fetch: improve output for FormData, Response, Request

lib/web/fetch/formdata.js

@@ -6,6 +6,7 @@ const { kEnumerableProperty } = require('../../core/util')
 const { File: UndiciFile, FileLike, isFileLike } = require('./file')
 const { webidl } = require('./webidl')
 const { File: NativeFile } = require('node:buffer')
+const nodeUtil = require('node:util')
 
 /** @type {globalThis['File']} */
 const File = NativeFile ?? UndiciFile
@@ -154,6 +155,19 @@ class FormData {
       this[kState].push(entry)
     }
   }
+
+  toString () {
+    let output = 'FormData:\n'
+    this[kState].forEach(entry => {
+      output += `${entry.name}: ${entry.value}\n`
+    })
+
+    return output
+  }
+
+  [nodeUtil.inspect.custom] (depth, options) {
+    return this.toString()
+  }
 }
 
 iteratorMixin('FormData', FormData, kState, 'name', 'value')

lib/web/fetch/request.js

@@ -6,6 +6,7 @@ const { extractBody, mixinBody, cloneBody } = require('./body')
 const { Headers, fill: fillHeaders, HeadersList } = require('./headers')
 const { FinalizationRegistry } = require('./dispatcher-weakref')()
 const util = require('../../core/util')
+const nodeUtil = require('node:util')
 const {
   isValidHTTPToken,
   sameOrigin,
@@ -771,6 +772,32 @@ class Request {
     // 4. Return clonedRequestObject.
     return fromInnerRequest(clonedRequest, ac.signal, this[kHeaders][kGuard], this[kRealm])
   }
+
+  [nodeUtil.inspect.custom] (depth, options) {
+    if (options.depth === null) {
+      options.depth = 2
+    }
+
+    const properties = {
+      method: this.method,
+      url: this.url,
+      headers: this.headers,
+      destination: this.destination,
+      referrer: this.referrer,
+      referrerPolicy: this.referrerPolicy,
+      mode: this.mode,
+      credentials: this.credentials,
+      cache: this.cache,
+      redirect: this.redirect,
+      integrity: this.integrity,
+      keepalive: this.keepalive,
+      isReloadNavigation: this.isReloadNavigation,
+      isHistoryNavigation: this.isHistoryNavigation,
+      signal: this.signal
+    }
+
+    return nodeUtil.formatWithOptions(options, { ...properties })
+  }
 }
 
 mixinBody(Request)

lib/web/fetch/response.js

@@ -3,6 +3,7 @@
 const { Headers, HeadersList, fill } = require('./headers')
 const { extractBody, cloneBody, mixinBody } = require('./body')
 const util = require('../../core/util')
+const nodeUtil = require('node:util')
 const { kEnumerableProperty } = util
 const {
   isValidReasonPhrase,
@@ -252,6 +253,17 @@ class Response {
     // clonedResponse, this’s headers’s guard, and this’s relevant Realm.
     return fromInnerResponse(clonedResponse, this[kHeaders][kGuard], this[kRealm])
   }
+
+  [nodeUtil.inspect.custom] (depth, options) {
+    if (options.depth === null) {
+      options.depth = 2
+    }
+
+    const { status, statusText, headersList } = this[kState]
+    const headersString = nodeUtil.inspect(headersList)
+
+    return `Response { status: ${status}, statusText: "${statusText}", headers: ${headersString} }`
+  }
 }
 
 mixinBody(Response)

test/fetch/formdata-inspect-custom.js

@@ -0,0 +1,15 @@
+'use strict'
+
+const { FormData } = require('../../')
+const { test } = require('node:test')
+const assert = require('node:assert')
+
+test('FormData class custom inspection', () => {
+  const formData = new FormData()
+  formData.append('username', 'john_doe')
+  formData.append('email', 'john@example.com')
+
+  const expectedOutput = 'FormData:\nusername: john_doe\nemail: john@example.com\n'
+
+  assert.strictEqual(formData.toString(), expectedOutput)
+})

test/fetch/request-inspect-custom.js

@@ -0,0 +1,23 @@
+'use strict'
+
+const { describe, it } = require('node:test')
+const assert = require('assert')
+const util = require('util')
+const { Request } = require('../../')
+
+describe('Request custom inspection', () => {
+  it('should return a custom inspect output', () => {
+    const request = new Request('https://example.com/api', {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json'
+      }
+    })
+
+    const inspectedOutput = util.inspect(request)
+
+    const expectedOutput = '{\n  method: \'POST\',\n  url: \'https://example.com/api\',\n  headers: Headers { \'Content-Type\': \'application/json\' },\n  destination: \'\',\n  referrer: \'about:client\',\n  referrerPolicy: \'\',\n  mode: \'cors\',\n  credentials: \'same-origin\',\n  cache: \'default\',\n  redirect: \'follow\',\n  integrity: \'\',\n  keepalive: false,\n  isReloadNavigation: false,\n  isHistoryNavigation: false,\n  signal: AbortSignal { aborted: false }\n}'
+
+    assert.strictEqual(inspectedOutput, expectedOutput)
+  })
+})

test/fetch/response-inspect-custom.js

@@ -0,0 +1,19 @@
+'use strict'
+
+const { describe, it } = require('node:test')
+const assert = require('assert')
+const util = require('util')
+const { Response } = require('../../')
+
+describe('Response custom inspection', () => {
+  it('should return a custom inspect output', () => {
+    const response = new Response(null)
+    const inspectedOutput = util.inspect(response)
+    const expectedOutput = `Response { status: 200, statusText: "", headers: HeadersList {
+  cookies: null,
+  [Symbol(headers map)]: Map(0) {},
+  [Symbol(headers map sorted)]: null
+} }`
+    assert.strictEqual(inspectedOutput, expectedOutput)
+  })
+})