support YAML for config files

CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 Please see [CONTRIBUTING.md](https://github.com/cucumber/cucumber/blob/master/CONTRIBUTING.md) on how to contribute to Cucumber.
 
 ## [Unreleased]
+### Added
+- Add support for YAML as a configuration file format ([#2199](https://github.com/cucumber/cucumber-js/pull/2199))
 
 ## [8.9.1] - 2022-12-16
 ### Fixed

docs/configuration.md

@@ -12,6 +12,8 @@ You can keep your configuration in a file. Cucumber will look for one of these f
 - `cucumber.cjs`
 - `cucumber.mjs`
 - `cucumber.json`
+- `cucumber.yaml`
+- `cucumber.yml`
 
 You can also put your file somewhere else and tell Cucumber via the `--config` CLI option:
 
@@ -45,11 +47,20 @@ And the same in JSON format:
 {
   "default": {
     "parallel": 2,
-      "format": ["html:cucumber-report.html"]
+    "format": ["html:cucumber-report.html"]
   }
 }
 ```
 
+And the same in YAML format:
+
+```yaml
+default:
+  parallel: 2
+  format:
+    - "html:cucumber-report.html"
+```
+
 Cucumber also supports the configuration being a string of options in the style of the CLI, though this isn't recommended:
 
 ```js

features/profiles.feature

@@ -117,3 +117,19 @@ Feature: default command line arguments
       1 step (1 skipped)
       <duration-stat>
       """
+
+  Scenario: using a YAML file
+    Given a file named ".cucumber-rc.yaml" with:
+      """
+      default:
+        dryRun: true
+      """
+    When I run cucumber-js with `--config .cucumber-rc.yaml`
+    Then it outputs the text:
+      """
+      -
+
+      1 scenario (1 skipped)
+      1 step (1 skipped)
+      <duration-stat>
+      """

package.json

@@ -234,6 +234,7 @@
     "util-arity": "^1.1.0",
     "verror": "^1.10.0",
     "xmlbuilder": "^15.1.1",
+    "yaml": "1.10.2",
     "yup": "^0.32.11"
   },
   "devDependencies": {

src/configuration/from_file.ts

@@ -1,5 +1,8 @@
 import stringArgv from 'string-argv'
+import fs from 'fs'
 import path from 'path'
+import YAML from 'yaml'
+import { promisify } from 'util'
 import { pathToFileURL } from 'url'
 import { IConfiguration } from './types'
 import { mergeConfigurations } from './merge_configurations'
@@ -44,16 +47,31 @@ async function loadFile(
   file: string
 ): Promise<Record<string, any>> {
   const filePath: string = path.join(cwd, file)
+  const extension = path.extname(filePath)
   let definitions
-  try {
-    // eslint-disable-next-line @typescript-eslint/no-var-requires
-    definitions = require(filePath)
-  } catch (error) {
-    if (error.code === 'ERR_REQUIRE_ESM') {
-      definitions = await importer(pathToFileURL(filePath))
-    } else {
-      throw error
-    }
+  switch (extension) {
+    case '.json':
+      definitions = JSON.parse(
+        await promisify(fs.readFile)(filePath, { encoding: 'utf-8' })
+      )
+      break
+    case '.yaml':
+    case '.yml':
+      definitions = YAML.parse(
+        await promisify(fs.readFile)(filePath, { encoding: 'utf-8' })
+      )
+      break
+    default:
+      try {
+        // eslint-disable-next-line @typescript-eslint/no-var-requires
+        definitions = require(filePath)
+      } catch (error) {
+        if (error.code === 'ERR_REQUIRE_ESM') {
+          definitions = await importer(pathToFileURL(filePath))
+        } else {
+          throw error
+        }
+      }
   }
   if (typeof definitions !== 'object') {
     throw new Error(`Configuration file ${filePath} does not export an object`)

src/configuration/from_file_spec.ts

@@ -99,5 +99,20 @@ describe('fromFile', () => {
       const result = await fromFile(logger, cwd, 'cucumber.json', ['p1'])
       expect(result).to.deep.eq({ paths: ['other/path/*.feature'] })
     })
+
+    it('should work with yaml', async () => {
+      const { logger, cwd } = await setup(
+        'cucumber.yaml',
+        `default:
+
+p1:
+  paths:
+    - "other/path/*.feature"
+`
+      )
+
+      const result = await fromFile(logger, cwd, 'cucumber.yaml', ['p1'])
+      expect(result).to.deep.eq({ paths: ['other/path/*.feature'] })
+    })
   })
 })

src/configuration/locate_file.ts

@@ -6,6 +6,8 @@ const DEFAULT_FILENAMES = [
   'cucumber.cjs',
   'cucumber.mjs',
   'cucumber.json',
+  'cucumber.yaml',
+  'cucumber.yml',
 ]
 
 export function locateFile(cwd: string): string | undefined {