Add PHP script to resolve minor and patch WP version

Author: thelovekesh

utils/wp-version-resolver.php

@@ -0,0 +1,71 @@
+<?php
+/**
+ * Resolve the WP version to use for the tests.
+ */
+
+use Composer\Semver\Semver;
+
+const WP_VERSIONS_JSON_FILE = '/wp-cli-tests-wp-versions.json';
+const WP_VERSIONS_JSON_URL  = 'https://raw.githubusercontent.com/wp-cli/wp-cli-tests/artifacts/wp-versions.json';
+
+$wp_version_env        = getenv( 'WP_VERSION' );
+$wp_versions_file_path = sys_get_temp_dir() . WP_VERSIONS_JSON_FILE;
+
+if ( ! file_exists( $wp_versions_file_path ) ) {
+	$ch = curl_init( WP_VERSIONS_JSON_URL );
+	$fp = fopen( $wp_versions_file_path, 'w' );
+
+	curl_setopt( $ch, CURLOPT_FILE, $fp );
+	curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
+
+	curl_exec( $ch );
+	curl_close( $ch );
+	fclose( $fp );
+}
+
+$wp_versions_json = json_decode( file_get_contents( sys_get_temp_dir() . WP_VERSIONS_JSON_FILE ), true );
+
+if ( empty( $wp_version_env ) ) {
+	echo $wp_version_env;
+	exit( 0 );
+}
+
+if ( empty( $wp_version_env ) || 'latest' === $wp_version_env ) {
+	$wp_version = array_search( 'latest', $wp_versions_json, true );
+
+	if ( empty( $wp_version ) ) {
+		$wp_version = $wp_version_env;
+	}
+
+	echo $wp_version;
+	exit( 0 );
+}
+
+$wp_version    = '';
+$constraint    = '';
+$wp_versions   = array_keys( $wp_versions_json );
+$version_count = count( explode( '.', $wp_version_env ) );
+
+if ( 1 === $version_count ) {
+	$constraint = ">=$wp_version_env"; // Get the latest minor version.
+} elseif ( 2 === $version_count ) {
+	$constraint = "~$wp_version_env.0"; // Get the latest patch version.
+} elseif ( 3 === $version_count ) {
+	$constraint = "=$wp_version_env"; // Get the exact version.
+} else {
+	$constraint = $wp_version_env;
+}
+
+if ( ! class_exists( 'Composer\Semver\Semver' ) ) {
+	require_once __DIR__ . '/../vendor/autoload.php';
+}
+
+try {
+	$wp_satisfied_versions = Semver::satisfiedBy( $wp_versions, $constraint );
+} catch ( Exception $e ) {
+	echo $wp_version_env;
+	exit( 0 );
+}
+
+$wp_version = end( $wp_satisfied_versions );
+echo $wp_version ? : $wp_version_env;