#2517 only fetch plugin package info from NPM when needed

bin/cli

@@ -403,8 +403,6 @@ async function runDev () {
 async function runServe () {
   warnIfNpmStart(argv, process.env)
   process.env.NODE_ENV = process.env.NODE_ENV || 'production'
-  const { waitForPackagesCache } = require('../lib/plugins/packages')
-  await waitForPackagesCache()
   require('../lib/build.js').generateAssetsSync()
   require('../listen-on-port')
 }

lib/build.test.js

@@ -5,6 +5,16 @@ const sass = require('sass')
 const { setPackagesCache } = require('./plugins/packages')
 const { sassFunctions } = require('./build')
 
+jest.mock('../package.json', () => {
+  return {
+    dependencies: {
+      '@govuk-prototype-kit/common-templates': '1.0.0',
+      "available-installed-plugin": "^1.0.0",
+      "available-prerelease-plugin": "2.0.0-rc.0"
+    }
+  }
+})
+
 describe('build', () => {
   describe('sassFunctions', () => {
     describe('plugin-version-satisfies', () => {

lib/dev-server.js

@@ -29,17 +29,13 @@ const {
 } = require('./utils/paths')
 const fs = require('fs')
 const { logPerformanceSummaryOnce, startPerformanceTimer, endPerformanceTimer } = require('./utils/performance')
-const { waitForPackagesCache } = require('./plugins/packages')
 
 // Build watch and serve
 async function runDevServer () {
   await collectDataUsage()
   let startupError
 
   try {
-    // Wait for the package cache to be built before doing anything
-    // to ensure that `pluginVersionSatisfies` runs against accurate data
-    await waitForPackagesCache()
     generateAssetsSync()
     generateCssSync()
     await utils.waitUntilFileExists(path.join(publicCssDir, 'application.css'), 5000)

lib/manage-prototype-handlers.js

@@ -21,7 +21,6 @@ const {
   getAllPackages,
   getDependentPackages,
   getDependencyPackages,
-  waitForPackagesCache,
   pluginVersionSatisfies
 } = require('./plugins/packages')
 
@@ -148,15 +147,6 @@ function developmentOnlyMiddleware (req, res, next) {
   }
 }
 
-// Middleware to ensure pages load when plugin cache has been initially loaded
-async function pluginCacheMiddleware (req, res, next) {
-  await Promise.race([
-    waitForPackagesCache(),
-    new Promise((resolve) => setTimeout(resolve, 1000))
-  ])
-  next()
-}
-
 const managementLinks = [
   {
     text: 'Manage your prototype',
@@ -775,7 +765,6 @@ module.exports = {
   getPasswordHandler,
   postPasswordHandler,
   developmentOnlyMiddleware,
-  pluginCacheMiddleware,
   getHomeHandler,
   getTemplatesHandler,
   getTemplatesViewHandler,

lib/manage-prototype-routes.js

@@ -23,7 +23,6 @@ const {
   postPluginsModeMiddleware,
   postPluginsModeHandler,
   postPluginsStatusHandler,
-  pluginCacheMiddleware,
   postPluginsHandler
 } = require('./manage-prototype-handlers')
 const { packageDir, projectDir } = require('./utils/paths')
@@ -51,8 +50,6 @@ router.post('/password', postPasswordHandler)
 // view when the prototype is not running in development
 router.use(developmentOnlyMiddleware)
 
-router.use(pluginCacheMiddleware)
-
 router.get('/', getHomeHandler)
 
 router.get('/templates', getTemplatesHandler)

lib/plugins/packages.js

@@ -17,13 +17,16 @@ const { getConfigForPackage } = require('../utils/requestHttps')
 const { getProxyPluginConfig } = require('./plugin-utils')
 const { sortByObjectKey, hasNewVersion } = require('../utils')
 
-let packageTrackerInterval
-
 const packagesCache = {}
+let packagesCacheLastFetchTimeMs = 0;
+const packagesCacheMaxAgeMs = 60 * 1000 // 1 minute
 
