@ai-sdk/ui-utils/dist/index.mjs.map

Important: this is an internal API. Expect breaking changes.

{"version":3,"sources":["../src/index.ts","../src/assistant-stream-parts.ts","../src/process-chat-response.ts","../src/duplicated/usage.ts","../src/parse-partial-json.ts","../src/fix-json.ts","../src/data-stream-parts.ts","../src/process-data-stream.ts","../src/process-chat-text-response.ts","../src/process-text-stream.ts","../src/call-chat-api.ts","../src/call-completion-api.ts","../src/data-url.ts","../src/extract-max-tool-invocation-step.ts","../src/get-message-parts.ts","../src/fill-message-parts.ts","../src/is-deep-equal-data.ts","../src/prepare-attachments-for-request.ts","../src/process-assistant-stream.ts","../src/schema.ts","../src/zod-schema.ts","../src/should-resubmit-messages.ts","../src/update-tool-call-result.ts"],"sourcesContent":["export * from './types';\n\nexport { generateId } from '@ai-sdk/provider-utils';\n\n// Export stream data utilities for custom stream implementations,\n// both on the client and server side.\n// NOTE: this is experimental / internal and may change without notice\nexport {\n  formatAssistantStreamPart,\n  parseAssistantStreamPart,\n} from './assistant-stream-parts';\nexport type {\n  AssistantStreamPart,\n  AssistantStreamString,\n} from './assistant-stream-parts';\nexport { callChatApi } from './call-chat-api';\nexport { callCompletionApi } from './call-completion-api';\nexport { formatDataStreamPart, parseDataStreamPart } from './data-stream-parts';\nexport type { DataStreamPart, DataStreamString } from './data-stream-parts';\nexport { getTextFromDataUrl } from './data-url';\nexport type { DeepPartial } from './deep-partial';\nexport { extractMaxToolInvocationStep } from './extract-max-tool-invocation-step';\nexport { fillMessageParts } from './fill-message-parts';\nexport { getMessageParts } from './get-message-parts';\nexport { isDeepEqualData } from './is-deep-equal-data';\nexport { parsePartialJson } from './parse-partial-json';\nexport { prepareAttachmentsForRequest } from './prepare-attachments-for-request';\nexport { processAssistantStream } from './process-assistant-stream';\nexport { processDataStream } from './process-data-stream';\nexport { processTextStream } from './process-text-stream';\nexport { asSchema, jsonSchema } from './schema';\nexport type { Schema } from './schema';\nexport {\n  isAssistantMessageWithCompletedToolCalls,\n  shouldResubmitMessages,\n} from './should-resubmit-messages';\nexport { updateToolCallResult } from './update-tool-call-result';\nexport { zodSchema } from './zod-schema';\n","import { AssistantMessage, DataMessage, JSONValue } from './types';\n\nexport type AssistantStreamString =\n  `${(typeof StreamStringPrefixes)[keyof typeof StreamStringPrefixes]}:${string}\\n`;\n\nexport interface AssistantStreamPart<\n  CODE extends string,\n  NAME extends string,\n  TYPE,\n> {\n  code: CODE;\n  name: NAME;\n  parse: (value: JSONValue) => { type: NAME; value: TYPE };\n}\n\nconst textStreamPart: AssistantStreamPart<'0', 'text', string> = {\n  code: '0',\n  name: 'text',\n  parse: (value: JSONValue) => {\n    if (typeof value !== 'string') {\n      throw new Error('\"text\" parts expect a string value.');\n    }\n    return { type: 'text', value };\n  },\n};\n\nconst errorStreamPart: AssistantStreamPart<'3', 'error', string> = {\n  code: '3',\n  name: 'error',\n  parse: (value: JSONValue) => {\n    if (typeof value !== 'string') {\n      throw new Error('\"error\" parts expect a string value.');\n    }\n    return { type: 'error', value };\n  },\n};\n\nconst assistantMessageStreamPart: AssistantStreamPart<\n  '4',\n  'assistant_message',\n  AssistantMessage\n> = {\n  code: '4',\n  name: 'assistant_message',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('id' in value) ||\n      !('role' in value) ||\n      !('content' in value) ||\n      typeof value.id !== 'string' ||\n      typeof value.role !== 'string' ||\n      value.role !== 'assistant' ||\n      !Array.isArray(value.content) ||\n      !value.content.every(\n        item =>\n          item != null &&\n          typeof item === 'object' &&\n          'type' in item &&\n          item.type === 'text' &&\n          'text' in item &&\n          item.text != null &&\n          typeof item.text === 'object' &&\n          'value' in item.text &&\n          typeof item.text.value === 'string',\n      )\n    ) {\n      throw new Error(\n        '\"assistant_message\" parts expect an object with an \"id\", \"role\", and \"content\" property.',\n      );\n    }\n\n    return {\n      type: 'assistant_message',\n      value: value as AssistantMessage,\n    };\n  },\n};\n\nconst assistantControlDataStreamPart: AssistantStreamPart<\n  '5',\n  'assistant_control_data',\n  {\n    threadId: string;\n    messageId: string;\n  }\n> = {\n  code: '5',\n  name: 'assistant_control_data',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('threadId' in value) ||\n      !('messageId' in value) ||\n      typeof value.threadId !== 'string' ||\n      typeof value.messageId !== 'string'\n    ) {\n      throw new Error(\n        '\"assistant_control_data\" parts expect an object with a \"threadId\" and \"messageId\" property.',\n      );\n    }\n\n    return {\n      type: 'assistant_control_data',\n      value: {\n        threadId: value.threadId,\n        messageId: value.messageId,\n      },\n    };\n  },\n};\n\nconst dataMessageStreamPart: AssistantStreamPart<\n  '6',\n  'data_message',\n  DataMessage\n> = {\n  code: '6',\n  name: 'data_message',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('role' in value) ||\n      !('data' in value) ||\n      typeof value.role !== 'string' ||\n      value.role !