fix: retry on EMFILE always, lint sync FS calls (#22175)

* fix: use graceful-fs always, warn in development on sync calls * skip prop linting in some dirs * eslint rules * use AST-based lint rule instead * comment * ignore existsSync * run without nextTick * remove dev warning code * fix order * register TS first * fix tests * fix test * cover new call site * fix new test
2026-01-28 18:08:47 -06:00 · 2022-06-16 00:35:31 -04:00
parent e87c492479
commit d01932bf75
44 changed files with 161 additions and 192 deletions
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -5,6 +5,7 @@ const { specifiedRules } = require('graphql')
 const graphqlOpts = {
  env: 'literal',
  tagName: 'gql',
+  // eslint-disable-next-line no-restricted-syntax
  schemaString: fs.readFileSync(
    path.join(__dirname, 'packages/graphql/schemas/schema.graphql'),
    'utf8',
@@ -33,6 +34,24 @@ module.exports = {
    'plugin:@cypress/dev/tests',
  ],
  parser: '@typescript-eslint/parser',
+  overrides: [
+    {
+      files: [
+        // ignore in tests and scripts
+        '**/scripts/**',
+        '**/test/**',
+        '**/system-tests/**',
+        'packages/{app,driver,frontend-shared,launchpad}/cypress/**',
+        '*.test.ts',
+        // ignore in packages that don't run in the Cypress process
+        'npm/create-cypress-tests/**',
+      ],
+      rules: {
+        'no-restricted-properties': 'off',
+        'no-restricted-syntax': 'off',
+      },
+    },
+  ],
  rules: {
    'no-duplicate-imports': 'off',
    'import/no-duplicates': 'off',
@@ -55,6 +74,16 @@ module.exports = {
        message: 'os.userInfo() will throw when there is not an `/etc/passwd` entry for the current user (like when running with --user 12345 in Docker). Do not use it unless you catch any potential errors.',
      },
    ],
+    'no-restricted-syntax': [
+      // esquery tool: https://estools.github.io/esquery/
+      'error',
+      {
+        // match sync FS methods except for `existsSync`
+        // examples: fse.readFileSync, fs.readFileSync, this.ctx.fs.readFileSync...
+        selector: `MemberExpression[object.name='fs'][property.name=/^[A-z]+Sync$/]:not(MemberExpression[property.name='existsSync']), MemberExpression[property.name=/^[A-z]+Sync$/]:not(MemberExpression[property.name='existsSync']):has(MemberExpression[property.name='fs'])`,
+        message: 'Synchronous fs calls should not be used in Cypress. Use an async API instead.',
+      },
+    ],
    'graphql/capitalized-type-name': ['warn', graphqlOpts],
    'graphql/no-deprecated-fields': ['error', graphqlOpts],
    'graphql/template-strings': ['error', { ...graphqlOpts, validators }],
--- a/npm/eslint-plugin-dev/lib/custom-rules/index.js
+++ b/npm/eslint-plugin-dev/lib/custom-rules/index.js
@@ -2,6 +2,7 @@ const fs = require('fs')
 const path = require('path')

 module.exports =
+  // eslint-disable-next-line no-restricted-syntax
  Object.assign({}, ...fs.readdirSync(__dirname)
  .filter((filename) => filename.endsWith('.js') && filename !== 'index.js')
  .map((filename) => ({ [filename.replace(/\.js$/u, '')]: require(path.resolve(__dirname, filename)) })))
--- a/npm/vite-dev-server/cypress/e2e/vite-dev-server.cy.ts
+++ b/npm/vite-dev-server/cypress/e2e/vite-dev-server.cy.ts
@@ -38,7 +38,7 @@ describe('Config options', () => {
    cy.startAppServer('component')

    cy.withCtx(async (ctx, { specWithWhitespace }) => {
-      ctx.actions.file.writeFileInProject(
+      await ctx.actions.file.writeFileInProject(
        ctx.path.join('src', specWithWhitespace),
        await ctx.file.readFileInProject(ctx.path.join('src', 'App.cy.jsx')),
      )
--- a/npm/vite-dev-server/src/plugins/cypress.ts
+++ b/npm/vite-dev-server/src/plugins/cypress.ts
@@ -38,6 +38,8 @@ export const Cypress = (
  const indexHtmlFile = options.cypressConfig.indexHtmlFile

  let specsPathsSet = getSpecsPathsSet(specs)
+  // TODO: use async fs methods here
+  // eslint-disable-next-line no-restricted-syntax
  let loader = fs.readFileSync(INIT_FILEPATH, 'utf8')

  devServerEvents.on('dev-server:specs:changed', (specs: Spec[]) => {
--- a/npm/webpack-dev-server/src/CypressCTWebpackPlugin.ts
+++ b/npm/webpack-dev-server/src/CypressCTWebpackPlugin.ts
@@ -99,13 +99,15 @@ export class CypressCTWebpackPlugin {
   * has been "updated on disk", causing a recompliation (and pulling the new specs in as
   * dependencies).
   */
-  private onSpecsChange = (specs: Cypress.Cypress['spec'][]) => {
+  private onSpecsChange = async (specs: Cypress.Cypress['spec'][]) => {
    if (!this.compilation || _.isEqual(specs, this.files)) {
      return
    }

    this.files = specs
    const inputFileSystem = this.compilation.inputFileSystem
+    // TODO: don't use a sync fs method here
+    // eslint-disable-next-line no-restricted-syntax
    const utimesSync: UtimesSync = inputFileSystem.fileSystem.utimesSync ?? fs.utimesSync

    utimesSync(path.resolve(__dirname, 'browser.js'), new Date(), new Date())
--- a/npm/webpack-dev-server/src/helpers/nextHandler.ts
+++ b/npm/webpack-dev-server/src/helpers/nextHandler.ts
@@ -69,7 +69,7 @@ async function loadWebpackConfig (devServerConfig: WebpackDevServerConfig): Prom
      buildId: `@cypress/react-${Math.random().toString()}`,
      config: nextConfig,
      dev: true,
-      pagesDir: findPagesDir(devServerConfig.cypressConfig.projectRoot),
+      pagesDir: await findPagesDir(devServerConfig.cypressConfig.projectRoot),
      entrypoints: {},
      rewrites: { fallback: [], afterFiles: [], beforeFiles: [] },
      ...runWebpackSpan,
@@ -106,9 +106,9 @@ function checkSWC (
  return false
 }

