Avoid calling PHP directly in build process

package.json

@@ -66,6 +66,7 @@
 		"grunt-webpack": "7.0.1",
 		"install-changed": "1.1.0",
 		"json2php": "0.0.12",
+		"php-array-reader": "2.1.3",
 		"postcss": "8.5.8",
 		"prettier": "npm:wp-prettier@3.0.3",
 		"qunit": "~2.25.0",

tools/gutenberg/copy.js

@@ -9,10 +9,10 @@
  * @package WordPress
  */
 
-const child_process = require( 'child_process' );
 const fs = require( 'fs' );
 const path = require( 'path' );
 const json2php = require( 'json2php' );
+const { fromString } = require( 'php-array-reader' );
 
 // Paths.
 const rootDir = path.resolve( __dirname, '../..' );
@@ -78,36 +78,14 @@ const COPY_CONFIG = {
  * Given a path to a PHP file which returns a single value, converts that
  * value into a native JavaScript value (limited by JSON serialization).
  *
- * @throws Error when PHP source file unable to be read, or PHP is unavailable.
+ * @throws Error when PHP source file unable to be read or parsed.
  *
  * @param {string} phpFilepath Absolute path of PHP file returning a single value.
  * @return {Object|Array} JavaScript representation of value from input file.
  */
 function readReturnedValueFromPHPFile( phpFilepath ) {
-	const results = child_process.spawnSync(
-		'php',
-		[ '-r', '$path = file_get_contents( "php://stdin" ); if ( ! is_file( $path ) ) { die( 1 ); } try { $data = require $path; } catch ( \\Throwable $e ) { die( 2 ); } $json = json_encode( $data ); if ( ! is_string( $json ) ) { die( 3 ); } echo $json;' ],
-		{
-			encoding: 'utf8',
-			input: phpFilepath,
-		}
-	);
-
-	switch ( results.status ) {
-		case 0:
-			return JSON.parse( results.stdout );
-
-		case 1:
-			throw new Error( `Could not read PHP source file: '${ phpFilepath }'` );
-
-		case 2:
-			throw new Error( `PHP source file did not return value when imported: '${ phpFilepath }'` );
-
-		case 3:
-			throw new Error( `Could not serialize PHP source value into JSON: '${ phpFilepath }'` );
-	}
-
-	throw new Error( `Unknown error while reading PHP source file: '${ phpFilepath }'` );
+	const content = fs.readFileSync( phpFilepath, 'utf8' );
+	return fromString( content );
 }
 
 /**