== 'data'\n    ) {\n      throw new Error(\n        '\"data_message\" parts expect an object with a \"role\" and \"data\" property.',\n      );\n    }\n\n    return {\n      type: 'data_message',\n      value: value as DataMessage,\n    };\n  },\n};\n\nconst assistantStreamParts = [\n  textStreamPart,\n  errorStreamPart,\n  assistantMessageStreamPart,\n  assistantControlDataStreamPart,\n  dataMessageStreamPart,\n] as const;\n\ntype AssistantStreamParts =\n  | typeof textStreamPart\n  | typeof errorStreamPart\n  | typeof assistantMessageStreamPart\n  | typeof assistantControlDataStreamPart\n  | typeof dataMessageStreamPart;\n\ntype AssistantStreamPartValueType = {\n  [P in AssistantStreamParts as P['name']]: ReturnType<P['parse']>['value'];\n};\n\nexport type AssistantStreamPartType =\n  | ReturnType<typeof textStreamPart.parse>\n  | ReturnType<typeof errorStreamPart.parse>\n  | ReturnType<typeof assistantMessageStreamPart.parse>\n  | ReturnType<typeof assistantControlDataStreamPart.parse>\n  | ReturnType<typeof dataMessageStreamPart.parse>;\n\nexport const assistantStreamPartsByCode = {\n  [textStreamPart.code]: textStreamPart,\n  [errorStreamPart.code]: errorStreamPart,\n  [assistantMessageStreamPart.code]: assistantMessageStreamPart,\n  [assistantControlDataStreamPart.code]: assistantControlDataStreamPart,\n  [dataMessageStreamPart.code]: dataMessageStreamPart,\n} as const;\n\nexport const StreamStringPrefixes = {\n  [textStreamPart.name]: textStreamPart.code,\n  [errorStreamPart.name]: errorStreamPart.code,\n  [assistantMessageStreamPart.name]: assistantMessageStreamPart.code,\n  [assistantControlDataStreamPart.name]: assistantControlDataStreamPart.code,\n  [dataMessageStreamPart.name]: dataMessageStreamPart.code,\n} as const;\n\nexport const validCodes = assistantStreamParts.map(part => part.code);\n\nexport const parseAssistantStreamPart = (\n  line: string,\n): AssistantStreamPartType => {\n  const firstSeparatorIndex = line.indexOf(':');\n\n  if (firstSeparatorIndex === -1) {\n    throw new Error('Failed to parse stream string. No separator found.');\n  }\n\n  const prefix = line.slice(0, firstSeparatorIndex);\n\n  if (!validCodes.includes(prefix as keyof typeof assistantStreamPartsByCode)) {\n    throw new Error(`Failed to parse stream string. Invalid code ${prefix}.`);\n  }\n\n  const code = prefix as keyof typeof assistantStreamPartsByCode;\n\n  const textValue = line.slice(firstSeparatorIndex + 1);\n  const jsonValue: JSONValue = JSON.parse(textValue);\n\n  return assistantStreamPartsByCode[code].parse(jsonValue);\n};\n\nexport function formatAssistantStreamPart<\n  T extends keyof AssistantStreamPartValueType,\n>(type: T, value: AssistantStreamPartValueType[T]): AssistantStreamString {\n  const streamPart = assistantStreamParts.find(part => part.name === type);\n\n  if (!streamPart) {\n    throw new Error(`Invalid stream part type: ${type}`);\n  }\n\n  return `${streamPart.code}:${JSON.stringify(value)}\\n`;\n}\n","import { LanguageModelV1FinishReason } from '@ai-sdk/provider';\nimport { generateId as generateIdFunction } from '@ai-sdk/provider-utils';\nimport {\n  calculateLanguageModelUsage,\n  LanguageModelUsage,\n} from './duplicated/usage';\nimport { parsePartialJson } from './parse-partial-json';\nimport { processDataStream } from './process-data-stream';\nimport type {\n  JSONValue,\n  ReasoningUIPart,\n  TextUIPart,\n  ToolInvocation,\n  ToolInvocationUIPart,\n  UIMessage,\n  UseChatOptions,\n} from './types';\n\nexport async function processChatResponse({\n  stream,\n  update,\n  onToolCall,\n  onFinish,\n  generateId = generateIdFunction,\n  getCurrentDate = () => new Date(),\n  lastMessage,\n}: {\n  stream: ReadableStream<Uint8Array>;\n  update: (options: {\n    message: UIMessage;\n    data: JSONValue[] | undefined;\n    replaceLastMessage: boolean;\n  }) => void;\n  onToolCall?: UseChatOptions['onToolCall'];\n  onFinish?: (options: {\n    message: UIMessage | undefined;\n    finishReason: LanguageModelV1FinishReason;\n    usage: LanguageModelUsage;\n  }) => void;\n  generateId?: () => string;\n  getCurrentDate?: () => Date;\n  lastMessage: UIMessage | undefined;\n}) {\n  const replaceLastMessage = lastMessage?.role === 'assistant';\n  let step = replaceLastMessage\n    ? 1 +\n      // find max step in existing tool invocations:\n      (lastMessage.toolInvocations?.reduce((max, toolInvocation) => {\n        return Math.max(max, toolInvocation.step ?? 0);\n      }, 0) ?? 0)\n    : 0;\n\n  const message: UIMessage = replaceLastMessage\n    ? structuredClone(lastMessage)\n    : {\n        id: generateId(),\n        createdAt: getCurrentDate(),\n        role: 'assistant',\n        content: '',\n        parts: [],\n      };\n\n  let currentTextPart: TextUIPart | undefined = undefined;\n  let currentReasoningPart: ReasoningUIPart | undefined = undefined;\n  let currentReasoningTextDetail:\n    | { type: 'text'; text: string; signature?: string }\n    | undefined = undefined;\n\n  function updateToolInvocationPart(\n    toolCallId: string,\n    invocation: ToolInvocation,\n  ) {\n    const part = message.parts.find(\n      part =>\n        part.type === 'tool-invocation' &&\n        part.toolInvocation.toolCallId === toolCallId,\n    ) as ToolInvocationUIPart | undefined;\n\n    if (part != null) {\n      part.toolInvocation = invocation;\n    } else {\n      message.parts.push({\n        type: 'tool-invocation',\n        toolInvocation: invocation,\n      });\n    }\n  }\n\n  const data: JSONValue[] = [];\n\n  // keep list of current message annotations for message\n  let messageAnnotations: JSONValue[] | undefined = replaceLastMessage\n    ? lastMessage?.annotations\n    : undefined;\n\n  // keep track of partial tool calls\n  const partialToolCalls: Record<\n    string,\n    { text: string; step: number; index: number; toolName: string }\n  > = {};\n\n  let usage: LanguageModelUsage = {\n    completionTokens: NaN,\n    promptTokens: NaN,\n    totalTokens: NaN,\n  };\n  let finishReason: LanguageModelV1FinishReason = 'unknown';\n\n  function execUpdate() {\n    // make a copy of the data array to ensure UI is updated (SWR)\n    const copiedData = [...data];\n\n    // keeps the currentMessage up to date with the latest annotations,\n    // even if annotations preceded the message creation\n    if (messageAnnotations?.length) {\n      message.annotations = messageAnnotations;\n    }\n\n    const copiedMessage = {\n      // deep copy the message to ensure that deep changes (msg attachments) are updated\n      // with SolidJS. SolidJS uses referential integration of sub-objects to detect changes.