Extract table results to a file

app/services/db-export/convert-to-csv.service.js

@@ -0,0 +1,88 @@
+'use strict'
+
+/**
+ * Convert data to CSV format
+ * @module ConvertToCSVService
+ */
+
+/**
+ * Converts data to a CSV formatted string
+ *
+ * @param {Object} data An object containing the tables column names and the tables data
+ *
+ * @returns {String} A CSV formatted string
+ */
+function go (data) {
+  const transformedHeaders = _transformDataToCSV([data.headers])[0]
+
+  if (!data.rows) {
+    return transformedHeaders
+  }
+
+  const transformedRows = _transformDataToCSV(data.rows)
+  const dataToCSV = _joinHeaderAndRows(transformedHeaders, transformedRows)
+
+  return dataToCSV
+}
+
+/**
+ * Transforms each row to CSV format and joins the values with commas
+ *
+ * @param {Object} rows The data to be transformed to CSV
+ *
+ * @returns {String[]} An array of transformed data
+ */
+function _transformDataToCSV (rows) {
+  const transformedRows = []
+
+  rows.forEach((row) => {
+    const transformedRow = row.map((value) => {
+      return _transformValueToCSV(value)
+    }).join(',')
+    transformedRows.push(transformedRow)
+  })
+
+  return transformedRows
+}
+
+/**
+ * Transform a value to CSV format
+ *
+ * @param {*} value The value to transform
+ *
+ * @returns {*} The value transformed to CSV format
+ */
+function _transformValueToCSV (value) {
+  // Return empty string for undefined or null values
+  if (!value && value !== false) {
+    return ''
+  }
+
+  // Return ISO date if value is a date object
+  if (value instanceof Date) {
+    return value.toISOString()
+  }
+
+  // Return integers and booleans as they are (not converted to a string)
+  if (Number.isInteger(value) || typeof value === 'boolean') {
+    return `${value}`
+  }
+
+  // Return objects by serializing them to JSON
+  if (typeof value === 'object') {
+    return JSON.stringify(value)
+  }
+
+  // Return strings by quoting them and escaping any double quotes
+  const stringValue = value.toString().replace(/"/g, '""')
+
+  return `"${stringValue}"`
+}
+
+function _joinHeaderAndRows (header, rows) {
+  return [header, ...rows].join('\n')
+}
+
+module.exports = {
+  go
+}

app/services/db-export/export-data-files.service.js

@@ -0,0 +1,53 @@
+'use strict'
+
+/**
+ * Export converted data to a temporary file
+ * @module ExportDataFilesService
+*/
+
+const path = require('path')
+
+const fs = require('fs').promises
+const os = require('os')
+
+/**
+ * Converts the provided data to CSV format using the ConvertToCsvService and writes it to a file
+ *
+ * @param {Object} data The data to be converted to CSV and written to the file
+ *
+ * @returns {Boolean} True if the file is written successfully and false if not
+ */
+async function go (data) {
+  try {
+    await fs.writeFile(_filenameWithPath('billing_charge_categories_table_export.csv'), data)
+    global.GlobalNotifier.omg('Billing Charge Categories Table exported successfully')
+
+    return true
+  } catch (error) {
+    global.GlobalNotifier.omfg('Billing Charge Categories Table Export request errored', error)
+
+    return false
+  }
+}
+
+/**
+ * Returns a file path by joining the temp directory path with the given file name
+ *
+ * @param {String} name The name the file will be saved under
+ *
+ * @returns {String} The file path to save the file under
+ */
+function _filenameWithPath (name) {
+  const temporaryFilePath = os.tmpdir()
+
+  return path.normalize(
+    path.format({
+      dir: temporaryFilePath,
+      name
+    })
+  )
+}
+
+module.exports = {
+  go
+}

app/services/db-export/fetch-billing-charge-categories.service.js

@@ -2,23 +2,43 @@
 
 /**
  * Fetch all records from the water.billing_charge_categories table
- * @module BillingChargeCategoriesTableExportService
+ * @module FetchBillingChargeCategoriesService
  */
 
 const { db } = require('../../../db/db.js')
 