-async function startPackageTracker () {
-  await updatePackagesInfo()
-  packageTrackerInterval = setInterval(updatePackagesInfo, 36000)
+async function getOrFetchPackagesCache() {
+  if (Date.now() - packagesCacheLastFetchTimeMs > packagesCacheMaxAgeMs) {
+    await updatePackagesInfo()
+    packagesCacheLastFetchTimeMs = Date.now()
+  }
+  return packagesCache
 }
 
 async function updatePackagesInfo () {
@@ -176,71 +179,41 @@ function packageNameSort (pkgA, pkgB) {
  * NOTE: Treats pre-releases version numbers as if they were the actual version
  * to facilitate testing pre-releases
  *
- * WARNING: Needs to be run after the package cache is built.
- * Use `waitForPackageCache` to make sure this function
- * is called once the cache is ready.
- *
  * @param {string} pluginName
  * @param {string} semverRange
  *
  * @returns {Boolean} `true` if a plugin with the name is installed and satisfies the range, `false` otherwise
  * @internal
  */
 function pluginVersionSatisfies (pluginName, semverRange) {
-  if (!Object.keys(packagesCache).length) {
-    throw new Error("The package cache need to be populated before checking plugins' version range")
-  }
-
-  const plugin = packagesCache[pluginName]
+  // No need to do a network fetch to npm for the installed version, it will be in package.json
+  // This will avoid a network request every time the app launches.
+  // We only need to fetch from npm if the package management pages are loaded
+  const installedVersion = projectPackage?.dependencies?.[pluginName]
 
-  if (!plugin?.pluginConfig) {
+  if (!installedVersion) {
     return false
   }
 
   // Use `coerce` to treat pre-releases like if they were the actual package
-  return semver.satisfies(semver.coerce(plugin.installedVersion), semverRange)
+  return semver.satisfies(semver.coerce(installedVersion), semverRange)
 }
 
 async function getInstalledPackages () {
-  if (!Object.keys(packagesCache).length) {
-    await startPackageTracker()
-  }
-  await waitForPackagesCache()
+  const packagesCache = await getOrFetchPackagesCache();
   return Object.values(packagesCache)
     .filter(({ installed }) => installed)
     .sort(packageNameSort)
     .reduce(emphasizeBasePlugins, [])
 }
 
 async function getAllPackages () {
-  if (!Object.keys(packagesCache).length) {
-    await startPackageTracker()
-  }
-  await waitForPackagesCache()
+  const packagesCache = await getOrFetchPackagesCache();
   return Object.values(packagesCache)
     .sort(packageNameSort)
     .reduce(emphasizeBasePlugins, [])
 }
 
-function sleep (ms) {
-  return new Promise((resolve) => setTimeout(resolve, ms))
-}
-
-async function waitForPackagesCache () {
-  let numberOfRetries = 20
-  let waiting = !packageTrackerInterval
-  while (waiting) {
-    // If the packageTrackerInterval has been set, then packages cache has been populated at least once
-    waiting = !packageTrackerInterval && numberOfRetries > 0
-    numberOfRetries--
-    if (numberOfRetries === 0) {
-      console.log('Failed to load the package cache')
-    } else {
-      await sleep(250)
-    }
-  }
-}
-
 function normaliseDependencies (dependencies) {
   return dependencies.map((dependency) => {
     if (typeof dependency === 'string') {
@@ -256,19 +229,13 @@ async function getDependentPackages (packageName, version, mode) {
   if (mode !== 'uninstall') {
     return []
   }
-  if (!Object.keys(packagesCache).length) {
-    await startPackageTracker()
-  }
-  await waitForPackagesCache()
+  const packagesCache = await getOrFetchPackagesCache();
   return Object.values(packagesCache)
     .filter(({ pluginDependencies }) => pluginDependencies?.some((pluginDependency) => pluginDependency === packageName || pluginDependency.packageName === packageName))
 }
 
 async function getDependencyPackages (packageName, version, mode) {
-  if (!Object.keys(packagesCache).length) {
-    await startPackageTracker()
-  }
-  await waitForPackagesCache()
+  await getOrFetchPackagesCache();
   const pkg = await lookupPackageInfo(packageName, version)
   let pluginDependencies = pkg?.pluginDependencies
   if (version || mode === 'update') {
@@ -289,24 +256,19 @@ async function getDependencyPackages (packageName, version, mode) {
   return dependencyPlugins.filter(({ installed }) => !installed)
 }
 
