allow single-item arrays as a format (#2324)

Author: davidjgoss

CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 Please see [CONTRIBUTING.md](./CONTRIBUTING.md) on how to contribute to Cucumber.
 
 ## [Unreleased]
+### Fixed
+- Allow single-item arrays as a format ([#2324](https://github.com/cucumber/cucumber-js/pull/2324))
 
 ## [9.5.0] - 2023-09-03
 ### Added

src/api/convert_configuration_spec.ts

@@ -39,14 +39,39 @@ describe('convertConfiguration', () => {
     })
   })
 
-  it('should map multiple formatters with string and array notations', async () => {
+  it('should map multiple formatters with string notation', async () => {
     const result = await convertConfiguration(
       {
         ...DEFAULT_CONFIGURATION,
         format: [
           'summary',
           'message',
           'json:./report.json',
+          'html:./report.html',
+        ],
+      },
+      {}
+    )
+
+    expect(result.formats).to.eql({
+      stdout: 'message',
+      files: {
+        './report.html': 'html',
+        './report.json': 'json',
+      },
+      publish: false,
+      options: {},
+    })
+  })
+
+  it('should map multiple formatters with array notation', async () => {
+    const result = await convertConfiguration(
+      {
+        ...DEFAULT_CONFIGURATION,
+        format: [
+          ['summary'],
+          ['message'],
+          ['json', './report.json'],
           ['html', './report.html'],
         ],
       },

src/configuration/types.ts

@@ -1,7 +1,7 @@
 import { FormatOptions } from '../formatter'
 import { PickleOrder } from '../models/pickle_order'
 
-type FormatsConfiguration = Array<string | [string, string]>
+type FormatsConfiguration = Array<string | [string, string?]>
 
 export interface IConfiguration {
   backtrace: boolean