overlay: keep comments and linewidth when dumping to YAML

If the original file is YAML and the target overlayed definition is
YAML, we now preserve comments from the original document and also
keep the same line width as the original file.

examples/valid/asyncapi.v2.overlayed.yml

@@ -0,0 +1,177 @@
+# Some comments in the API definition
+asyncapi: 2.2.0
+info:
+  title: Streetlights API
+  version: 1.0.0
+  description: |
+    Turn lights on or off. And get notified when lights are dimmed or switched.
+  license:
+    name: Apache 2.0
+    url: 'https://www.apache.org/licenses/LICENSE-2.0'
+servers:
+  # This is a Production MQTT server
+  production:
+    url: 'test.mosquitto.org:{port}'
+    protocol: mqtt
+    description: Test broker
+    variables:
+      port:
+        description: Secure connection (TLS) is available through port 8883.
+        default: '1883'
+        enum:
+          - '1883'
+          - '8883'
+    security:
+      - apiKey: []
+      - supportedOauthFlows:
+          - 'streetlights:on'
+          - 'streetlights:off'
+          - 'streetlights:dim'
+      - openIdConnectWellKnown: []
+defaultContentType: application/json
+channels:
+  'smartylighting/streetlights/1/0/event/{streetlightId}/lighting/measured':
+    description: The topic on which measured values may be produced and consumed.
+    parameters:
+      streetlightId:
+        $ref: 'http://example.org/param-lights.json'
+    publish:
+      summary: Inform about environmental lighting conditions of a particular streetlight.
+      operationId: receiveLightMeasurement
+      traits:
+        - $ref: ./traits/kafka.yml
+      message:
+        $ref: '#/components/messages/lightMeasured'
+  'smartylighting/streetlights/1/0/action/{streetlightId}/turn/on':
+    parameters:
+      streetlightId:
+        $ref: ./params/streetlightId.json
+    subscribe:
+      operationId: turnOn
+      traits:
+        - $ref: ./traits/kafka.yml
+      message:
+        $ref: '#/components/messages/turnOnOff'
+  'smartylighting/streetlights/1/0/action/{streetlightId}/turn/off':
+    parameters:
+      streetlightId:
+        $ref: ./params/streetlightId.json
+  'smartylighting/streetlights/1/0/action/{streetlightId}/dim':
+    parameters:
+      streetlightId:
+        $ref: params/streetlightId.json
+    subscribe:
+      operationId: dimLight
+      traits:
+        - $ref: ./traits/kafka.yml
+      message:
+        $ref: '#/components/messages/dimLight'
+components:
+  messages:
+    lightMeasured:
+      name: lightMeasured
+      title: Light measured
+      summary: Inform about environmental lighting conditions of a particular streetlight.
+      contentType: application/json
+      traits:
+        - $ref: '#/components/messageTraits/commonHeaders'
+      payload:
+        $ref: '#/components/schemas/lightMeasuredPayload'
+    turnOnOff:
+      name: turnOnOff
+      title: Turn on/off
+      summary: Command a particular streetlight to turn the lights on or off.
+      traits:
+        - $ref: '#/components/messageTraits/commonHeaders'
+      payload:
+        $ref: '#/components/schemas/turnOnOffPayload'
+    dimLight:
+      name: dimLight
+      title: Dim light
+      summary: Command a particular streetlight to dim the lights.
+      traits:
+        - $ref: '#/components/messageTraits/commonHeaders'
+      payload:
+        $ref: '#/components/schemas/dimLightPayload'
+  schemas:
+    lightMeasuredPayload:
+      type: object
+      properties:
+        lumens:
+          type: integer
+          minimum: 0
+          description: Light intensity measured in lumens.
+        sentAt:
+          $ref: '#/components/schemas/sentAt'
+    turnOnOffPayload:
+      type: object
+      properties:
+        command:
+          type: string
+          enum:
+            - 'on'
+            - 'off'
+          description: Whether to turn on or off the light.
+        sentAt:
+          $ref: '#/components/schemas/sentAt'
+    dimLightPayload:
+      type: object
+      properties:
+        percentage:
+          type: integer
+          description: Percentage to which the light should be dimmed to.
+          minimum: 0
+          maximum: 100
+        sentAt:
+          $ref: '#/components/schemas/sentAt'
+    sentAt:
+      type: string
+      format: date-time
+      description: Date and time when the message was sent.
+  securitySchemes:
+    apiKey:
+      type: apiKey
+      in: user
+      description: Provide your API key as the user and leave the password empty.
+    supportedOauthFlows:
+      type: oauth2
+      description: Flows to support OAuth 2.0
+      flows:
+        implicit:
+          authorizationUrl: 'https://authserver.example/auth'
+          scopes:
+            'streetlights:on': Ability to switch lights on
+            'streetlights:off': Ability to switch lights off
+            'streetlights:dim': Ability to dim the lights
+        password:
+          tokenUrl: 'https://authserver.example/token'
+          scopes:
+            'streetlights:on': Ability to switch lights on
+            'streetlights:off': Ability to switch lights off
+            'streetlights:dim': Ability to dim the lights
+        clientCredentials:
+          tokenUrl: 'https://authserver.example/token'
+          scopes:
+            'streetlights:on': Ability to switch lights on
+            'streetlights:off': Ability to switch lights off
+            'streetlights:dim': Ability to dim the lights
+        authorizationCode:
+          authorizationUrl: 'https://authserver.example/auth'
+          tokenUrl: 'https://authserver.example/token'
+          refreshUrl: 'https://authserver.example/refresh'
+          scopes:
+            'streetlights:on': Ability to switch lights on
+            'streetlights:off': Ability to switch lights off
+            'streetlights:dim': Ability to dim the lights
+    openIdConnectWellKnown:
+      type: openIdConnect
+      openIdConnectUrl: 'https://authserver.example/.well-known'
+  messageTraits:
+    commonHeaders:
+      headers:
+        type: object
+        properties:
+          my-app-header:
+            type: integer
+            minimum: 0
+            maximum: 100