-if (!config.getConfig().isTest) {
-  startPackageTracker()
-}
-
+// Only used for unit tests
 function setPackagesCache (packagesInfo) {
-  // Only used for unit tests
   for (const key in packagesCache) {
     delete packagesCache[key]
   }
   packagesInfo.forEach((packageInfo) => {
     packagesCache[packageInfo.packageName] = packageInfo
   })
-  packageTrackerInterval = true
+  packagesCacheLastFetchTimeMs = Date.now()
 }
 
 module.exports = {
   setPackagesCache, // Only for unit testing purposes
-  waitForPackagesCache,
   lookupPackageInfo,
   getInstalledPackages,
   getAllPackages,

lib/plugins/packages.spec.js

@@ -26,7 +26,9 @@ const registryUrl = 'https://registry.npmjs.org/'
 jest.mock('../../package.json', () => {
   return {
     dependencies: {
-      '@govuk-prototype-kit/common-templates': '1.0.0'
+      '@govuk-prototype-kit/common-templates': '1.0.0',
+      "available-installed-plugin": "^1.0.0",
+      "available-prerelease-plugin": "2.0.0-rc.0"
     }
   }
 })
@@ -117,59 +119,20 @@ describe('packages', () => {
   })
 
   describe('pluginVersionSatisfies', () => {
-    describe('with an empty cache', () => {
-      it('throws an error', () => {
-        expect(() => pluginVersionSatisfies('available-installed-plugin', '>=1.0.0'))
-          .toThrow("The package cache need to be populated before checking plugins' version range")
-      })
-    })
 
-    describe('with a populated cache', () => {
-      const availableInstalledPackage = {
-        packageName: 'available-installed-package',
-        installed: true,
-        installedVersion: '1.0.0'
-      }
-      const availableInstalledPlugin = {
-        packageName: 'available-installed-plugin',
-        installed: true,
-        installedVersion: '1.0.0',
-        pluginConfig: {}
-      }
-      const availableUninstalledPackage = {
-        packageName: 'available-uninstalled-package',
-        installed: false
-      }
-      const availableInstalledPrereleasePlugin = {
-        packageName: 'available-prerelease-plugin',
-        installedVersion: '2.0.0-rc.0',
-        pluginConfig: {}
-      }
+    // See jest.mock('../../package.json') above
 
-      beforeEach(() => {
-        setPackagesCache([
-          availableInstalledPackage,
-          availableInstalledPlugin,
-          availableUninstalledPackage,
-          availableInstalledPrereleasePlugin
-        ])
-      })
-
-      it('returns `true` if plugin is installed and matches the range', () => {
-        expect(pluginVersionSatisfies('available-installed-plugin', '>=1.0.0')).toBe(true)
-      })
-      it('returns `true` if pre-release for the minimum of the range is installed', () => {
-        expect(pluginVersionSatisfies('available-prerelease-plugin', '>=2.0.0')).toBe(true)
-      })
-      it('returns `false` if plugin is installed and version does not match the range', () => {
-        expect(pluginVersionSatisfies('available-installed-plugin', '<1.0.0')).toBe(false)
-      })
-      it('returns `false` if plugin is not installed', () => {
-        expect(pluginVersionSatisfies('available-uninstalled-package', '>=1.0.0')).toBe(false)
-      })
-      it('returns `false` if the package is installed but not a plugin', () => {
-        expect(pluginVersionSatisfies('available-installed-package', '>=1.0.0')).toBe(false)
-      })
+    it('returns `true` if plugin is installed and matches the range', () => {
+      expect(pluginVersionSatisfies('available-installed-plugin', '>=1.0.0')).toBe(true)
+    })
+    it('returns `true` if pre-release for the minimum of the range is installed', () => {
+      expect(pluginVersionSatisfies('available-prerelease-plugin', '>=2.0.0')).toBe(true)
+    })
+    it('returns `false` if plugin is installed and version does not match the range', () => {
+      expect(pluginVersionSatisfies('available-installed-plugin', '<1.0.0')).toBe(false)
+    })
+    it('returns `false` if plugin is not installed', () => {
+      expect(pluginVersionSatisfies('available-uninstalled-package', '>=1.0.0')).toBe(false)
     })
   })
 

listen-on-port.js

@@ -1,16 +1,11 @@
 // npm dependencies
 const { runErrorServer } = require('./lib/errorServer')
-const { waitForPackagesCache } = require('./lib/plugins/packages.js')
 const { verboseLog } = require('./lib/utils/verboseLogger')
 
 const config = require('./lib/config.js').getConfig(null, false)
 
 ;(async () => {
   try {
-    // Wait for the package cache to be built before doing anything
-    // to ensure that `pluginVersionSatisfies` runs against accurate data
-    await waitForPackagesCache()
-
     // local dependencies
     const syncChanges = require('./lib/sync-changes')
     const server = require('./server.js')