 /**
- * Generates an array of the table billing_charge_categories
+ * Retrieves headers and rows from the table in the db, and returns them as an object
  *
- * This is a dump of running 'SELECT * FROM water.billing_charge_categories' for the database.
- * Its part of the full db schema export work.
- *
- * @returns An array of objects containing the data from the table.
+ * @returns {Object} The headers and rows from the table
  */
 async function go () {
-  return db
+  const data = {
+    headers: await _headers(),
+    rows: await _rows()
+  }
+
+  return data
+}
+
+async function _rows () {
+  // Retrieves all rows from the water.billingChargeCategories table
+  const rows = await db
+    .withSchema('water')
     .select('*')
-    .from('water.billing_charge_categories')
+    .from('billingChargeCategories')
+
+  // We are only interested in the values from the table
+  return rows.map((row) => {
+    return Object.values(row)
+  })
+}
+
+async function _headers () {
+  const columns = await db('billingChargeCategories').withSchema('water').columnInfo()
+
+  // We are only interested in the column names
+  return Object.keys(columns)
 }
 
 module.exports = {

test/services/db-export/convert-to-csv.service.test.js

@@ -0,0 +1,124 @@
+'use strict'
+
+// Test framework dependencies
+const Lab = require('@hapi/lab')
+const Code = require('@hapi/code')
+
+const { describe, it } = exports.lab = Lab.script()
+const { expect } = Code
+
+// Thing under test
+const ConvertToCSVService = require('../../../app/services/db-export/convert-to-csv.service')
+
+/**
+ * billingChargeCategoriesTable has all data types we are testing for
+ * objects{Date} - dateCreated
+ * String - description
+ * String (with added quotes)- shortDescription
+ * Integer - maxVolume
+ * Null - lossFactor
+ * Undefined - modelTier
+ */
+const billingChargeCategoryRow = [
+  '20146cdc-9b40-4769-aa78-b51c17080d56',
+  '4.1.1',
+  9700,
+  'Low loss tidal abstraction of water up to and "including" 25,002 megalitres a year where no model applies',
+  'Low loss, tidal, up to and including 25,002 ML/yr',
+  new Date(2022, 11, 14, 18, 39, 45),
+  new Date(2022, 11, 14, 18, 39, 45),
+  true,
+  null,
+  undefined,
+  false,
+  '',
+  25002
+]
+
+const billingChargeCategoriesColumnInfo = [
+  'billingChargeCategoryId',
+  'reference',
+  'subsistenceCharge',
+  'description',
+  'shortDescription',
+  'dateCreated',
+  'dateUpdated',
+  'isTidal',
+  'lossFactor',
+  'modelTier',
+  'isRestrictedSource',
+  'minVolume',
+  'maxVolume'
+]
+
+const csvHeaders = [
+  '"billingChargeCategoryId"',
+  '"reference"',
+  '"subsistenceCharge"',
+  '"description"',
+  '"shortDescription"',
+  '"dateCreated"',
+  '"dateUpdated"',
+  '"isTidal"',
+  '"lossFactor"',
+  '"modelTier"',
+  '"isRestrictedSource"',
+  '"minVolume"',
+  '"maxVolume"'
+]
+
+const csvValues = [
+  '"20146cdc-9b40-4769-aa78-b51c17080d56"',
+  '"4.1.1"',
+  '9700',
+  '"Low loss tidal abstraction of water up to and ""including"" 25,002 megalitres a year where no model applies"',
+  '"Low loss, tidal, up to and including 25,002 ML/yr"',
+  '2022-12-14T18:39:45.000Z',
+  '2022-12-14T18:39:45.000Z',
+  'true',
+  '',
+  '',
+  'false',
+  '',
+  '25002'
+]
+
+describe('Convert to CSV service', () => {
+  describe('when given data to convert', () => {
+    describe('that only has one row of data', () => {
+      it('has the table columns as headers', () => {
+        const result = ConvertToCSVService.go({ headers: billingChargeCategoriesColumnInfo, rows: [billingChargeCategoryRow] })
+        const resultLines = result.split(/\r?\n/)
+
+        expect(resultLines[0]).to.equal(csvHeaders.join(','))
+      })
+
+      it('converts the data to a CSV format', () => {
+        const result = ConvertToCSVService.go({ headers: billingChargeCategoriesColumnInfo, rows: [billingChargeCategoryRow] })
+        const resultLines = result.split(/\r?\n/)
+
+        expect(resultLines[1]).to.equal(csvValues.join(','))
+      })
+    })
+
+    describe('that has multiple rows of data', () => {
+      it('transforms all the rows to CSV', () => {
+        const result = ConvertToCSVService.go({ headers: billingChargeCategoriesColumnInfo, rows: [billingChargeCategoryRow, billingChargeCategoryRow] })
+        const resultLines = result.split(/\r?\n/)
+
+        expect(resultLines[1]).to.equal(csvValues.join(','))
+        expect(resultLines[2]).to.equal(csvValues.join(','))
+      })
+    })
+  })
+
+  describe('when not given data to convert', () => {
+    describe('that has no rows of data', () => {
+      it('exports the table to CSV without any rows', () => {
+        const result = ConvertToCSVService.go({ headers: billingChargeCategoriesColumnInfo })
+
+        expect(result).to.equal(csvHeaders.toString())
+      })
+    })
+  })
+})