Just insert user's code into starter application code

alphagov · Apr 3, 2023 · 2dbd2f9 · 2dbd2f9
1 parent 8813986
commit 2dbd2f9
Show file tree

Hide file tree

Showing 3 changed files with 79 additions and 83 deletions.
diff --git a/__tests__/spec/migrate.js b/__tests__/spec/migrate.js
@@ -112,17 +112,22 @@ describe('migrate test prototype', () => {
   it('application.js should be overwritten', () => {
     const jsFileContents = getNormalisedFileContent(path.join(assetsDirectory, 'javascripts', 'application.js'))
 
-    expect(jsFileContents).toEqual(
-      '//\n' +
-      '// For guidance on how to add JavaScript see:\n' +
-      '// https://prototype-kit.service.gov.uk/docs/adding-css-javascript-and-images\n' +
-      '//\n' +
-      '\n' +
-      'window.GOVUKPrototypeKit.documentReady(() => {' + '\n' +
-      '  // Add JavaScript here' + '\n' +
-      '  console.log(\'Hello\')' + '\n' +
-      '})' + '\n'
-    )
+    expect(jsFileContents).toEqual(`/* global $ */
+
+//
+// For guidance on how to add JavaScript see:
+// https://prototype-kit.service.gov.uk/docs/adding-css-javascript-and-images
+//
+
+window.GOVUKPrototypeKit.documentReady(() => {
+  // Add JavaScript here
+
+  $(document).ready(function () {
+    console.log('Hello')
+  })
+
+})
+`)
   })
 
   it('application.scss should be updated correctly', () => {

diff --git a/migrator/migration-steps.js b/migrator/migration-steps.js
@@ -9,7 +9,7 @@ const lodash = require('lodash')
 
 // local dependencies
 const { searchAndReplaceFiles } = require('../lib/utils')
-const { appDir, projectDir, packageDir } = require('../lib/utils/paths')
+const { appDir, projectDir, packageDir, starterDir } = require('../lib/utils/paths')
 const config = require('../lib/config')
 const logger = require('./logger')
 const { addReporter, reportSuccess, reportFailure } = require('./reporter')
@@ -258,77 +258,52 @@ async function upgradeIfPossible (filePath, matchFound) {
 }
 
 async function upgradeApplicationJs (fullPath, reporter) {
-  const textToReplace = [
-    {
-      originalText: '/* global $ */',
-      replacementText:
-        `//
-// For guidance on how to add JavaScript see:
-// https://prototype-kit.service.gov.uk/docs/adding-css-javascript-and-images
-//`
-    },
-    {
-      originalText:
-        `// Warn about using the kit in production
-if (window.console && window.console.info) {
-window.console.info('GOV.UK Prototype Kit - do not use for production')
-}`
-    },
-    {
-      originalText: '$(document).ready(function () {',
-      replacementText: 'window.GOVUKPrototypeKit.documentReady(() => {'
-    },
-    {
-      originalText: 'window.GOVUKFrontend.initAll()',
-      replacementText: '  // Add JavaScript here'
-    }
+  const searchText = '// Add JavaScript here'
+  const matchText = [
+    ['/* global $ */'],
+    [
+      '// Warn about using the kit in production',
+      'if (window.console && window.console.info) {',
+      'window.console.info(\'GOV.UK Prototype Kit - do not use for production\')',
+      '}'
+    ],
+    ['window.GOVUKFrontend.initAll()']
   ]
-  const fileContent = await fsp.readFile(fullPath, 'utf8')
-  const fileLines = fileContent.split('\n')
+  const starterFile = path.join(starterDir, 'app', 'assets', 'javascripts', 'application.js')
+  const starterContent = await fsp.readFile(starterFile, 'utf8')
   const newContentLines = []
-  let currentPos = 0
-  textToReplace.forEach(({ originalText, replacementText }) => {
-    const linesToFind = originalText.split('\n')
-    // Find the start position of the original text in the file
-    const startPos = fileLines.findIndex((line) => line.trim() === linesToFind[0].trim())
-    if (startPos === -1) {
-      // Original text wasn't found
-      return
-    }
-    currentPos = currentPos + linesToFind.length
-    // Include the lines in between each set of lines that are being replaced
-    while (currentPos < startPos) {
-      newContentLines.push(fileLines[currentPos++])
-    }
-
-    if (replacementText) {
-      // Make sure all original lines exist in sequence within the file before replacing them
-      const canReplace = linesToFind.every((originalLine, index) => {
-        return originalLine.trim() === fileLines[startPos + index].trim()
-      })
-      if (canReplace) {
-        const replacementLines = replacementText.split('\n')
-        for (let i = 0; i < replacementLines.length; i++) {
-          newContentLines.push(replacementLines[i])
-        }
+  const originalContent = await fsp.readFile(fullPath, 'utf8')
+  const originalContentLines = originalContent.split('\n')
+
+  // Remove the matchText from the original code
+  while (originalContentLines.length) {
+    const match = matchText.findIndex((text) => text.every((line, index) => {
+      const originalContentLine = originalContentLines[index]
+      return line === originalContentLine.trim()
+    }))
+    if (match === -1) {
+      let originalLine = originalContentLines.shift()
+      if (originalLine.trim().length) {
+        // indent line if the line isn't empty
+        originalLine = '  ' + originalLine
       }
+      newContentLines.unshift(originalLine)
+    } else {
+      matchText[match].forEach(() => originalContentLines.shift())
     }
-  })
-  if (newContentLines.length) {
-    currentPos++
-    while (currentPos < fileLines.length) {
-      newContentLines.push(fileLines[currentPos++])
-    }
-    let content = newContentLines.join('\n')
+  }
 
