{"record":{"id":"daed2b4a86502a89","repo":"microsoft/playwright","slug":"unexpected-buffer-type-of-data-name","errorCode":null,"errorMessage":"Unexpected buffer type of 'data.${name}'","messagePattern":"Unexpected buffer type of 'data\\.(.+?)'","errorType":"validation","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/playwright-core/src/client/fetch.ts","lineNumber":287,"sourceCode":"    });\n  }\n\n  async storageState(options: { path?: string, indexedDB?: boolean } = {}): Promise<StorageState> {\n    const state = await this._channel.storageState({ indexedDB: options.indexedDB }, kNoTimeout);\n    if (options.path) {\n      await mkdirIfNeeded(options.path);\n      await fs.promises.writeFile(options.path, JSON.stringify(state, undefined, 2), 'utf8');\n    }\n    return state;\n  }\n}\n\nasync function toFormField(name: string, value: string | number | boolean | fs.ReadStream | FilePayload): Promise<channels.FormField> {\n  const typeOfValue = typeof value;\n  if (isFilePayload(value)) {\n    const payload = value as FilePayload;\n    if (!Buffer.isBuffer(payload.buffer))\n      throw new Error(`Unexpected buffer type of 'data.${name}'`);\n    return { name, file: filePayloadToJson(payload) };\n  } else if (typeOfValue === 'string' || typeOfValue === 'number' || typeOfValue === 'boolean') {\n    return { name, value: String(value) };\n  } else {\n    return { name, file: await readStreamToJson(value as fs.ReadStream) };\n  }\n}\n\nfunction isJsonParsable(value: any) {\n  if (typeof value !== 'string')\n    return false;\n  try {\n    JSON.parse(value);\n    return true;\n  } catch (e) {\n    if (e instanceof SyntaxError)\n      return false;\n    else","sourceCodeStart":269,"sourceCodeEnd":305,"githubUrl":"https://github.com/microsoft/playwright/blob/c8fc3bf8d31542d59b4d4d9eaab1df93ff541dc6/packages/playwright-core/src/client/fetch.ts#L269-L305","documentation":"Error \"Unexpected buffer type of 'data.${name}'\" thrown in microsoft/playwright.","triggerScenarios":"Thrown at packages/playwright-core/src/client/fetch.ts:287 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"c8fc3bf8d31542d59b4d4d9eaab1df93ff541dc6","analyzedAt":"2026-08-12T07:26:36.950Z","schemaVersion":2},"datasetVersion":"2026-08-12T13:17:24.610Z"}