Blocks: Display browser console warnings for blocks with apiVersion below 2

docs/reference-guides/block-api/block-api-versions.md

@@ -4,6 +4,7 @@ This document lists the changes made between the different API versions.
 
 ## Version 3 (>= WordPress 6.3)
 - The post editor will be iframed if all registered blocks have a Block API version 3 or higher. Adding version 3 support means that the block should work inside an iframe, though the block may still be rendered outside the iframe if not all blocks support version 3.
+- See [this article](https://make.wordpress.org/core/2021/06/29/blocks-in-an-iframed-template-editor/) for a migration guide to bump the API version to 3 and make them work in an iframe editor.
 
 ## Version 2 (>= WordPress 5.6)
 

packages/blocks/src/store/process-block-type.js

@@ -110,6 +110,14 @@ export const processBlockType =
 			null
 		);
 
+		if ( settings.apiVersion <= 2 ) {
+			warning(
+				`The block "${ name }" is registered with API version 2 or lower. This means that the post editor may work as a non-iframe editor.\n` +
+					`Since all editors are planned to work as iframes in the future, set the \`apiVersion\` field to 3 and test the block inside the iframe editor.\n` +
+					`See: https://developer.wordpress.org/block-editor/reference-guides/block-api/block-api-versions/#version-3-wordpress-6-3`
+			);
+		}
+
 		if (
 			settings.description &&
 			typeof settings.description !== 'string'

test/unit/config/suppress-browser-warnings.js

@@ -0,0 +1,34 @@
+/**
+ * Suppress specific browser warnings for unit tests
+ *
+ * This file mocks the @wordpress/warning module to suppress specific
+ * warnings that are expected or not relevant in the test environment,
+ * while allowing other warnings to pass through normally.
+ *
+ * Note: This mock can be removed once the apiVersion:3 becomes the default.
+ */
+
+jest.mock( '@wordpress/warning', () => {
+	const mockOriginalWarning =
+		jest.requireActual( '@wordpress/warning' ).default;
+
+	return {
+		__esModule: true,
+		default: jest.fn( ( message ) => {
+			const suppressedWarningRegexes = [
+				/The block ".*" is registered with API version 2 or lower/, // apiVersion warnings
+			];
+			if ( typeof message === 'string' ) {
+				const shouldSuppress = suppressedWarningRegexes.some(
+					( regex ) => regex.test( message )
+				);
+				if ( shouldSuppress ) {
+					return;
+				}
+			}
+			if ( typeof mockOriginalWarning === 'function' ) {
+				mockOriginalWarning( message );
+			}
+		} ),
+	};
+} );

test/unit/jest.config.js

@@ -22,6 +22,7 @@ module.exports = {
 	setupFiles: [
 		'<rootDir>/test/unit/config/global-mocks.js',
 		'<rootDir>/test/unit/config/gutenberg-env.js',
+		'<rootDir>/test/unit/config/suppress-browser-warnings.js',
 	],
 	setupFilesAfterEnv: [
 		'<rootDir>/test/unit/config/testing-library.js',