\n      ...structuredClone(message),\n      // add a revision id to ensure that the message is updated with SWR. SWR uses a\n      // hashing approach by default to detect changes, but it only works for shallow\n      // changes. This is why we need to add a revision id to ensure that the message\n      // is updated with SWR (without it, the changes get stuck in SWR and are not\n      // forwarded to rendering):\n      revisionId: generateId(),\n    } as UIMessage;\n\n    update({\n      message: copiedMessage,\n      data: copiedData,\n      replaceLastMessage,\n    });\n  }\n\n  await processDataStream({\n    stream,\n    onTextPart(value) {\n      if (currentTextPart == null) {\n        currentTextPart = {\n          type: 'text',\n          text: value,\n        };\n        message.parts.push(currentTextPart);\n      } else {\n        currentTextPart.text += value;\n      }\n\n      message.content += value;\n      execUpdate();\n    },\n    onReasoningPart(value) {\n      if (currentReasoningTextDetail == null) {\n        currentReasoningTextDetail = { type: 'text', text: value };\n        if (currentReasoningPart != null) {\n          currentReasoningPart.details.push(currentReasoningTextDetail);\n        }\n      } else {\n        currentReasoningTextDetail.text += value;\n      }\n\n      if (currentReasoningPart == null) {\n        currentReasoningPart = {\n          type: 'reasoning',\n          reasoning: value,\n          details: [currentReasoningTextDetail],\n        };\n        message.parts.push(currentReasoningPart);\n      } else {\n        currentReasoningPart.reasoning += value;\n      }\n\n      message.reasoning = (message.reasoning ?? '') + value;\n\n      execUpdate();\n    },\n    onReasoningSignaturePart(value) {\n      if (currentReasoningTextDetail != null) {\n        currentReasoningTextDetail.signature = value.signature;\n      }\n    },\n    onRedactedReasoningPart(value) {\n      if (currentReasoningPart == null) {\n        currentReasoningPart = {\n          type: 'reasoning',\n          reasoning: '',\n          details: [],\n        };\n        message.parts.push(currentReasoningPart);\n      }\n\n      currentReasoningPart.details.push({\n        type: 'redacted',\n        data: value.data,\n      });\n\n      currentReasoningTextDetail = undefined;\n\n      execUpdate();\n    },\n    onFilePart(value) {\n      message.parts.push({\n        type: 'file',\n        mimeType: value.mimeType,\n        data: value.data,\n      });\n\n      execUpdate();\n    },\n    onSourcePart(value) {\n      message.parts.push({\n        type: 'source',\n        source: value,\n      });\n\n      execUpdate();\n    },\n    onToolCallStreamingStartPart(value) {\n      if (message.toolInvocations == null) {\n        message.toolInvocations = [];\n      }\n\n      // add the partial tool call to the map\n      partialToolCalls[value.toolCallId] = {\n        text: '',\n        step,\n        toolName: value.toolName,\n        index: message.toolInvocations.length,\n      };\n\n      const invocation = {\n        state: 'partial-call',\n        step,\n        toolCallId: value.toolCallId,\n        toolName: value.toolName,\n        args: undefined,\n      } as const;\n\n      message.toolInvocations.push(invocation);\n\n      updateToolInvocationPart(value.toolCallId, invocation);\n\n      execUpdate();\n    },\n    onToolCallDeltaPart(value) {\n      const partialToolCall = partialToolCalls[value.toolCallId];\n\n      partialToolCall.text += value.argsTextDelta;\n\n      const { value: partialArgs } = parsePartialJson(partialToolCall.text);\n\n      const invocation = {\n        state: 'partial-call',\n        step: partialToolCall.step,\n        toolCallId: value.toolCallId,\n        toolName: partialToolCall.toolName,\n        args: partialArgs,\n      } as const;\n\n      message.toolInvocations![partialToolCall.index] = invocation;\n\n      updateToolInvocationPart(value.toolCallId, invocation);\n\n      execUpdate();\n    },\n    async onToolCallPart(value) {\n      const invocation = {\n        state: 'call',\n        step,\n        ...value,\n      } as const;\n\n      if (partialToolCalls[value.toolCallId] != null) {\n        // change the partial tool call to a full tool call\n        message.toolInvocations![partialToolCalls[value.toolCallId].index] =\n          invocation;\n      } else {\n        if (message.toolInvocations == null) {\n          message.toolInvocations = [];\n        }\n\n        message.toolInvocations.push(invocation);\n      }\n\n      updateToolInvocationPart(value.toolCallId, invocation);\n\n      execUpdate();\n\n      // invoke the onToolCall callback if it exists. This is blocking.\n      // In the future we should make this non-blocking, which\n      // requires additional state management for error handling etc.