-    // Put back the global line to satisfy linter if jQuery is still necessary
-    if (content.includes('$(') || content.includes('$.')) {
-      content = '/* global $ */\n\n' + content
-    }
-    await fsp.writeFile(fullPath, content)
-    await reporter(true)
-    return true
+  // Place the original code inside the starter code
+  let newContent = starterContent.replace(searchText, searchText + newContentLines.reverse().join('\n'))
+
+  // Put back the global line to satisfy linter if jQuery is still necessary
+  if (newContent.includes('$(') || newContent.includes('$.')) {
+    newContent = '/* global $ */\n\n' + newContent
   }
+
+  await fsp.writeFile(fullPath, newContent)
+  await reporter(true)
+  return true
 }
 
 module.exports = {

diff --git a/migrator/migration-steps.spec.js b/migrator/migration-steps.spec.js
@@ -351,7 +351,7 @@ describe('migration steps', () => {
   it('upgrade application file if possible', async () => {
     const applicationJsFile = path.join('app', 'assets', 'javascripts', 'application.js')
     const matchFound = false
-    const fileContents = `/* global $ */
+    const originalFileContents = `/* global $ */
 
 // Warn about using the kit in production
 if (window.console && window.console.info) {
@@ -363,26 +363,42 @@ $(document).ready(function () {
   console.log('Hello')
 })
 `
-    const expectedFileContents =
-`//
+    const starterFileContents = `//
 // For guidance on how to add JavaScript see:
 // https://prototype-kit.service.gov.uk/docs/adding-css-javascript-and-images
 //
 
 window.GOVUKPrototypeKit.documentReady(() => {
   // Add JavaScript here
-  console.log('Hello')
+})
+`
+    const expectedFileContents = `/* global $ */
+
+//
+// For guidance on how to add JavaScript see:
+// https://prototype-kit.service.gov.uk/docs/adding-css-javascript-and-images
+//
+
+window.GOVUKPrototypeKit.documentReady(() => {
+  // Add JavaScript here
+
+  $(document).ready(function () {
+    console.log('Hello')
+  })
+
 })
 `
 
-    fsp.readFile.mockReturnValue(fileContents)
+    fsp.readFile
+      .mockReturnValueOnce(starterFileContents) // For the first call
+      .mockReturnValueOnce(originalFileContents) // For the second call
 
     // mock call upgradeIfPossible method (get this working first)
     const result = await upgradeIfPossible(applicationJsFile, matchFound)
     expect(result).toBeTruthy()
     const expectedFileName = path.join(projectDir, applicationJsFile)
 
-    expect(fsp.readFile).toHaveBeenCalledTimes(1)
+    expect(fsp.readFile).toHaveBeenCalledTimes(2)
     expect(fsp.readFile).toHaveBeenCalledWith(expectedFileName, 'utf8')
 
     expect(fsp.writeFile).toHaveBeenCalledTimes(1)