-const existsSync = (file: string) => {
+const exists = async (file: string) => {
  try {
-    fs.accessSync(file, fs.constants.F_OK)
+    await fs.promises.access(file, fs.constants.F_OK)

    return true
  } catch (_) {
@@ -121,16 +121,16 @@ const existsSync = (file: string) => {
 * `${projectRoot}/pages` or `${projectRoot}/src/pages`.
 * If neither is found, return projectRoot
 */
-function findPagesDir (projectRoot: string) {
+async function findPagesDir (projectRoot: string) {
  // prioritize ./pages over ./src/pages
  let pagesDir = path.join(projectRoot, 'pages')

-  if (existsSync(pagesDir)) {
+  if (await exists(pagesDir)) {
    return pagesDir
  }

  pagesDir = path.join(projectRoot, 'src', 'pages')
-  if (existsSync(pagesDir)) {
+  if (await exists(pagesDir)) {
    return pagesDir
  }

--- a/npm/webpack-dev-server/src/measureWebpackPerformance.ts
+++ b/npm/webpack-dev-server/src/measureWebpackPerformance.ts
@@ -1,3 +1,4 @@
+/* eslint-disable no-restricted-syntax */
 /* eslint-disable no-console */
 import path from 'path'
 import fs from 'fs'
--- a/npm/webpack-preprocessor/package.json
+++ b/npm/webpack-preprocessor/package.json
@@ -11,7 +11,7 @@
    "secure": "nsp check",
    "semantic-release": "semantic-release",
    "size": "npm pack --dry",
-    "test": "node ./test-webpack-5.js",
+    "test": "node ./scripts/test-webpack-5.js",
    "test-debug": "node --inspect --debug-brk ./node_modules/.bin/_mocha",
    "test-e2e": "mocha test/e2e/*.spec.*",
    "test-unit": "mocha test/unit/*.spec.*",
--- a/npm/webpack-preprocessor/scripts/test-webpack-5.js
+++ b/npm/webpack-preprocessor/scripts/test-webpack-5.js
@@ -1,7 +1,10 @@
 const execa = require('execa')
-const pkg = require('./package.json')
+const path = require('path')
+const pkg = require('../package.json')
 const fs = require('fs')

+const pkgJsonPath = path.join(__dirname, '..', 'package.json')
+
 /**
 * This file installs Webpack 5 and runs the unit and e2e tests for the preprocessor.
 * We read package.json, update the webpack version, then re-run yarn install.
@@ -17,7 +20,7 @@ const main = async () => {
  const install = () => execa('yarn', ['install', '--ignore-scripts'], { stdio: 'inherit' })

  const resetPkg = async () => {
-    fs.writeFileSync('package.json', originalPkg, 'utf8')
+    fs.writeFileSync(pkgJsonPath, originalPkg, 'utf8')
    await install()
  }

@@ -38,7 +41,7 @@ const main = async () => {
  delete pkg.devDependencies['webpack']
  // eslint-disable-next-line no-console
  console.log('[@cypress/webpack-preprocessor]: updating package.json...')
-  fs.writeFileSync('package.json', JSON.stringify(pkg, null, 2))
+  fs.writeFileSync(pkgJsonPath, JSON.stringify(pkg, null, 2))

  // eslint-disable-next-line no-console
  console.log('[@cypress/webpack-preprocessor]: install dependencies...')
--- a/packages/app/cypress/e2e/cypress-in-cypress-component.cy.ts
+++ b/packages/app/cypress/e2e/cypress-in-cypress-component.cy.ts
@@ -208,8 +208,8 @@ describe('Cypress In Cypress CT', { viewportWidth: 1500, defaultCommandTimeout:
        }).invoke('connected').should('be.true')
      })

-      cy.withCtx((ctx, o) => {
-        ctx.actions.file.writeFileInProject(o.path, `
+      cy.withCtx(async (ctx, o) => {
+        await ctx.actions.file.writeFileInProject(o.path, `
  import React from 'react'
  import { mount } from '@cypress/react'

--- a/packages/app/cypress/e2e/cypress-in-cypress-e2e.cy.ts
+++ b/packages/app/cypress/e2e/cypress-in-cypress-e2e.cy.ts
@@ -259,8 +259,8 @@ describe('Cypress In Cypress E2E', { viewportWidth: 1500, defaultCommandTimeout:
      }).invoke('connected').should('be.true')
    })

-    cy.withCtx((ctx, o) => {
-      ctx.actions.file.writeFileInProject(o.path, `
+    cy.withCtx(async (ctx, o) => {
+      await ctx.actions.file.writeFileInProject(o.path, `
 describe('Dom Content', () => {
  it('renders the new test content', () => {
    cy.visit('cypress/e2e/dom-content.html')
--- a/packages/app/cypress/e2e/cypress-in-cypress.cy.ts
+++ b/packages/app/cypress/e2e/cypress-in-cypress.cy.ts
@@ -228,13 +228,13 @@ describe('Cypress in Cypress', { viewportWidth: 1500, defaultCommandTimeout: 100
    startAtSpecsPage('e2e')
    cy.get('[data-cy="spec-item"]')