\n      if (onToolCall) {\n        const result = await onToolCall({ toolCall: value });\n        if (result != null) {\n          const invocation = {\n            state: 'result',\n            step,\n            ...value,\n            result,\n          } as const;\n\n          // store the result in the tool invocation\n          message.toolInvocations![message.toolInvocations!.length - 1] =\n            invocation;\n\n          updateToolInvocationPart(value.toolCallId, invocation);\n\n          execUpdate();\n        }\n      }\n    },\n    onToolResultPart(value) {\n      const toolInvocations = message.toolInvocations;\n\n      if (toolInvocations == null) {\n        throw new Error('tool_result must be preceded by a tool_call');\n      }\n\n      // find if there is any tool invocation with the same toolCallId\n      // and replace it with the result\n      const toolInvocationIndex = toolInvocations.findIndex(\n        invocation => invocation.toolCallId === value.toolCallId,\n      );\n\n      if (toolInvocationIndex === -1) {\n        throw new Error(\n          'tool_result must be preceded by a tool_call with the same toolCallId',\n        );\n      }\n\n      const invocation = {\n        ...toolInvocations[toolInvocationIndex],\n        state: 'result' as const,\n        ...value,\n      } as const;\n\n      toolInvocations[toolInvocationIndex] = invocation;\n\n      updateToolInvocationPart(value.toolCallId, invocation);\n\n      execUpdate();\n    },\n    onDataPart(value) {\n      data.push(...value);\n      execUpdate();\n    },\n    onMessageAnnotationsPart(value) {\n      if (messageAnnotations == null) {\n        messageAnnotations = [...value];\n      } else {\n        messageAnnotations.push(...value);\n      }\n\n      execUpdate();\n    },\n    onFinishStepPart(value) {\n      step += 1;\n\n      // reset the current text and reasoning parts\n      currentTextPart = value.isContinued ? currentTextPart : undefined;\n      currentReasoningPart = undefined;\n      currentReasoningTextDetail = undefined;\n    },\n    onStartStepPart(value) {\n      // keep message id stable when we are updating an existing message:\n      if (!replaceLastMessage) {\n        message.id = value.messageId;\n      }\n\n      // add a step boundary part to the message\n      message.parts.push({ type: 'step-start' });\n      execUpdate();\n    },\n    onFinishMessagePart(value) {\n      finishReason = value.finishReason;\n      if (value.usage != null) {\n        usage = calculateLanguageModelUsage(value.usage);\n      }\n    },\n    onErrorPart(error) {\n      throw new Error(error);\n    },\n  });\n\n  onFinish?.({ message, finishReason, usage });\n}\n","/**\nRepresents the number of tokens used in a prompt and completion.\n */\nexport type LanguageModelUsage = {\n  /**\nThe number of tokens used in the prompt.\n   */\n  promptTokens: number;\n\n  /**\nThe number of tokens used in the completion.\n */\n  completionTokens: number;\n\n  /**\nThe total number of tokens used (promptTokens + completionTokens).\n   */\n  totalTokens: number;\n};\n\n/**\nRepresents the number of tokens used in an embedding.\n */\nexport type EmbeddingModelUsage = {\n  /**\nThe number of tokens used in the embedding.\n   */\n  tokens: number;\n};\n\nexport function calculateLanguageModelUsage({\n  promptTokens,\n  completionTokens,\n}: {\n  promptTokens: number;\n  completionTokens: number;\n}): LanguageModelUsage {\n  return {\n    promptTokens,\n    completionTokens,\n    totalTokens: promptTokens + completionTokens,\n  };\n}\n","import { JSONValue } from '@ai-sdk/provider';\nimport { safeParseJSON } from '@ai-sdk/provider-utils';\nimport { fixJson } from './fix-json';\n\nexport function parsePartialJson(jsonText: string | undefined): {\n  value: JSONValue | undefined;\n  state:\n    | 'undefined-input'\n    | 'successful-parse'\n    | 'repaired-parse'\n    | 'failed-parse';\n} {\n  if (jsonText === undefined) {\n    return { value: undefined, state: 'undefined-input' };\n  }\n\n  let result = safeParseJSON({ text: jsonText });\n\n  if (result.success) {\n    return { value: result.value, state: 'successful-parse' };\n  }\n\n  result = safeParseJSON({ text: fixJson(jsonText) });\n\n  if (result.success) {\n    return { value: result.value, state: 'repaired-parse' };\n  }\n\n  return { value: undefined, state: 'failed-parse' };\n}\n","type State =\n  | 'ROOT'\n  | 'FINISH'\n  | 'INSIDE_STRING'\n  | 'INSIDE_STRING_ESCAPE'\n  | 'INSIDE_LITERAL'\n  | 'INSIDE_NUMBER'\n  | 'INSIDE_OBJECT_START'\n  | 'INSIDE_OBJECT_KEY'\n  | 'INSIDE_OBJECT_AFTER_KEY'\n  | 'INSIDE_OBJECT_BEFORE_VALUE'\n  | 'INSIDE_OBJECT_AFTER_VALUE'\n  | 'INSIDE_OBJECT_AFTER_COMMA'\n  | 'INSIDE_ARRAY_START'\n  | 'INSIDE_ARRAY_AFTER_VALUE'\n  | 'INSIDE_ARRAY_AFTER_COMMA';\n\n// Implemented as a scanner with additional fixing\n// that performs a single linear time scan pass over the partial JSON.\n//\n// The states should ideally match relevant states from the JSON spec:\n// https://www.json.org/json-en.html\n//\n// Please note that invalid JSON is not considered/covered, because it\n// is assumed that the resulting JSON will be processed by a standard\n// JSON parser that will detect any invalid JSON.