Build: Use globalThis over process.env and enable TS lib checking

.eslintrc.js

@@ -92,6 +92,7 @@ module.exports = {
 	],
 	globals: {
 		wp: 'off',
+		globalThis: 'readonly',
 	},
 	settings: {
 		jsdoc: {
@@ -104,7 +105,7 @@ module.exports = {
 		'jest/expect-expect': 'off',
 		'react/jsx-boolean-value': 'error',
 		'@wordpress/dependency-group': 'error',
-		'@wordpress/is-gutenberg-plugin': 'error',
+		'@wordpress/wp-global-usage': 'error',
 		'@wordpress/react-no-unsafe-timeout': 'error',
 		'@wordpress/i18n-text-domain': [
 			'error',

docs/contributors/code/coding-guidelines.md

@@ -141,9 +141,9 @@ An **plugin-only API** is one which is planned for eventual public availability,
 Plugin-only APIs are excluded from WordPress Core and only available in the Gutenberg Plugin:
 
 ```js
-// Using process.env.IS_GUTENBERG_PLUGIN allows Webpack to exclude this
+// Using globalThis.IS_GUTENBERG_PLUGIN allows Webpack to exclude this
 // export from WordPress core:
-if ( process.env.IS_GUTENBERG_PLUGIN ) {
+if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 	export { doSomethingExciting } from './api';
 }
 ```
@@ -448,8 +448,8 @@ lock( privateApis, { privateEverywhere, privateInCorePublicInPlugin } );
 
 // The privateInCorePublicInPlugin function is explicitly exported,
 // but this export will not be merged into WordPress core thanks to
-// the process.env.IS_GUTENBERG_PLUGIN check.
-if ( process.env.IS_GUTENBERG_PLUGIN ) {
+// the globalThis.IS_GUTENBERG_PLUGIN check.
+if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 	export const privateInCorePublicInPlugin =
 		unlock( privateApis ).privateInCorePublicInPlugin;
 }

docs/how-to-guides/feature-flags.md

@@ -2,9 +2,9 @@
 
 'Feature flags' are variables that allow you to prevent specific code in the Gutenberg project from being shipped to WordPress core, and to run certain experimental features only in the plugin.
 
-## Introducing `process.env.IS_GUTENBERG_PLUGIN`
+## Introducing `globalThis.IS_GUTENBERG_PLUGIN`
 
-The `process.env.IS_GUTENBERG_PLUGIN` is an environment variable whose value 'flags' whether code is running within the Gutenberg plugin. 
+The `globalThis.IS_GUTENBERG_PLUGIN` is an environment variable whose value 'flags' whether code is running within the Gutenberg plugin.
 
 When the codebase is built for the plugin, this variable will be set to `true`. When building for WordPress core, it will be set to `false` or `undefined`.
 
@@ -19,8 +19,9 @@ function myPluginOnlyFeature() {
 	// implementation
 }
 
-export const pluginOnlyFeature =
-	process.env.IS_GUTENBERG_PLUGIN ? myPluginOnlyFeature : undefined;
+export const pluginOnlyFeature = globalThis.IS_GUTENBERG_PLUGIN
+	? myPluginOnlyFeature
+	: undefined;
 ```
 
 In the above example, the `pluginOnlyFeature` export will be `undefined` in non-plugin environments such as WordPress core.
@@ -32,37 +33,39 @@ If you're attempting to import and call a plugin-only feature, be sure to wrap t
 ```js
 import { pluginOnlyFeature } from '@wordpress/foo';
 
-if ( process.env.IS_GUTENBERG_PLUGIN ) {
+if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 	pluginOnlyFeature();
 }
 ```
 
 ## How it works
 
-During the webpack build, instances of `process.env.IS_GUTENBERG_PLUGIN` will be replaced using webpack's [define plugin](https://webpack.js.org/plugins/define-plugin/).
+During the webpack build, instances of `globalThis.IS_GUTENBERG_PLUGIN` will be replaced using webpack's [define plugin](https://webpack.js.org/plugins/define-plugin/).
 
 For example, in the following code –
 