-    cy.withCtx((ctx, o) => {
+    cy.withCtx(async (ctx, o) => {
      ctx.coreData.app.browserStatus = 'open'

-      let config = ctx.actions.file.readFileInProject('cypress.config.js')
+      let config = await ctx.actions.file.readFileInProject('cypress.config.js')

      config = config.replace(`e2e: {`, `e2e: {\n  chromeWebSecurity: false,\n`)
-      ctx.actions.file.writeFileInProject('cypress.config.js', config)
+      await ctx.actions.file.writeFileInProject('cypress.config.js', config)

      o.sinon.stub(ctx.actions.browser, 'closeBrowser')
      o.sinon.stub(ctx.actions.browser, 'relaunchBrowser')
@@ -252,24 +252,24 @@ describe('Cypress in Cypress', { viewportWidth: 1500, defaultCommandTimeout: 100
  it('restarts browser if there is a before:browser:launch task and there is a change on the config', () => {
    startAtSpecsPage('e2e')

-    cy.withCtx((ctx, o) => {
+    cy.withCtx(async (ctx, o) => {
      ctx.coreData.app.browserStatus = 'open'

-      let config = ctx.actions.file.readFileInProject('cypress.config.js')
+      let config = await ctx.actions.file.readFileInProject('cypress.config.js')

      config = config.replace(`e2e: {`, `e2e: {\n  setupNodeEvents(on) {\n on('before:browser:launch', () => {})\n},\n`)
-      ctx.actions.file.writeFileInProject('cypress.config.js', config)
+      await ctx.actions.file.writeFileInProject('cypress.config.js', config)
    })

    cy.get('[data-cy="spec-item"]')

-    cy.withCtx((ctx, o) => {
+    cy.withCtx(async (ctx, o) => {
      ctx.coreData.app.browserStatus = 'open'

-      let config = ctx.actions.file.readFileInProject('cypress.config.js')
+      let config = await ctx.actions.file.readFileInProject('cypress.config.js')

      config = config.replace(`e2e: {`, `e2e: {\n  viewportHeight: 600,\n`)
-      ctx.actions.file.writeFileInProject('cypress.config.js', config)
+      await ctx.actions.file.writeFileInProject('cypress.config.js', config)

      o.sinon.stub(ctx.actions.browser, 'closeBrowser')
      o.sinon.stub(ctx.actions.browser, 'relaunchBrowser')
@@ -288,14 +288,14 @@ describe('Cypress in Cypress', { viewportWidth: 1500, defaultCommandTimeout: 100
    startAtSpecsPage('e2e')
    cy.get('[data-cy="spec-item"]')

-    cy.withCtx((ctx, o) => {
+    cy.withCtx(async (ctx, o) => {
      ctx.coreData.app.browserStatus = 'open'
      o.sinon.stub(ctx.actions.project, 'initializeActiveProject')

-      let config = ctx.actions.file.readFileInProject('cypress.config.js')
+      let config = await ctx.actions.file.readFileInProject('cypress.config.js')

      config = config.replace(`{`, `{\n  watchForFileChanges: false,\n`)
-      ctx.actions.file.writeFileInProject('cypress.config.js', config)
+      await ctx.actions.file.writeFileInProject('cypress.config.js', config)
    })

    cy.get('[data-cy="loading-spinner"]').should('be.visible')
@@ -310,14 +310,14 @@ describe('Cypress in Cypress', { viewportWidth: 1500, defaultCommandTimeout: 100
    startAtSpecsPage('e2e')
    cy.get('[data-cy="spec-item"]')

-    cy.withCtx((ctx, o) => {
+    cy.withCtx(async (ctx, o) => {
      ctx.coreData.app.browserStatus = 'open'
      o.sinon.stub(ctx.actions.project, 'initializeActiveProject')

-      let config = ctx.actions.file.readFileInProject('cypress.config.js')
+      let config = await ctx.actions.file.readFileInProject('cypress.config.js')

      config = config.replace(`  e2e: {`, `  e2e: {\n  baseUrl: 'https://example.cypress.io',\n`)
-      ctx.actions.file.writeFileInProject('cypress.config.js', config)
+      await ctx.actions.file.writeFileInProject('cypress.config.js', config)
    })

    cy.get('[data-cy="loading-spinner"]').should('be.visible')
--- a/packages/app/cypress/e2e/specs.cy.ts
+++ b/packages/app/cypress/e2e/specs.cy.ts
@@ -423,7 +423,7 @@ describe('App: Specs', () => {

        it('generates spec with file name that does not contain a known spec extension', () => {
          cy.withCtx(async (ctx) => {
-            let config = ctx.actions.file.readFileInProject('cypress.config.js')
+            let config = await ctx.actions.file.readFileInProject('cypress.config.js')

            config = config.replace(
                `specPattern: 'src/**/*.{cy,spec}.{js,jsx}'`,
@@ -700,7 +700,7 @@ describe('App: Specs', () => {

      it('generates spec with file name that does not contain a known spec extension', () => {
        cy.withCtx(async (ctx) => {
-          let config = ctx.actions.file.readFileInProject('cypress.config.js')
+          let config = await ctx.actions.file.readFileInProject('cypress.config.js')

