Apply browser-targeted WordPress patches via Blueprints, not in remote.html.

Enables patching arbitrary WordPress bundles for compatibility with web
browsers. Without this PR, remote.html applies these patch right after
the WordPress module is loaded into the /wordpress VFS directory.
However, in #700 we want to enable using an arbitrary WordPress build
from any PR in wordpress-develop. We must, thus, expose a way of
applying the necessary patches.

Testing instructions

1. Start Playground, log out
2. Go to /wp-login.php
3. Confirm there's a message explaining what login credentials to use

Author: adamziel

packages/playground/blueprints/src/lib/steps/apply-wordpress-patches/index.ts

@@ -3,6 +3,19 @@ import { StepHandler } from '..';
 import { updateFile } from '../common';
 import { defineWpConfigConsts } from '../define-wp-config-consts';
 
+/** @ts-ignore */
+import transportFetch from './wp-content/mu-plugins/includes/requests_transport_fetch.php?raw';
+/** @ts-ignore */
+import transportDummy from './wp-content/mu-plugins/includes/requests_transport_dummy.php?raw';
+/** @ts-ignore */
+import addRequests from './wp-content/mu-plugins/add_requests_transport.php?raw';
+/** @ts-ignore */
+import showAdminCredentialsOnWpLogin from './wp-content/mu-plugins/1-show-admin-credentials-on-wp-login.php?raw';
+/** @ts-ignore */
+import niceErrorMessagesForPluginsAndThemesDirectories from './wp-content/mu-plugins/2-nice-error-messages-for-plugins-and-themes-directories.php?raw';
+/** @ts-ignore */
+import linksTargetingTopFrameShouldTargetPlaygroundIframe from './wp-content/mu-plugins/3-links-targeting-top-frame-should-target-playground-iframe.php?raw';
+
 /**
  * @private
  */
@@ -15,6 +28,7 @@ export interface ApplyWordPressPatchesStep {
 	disableSiteHealth?: boolean;
 	disableWpNewBlogNotification?: boolean;
 	makeEditorFrameControlled?: boolean;
+	prepareForRunningInsideWebBrowser?: boolean;
 }
 
 export const applyWordPressPatches: StepHandler<
@@ -47,6 +61,9 @@ export const applyWordPressPatches: StepHandler<
 			`${patch.wordpressPath}/wp-includes/js/dist/block-editor.min.js`,
 		]);
 	}
+	if (options.prepareForRunningInsideWebBrowser === true) {
+		await patch.prepareForRunningInsideWebBrowser();
+	}
 };
 
 class WordPressPatcher {
@@ -120,6 +137,63 @@ class WordPressPatcher {
 				`${contents} function wp_new_blog_notification(...$args){} `
 		);
 	}
+
+	async prepareForRunningInsideWebBrowser() {
+		await updateFile(
+			this.php,
+			`${this.wordpressPath}/wp-config.php`,
+			(contents) => `${contents} define('USE_FETCH_FOR_REQUESTS', false);`
+		);
+
+		// Force the fsockopen and cUrl transports to report they don't work:
+		const transports = [
+			`${this.wordpressPath}/wp-includes/Requests/Transport/fsockopen.php`,
+			`${this.wordpressPath}/wp-includes/Requests/Transport/cURL.php`,
+		];
+		for (const transport of transports) {
+			// One of the transports might not exist in the latest WordPress version.
+			if (!(await this.php.fileExists(transport))) {
+				continue;
+			}
+			await updateFile(this.php, transport, (contents) =>
+				contents.replace(
+					'public static function test',
+					'public static function test( $capabilities = array() ) { return false; } public static function test2'
+				)
+			);
+		}
+
+		// Add fetch and dummy transports for HTTP requests
+		await this.php.mkdirTree(
+			`${this.wordpressPath}/wp-content/mu-plugins/includes`
+		);
+		await this.php.writeFile(
+			`${this.wordpressPath}/wp-content/mu-plugins/includes/requests_transport_fetch.php`,
+			transportFetch
+		);
+		await this.php.writeFile(
+			`${this.wordpressPath}/wp-content/mu-plugins/includes/requests_transport_dummy.php`,
+			transportDummy
+		);
+		await this.php.writeFile(
+			`${this.wordpressPath}/wp-content/mu-plugins/add_requests_transport.php`,
+			addRequests
+		);
+
+		// Various tweaks
+		await this.php.writeFile(
+			`${this.wordpressPath}/wp-content/mu-plugins/1-show-admin-credentials-on-wp-login.php`,
+			showAdminCredentialsOnWpLogin
+		);
+		await this.php.writeFile(
+			`${this.wordpressPath}/wp-content/mu-plugins/2-nice-error-messages-for-plugins-and-themes-directories.php`,
+			niceErrorMessagesForPluginsAndThemesDirectories
+		);
+		await this.php.writeFile(
+			`${this.wordpressPath}/wp-content/mu-plugins/3-links-targeting-top-frame-should-target-playground-iframe.php`,
+			linksTargetingTopFrameShouldTargetPlaygroundIframe
+		);
+	}
 }
 
 function randomString(length: number) {

packages/playground/compile-wordpress/Dockerfile

@@ -62,7 +62,7 @@ RUN cd wordpress && \
     -o -name '*.ttf' -o -name '*.txt' -o -name '*.woff' \
     -o -name '*.woff2' -o -name '*.jpeg' -o -name '*.jpg' \
     \) \
-    # Preserve the wp-admin SVG files that are read by PHP
+    # Preserve the wp-admin SVG files that are read  by PHP
     -not -path '*/wp-admin/images/*.svg' \
     -delete