\nexport function fixJson(input: string): string {\n  const stack: State[] = ['ROOT'];\n  let lastValidIndex = -1;\n  let literalStart: number | null = null;\n\n  function processValueStart(char: string, i: number, swapState: State) {\n    {\n      switch (char) {\n        case '\"': {\n          lastValidIndex = i;\n          stack.pop();\n          stack.push(swapState);\n          stack.push('INSIDE_STRING');\n          break;\n        }\n\n        case 'f':\n        case 't':\n        case 'n': {\n          lastValidIndex = i;\n          literalStart = i;\n          stack.pop();\n          stack.push(swapState);\n          stack.push('INSIDE_LITERAL');\n          break;\n        }\n\n        case '-': {\n          stack.pop();\n          stack.push(swapState);\n          stack.push('INSIDE_NUMBER');\n          break;\n        }\n        case '0':\n        case '1':\n        case '2':\n        case '3':\n        case '4':\n        case '5':\n        case '6':\n        case '7':\n        case '8':\n        case '9': {\n          lastValidIndex = i;\n          stack.pop();\n          stack.push(swapState);\n          stack.push('INSIDE_NUMBER');\n          break;\n        }\n\n        case '{': {\n          lastValidIndex = i;\n          stack.pop();\n          stack.push(swapState);\n          stack.push('INSIDE_OBJECT_START');\n          break;\n        }\n\n        case '[': {\n          lastValidIndex = i;\n          stack.pop();\n          stack.push(swapState);\n          stack.push('INSIDE_ARRAY_START');\n          break;\n        }\n      }\n    }\n  }\n\n  function processAfterObjectValue(char: string, i: number) {\n    switch (char) {\n      case ',': {\n        stack.pop();\n        stack.push('INSIDE_OBJECT_AFTER_COMMA');\n        break;\n      }\n      case '}': {\n        lastValidIndex = i;\n        stack.pop();\n        break;\n      }\n    }\n  }\n\n  function processAfterArrayValue(char: string, i: number) {\n    switch (char) {\n      case ',': {\n        stack.pop();\n        stack.push('INSIDE_ARRAY_AFTER_COMMA');\n        break;\n      }\n      case ']': {\n        lastValidIndex = i;\n        stack.pop();\n        break;\n      }\n    }\n  }\n\n  for (let i = 0; i < input.length; i++) {\n    const char = input[i];\n    const currentState = stack[stack.length - 1];\n\n    switch (currentState) {\n      case 'ROOT':\n        processValueStart(char, i, 'FINISH');\n        break;\n\n      case 'INSIDE_OBJECT_START': {\n        switch (char) {\n          case '\"': {\n            stack.pop();\n            stack.push('INSIDE_OBJECT_KEY');\n            break;\n          }\n          case '}': {\n            lastValidIndex = i;\n            stack.pop();\n            break;\n          }\n        }\n        break;\n      }\n\n      case 'INSIDE_OBJECT_AFTER_COMMA': {\n        switch (char) {\n          case '\"': {\n            stack.pop();\n            stack.push('INSIDE_OBJECT_KEY');\n            break;\n          }\n        }\n        break;\n      }\n\n      case 'INSIDE_OBJECT_KEY': {\n        switch (char) {\n          case '\"': {\n            stack.pop();\n            stack.push('INSIDE_OBJECT_AFTER_KEY');\n            break;\n          }\n        }\n        break;\n      }\n\n      case 'INSIDE_OBJECT_AFTER_KEY': {\n        switch (char) {\n          case ':': {\n            stack.pop();\n            stack.push('INSIDE_OBJECT_BEFORE_VALUE');\n\n            break;\n          }\n        }\n        break;\n      }\n\n      case 'INSIDE_OBJECT_BEFORE_VALUE': {\n        processValueStart(char, i, 'INSIDE_OBJECT_AFTER_VALUE');\n        break;\n      }\n\n      case 'INSIDE_OBJECT_AFTER_VALUE': {\n        processAfterObjectValue(char, i);\n        break;\n      }\n\n      case 'INSIDE_STRING': {\n        switch (char) {\n          case '\"': {\n            stack.pop();\n            lastValidIndex = i;\n            break;\n          }\n\n          case '\\\\': {\n            stack.push('INSIDE_STRING_ESCAPE');\n            break;\n          }\n\n          default: {\n            lastValidIndex = i;\n          }\n        }\n\n        break;\n      }\n\n      case 'INSIDE_ARRAY_START': {\n        switch (char) {\n          case ']': {\n            lastValidIndex = i;\n            stack.pop();\n            break;\n          }\n\n          default: {\n            lastValidIndex = i;\n            processValueStart(char, i, 'INSIDE_ARRAY_AFTER_VALUE');\n            break;\n          }\n        }\n        break;\n      }\n\n      case 'INSIDE_ARRAY_AFTER_VALUE': {\n        switch (char) {\n          case ',': {\n            stack.pop();\n            stack.push('INSIDE_ARRAY_AFTER_COMMA');\n            break;\n          }\n\n          case ']': {\n            lastValidIndex = i;\n            stack.pop();\n            break;\n          }\n\n          default: {\n            lastValidIndex = i;\n            break;\n          }\n        }\n\n        break;\n      }\n\n      case 'INSIDE_ARRAY_AFTER_COMMA': {\n        processValueStart(char, i, 'INSIDE_ARRAY_AFTER_VALUE');\n        break;\n      }\n\n      case 'INSIDE_STRING_ESCAPE': {\n        stack.pop();\n        lastValidIndex = i;\n\n        break;\n      }\n\n      case 'INSIDE_NUMBER': {\n        switch (char) {\n          case '0':\n          case '1':\n          case '2':\n          case '3':\n          case '4':\n          case '5':\n          case '6':\n          case '7':\n          case '8':\n          case '9': {\n            lastValidIndex = i;\n            break;\n          }\n\n          case 'e':\n          case 'E':\n          case '-':\n          case '.': {\n            break;\n          }\n\n          case ',': {\n            stack.pop();\n\n            if (stack[stack.length - 1] === 'INSIDE_ARRAY_AFTER_VALUE') {\n              processAfterArrayValue(char, i);\n            }\n\n            if (stack[stack.length - 1] === 'INSIDE_OBJECT_AFTER_VALUE') {\n              processAfterObjectValue(char, i);\n            }\n\n            break;\n          }\n\n          case '}': {\n            stack.pop();\n\n            if (stack[stack.length - 1] === 'INSIDE_OBJECT_AFTER_VALUE') {\n              processAfterObjectValue(char, i);\n            }\n\n            break;\n          }\n\n          case ']': {\n            stack.pop();\n\n            if (stack[stack.length - 1] === 'INSIDE_ARRAY_AFTER_VALUE') {\n              processAfterArrayValue(char, i);\n            }\n\n            break;\n          }\n\n          default: {\n            stack.pop();\n            break;\n          }\n        }\n\n        break;\n      }\n\n      case 'INSIDE_LITERAL': {\n        const partialLiteral = input.substring(literalStart!, i + 1);\n\n        if (\n          !'false'.startsWith(partialLiteral) &&\n          !'true'.startsWith(partialLiteral) &&\n          !'null'.startsWith(partialLiteral)\n        ) {\n          stack.pop();\n\n          if (stack[stack.length - 1] === 'INSIDE_OBJECT_AFTER_VALUE') {\n            processAfterObjectValue(char, i);\n          } else if (stack[stack.length - 1] === 'INSIDE_ARRAY_AFTER_VALUE') {\n            processAfterArrayValue(char, i);\n          }\n        } else {\n          lastValidIndex = i;\n        }\n\n        break;\n      }\n    }\n  }\n\n  let result = input.slice(0, lastValidIndex + 1);\n\n  for (let i = stack.length - 1; i >= 0; i--) {\n    const state = stack[i];\n\n    switch (state) {\n      case 'INSIDE_STRING': {\n        result += '\"';\n        break;\n      }\n\n      case 'INSIDE_OBJECT_KEY':\n      case 'INSIDE_OBJECT_AFTER_KEY':\n      case 'INSIDE_OBJECT_AFTER_COMMA':\n      case 'INSIDE_OBJECT_START':\n      case 'INSIDE_OBJECT_BEFORE_VALUE':\n      case 'INSIDE_OBJECT_AFTER_VALUE': {\n        result += '}';\n        break;\n      }\n\n      case 'INSIDE_ARRAY_START':\n      case 'INSIDE_ARRAY_AFTER_COMMA':\n      case 'INSIDE_ARRAY_AFTER_VALUE': {\n        result += ']';\n        break;\n      }\n\n      case 'INSIDE_LITERAL': {\n        const partialLiteral = input.substring(literalStart!, input.length);\n\n        if ('true'.startsWith(partialLiteral)) {\n          result += 'true'.slice(partialLiteral.length);\n        } else if ('false'.startsWith(partialLiteral)) {\n          result += 'false'.slice(partialLiteral.length);\n        } else if ('null'.startsWith(partialLiteral)) {\n          result += 'null'.slice(partialLiteral.length);\n        }\n      }\n    }\n  }\n\n  return result;\n}\n","import {\n  LanguageModelV1FinishReason,\n  LanguageModelV1Source,\n} from '@ai-sdk/provider';\nimport { ToolCall, ToolResult } from '@ai-sdk/provider-utils';\nimport { JSONValue } from './types';\n\nexport type DataStreamString =\n  `${(typeof DataStreamStringPrefixes)[keyof typeof DataStreamStringPrefixes]}:${string}\\n`;\n\nexport interface DataStreamPart<\n  CODE extends string,\n  NAME extends string,\n  TYPE,\n> {\n  code: CODE;\n  name: NAME;\n  parse: (value: JSONValue) => { type: NAME; value: TYPE };\n}\n\nconst textStreamPart: DataStreamPart<'0', 'text', string> = {\n  code: '0',\n  name: 'text',\n  parse: (value: JSONValue) => {\n    if (typeof value !== 'string') {\n      throw new Error('\"text\" parts expect a string value.');\n    }\n    return { type: 'text', value };\n  },\n};\n\nconst dataStreamPart: DataStreamPart<'2', 'data', Array<JSONValue>> = {\n  code: '2',\n  name: 'data',\n  parse: (value: JSONValue) => {\n    if (!Array.isArray(value)) {\n      throw new Error('\"data\" parts expect an array value.');\n    }\n\n    return { type: 'data', value };\n  },\n};\n\nconst errorStreamPart: DataStreamPart<'3', 'error', string> = {\n  code: '3',\n  name: 'error',\n  parse: (value: JSONValue) => {\n    if (typeof value !== 'string') {\n      throw new Error('\"error\" parts expect a string value.');\n    }\n    return { type: 'error', value };\n  },\n};\n\nconst messageAnnotationsStreamPart: DataStreamPart<\n  '8',\n  'message_annotations',\n  Array<JSONValue>\n> = {\n  code: '8',\n  name: 'message_annotations',\n  parse: (value: JSONValue) => {\n    if (!Array.isArray(value)) {\n      throw new Error('\"message_annotations\" parts expect an array value.');\n    }\n\n    return { type: 'message_annotations', value };\n  },\n};\n\nconst toolCallStreamPart: DataStreamPart<\n  '9',\n  'tool_call',\n  ToolCall<string, any>\n> = {\n  code: '9',\n  name: 'tool_call',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('toolCallId' in value) ||\n      typeof value.toolCallId !== 'string' ||\n      !('toolName' in value) ||\n      typeof value.toolName !== 'string' ||\n      !('args' in value) ||\n      typeof value.args !== 'object'\n    ) {\n      throw new Error(\n        '\"tool_call\" parts expect an object with a \"toolCallId\", \"toolName\", and \"args\" property.',\n      );\n    }\n\n    return {\n      type: 'tool_call',\n      value: value as unknown as ToolCall<string, any>,\n    };\n  },\n};\n\nconst toolResultStreamPart: DataStreamPart<\n  'a',\n  'tool_result',\n  Omit<ToolResult<string, any, any>, 'args' | 'toolName'>\n> = {\n  code: 'a',\n  name: 'tool_result',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('toolCallId' in value) ||\n      typeof value.toolCallId !== 'string' ||\n      !('result' in value)\n    ) {\n      throw new Error(\n        '\"tool_result\" parts expect an object with a \"toolCallId\" and a \"result\" property.',\n      );\n    }\n\n    return {\n      type: 'tool_result',\n      value: value as unknown as Omit<\n        ToolResult<string, any, any>,\n        'args' | 'toolName'\n      >,\n    };\n  },\n};\n\nconst toolCallStreamingStartStreamPart: DataStreamPart<\n  'b',\n  'tool_call_streaming_start',\n  { toolCallId: string; toolName: string }\n> = {\n  code: 'b',\n  name: 'tool_call_streaming_start',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('toolCallId' in value) ||\n      typeof value.toolCallId !== 'string' ||\n      !('toolName' in value) ||\n      typeof value.toolName !== 'string'\n    ) {\n      throw new Error(\n        '\"tool_call_streaming_start\" parts expect an object with a \"toolCallId\" and \"toolName\" property.',\n      );\n    }\n\n    return {\n      type: 'tool_call_streaming_start',\n      value: value as unknown as { toolCallId: string; toolName: string },\n    };\n  },\n};\n\nconst toolCallDeltaStreamPart: DataStreamPart<\n  'c',\n  'tool_call_delta',\n  { toolCallId: string; argsTextDelta: string }\n> = {\n  code: 'c',\n  name: 'tool_call_delta',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('toolCallId' in value) ||\n      typeof value.toolCallId !