[Fix] Revert breaking group change in order

CHANGELOG.md

@@ -6,6 +6,9 @@ This change log adheres to standards from [Keep a CHANGELOG](https://keepachange
 
 ## [Unreleased]
 
+### Fixed
+- [`order`]: revert breaking change to single nested group ([#2854], thanks [@yndajas])
+
 ### Changed
 - [Docs] remove duplicate fixable notices in docs ([#2850], thanks [@bmish])
 
@@ -1082,6 +1085,7 @@ for info on changes for earlier releases.
 
 [`memo-parser`]: ./memo-parser/README.md
 
+[#2854]: https://github.com/import-js/eslint-plugin-import/pull/2854
 [#2850]: https://github.com/import-js/eslint-plugin-import/pull/2850
 [#2842]: https://github.com/import-js/eslint-plugin-import/pull/2842
 [#2835]: https://github.com/import-js/eslint-plugin-import/pull/2835
@@ -1887,5 +1891,6 @@ for info on changes for earlier releases.
 [@wtgtybhertgeghgtwtg]: https://github.com/wtgtybhertgeghgtwtg
 [@xM8WVqaG]: https://github.com/xM8WVqaG
 [@xpl]: https://github.com/xpl
+[@yndajas]: https://github.com/yndajas
 [@yordis]: https://github.com/yordis
 [@zloirock]: https://github.com/zloirock

src/rules/order.js

@@ -422,10 +422,6 @@ const types = ['builtin', 'external', 'internal', 'unknown', 'parent', 'sibling'
 // Example: { index: 0, sibling: 1, parent: 1, external: 1, builtin: 2, internal: 2 }
 // Will throw an error if it contains a type that does not exist, or has a duplicate
 function convertGroupsToRanks(groups) {
-  if (groups.length === 1) {
-    // TODO: remove this `if` and fix the bug
-    return convertGroupsToRanks(groups[0]);
-  }
   const rankObject = groups.reduce(function (res, group, index) {
     [].concat(group).forEach(function (groupItem) {
       if (types.indexOf(groupItem) === -1) {

tests/src/rules/order.js

@@ -2753,7 +2753,7 @@ context('TypeScript', function () {
       };
 
       ruleTester.run('order', rule, {
-        valid: [
+        valid: [].concat(
           // #1667: typescript type import support
 
           // Option alphabetize: {order: 'asc'}
@@ -2962,7 +2962,31 @@ context('TypeScript', function () {
               },
             ],
           }),
-        ],
+          isCoreModule('node:child_process') && isCoreModule('node:fs/promises') ? [
+            test({
+              code: `
+                import express from 'express';
+                import log4js from 'log4js';
+                import chpro from 'node:child_process';
+                // import fsp from 'node:fs/promises';
+              `,
+              options: [{
+                groups: [
+                  [
+                    'builtin',
+                    'external',
+                    'internal',
+                    'parent',
+                    'sibling',
+                    'index',
+                    'object',
+                    'type',
+                  ],
+                ],
+              }],
+            }),
+          ] : [],
+        ),
         invalid: [].concat(
           // Option alphabetize: {order: 'asc'}
           test({
@@ -3218,39 +3242,6 @@ context('TypeScript', function () {
                 // { message: '`node:fs/promises` import should occur before import of `express`' },
               ],
             }),
-
-            test({
-              code: `
-                import express from 'express';
-                import log4js from 'log4js';
-                import chpro from 'node:child_process';
-                // import fsp from 'node:fs/promises';
-              `,
-              output: `
-                import chpro from 'node:child_process';
-                import express from 'express';
-                import log4js from 'log4js';
-                // import fsp from 'node:fs/promises';
-              `,
-              options: [{
-                groups: [
-                  [
-                    'builtin',
-                    'external',
-                    'internal',
-                    'parent',
-                    'sibling',
-                    'index',
-                    'object',
-                    'type',
-                  ],
-                ],
-              }],
-              errors: [
-                { message: '`node:child_process` import should occur before import of `express`' },
-                // { message: '`node:fs/promises` import should occur before import of `express`' },
-              ],
-            }),
           ] : [],
         ),
       });