 ```js
-if ( process.env.IS_GUTENBERG_PLUGIN ) {
+if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 	pluginOnlyFeature();
 }
 ```
 
-– the variable `process.env.IS_GUTENBERG_PLUGIN` will be replaced with the boolean `true` during the plugin-only build:
+– the variable `globalThis.IS_GUTENBERG_PLUGIN` will be replaced with the boolean `true` during the plugin-only build:
 
 ```js
-if ( true ) { // Wepack has replaced `process.env.IS_GUTENBERG_PLUGIN` with `true`
+if ( true ) {
+	// Wepack has replaced `globalThis.IS_GUTENBERG_PLUGIN` with `true`
 	pluginOnlyFeature();
 }
 ```
 
 This ensures that code within the body of the `if` statement will always be executed.
 
-In WordPress core, the `process.env.IS_GUTENBERG_PLUGIN` variable is replaced with `undefined`. The built code looks like this:
+In WordPress core, the `globalThis.IS_GUTENBERG_PLUGIN` variable is replaced with `undefined`. The built code looks like this:
 
 ```js
-if ( undefined ) { // Wepack has replaced `process.env.IS_GUTENBERG_PLUGIN` with `undefined`
+if ( undefined ) {
+	// Webpack has replaced `globalThis.IS_GUTENBERG_PLUGIN` with `undefined`
 	pluginOnlyFeature();
 }
 ```
@@ -99,6 +102,6 @@ In this case, the minification process will remove the entire `if` statement inc
 
 ## Frequently asked questions
 
-### Why shouldn't I assign the result of an expression involving `IS_GUTENBERG_PLUGIN` to a variable, e.g. `const isMyFeatureActive = process.env.IS_GUTENBERG_PLUGIN === 2`?
+### Why shouldn't I assign the result of an expression involving `IS_GUTENBERG_PLUGIN` to a variable, e.g. `const isMyFeatureActive = ! Object.is( undefined, globalThis.IS_GUTENBERG_PLUGIN )`?
 
 Introducing complexity may prevent webpack's minifier from identifying and therefore eliminating dead code. Therefore it is recommended to use the examples in this document to ensure your feature flag functions as intended. For further details, see the [Dead Code Elimination](#dead-code-elimination) section.

packages/block-library/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ## 8.35.0 (2024-05-16)
 
 ### Internal
@@ -84,7 +88,7 @@
 
 ### Breaking Changes
 
--   Updated dependencies to require React 18 ([45235](https://github.com/WordPress/gutenberg/pull/45235))
+-   Updated dependencies to require React 18 ([#45235](https://github.com/WordPress/gutenberg/pull/45235))
 
 ## 7.19.0 (2022-11-16)
 

packages/block-library/src/index.js

@@ -314,21 +314,21 @@ export const registerCoreBlocks = (
  * __experimentalRegisterExperimentalCoreBlocks( settings );
  * ```
  */
-export const __experimentalRegisterExperimentalCoreBlocks = process.env
-	.IS_GUTENBERG_PLUGIN
-	? ( { enableFSEBlocks } = {} ) => {
-			const enabledExperiments = [ enableFSEBlocks ? 'fse' : null ];
-			getAllBlocks()
-				.filter( ( { metadata } ) =>
-					isBlockMetadataExperimental( metadata )
-				)
-				.filter(
-					( { metadata: { __experimental } } ) =>
-						__experimental === true ||
-						enabledExperiments.includes( __experimental )
-				)
-				.forEach( ( { init } ) => init() );
-	  }
-	: undefined;
+export const __experimentalRegisterExperimentalCoreBlocks =
+	globalThis.IS_GUTENBERG_PLUGIN
+		? ( { enableFSEBlocks } = {} ) => {
+				const enabledExperiments = [ enableFSEBlocks ? 'fse' : null ];
+				getAllBlocks()
+					.filter( ( { metadata } ) =>
+						isBlockMetadataExperimental( metadata )
+					)
+					.filter(
+						( { metadata: { __experimental } } ) =>
+							__experimental === true ||
+							enabledExperiments.includes( __experimental )
+					)
+					.forEach( ( { init } ) => init() );
+		  }
+		: undefined;
 
 export { privateApis } from './private-apis';

packages/blocks/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ## 12.35.0 (2024-05-16)
 