          config = config.replace(
              `specPattern: 'src/specs-folder/*.cy.{js,jsx}'`,
--- a/packages/app/cypress/e2e/subscriptions/configChange-subscription.cy.ts
+++ b/packages/app/cypress/e2e/subscriptions/configChange-subscription.cy.ts
@@ -1,18 +1,18 @@
 function updateProjectIdInCypressConfig (value: string) {
-  return cy.withCtx((ctx, o) => {
-    let config = ctx.actions.file.readFileInProject('cypress.config.js')
+  return cy.withCtx(async (ctx, o) => {
+    let config = await ctx.actions.file.readFileInProject('cypress.config.js')

    config = config.replace(`projectId: 'abc123'`, `projectId: '${o.value}'`)
-    ctx.actions.file.writeFileInProject('cypress.config.js', config)
+    await ctx.actions.file.writeFileInProject('cypress.config.js', config)
  }, { value })
 }

 function updateViewportHeightInCypressConfig (value: number) {
-  return cy.withCtx((ctx, o) => {
-    let config = ctx.actions.file.readFileInProject('cypress.config.js')
+  return cy.withCtx(async (ctx, o) => {
+    let config = await ctx.actions.file.readFileInProject('cypress.config.js')

    config = config.replace(`e2e: {`, `e2e: {\n  viewportHeight: ${o.value},\n`)
-    ctx.actions.file.writeFileInProject('cypress.config.js', config)
+    await ctx.actions.file.writeFileInProject('cypress.config.js', config)
  }, { value })
 }

--- a/packages/app/cypress/e2e/subscriptions/specChange-subscription.cy.ts
+++ b/packages/app/cypress/e2e/subscriptions/specChange-subscription.cy.ts
@@ -18,8 +18,8 @@ describe('specChange subscription', () => {
      .should('contain', 'dom-content.spec.js')
      .should('contain', 'dom-list.spec.js')

-      cy.withCtx((ctx, o) => {
-        ctx.actions.file.writeFileInProject(o.path, '')
+      cy.withCtx(async (ctx, o) => {
+        await ctx.actions.file.writeFileInProject(o.path, '')
      }, { path: getPathForPlatform('cypress/e2e/new-file.spec.js') })

      cy.get('[data-cy="spec-item-link"]')
--- a/packages/data-context/src/actions/FileActions.ts
+++ b/packages/data-context/src/actions/FileActions.ts
@@ -8,29 +8,29 @@ import assert from 'assert'
 export class FileActions {
  constructor (private ctx: DataContext) {}

-  readFileInProject (relativePath: string): string {
+  async readFileInProject (relativePath: string): Promise<string> {
    if (!this.ctx.currentProject) {
      throw new Error(`Cannot write file in project without active project`)
    }

    const filePath = path.join(this.ctx.currentProject, relativePath)

-    this.ctx.fs.ensureDirSync(path.dirname(filePath))
+    await this.ctx.fs.ensureDir(path.dirname(filePath))

-    return this.ctx.fs.readFileSync(filePath, 'utf-8')
+    return this.ctx.fs.readFile(filePath, 'utf-8')
  }

-  writeFileInProject (relativePath: string, data: any) {
+  async writeFileInProject (relativePath: string, data: any) {
    if (!this.ctx.currentProject) {
      throw new Error(`Cannot write file in project without active project`)
    }

    const filePath = path.join(this.ctx.currentProject, relativePath)

-    this.ctx.fs.ensureDirSync(path.dirname(filePath))
+    await this.ctx.fs.ensureDir(path.dirname(filePath))

    // Typically used in e2e tests, simpler than forcing async
-    this.ctx.fs.writeFileSync(
+    await this.ctx.fs.writeFile(
      filePath,
      data,
    )
@@ -42,7 +42,7 @@ export class FileActions {
    }

    // Typically used in e2e tests, simpler than forcing async
-    this.ctx.fs.removeSync(path.join(this.ctx.currentProject, relativePath))
+    await this.ctx.fs.remove(path.join(this.ctx.currentProject, relativePath))
  }

  async moveFileInProject (relativePath: string, toRelativePath: string) {
@@ -51,7 +51,7 @@ export class FileActions {
    }

    // Typically used in e2e tests, simpler than forcing async
-    this.ctx.fs.moveSync(
+    await this.ctx.fs.move(
      path.join(this.ctx.currentProject, relativePath),
      path.join(this.ctx.currentProject, toRelativePath),
    )
--- a/packages/data-context/src/actions/MigrationActions.ts
+++ b/packages/data-context/src/actions/MigrationActions.ts
@@ -166,7 +166,7 @@ export class MigrationActions {
    }

    if (this.ctx.isGlobalMode) {
-      const version = this.locallyInstalledCypressVersion(this.ctx.currentProject)
+      const version = await this.locallyInstalledCypressVersion(this.ctx.currentProject)

      if (!version) {
        // Could not resolve Cypress. Unlikely, but they are using a
@@ -197,12 +197,12 @@ export class MigrationActions {
    })
  }

-  locallyInstalledCypressVersion (currentProject: string) {
+  async locallyInstalledCypressVersion (currentProject: string) {
    try {
      const localCypressPkgJsonPath = require.resolve(path.join('cypress', 'package.json'), {
        paths: [currentProject],
      })
-      const localCypressPkgJson = fs.readJsonSync(path.join(localCypressPkgJsonPath)) as { version: string }
+      const localCypressPkgJson = await fs.readJson(path.join(localCypressPkgJsonPath)) as { version: string }

      return localCypressPkgJson?.version ?? undefined
    } catch (e) {
@@ -365,7 +365,7 @@ export class MigrationActions {
      throw new NonStandardMigrationError('support')
    }