examples/valid/asyncapi.v2.yml

@@ -1,3 +1,4 @@
+# Some comments in the API definition
 asyncapi: '2.2.0'
 info:
   title: Streetlights API
@@ -9,6 +10,7 @@ info:
     url: https://www.apache.org/licenses/LICENSE-2.0
 
 servers:
+  # This is a Production MQTT server
   production:
     url: test.mosquitto.org:{port}
     protocol: mqtt
@@ -60,6 +62,7 @@ channels:
       streetlightId:
         $ref: './params/streetlightId.json'
     subscribe:
+      x-beta: true
       operationId: turnOff
       traits:
         - $ref: './traits/kafka.yml'

examples/valid/overlay-async.yaml

@@ -0,0 +1,13 @@
+overlay: 1.0.0
+info:
+  title: Overlay to customise API for Streetlights
+  version: 0.0.1
+actions:
+  - target: '$.info.description'
+    description: Provide a better introduction for our end users than this techno babble.
+    update: |
+      Turn lights on or off. And get notified when lights are dimmed or switched.
+
+  - target: '$..[?(@["x-beta"]==true)]'
+    description: Remove all beta operations
+    remove: true

src/definition.ts

@@ -1,7 +1,7 @@
 import {default as $RefParser, getJsonSchemaRefParserDefaultOptions} from '@apidevtools/json-schema-ref-parser'
 import asyncapi from '@asyncapi/specs'
 import {CLIError} from '@oclif/core/errors'
-import {safeStringify} from '@stoplight/yaml'
+import {parseWithPointers, safeStringify} from '@stoplight/yaml'
 import debug from 'debug'
 import {
   JSONSchema4,
@@ -277,9 +277,11 @@ class API {
 
   serializeDefinition(outputPath?: string): string {
     if (this.overlayedDefinition) {
+      const {comments} = parseWithPointers(this.rawDefinition, {attachComments: true})
+      const dumpOptions = {comments, lineWidth: Number.POSITIVE_INFINITY}
       return this.guessFormat(outputPath) === 'json'
         ? JSON.stringify(this.overlayedDefinition)
-        : safeStringify(this.overlayedDefinition)
+        : safeStringify(this.overlayedDefinition, dumpOptions)
     }
 
     return this.rawDefinition

test/unit/definition.test.ts

@@ -1,6 +1,7 @@
 import * as YAML from '@stoplight/yaml'
 import {expect} from 'chai'
 import nock from 'nock'
+import * as fs from 'node:fs'
 import path from 'node:path'
 
 import {API, APIDefinition} from '../../src/definition'
@@ -136,7 +137,18 @@ describe('API class', () => {
 
         expect(api.serializeDefinition()).to.equal(JSON.stringify(api.overlayedDefinition))
 
-        expect(api.serializeDefinition('destination/file.yaml')).to.equal(YAML.safeStringify(api.overlayedDefinition))
+        expect(api.serializeDefinition('destination/file.yaml')).to.equal(
+          YAML.safeStringify(api.overlayedDefinition, {lineWidth: Number.POSITIVE_INFINITY}),
+        )
+      })
+
+      it('preserves line width and YAML comments', async () => {
+        nock('http://example.org').get('/param-lights.json').reply(200, {})
+
+        const api = await API.load('examples/valid/asyncapi.v2.yml')
+        await api.applyOverlay('examples/valid/overlay-async.yaml')
+
+        expect(api.serializeDefinition()).to.equal(fs.readFileSync('examples/valid/asyncapi.v2.overlayed.yml', 'utf8'))
       })
     })
   })