 ## 12.34.0 (2024-05-02)
@@ -92,7 +96,8 @@
 
 ## 11.17.0 (2022-09-21)
 
-- The block attribute sources `children` and `node` have been deprecated. Please use the `html` source instead. See https://developer.wordpress.org/block-editor/how-to-guides/block-tutorial/introducing-attributes-and-editable-fields/ and the core blocks for examples.
+-   The block attribute sources `children` and `node` have been deprecated. Please use the `html` source instead. See https://developer.wordpress.org/block-editor/how-to-guides/block-tutorial/introducing-attributes-and-editable-fields/ and the core blocks for examples.
+
 ## 11.16.0 (2022-09-13)
 
 ## 11.15.0 (2022-08-24)

packages/blocks/src/api/parser/convert-legacy-block.js

@@ -79,7 +79,7 @@ export function convertLegacyBlockNameAndAttributes( name, attributes ) {
 
 	// The following code is only relevant for the Gutenberg plugin.
 	// It's a stand-alone if statement for dead-code elimination.
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		// Convert pattern overrides added during experimental phase.
 		// Only four blocks were supported initially.
 		// These checks can be removed in WordPress 6.6.

packages/components/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ### Enhancements
 
 -   `ComboboxControl`: Introduce Combobox expandOnFocus prop ([#61705](https://github.com/WordPress/gutenberg/pull/61705)).

packages/components/tsconfig.json

@@ -9,10 +9,7 @@
 			"gutenberg-test-env",
 			"jest",
 			"@testing-library/jest-dom"
-		],
-		// TODO: Remove `skipLibCheck` after resolving duplicate declaration of the `process` variable
-		// between `@types/webpack-env` (from @storybook packages) and `gutenberg-env`.
-		"skipLibCheck": true
+		]
 	},
 	"references": [
 		{ "path": "../a11y" },

packages/core-data/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ## 6.35.0 (2024-05-16)
 
 ## 6.34.0 (2024-05-02)
@@ -97,7 +101,7 @@
 
 ### Breaking Changes
 
-–   Add TypeScript types to the built package (via "types": "build-types" in the package.json)
+– Add TypeScript types to the built package (via "types": "build-types" in the package.json)
 
 ## 4.14.0 (2022-08-24)
 
@@ -132,6 +136,7 @@
 ## 4.3.0 (2022-03-23)
 
 ### New Features
+
 -   The saveEntityRecord, saveEditedEntityRecord, and deleteEntityRecord actions now accept an optional throwOnError option (defaults to false). When set to true, any exceptions occurring when the action was executing are re-thrown, causing dispatch().saveEntityRecord() to reject with an error. ([#39258](https://github.com/WordPress/gutenberg/pull/39258))
 -   Added support for fetching block patterns and their categories, with the `getBlockPatterns` and `getBlockPatternCategories` selectors.
 

packages/core-data/src/actions.js

@@ -396,7 +396,7 @@ export const editEntityRecord =
 			}, {} ),
 		};
 		if ( window.__experimentalEnableSync && entityConfig.syncConfig ) {
-			if ( process.env.IS_GUTENBERG_PLUGIN ) {
+			if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 				const objectId = entityConfig.getSyncObjectId( recordId );
 				getSyncProvider().update(
 					entityConfig.syncObjectType + '--edit',

packages/core-data/src/entities.js

@@ -485,7 +485,7 @@ export const getOrLoadEntitiesConfig =
 
 		if ( configs?.length > 0 && hasConfig ) {
 			if ( window.__experimentalEnableSync ) {
-				if ( process.env.IS_GUTENBERG_PLUGIN ) {
+				if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 					registerSyncConfigs( configs );
 				}
 			}
@@ -506,7 +506,7 @@ export const getOrLoadEntitiesConfig =
 
 		configs = await loader.loadEntities();
 		if ( window.__experimentalEnableSync ) {
-			if ( process.env.IS_GUTENBERG_PLUGIN ) {
+			if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 				registerSyncConfigs( configs );
 			}
 		}

packages/core-data/src/resolvers.js

@@ -81,7 +81,7 @@ export const getEntityRecord =
 				entityConfig.syncConfig &&
 				! query
 			) {
-				if ( process.env.IS_GUTENBERG_PLUGIN ) {
+				if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 					const objectId = entityConfig.getSyncObjectId( key );
 
