enable justInTimeCompile by default [run ci]

cli/CHANGELOG.md

@@ -15,6 +15,9 @@ _Released 12/3/2024 (PENDING)_
 - The undocumented methods `Cypress.backend('firefox:force:gc')` and `Cypress.backend('log:memory:pressure')` were removed. Addresses [#30222](https://github.com/cypress-io/cypress/issues/30222).
 - Upgraded bundled Node.js version from `18.17.0` to `20.18.0`. Addresses [#29547](https://github.com/cypress-io/cypress/issues/29547).
 - It is no longer possible to make a `fetch` or `XMLHttpRequest` request from the `about:blank` page in Electron (i.e. `cy.window().then((win) => win.fetch('<some-url>')`). You must use `cy.request` instead or perform some form of initial navigation via `cy.visit()`. Addressed in [#29547](https://github.com/cypress-io/cypress/pull/30394).
+- The
+  `experimentalJustInTimeCompile`
+  configuration option for component testing has been replaced with a `justInTimeCompile` option that is `true` by default. This option will only compile resources directly related to your spec, compiling them 'just-in-time' before spec execution. This should result in improved memory management and performance for component tests in `cypress open` and `cypress run` modes, in particular for large component testing suites. `justInTimeCompile` is now only supported for [`webpack`](https://www.npmjs.com/package/webpack). Addresses [#30234](https://github.com/cypress-io/cypress/issues/30234). Addressed in [#30402](https://github.com/cypress-io/cypress/pull/30402).
 - `@cypress/webpack-dev-server` no longer supports `webpack-dev-server` version 3. Additionally, `@cypress/webpack-dev-server` now ships with `webpack-dev-server` version 5 by default. `webpack-dev-server` version 4 will need to be installed along side Cypress if you are still using `webpack` version 4. Addresses [#29308](https://github.com/cypress-io/cypress/issues/29308), [#30347](https://github.com/cypress-io/cypress/issues/30347), and [#30141](https://github.com/cypress-io/cypress/issues/30141).
 - `@cypress/vite-dev-server` no longer supports `vite` versions 2 and 3. Addresses [#29377](https://github.com/cypress-io/cypress/issues/29377) and [#29378](https://github.com/cypress-io/cypress/issues/29378).
 - Cypress Component Testing no longer supports `React` versions 16 and 17. Addresses [#29607](https://github.com/cypress-io/cypress/issues/29607).

packages/config/__snapshots__/index.spec.ts.js

@@ -48,7 +48,7 @@ exports['config/src/index .getDefaultValues returns list of public config keys 1
   'fixturesFolder': 'cypress/fixtures',
   'excludeSpecPattern': '*.hot-update.js',
   'includeShadowDom': false,
-  'justInTimeCompile': false,
+  'justInTimeCompile': true,
   'keystrokeDelay': 0,
   'modifyObstructiveCode': true,
   'numTestsKeptInMemory': 50,
@@ -138,7 +138,7 @@ exports['config/src/index .getDefaultValues returns list of public config keys f
   'fixturesFolder': 'cypress/fixtures',
   'excludeSpecPattern': '*.hot-update.js',
   'includeShadowDom': false,
-  'justInTimeCompile': false,
+  'justInTimeCompile': true,
   'keystrokeDelay': 0,
   'modifyObstructiveCode': true,
   'numTestsKeptInMemory': 50,

packages/config/src/options.ts

@@ -233,7 +233,7 @@ const driverConfigOptions: Array<DriverConfigOption> = [
     requireRestartOnChange: 'server',
   }, {
     name: 'justInTimeCompile',
-    defaultValue: false,
+    defaultValue: true,
     validation: validate.isBoolean,
     requireRestartOnChange: 'server',
   }, {

packages/config/test/project/utils.spec.ts

@@ -1084,7 +1084,7 @@ describe('config/src/project/utils', () => {
             fixturesFolder: { value: 'cypress/fixtures', from: 'default' },
             hosts: { value: null, from: 'default' },
             includeShadowDom: { value: false, from: 'default' },
-            justInTimeCompile: { value: false, from: 'default' },
+            justInTimeCompile: { value: true, from: 'default' },
             isInteractive: { value: true, from: 'default' },
             keystrokeDelay: { value: 0, from: 'default' },
             modifyObstructiveCode: { value: true, from: 'default' },
@@ -1202,7 +1202,7 @@ describe('config/src/project/utils', () => {
             fixturesFolder: { value: 'cypress/fixtures', from: 'default' },
             hosts: { value: null, from: 'default' },
             includeShadowDom: { value: false, from: 'default' },
-            justInTimeCompile: { value: false, from: 'default' },
+            justInTimeCompile: { value: true, from: 'default' },
             isInteractive: { value: true, from: 'default' },
             keystrokeDelay: { value: 0, from: 'default' },
             modifyObstructiveCode: { value: true, from: 'default' },

packages/errors/src/errors.ts

@@ -1242,7 +1242,7 @@ export const AllCypressErrors = {
   EXPERIMENTAL_JIT_COMPILE_REMOVED: () => {
     return errTemplate`\
         The ${fmt.highlight(`experimentalJustInTimeCompile`)} configuration option was removed in ${fmt.cypressVersion(`14.0.0`)}.
-        A new ${fmt.highlightSecondary(`justInTimeCompile`)} configuration option is available and is now ${fmt.highlightSecondary(`false`)} by default.
+        A new ${fmt.highlightSecondary(`justInTimeCompile`)} configuration option is available and is now ${fmt.highlightSecondary(`true`)} by default.
         You can safely remove this option from your config.`
   },
   // TODO: verify configFile is absolute path

system-tests/__snapshots__/results_spec.ts.js

@@ -26,7 +26,7 @@ exports['module api and after:run results'] = `
     "experimentalMemoryManagement": false,
     "experimentalModifyObstructiveThirdPartyCode": false,
     "experimentalSkipDomainInjection": null,
-    "justInTimeCompile": false,
+    "justInTimeCompile": true,
     "experimentalOriginDependencies": false,
     "experimentalSourceRewriting": false,
     "experimentalSingleTabRunMode": false,