-    this.ctx.fs.renameSync(
+    await this.ctx.fs.rename(
      path.join(this.ctx.currentProject, beforeRelative),
      path.join(this.ctx.currentProject, afterRelative),
    )
--- a/packages/data-context/src/data/ProjectConfigIpc.ts
+++ b/packages/data-context/src/data/ProjectConfigIpc.ts
@@ -246,6 +246,8 @@ export class ProjectConfigIpc extends EventEmitter {
    let isProjectUsingESModules = false

    try {
+      // TODO: convert this to async FS methods
+      // eslint-disable-next-line no-restricted-syntax
      const pkgJson = fs.readJsonSync(path.join(this.projectRoot, 'package.json'))

      isProjectUsingESModules = pkgJson.type === 'module'
--- a/packages/data-context/src/data/ProjectLifecycleManager.ts
+++ b/packages/data-context/src/data/ProjectLifecycleManager.ts
@@ -469,7 +469,7 @@ export class ProjectLifecycleManager {
      // we run the legacy plugins/index.js in a child process
      // and mutate the config based on the return value for migration
      // only used in open mode (cannot migrate via terminal)
-      const legacyConfig = this.ctx.fs.readJsonSync(legacyConfigPath) as LegacyCypressConfigJson
+      const legacyConfig = await this.ctx.fs.readJson(legacyConfigPath) as LegacyCypressConfigJson

      // should never throw, unless there existing pluginsFile errors out,
      // in which case they are attempting to migrate an already broken project.
@@ -619,6 +619,8 @@ export class ProjectLifecycleManager {
    }

    try {
+      // TODO: convert to async FS method
+      // eslint-disable-next-line no-restricted-syntax
      const pkgJson = this.ctx.fs.readJsonSync(this._pathToFile('package.json'))

      if (pkgJson.type === 'module') {
@@ -701,6 +703,8 @@ export class ProjectLifecycleManager {

  private verifyProjectRoot (root: string) {
    try {
+      // TODO: convert to async fs call
+      // eslint-disable-next-line no-restricted-syntax
      if (!fs.statSync(root).isDirectory()) {
        throw new Error('NOT DIRECTORY')
      }
--- a/packages/data-context/src/sources/GitDataSource.ts
+++ b/packages/data-context/src/sources/GitDataSource.ts
@@ -273,7 +273,7 @@ export class GitDataSource {

        let toSet: GitInfo | null = null

-        const stat = fs.statSync(file)
+        const stat = await fs.promises.stat(file)
        const ctime = dayjs(stat.ctime)
        const birthtime = dayjs(stat.birthtime)

--- a/packages/data-context/src/sources/ProjectDataSource.ts
+++ b/packages/data-context/src/sources/ProjectDataSource.ts
@@ -363,6 +363,8 @@ export class ProjectDataSource {
        // chokidar is extremely inconsistent in whether or not it has the stats arg internally
        if (!stats) {
          try {
+            // TODO: find a way to avoid this sync call - might require patching chokidar
+            // eslint-disable-next-line no-restricted-syntax
            stats = fs.statSync(file)
          } catch {
            // If the file/folder is removed do not ignore it, in case it is added
--- a/packages/data-context/src/sources/migration/codegen.ts
+++ b/packages/data-context/src/sources/migration/codegen.ts
@@ -148,11 +148,11 @@ async function getPluginRelativePath (cfg: LegacyCypressConfigJson, projectRoot:
  return cfg.pluginsFile ? cfg.pluginsFile : await tryGetDefaultLegacyPluginsFile(projectRoot)
 }

-function createCypressConfig (config: ConfigOptions, pluginPath: string | undefined, options: CreateConfigOptions): string {
+async function createCypressConfig (config: ConfigOptions, pluginPath: string | undefined, options: CreateConfigOptions): Promise<string> {
  const globalString = Object.keys(config.global).length > 0 ? `${formatObjectForConfig(config.global)},` : ''
  const componentString = options.hasComponentTesting ? createComponentTemplate(config.component) : ''
  const e2eString = options.hasE2ESpec
-    ? createE2ETemplate(pluginPath, options, config.e2e)
+    ? await createE2ETemplate(pluginPath, options, config.e2e)
    : ''

  if (defineConfigAvailable(options.projectRoot)) {
@@ -188,7 +188,7 @@ function formatObjectForConfig (obj: Record<string, unknown>) {
  return JSON.stringify(obj, null, 2).replace(/^[{]|[}]$/g, '') // remove opening and closing {}
 }

-function createE2ETemplate (pluginPath: string | undefined, createConfigOptions: CreateConfigOptions, options: Record<string, unknown>) {
+async function createE2ETemplate (pluginPath: string | undefined, createConfigOptions: CreateConfigOptions, options: Record<string, unknown>) {
  if (createConfigOptions.shouldAddCustomE2ESpecPattern && !options.specPattern) {
    options.specPattern = 'cypress/e2e/**/*.{js,jsx,ts,tsx}'
  }
@@ -201,7 +201,7 @@ function createE2ETemplate (pluginPath: string | undefined, createConfigOptions:
    `
  }