 					// Loads the persisted document.

packages/customize-widgets/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ## 4.35.0 (2024-05-16)
 
 ## 4.34.0 (2024-05-02)

packages/customize-widgets/src/index.js

@@ -61,7 +61,7 @@ export function initialize( editorName, blockEditorSettings ) {
 	} );
 	registerCoreBlocks( coreBlocks );
 	registerLegacyWidgetBlock();
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		__experimentalRegisterExperimentalCoreBlocks( {
 			enableFSEBlocks: ENABLE_EXPERIMENTAL_FSE_BLOCKS,
 		} );

packages/dataviews/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ## 1.2.0 (2024-05-16)
 
 ### Internal

packages/dataviews/tsconfig.json

@@ -4,7 +4,6 @@
 	"compilerOptions": {
 		"rootDir": "src",
 		"declarationDir": "build-types",
-		"skipLibCheck": true,
 		"checkJs": false
 	},
 	"references": [

packages/e2e-tests/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ## 7.29.0 (2024-05-16)
 
 ## 7.28.0 (2024-05-02)
@@ -64,7 +68,7 @@
 
 ### Breaking Changes
 
--  Started requiring Jest v29 instead of v27 as a peer dependency. See [breaking changes in Jest 28](https://jestjs.io/blog/2022/04/25/jest-28) and [in jest 29](https://jestjs.io/blog/2022/08/25/jest-29) ([#47388](https://github.com/WordPress/gutenberg/pull/47388))
+-   Started requiring Jest v29 instead of v27 as a peer dependency. See [breaking changes in Jest 28](https://jestjs.io/blog/2022/04/25/jest-28) and [in jest 29](https://jestjs.io/blog/2022/08/25/jest-29) ([#47388](https://github.com/WordPress/gutenberg/pull/47388))
 
 ## 6.5.0 (2023-03-01)
 

packages/e2e-tests/config/is-gutenberg-plugin.js

@@ -1,6 +1,3 @@
-global.process.env = {
-	...global.process.env,
-	// Inject the `IS_GUTENBERG_PLUGIN` global, used for feature flagging.
-	// eslint-disable-next-line @wordpress/is-gutenberg-plugin
-	IS_GUTENBERG_PLUGIN: process.env.npm_package_config_IS_GUTENBERG_PLUGIN,
-};
+// eslint-disable-next-line @wordpress/wp-global-usage
+globalThis.IS_GUTENBERG_PLUGIN =
+	process.env.npm_package_config_IS_GUTENBERG_PLUGIN === 'true';

packages/edit-post/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Variables like `process.env.IS_GUTENBERG_PLUGIN` have been replaced by `globalThis.IS_GUTENBERG_PLUGIN`. Build systems using `process.env` should be updated ([#61486](https://github.com/WordPress/gutenberg/pull/61486)).
+
 ## 7.35.0 (2024-05-16)
 
 ### Internal

packages/edit-post/src/components/visual-editor/index.js

@@ -24,7 +24,7 @@ import { usePaddingAppender } from './use-padding-appender';
 
 const { EditorCanvas } = unlock( editorPrivateApis );
 
-const isGutenbergPlugin = process.env.IS_GUTENBERG_PLUGIN ? true : false;
+const isGutenbergPlugin = globalThis.IS_GUTENBERG_PLUGIN ? true : false;
 
 export default function VisualEditor( { styles } ) {
 	const {

packages/edit-post/src/index.js

@@ -80,7 +80,7 @@ export function initializeEditor(
 	registerCoreBlocks();
 	registerLegacyWidgetBlock( { inserter: false } );
 	registerWidgetGroupBlock( { inserter: false } );
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		__experimentalRegisterExperimentalCoreBlocks( {
 			enableFSEBlocks: settings.__unstableEnableFullSiteEditingBlocks,
 		} );