== 'string' ||\n      !('argsTextDelta' in value) ||\n      typeof value.argsTextDelta !== 'string'\n    ) {\n      throw new Error(\n        '\"tool_call_delta\" parts expect an object with a \"toolCallId\" and \"argsTextDelta\" property.',\n      );\n    }\n\n    return {\n      type: 'tool_call_delta',\n      value: value as unknown as {\n        toolCallId: string;\n        argsTextDelta: string;\n      },\n    };\n  },\n};\n\nconst finishMessageStreamPart: DataStreamPart<\n  'd',\n  'finish_message',\n  {\n    finishReason: LanguageModelV1FinishReason;\n    // TODO v5 remove usage from finish event (only on step-finish)\n    usage?: {\n      promptTokens: number;\n      completionTokens: number;\n    };\n  }\n> = {\n  code: 'd',\n  name: 'finish_message',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('finishReason' in value) ||\n      typeof value.finishReason !== 'string'\n    ) {\n      throw new Error(\n        '\"finish_message\" parts expect an object with a \"finishReason\" property.',\n      );\n    }\n\n    const result: {\n      finishReason: LanguageModelV1FinishReason;\n      usage?: {\n        promptTokens: number;\n        completionTokens: number;\n      };\n    } = {\n      finishReason: value.finishReason as LanguageModelV1FinishReason,\n    };\n\n    if (\n      'usage' in value &&\n      value.usage != null &&\n      typeof value.usage === 'object' &&\n      'promptTokens' in value.usage &&\n      'completionTokens' in value.usage\n    ) {\n      result.usage = {\n        promptTokens:\n          typeof value.usage.promptTokens === 'number'\n            ? value.usage.promptTokens\n            : Number.NaN,\n        completionTokens:\n          typeof value.usage.completionTokens === 'number'\n            ? value.usage.completionTokens\n            : Number.NaN,\n      };\n    }\n\n    return {\n      type: 'finish_message',\n      value: result,\n    };\n  },\n};\n\nconst finishStepStreamPart: DataStreamPart<\n  'e',\n  'finish_step',\n  {\n    isContinued: boolean;\n    finishReason: LanguageModelV1FinishReason;\n    usage?: {\n      promptTokens: number;\n      completionTokens: number;\n    };\n  }\n> = {\n  code: 'e',\n  name: 'finish_step',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('finishReason' in value) ||\n      typeof value.finishReason !== 'string'\n    ) {\n      throw new Error(\n        '\"finish_step\" parts expect an object with a \"finishReason\" property.',\n      );\n    }\n\n    const result: {\n      isContinued: boolean;\n      finishReason: LanguageModelV1FinishReason;\n      usage?: {\n        promptTokens: number;\n        completionTokens: number;\n      };\n    } = {\n      finishReason: value.finishReason as LanguageModelV1FinishReason,\n      isContinued: false,\n    };\n\n    if (\n      'usage' in value &&\n      value.usage != null &&\n      typeof value.usage === 'object' &&\n      'promptTokens' in value.usage &&\n      'completionTokens' in value.usage\n    ) {\n      result.usage = {\n        promptTokens:\n          typeof value.usage.promptTokens === 'number'\n            ? value.usage.promptTokens\n            : Number.NaN,\n        completionTokens:\n          typeof value.usage.completionTokens === 'number'\n            ? value.usage.completionTokens\n            : Number.NaN,\n      };\n    }\n\n    if ('isContinued' in value && typeof value.isContinued === 'boolean') {\n      result.isContinued = value.isContinued;\n    }\n\n    return {\n      type: 'finish_step',\n      value: result,\n    };\n  },\n};\n\nconst startStepStreamPart: DataStreamPart<\n  'f',\n  'start_step',\n  {\n    messageId: string;\n  }\n> = {\n  code: 'f',\n  name: 'start_step',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('messageId' in value) ||\n      typeof value.messageId !== 'string'\n    ) {\n      throw new Error(\n        '\"start_step\" parts expect an object with an \"id\" property.',\n      );\n    }\n\n    return {\n      type: 'start_step',\n      value: {\n        messageId: value.messageId,\n      },\n    };\n  },\n};\n\nconst reasoningStreamPart: DataStreamPart<'g', 'reasoning', string> = {\n  code: 'g',\n  name: 'reasoning',\n  parse: (value: JSONValue) => {\n    if (typeof value !== 'string') {\n      throw new Error('\"reasoning\" parts expect a string value.');\n    }\n    return { type: 'reasoning', value };\n  },\n};\n\nconst sourcePart: DataStreamPart<'h', 'source', LanguageModelV1Source> = {\n  code: 'h',\n  name: 'source',\n  parse: (value: JSONValue) => {\n    if (value == null || typeof value !== 'object') {\n      throw new Error('\"source\" parts expect a Source object.');\n    }\n\n    return {\n      type: 'source',\n      value: value as LanguageModelV1Source,\n    };\n  },\n};\n\nconst redactedReasoningStreamPart: DataStreamPart<\n  'i',\n  'redacted_reasoning',\n  { data: string }\n> = {\n  code: 'i',\n  name: 'redacted_reasoning',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('data' in value) ||\n      typeof value.data !== 'string'\n    ) {\n      throw new Error(\n        '\"redacted_reasoning\" parts expect an object with a \"data\" property.',\n      );\n    }\n    return { type: 'redacted_reasoning', value: { data: value.data } };\n  },\n};\n\nconst reasoningSignatureStreamPart: DataStreamPart<\n  'j',\n  'reasoning_signature',\n  { signature: string }\n> = {\n  code: 'j',\n  name: 'reasoning_signature',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('signature' in value) ||\n      typeof value.signature !