Add Charging Module create transaction service (#140)

https://eaflood.atlassian.net/browse/WATER-3911

The transactions we generate in the WRLS service as part of the SROC supplementary bill run need to be added to the Charging Module’s bill run. We already created the bill run using `app/services/charging-module/create-bill-run.service.js`. So, following that pattern, we add `app/services/charging-module/create-transaction.service.js` in this change.

---

**Housekeeping**

It is a personal preference that has become a convention in our tests. Executing the thing under test should be done within the test rather than a `before()` block.

It's our opinion when this isn't done you lose sight of what a test is testing as you add more and more unit tests. It does mean you get some duplication. But we think it makes for more readable code.

Because we based on unit tests on those in `test/services/charging-module/create-bill-run.service.test.js` we spotted this deviation and corrected it as part of this change.

app/services/charging-module/create-transaction.service.js

@@ -0,0 +1,19 @@
+'use strict'
+
+/**
+ * Connects with the Charging Module to create a new transaction
+ * @module ChargingModuleCreateTransactionService
+ */
+
+const ChargingModuleRequestLib = require('../../lib/charging-module-request.lib.js')
+
+async function go (billingBatchId, transactionData) {
+  const path = `v3/wrls/bill-runs/${billingBatchId}/transactions`
+  const result = await ChargingModuleRequestLib.post(path, transactionData)
+
+  return result
+}
+
+module.exports = {
+  go
+}

test/services/charging-module/create-bill-run.service.test.js

@@ -31,8 +31,6 @@ describe('Charge module create bill run service', () => {
   })
 
   describe('when the service can create a bill run', () => {
-    let result
-
     beforeEach(async () => {
       Sinon.stub(ChargingModuleRequestLib, 'post').resolves({
         succeeded: true,
@@ -50,19 +48,19 @@ describe('Charge module create bill run service', () => {
           }
         }
       })
-
-      result = await ChargingModuleCreateBillRunService.go(testRegion.regionId, 'sroc')
     })
 
     it('returns a `true` success status', async () => {
+      const result = await ChargingModuleCreateBillRunService.go(testRegion.regionId, 'sroc')
+
       expect(result.succeeded).to.be.true()
     })
 
     it('returns the bill run id and number in the `response`', async () => {
-      const { response } = result
+      const result = await ChargingModuleCreateBillRunService.go(testRegion.regionId, 'sroc')
 
-      expect(response.body.billRun.id).to.equal('2bbbe459-966e-4026-b5d2-2f10867bdddd')
-      expect(response.body.billRun.billRunNumber).to.equal(10004)
+      expect(result.response.body.billRun.id).to.equal('2bbbe459-966e-4026-b5d2-2f10867bdddd')
+      expect(result.response.body.billRun.billRunNumber).to.equal(10004)
     })
   })
 

test/services/charging-module/create-transaction.service.test.js

@@ -0,0 +1,118 @@
+'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 ChargingModuleRequestLib = require('../../../app/lib/charging-module-request.lib.js')
+
+// Thing under test
+const ChargingModuleCreateTransactionService = require('../../../app/services/charging-module/create-transaction.service.js')
+
+describe('Charge module create transaction service', () => {
+  const billingBatchId = '2bbbe459-966e-4026-b5d2-2f10867bdddd'
+  const transactionData = { billingTransactionId: '2395429b-e703-43bc-8522-ce3f67507ffa' }
+
+  afterEach(() => {
+    Sinon.restore()
+  })
+
+  describe('when the service can create a transaction', () => {
+    beforeEach(async () => {
+      Sinon.stub(ChargingModuleRequestLib, 'post').resolves({
+        succeeded: true,
+        response: {
+          info: {
+            gitCommit: '273604040a47e0977b0579a0fef0f09726d95e39',
+            dockerTag: 'ghcr.io/defra/sroc-charging-module-api:v0.19.0'
+          },
+          statusCode: 200,
+          body: {
+            transaction: {
+              id: 'fd88e6c5-8da8-4e4f-b22f-c66554cd5bf3',
+              clientId: transactionData.billingTransactionId
+            }
+          }
+        }
+      })
+    })
+
+    it('returns a `true` success status', async () => {
+      const result = await ChargingModuleCreateTransactionService.go(billingBatchId, transactionData)
+
+      expect(result.succeeded).to.be.true()
+    })
+
+    it('returns the CM transaction ID and our ID in the `response`', async () => {
+      const result = await ChargingModuleCreateTransactionService.go(billingBatchId, transactionData)
+
+      expect(result.response.body.transaction.id).to.equal('fd88e6c5-8da8-4e4f-b22f-c66554cd5bf3')
+      expect(result.response.body.transaction.clientId).to.equal(transactionData.billingTransactionId)
+    })
+  })
+
+  describe('when the service cannot create a transaction', () => {
+    describe('because the request did not return a 2xx/3xx response', () => {
+      beforeEach(async () => {
+        Sinon.stub(ChargingModuleRequestLib, 'post').resolves({
+          succeeded: false,
+          response: {
+            info: {
+              gitCommit: '273604040a47e0977b0579a0fef0f09726d95e39',
+              dockerTag: 'ghcr.io/defra/sroc-charging-module-api:v0.19.0'
+            },
+            statusCode: 401,
+            body: {
+              statusCode: 401,
+              error: 'Unauthorized',
+              message: 'Invalid JWT: Token format not valid',
+              attributes: { error: 'Invalid JWT: Token format not valid' }
+            }
+          }
+        })
+      })
+
+      it('returns a `false` success status', async () => {
+        const result = await ChargingModuleCreateTransactionService.go(billingBatchId, transactionData)
+
+        expect(result.succeeded).to.be.false()
+      })
+
+      it('returns the error in the `response`', async () => {
+        const result = await ChargingModuleCreateTransactionService.go(billingBatchId, transactionData)
+
+        expect(result.response.body.statusCode).to.equal(401)
+        expect(result.response.body.error).to.equal('Unauthorized')
+        expect(result.response.body.message).to.equal('Invalid JWT: Token format not valid')
+      })
+    })
+
+    describe('because the request attempt returned an error, for example, TimeoutError', () => {
+      beforeEach(async () => {
+        Sinon.stub(ChargingModuleRequestLib, 'post').resolves({
+          succeeded: false,
+          response: new Error("Timeout awaiting 'request' for 5000ms")
+        })
+      })
+
+      it('returns a `false` success status', async () => {
+        const result = await ChargingModuleCreateTransactionService.go(billingBatchId, transactionData)
+
+        expect(result.succeeded).to.be.false()
+      })
+
+      it('returns the error in the `response`', async () => {
+        const result = await ChargingModuleCreateTransactionService.go(billingBatchId, transactionData)
+
+        expect(result.response.statusCode).not.to.exist()
+        expect(result.response.body).not.to.exist()
+        expect(result.response.message).to.equal("Timeout awaiting 'request' for 5000ms")
+      })
+    })
+  })
+})