-  const pluginFile = fs.readFileSync(path.join(createConfigOptions.projectRoot, pluginPath), 'utf8')
+  const pluginFile = await fs.readFile(path.join(createConfigOptions.projectRoot, pluginPath), 'utf8')
  let relPluginsPath

  const startsWithDotSlash = new RegExp(/^.\//)
--- a/packages/data-context/test/unit/sources/ProjectDataSource.spec.ts
+++ b/packages/data-context/test/unit/sources/ProjectDataSource.spec.ts
@@ -477,11 +477,13 @@ describe('_makeSpecWatcher', () => {
  const SPEC_FILE_ABC = path.join('cypress', 'e2e', 'some', 'new', 'folder', 'abc.ts')

  const writeFiles = () => {
-    ctx.actions.file.writeFileInProject(SUPPORT_FILE, '// foo')
-    ctx.actions.file.writeFileInProject(SPEC_FILE1, '// foo')
-    ctx.actions.file.writeFileInProject(SPEC_FILE2, '// foo')
-    ctx.actions.file.writeFileInProject(SPEC_FILE3, '// foo')
-    ctx.actions.file.writeFileInProject(SPEC_FILE_ABC, '// foo')
+    return Promise.all([
+      ctx.actions.file.writeFileInProject(SUPPORT_FILE, '// foo'),
+      ctx.actions.file.writeFileInProject(SPEC_FILE1, '// foo'),
+      ctx.actions.file.writeFileInProject(SPEC_FILE2, '// foo'),
+      ctx.actions.file.writeFileInProject(SPEC_FILE3, '// foo'),
+      ctx.actions.file.writeFileInProject(SPEC_FILE_ABC, '// foo'),
+    ])
  }

  it('watch for changes on files based on the specPattern', async function () {
@@ -499,7 +501,7 @@ describe('_makeSpecWatcher', () => {
    specWatcher.on('add', (filePath) => allFiles.add(filePath))
    specWatcher.on('change', (filePath) => allFiles.add(filePath))

-    writeFiles()
+    await writeFiles()

    let attempt = 0

@@ -531,7 +533,7 @@ describe('_makeSpecWatcher', () => {
    specWatcher.on('add', (filePath) => allFiles.add(filePath))
    specWatcher.on('change', (filePath) => allFiles.add(filePath))

-    writeFiles()
+    await writeFiles()

    let attempt = 0

@@ -563,16 +565,11 @@ describe('_makeSpecWatcher', () => {

    specWatcher.on('add', (filePath) => allFiles.add(filePath))
    specWatcher.on('change', (filePath) => allFiles.add(filePath))
+    specWatcher.on('unlink', (filePath) => allFiles.delete(filePath))

-    writeFiles()
-
+    await writeFiles()
    await ctx.actions.file.removeFileInProject(SPEC_FILE1)
-
-    let attempt = 0
-
-    while (allFiles.size < 3 && attempt++ <= 100) {
-      await delay(10)
-    }
+    await delay(1000)

    expect(Array.from(allFiles).sort()).to.eql([
      SPEC_FILE_ABC,
--- a/packages/graphql/src/stitching/remoteSchema.ts
+++ b/packages/graphql/src/stitching/remoteSchema.ts
@@ -21,6 +21,8 @@ extend type Mutation {

 // Get the Remote schema we've sync'ed locally
 export const remoteSchema = buildSchema(
+  // ignoring since this happens on the first tick
+  // eslint-disable-next-line no-restricted-syntax
  fs.readFileSync(path.join(__dirname, '../../schemas', 'cloud.graphql'), 'utf-8') + LOCAL_SCHEMA_EXTENSIONS,
  { assumeValid: true },
 )
--- a/packages/icons/package.json
+++ b/packages/icons/package.json
@@ -6,7 +6,7 @@
  "main": "index.js",
  "scripts": {
    "build-prod": "yarn build",
-    "build": "ts-node ./scripts/build.ts && ts-node ./src/ico.ts",
+    "build": "ts-node ./scripts/build.ts && ts-node ./scripts/ico.ts",
    "test-unit": "NODE_ENV=test mocha -r @packages/ts/register test/*.ts",
    "test": "yarn test-unit"
  },
--- a/packages/icons/scripts/build.ts
+++ b/packages/icons/scripts/build.ts
@@ -7,6 +7,7 @@ async function build () {
  const distPath = path.join(__dirname, '../dist')
  const assetsPath = path.join(__dirname, '../assets')
  const iconsPath = path.join(distPath, 'icons')
+
  const iconsetPath = path.join(distPath, 'cypress.iconset')

  await fs.remove(distPath)
--- a/packages/icons/scripts/ico.ts
+++ b/packages/icons/scripts/ico.ts
--- a/packages/launchpad/cypress/e2e/config-warning.cy.ts
+++ b/packages/launchpad/cypress/e2e/config-warning.cy.ts
@@ -23,8 +23,8 @@ describe('baseUrl', () => {
    cy.get('[data-cy-testingtype="e2e"]').click()
    cy.get('[data-cy="alert"]').contains('Warning: Cannot Connect Base Url Warning')

-    cy.withCtx((ctx) => {
-      ctx.actions.file.writeFileInProject('cypress.config.js', `
+    cy.withCtx(async (ctx) => {
+      await ctx.actions.file.writeFileInProject('cypress.config.js', `
        module.exports = {
          e2e: {
            supportFile: false,
@@ -47,8 +47,8 @@ describe('baseUrl', () => {
    cy.get('h1').should('contain', 'Choose a Browser')
    cy.get('[data-cy="alert"]').should('not.exist')

-    cy.withCtx((ctx) => {
-      ctx.actions.file.writeFileInProject('cypress.config.js', `
+    cy.withCtx(async (ctx) => {
+      await ctx.actions.file.writeFileInProject('cypress.config.js', `
        module.exports = {
          pageLoadTimeout: 10000,
          e2e: {
@@ -86,8 +86,8 @@ describe('experimentalStudio', () => {
    cy.get('[data-cy="warning-alert"]').contains('Warning: Experimental Studio Removed')
    cy.findAllByLabelText(cy.i18n.components.modal.dismiss).first().click()
    cy.get('[data-cy="warning-alert"]').should('not.exist')
-    cy.withCtx((ctx) => {
-      ctx.actions.file.writeFileInProject('cypress.config.js', ctx.actions.file.readFileInProject('cypress.config.js'))
+    cy.withCtx(async (ctx) => {
+      await ctx.actions.file.writeFileInProject('cypress.config.js', await ctx.actions.file.readFileInProject('cypress.config.js'))
    })

    cy.get('[data-cy="loading-spinner"]')
--- a/packages/launchpad/cypress/e2e/error-handling.cy.ts
+++ b/packages/launchpad/cypress/e2e/error-handling.cy.ts
@@ -79,8 +79,8 @@ describe('Error handling', () => {

      cy.contains('Choose a Browser').should('not.exist')

