })
 
@@ -75,9 +75,9 @@ describe('Supplementary service', () => {
       })
 
       it('returns no applicable charge versions', async () => {
-        const result = await SupplementaryService.go(regionId)
+        const result = await FetchChargeVersionsService.go(regionId)
 
-        expect(result.chargeVersions.length).to.equal(0)
+        expect(result.length).to.equal(0)
       })
     })
 
@@ -92,9 +92,9 @@ describe('Supplementary service', () => {
       })
 
       it('returns no applicable charge versions', async () => {
-        const result = await SupplementaryService.go(regionId)
+        const result = await FetchChargeVersionsService.go(regionId)
 
-        expect(result.chargeVersions.length).to.equal(0)
+        expect(result.length).to.equal(0)
       })
     })
 
@@ -112,9 +112,9 @@ describe('Supplementary service', () => {
       })
 
       it('returns no applicable charge versions', async () => {
-        const result = await SupplementaryService.go(regionId)
+        const result = await FetchChargeVersionsService.go(regionId)
 
-        expect(result.chargeVersions.length).to.equal(0)
+        expect(result.length).to.equal(0)
       })
     })
   })

test/services/supplementary_billing/supplementary.service.test.js

@@ -0,0 +1,48 @@
+'use strict'
+
+// Test framework dependencies
+const Lab = require('@hapi/lab')
+const Code = require('@hapi/code')
+const Sinon = require('sinon')
+
+const { describe, it, beforeEach, afterEach } = exports.lab = Lab.script()
+const { expect } = Code
+
+// Things we need to stub
+const FetchChargeVersionsService = require('../../../app/services/supplementary_billing/fetch_charge_versions.service.js')
+
+// Thing under test
+const SupplementaryService = require('../../../app/services/supplementary_billing/supplementary.service.js')
+
+describe('Supplementary service', () => {
+  afterEach(() => {
+    Sinon.restore()
+  })
+
+  describe('when there are licences to be included in supplementary billing', () => {
+    const testRecords = [{ charge_version_id: '878bc903-836d-4549-83f5-4e20ccf87d2f' }]
+
+    beforeEach(async () => {
+      Sinon.stub(FetchChargeVersionsService, 'go').resolves(testRecords)
+    })
+
+    it('returns only the current SROC charge versions that are applicable', async () => {
+      const result = await SupplementaryService.go('regionId')
+
+      expect(result.chargeVersions.length).to.equal(1)
+      expect(result.chargeVersions[0].charge_version_id).to.equal(testRecords[0].charge_version_id)
+    })
+  })
+
+  describe('when there are no licences to be included in supplementary billing', () => {
+    beforeEach(async () => {
+      Sinon.stub(FetchChargeVersionsService, 'go').resolves([])
+    })
+
+    it('returns no charge versions', async () => {
+      const result = await SupplementaryService.go('regionId')
+
+      expect(result.chargeVersions).to.be.empty()
+    })
+  })
+})