-      cy.withCtx((ctx) => {
-        ctx.actions.file.writeFileInProject('cypress.config.ts', `
+      cy.withCtx(async (ctx) => {
+        await ctx.actions.file.writeFileInProject('cypress.config.ts', `
          import { defineConfig } from 'cypress'
          import { defineConfig as viteConfig } from 'vite'
          export default defineConfig({
--- a/packages/launchpad/cypress/e2e/migration.cy.ts
+++ b/packages/launchpad/cypress/e2e/migration.cy.ts
@@ -109,7 +109,7 @@ describe('global mode', () => {
    cy.visitLaunchpad()

    cy.withCtx((ctx, o) => {
-      o.sinon.stub(ctx.actions.migration, 'locallyInstalledCypressVersion').returns('10.0.0')
+      o.sinon.stub(ctx.actions.migration, 'locallyInstalledCypressVersion').resolves('10.0.0')
    })

    cy.contains('migration-e2e-export-default').click()
--- a/packages/network/lib/client-certificates.ts
+++ b/packages/network/lib/client-certificates.ts
@@ -347,12 +347,16 @@ export function loadClientCertificateConfig (config) {
 function loadBinaryFromFile (filepath: string): Buffer {
  debug(`loadCertificateFile: ${filepath}`)

+  // TODO: update to async
+  // eslint-disable-next-line no-restricted-syntax
  return fs.readFileSync(filepath)
 }

 function loadTextFromFile (filepath: string): string {
  debug(`loadPassphraseFile: ${filepath}`)

+  // TODO: update to async
+  // eslint-disable-next-line no-restricted-syntax
  return fs.readFileSync(filepath, 'utf8').toString()
 }

--- a/packages/scaffold-config/src/frameworks.ts
+++ b/packages/scaffold-config/src/frameworks.ts
@@ -26,6 +26,8 @@ export function inPkgJson (dependency: WizardDependency, projectPath: string): D
    const loc = require.resolve(path.join(dependency.package, 'package.json'), {
      paths: [projectPath],
    })
+    // TODO: convert to async FS method
+    // eslint-disable-next-line no-restricted-syntax
    const pkg = fs.readJsonSync(loc) as PkgJson
    const pkgVersion = semver.coerce(pkg.version)

--- a/packages/server/index.js
+++ b/packages/server/index.js
@@ -1,4 +1,14 @@
-//
+// if running in production mode (CYPRESS_INTERNAL_ENV)
+// all transpile should have been done already
+// and these calls should do nothing
+require('@packages/ts/register')
+
+const { patchFs } = require('./lib/util/patch-fs')
+const fs = require('fs')
+
+// prevent EMFILE errors
+patchFs(fs)
+
 // override tty if we're being forced to
 require('./lib/util/tty').override()

@@ -17,12 +27,6 @@ require('./lib/unhandled_exceptions')

 process.env.UV_THREADPOOL_SIZE = 128

-require('graceful-fs').gracefulify(require('fs'))
-// if running in production mode (CYPRESS_INTERNAL_ENV)
-// all transpile should have been done already
-// and these calls should do nothing
-require('@packages/ts/register')
-
 if (isRunningElectron) {
  require('./lib/util/process_profiler').start()
 }
--- a/packages/server/lib/cache.js
+++ b/packages/server/lib/cache.js
@@ -188,10 +188,4 @@ module.exports = {
  // for testing purposes

  __get: fileUtil.get.bind(fileUtil),
-
-  __removeSync () {
-    fileUtil._cache = {}
-
-    return fs.removeSync(this.path)
-  },
 }
--- a/packages/server/lib/controllers/client.js
+++ b/packages/server/lib/controllers/client.js
@@ -2,7 +2,7 @@ const debug = require('debug')('cypress:server:controllers:client')
 const socketIo = require('@packages/socket')

 // hold onto the client source + version in memory
-const clientSource = socketIo.getClientSource()
+const clientSourcePath = socketIo.getPathToClientSource()
 const clientVersion = socketIo.getClientVersion()

 module.exports = {
@@ -19,6 +19,7 @@ module.exports = {
    .type('application/javascript')
    .set('ETag', clientVersion)
    .status(200)
-    .send(clientSource)
+    // TODO: replace this entire file and sendFile call with `express.static`.
+    .sendFile(clientSourcePath)
  },
 }
--- a/packages/server/lib/project-base.ts
+++ b/packages/server/lib/project-base.ts
@@ -19,7 +19,6 @@ import { SocketCt } from './socket-ct'
 import { SocketE2E } from './socket-e2e'
 import { ensureProp } from './util/class-helpers'

-import { fs } from './util/fs'
 import system from './util/system'
 import type { FoundBrowser, FoundSpec, OpenProjectLaunchOptions, ReceivedCypressOptions, TestingType } from '@packages/types'
 import { DataContext, getCtx } from '@packages/data-context'
@@ -521,10 +520,6 @@ export class ProjectBase<TServer extends Server> extends EE {
    return cfg
  }

-  writeConfigFile ({ code, configFilename }: { code: string, configFilename: string }) {
-    fs.writeFileSync(path.resolve(this.projectRoot, configFilename), code)
-  }
-
  // These methods are not related to start server/sockets/runners

  async getProjectId () {
--- a/packages/server/lib/util/fs.ts
+++ b/packages/server/lib/util/fs.ts
@@ -13,38 +13,4 @@ interface PromisifiedFsExtra {
  pathExistsAsync: Promisified<typeof fsExtra.pathExistsSync>
 }

-// warn users if somehow synchronous file methods are invoked
-// these methods due to "too many files" errors are a huge pain
-const warnOnSyncFileSystem = () => {
-  console.error('WARNING: fs sync methods can fail due to EMFILE errors')
-  console.error('Cypress only works reliably when ALL fs calls are async')
-
-  return console.error('You should modify these sync calls to be async')
-}
-
-const topLines = (from, n, text) => {
-  return text.split('\n').slice(from, n).join('\n')
-}
-
-// just hide this function itself
-// stripping top few lines of the stack
-const getStack = () => {
-  const err = new Error()
-
-  return topLines(3, 10, err.stack)
-}
-
-const addSyncFileSystemWarnings = (fs) => {
-  const oldExistsSync = fs.existsSync
-
-  fs.existsSync = (filename) => {
-    warnOnSyncFileSystem()
-    console.error(getStack())
-
-    return oldExistsSync(filename)
-  }
-}
-
-addSyncFileSystemWarnings(fsExtra)
-
 export const fs = Bluebird.promisifyAll(fsExtra) as PromisifiedFsExtra & typeof fsExtra
--- a/packages/server/lib/util/net_profiler.js
+++ b/packages/server/lib/util/net_profiler.js
@@ -1,3 +1,4 @@
+/* eslint-disable no-restricted-syntax */
 const fs = require('fs')
 const debug = require('debug')('net-profiler')

--- a/packages/server/lib/util/patch-fs.ts
+++ b/packages/server/lib/util/patch-fs.ts
@@ -0,0 +1,7 @@
+import gracefulFs from 'graceful-fs'
+import type fs from 'fs'
+
+export function patchFs (_fs: typeof fs) {
+  // Add gracefulFs for EMFILE queuing.
+  gracefulFs.gracefulify(_fs)
+}
--- a/packages/server/test/integration/cypress_spec.js
+++ b/packages/server/test/integration/cypress_spec.js
@@ -1,4 +1,3 @@
-/* eslint-disable no-restricted-properties */
 require('../spec_helper')
 const _ = require('lodash')
 const path = require('path')
@@ -105,12 +104,12 @@ let ctx
 describe('lib/cypress', () => {
  require('mocha-banner').register()

-  beforeEach(function () {
+  beforeEach(async function () {
    ctx = getCtx()
    process.chdir(previousCwd)
    this.timeout(8000)

-    cache.__removeSync()
+    await cache.remove()

    Fixtures.scaffold()
    this.todosPath = Fixtures.projectPath('todos')
--- a/packages/server/test/unit/fs_spec.js
+++ b/packages/server/test/unit/fs_spec.js
@@ -1,32 +0,0 @@
-require('../spec_helper')
-
-const { fs } = require(`../../lib/util/fs`)
-
-describe('lib/util/fs', () => {
-  beforeEach(() => {
-    return sinon.spy(console, 'error')
-  })
-
-  it('warns when trying to use fs.existsSync', () => {
-    fs.existsSync(__filename)
-    const warning = 'WARNING: fs sync methods can fail due to EMFILE errors'
-
-    expect(console.error).to.be.calledWith(warning)
-  })
-
-  context('fs.pathExists', () => {
-    it('finds this file', () => {
-      return fs.pathExists(__filename)
-      .then((found) => {
-        expect(found).to.be.true
-      })
-    })
-
-    it('does not find non-existent file', () => {
-      return fs.pathExists('does-not-exist')
-      .then((found) => {
-        expect(found).to.be.false
-      })
-    })
-  })
-})
--- a/packages/socket/lib/socket.ts
+++ b/packages/socket/lib/socket.ts
@@ -1,4 +1,3 @@
-import fs from 'fs'
 import buffer from 'buffer'
 import type http from 'http'
 import server, { Server as SocketIOBaseServer, ServerOptions, Socket, Namespace } from 'socket.io'
@@ -40,7 +39,3 @@ export const getPathToClientSource = () => {
 export const getClientVersion = () => {
  return version
 }
-
-export const getClientSource = () => {
-  return fs.readFileSync(getPathToClientSource(), 'utf8')
-}
--- a/packages/socket/test/socket_spec.js
+++ b/packages/socket/test/socket_spec.js
@@ -39,19 +39,6 @@ describe('Socket', function () {
    })
  })

-  context('.getClientSource', function () {
-    it('returns client source as a string', function (done) {
-      const clientPath = path.join(resolvePkg('socket.io-client'), 'dist', 'socket.io.js')
-
-      fs.readFile(clientPath, 'utf8', function (err, str) {
-        if (err) done(err)
-
-        expect(lib.getClientSource()).to.eq(str)
-        done()
-      })
-    })
-  })
-
  context('blob encoding + decoding', () => {
    it('correctly encodes and decodes binary blob data', (done) => {
      const encoder = new parser.Encoder()
--- a/system-tests/projects/read-only-project-root/cypress.config.js
+++ b/system-tests/projects/read-only-project-root/cypress.config.js
@@ -1,4 +1,4 @@
-/* eslint-disable no-restricted-properties */
+/* eslint-disable no-restricted-syntax */
 const fs = require('fs')
 const { expect } = require('chai')