== 'string'\n    ) {\n      throw new Error(\n        '\"reasoning_signature\" parts expect an object with a \"signature\" property.',\n      );\n    }\n    return {\n      type: 'reasoning_signature',\n      value: { signature: value.signature },\n    };\n  },\n};\n\nconst fileStreamPart: DataStreamPart<\n  'k',\n  'file',\n  {\n    data: string; // base64 encoded data\n    mimeType: string;\n  }\n> = {\n  code: 'k',\n  name: 'file',\n  parse: (value: JSONValue) => {\n    if (\n      value == null ||\n      typeof value !== 'object' ||\n      !('data' in value) ||\n      typeof value.data !== 'string' ||\n      !('mimeType' in value) ||\n      typeof value.mimeType !== 'string'\n    ) {\n      throw new Error(\n        '\"file\" parts expect an object with a \"data\" and \"mimeType\" property.',\n      );\n    }\n    return { type: 'file', value: value as { data: string; mimeType: string } };\n  },\n};\n\nconst dataStreamParts = [\n  textStreamPart,\n  dataStreamPart,\n  errorStreamPart,\n  messageAnnotationsStreamPart,\n  toolCallStreamPart,\n  toolResultStreamPart,\n  toolCallStreamingStartStreamPart,\n  toolCallDeltaStreamPart,\n  finishMessageStreamPart,\n  finishStepStreamPart,\n  startStepStreamPart,\n  reasoningStreamPart,\n  sourcePart,\n  redactedReasoningStreamPart,\n  reasoningSignatureStreamPart,\n  fileStreamPart,\n] as const;\n\nexport const dataStreamPartsByCode = Object.fromEntries(\n  dataStreamParts.map(part => [part.code, part]),\n) as {\n  [K in (typeof dataStreamParts)[number]['code']]: (typeof dataStreamParts)[number];\n};\n\ntype DataStreamParts = (typeof dataStreamParts)[number];\n\n/**\n * Maps the type of a stream part to its value type.\n */\ntype DataStreamPartValueType = {\n  [P in DataStreamParts as P['name']]: ReturnType<P['parse']>['value'];\n};\n\nexport type DataStreamPartType = ReturnType<DataStreamParts['parse']>;\n\n/**\n * The map of prefixes for data in the stream\n *\n * - 0: Text from the LLM response\n * - 1: (OpenAI) function_call responses\n * - 2: custom JSON added by the user using `Data`\n * - 6: (OpenAI) tool_call responses\n *\n * Example:\n * ```\n * 0:Vercel\n * 0:'s\n * 0: AI\n * 0: AI\n * 0: SDK\n * 0: is great\n * 0:!\n * 2: { \"someJson\": \"value\" }\n * 1: {\"function_call\": {\"name\": \"get_current_weather\", \"arguments\": \"{\\\\n\\\\\"location\\\\\": \\\\\"Charlottesville, Virginia\\\\\",\\\\n\\\\\"format\\\\\": \\\\\"celsius\\\\\"\\\\n}\"}}\n * 6: {\"tool_call\": {\"id\": \"tool_0\", \"type\": \"function\", \"function\": {\"name\": \"get_current_weather\", \"arguments\": \"{\\\\n\\\\\"location\\\\\": \\\\\"Charlottesville, Virginia\\\\\",\\\\n\\\\\"format\\\\\": \\\\\"celsius\\\\\"\\\\n}\"}}}\n *```\n */\nexport const DataStreamStringPrefixes = Object.fromEntries(\n  dataStreamParts.map(part => [part.name, part.code]),\n) as {\n  [K in DataStreamParts['name']]: (typeof dataStreamParts)[number]['code'];\n};\n\nexport const validCodes = dataStreamParts.map(part => part.code);\n\n/**\nParses a stream part from a string.\n\n@param line The string to parse.\n@returns The parsed stream part.\n@throws An error if the string cannot be parsed.\n */\nexport const parseDataStreamPart = (line: string): DataStreamPartType => {\n  const firstSeparatorIndex = line.indexOf(':');\n\n  if (firstSeparatorIndex === -1) {\n    throw new Error('Failed to parse stream string. No separator found.');\n  }\n\n  const prefix = line.slice(0, firstSeparatorIndex);\n\n  if (!validCodes.includes(prefix as keyof typeof dataStreamPartsByCode)) {\n    throw new Error(`Failed to parse stream string. Invalid code ${prefix}.`);\n  }\n\n  const code = prefix as keyof typeof dataStreamPartsByCode;\n\n  const textValue = line.slice(firstSeparatorIndex + 1);\n  const jsonValue: JSONValue = JSON.parse(textValue);\n\n  return dataStreamPartsByCode[code].parse(jsonValue);\n};\n\n/**\nPrepends a string with a prefix from the `StreamChunkPrefixes`, JSON-ifies it,\nand appends a new line.\n\nIt ensures type-safety for the part type and value.\n */\nexport function formatDataStreamPart<T extends keyof DataStreamPartValueType>(\n  type: T,\n  value: DataStreamPartValueType[T],\n): DataStreamString {\n  const streamPart = dataStreamParts.find(part => part.name === type);\n\n  if (!streamPart) {\n    throw new Error(`Invalid stream part type: ${type}`);\n  }\n\n  return `${streamPart.code}:${JSON.stringify(value)}\\n`;\n}\n","import { DataStreamPartType, parseDataStreamPart } from './data-stream-parts';\n\nconst NEWLINE = '\\n'.charCodeAt(0);\n\n// concatenates all the chunks into a single Uint8Array\nfunction concatChunks(chunks: Uint8Array[], totalLength: number) {\n  const concatenatedChunks = new Uint8Array(totalLength);\n\n  let offset = 0;\n  for (const chunk of chunks) {\n    concatenatedChunks.set(chunk, offset);\n    offset += chunk.length;\n  }\n  chunks.length = 0;\n\n  return concatenatedChunks;\n}\n\nexport async function processDataStream({\n  stream,\n  onTextPart,\n  onReasoningPart,\n  onReasoningSignaturePart,\n  onRedactedReasoningPart,\n  onSourcePart,\n  onFilePart,\n  onDataPart,\n  onErrorPart,\n  onToolCallStreamingStartPart,\n  onToolCallDeltaPart,\n  onToolCallPart,\n  onToolResultPart,\n  onMessageAnnotationsPart,\n  onFinishMessagePart,\n  onFinishStepPart,\n  onStartStepPart,\n}: {\n  stream: ReadableStream<Uint8Array>;\n  onTextPart?: (\n    streamPart: (DataStreamPartType & { type: 'text' })['value'],\n  ) => Promise<void> | void;\n  onReasoningPart?: (\n    streamPart: (DataStreamPartType & { type: 'reasoning' })['value'],\n  ) => Promise<void> | void;\n  onReasoningSignaturePart?: (\n    streamPart: (DataStreamPartType & { type: 'reasoning_signature' })['value'],\n  ) => Promise<void> | void;\n  onRedactedReasoningPart?: (\n    streamPart: (DataStreamPartType & { type: 'redacted_reasoning' })['value'],\n  ) => Promise<void> | void;\n  onFilePart?: (\n    streamPart: (DataStreamPartType & { type: 'file' })['value'],\n  ) => Promise<void> | void;\n  onSourcePart?: (\n    streamPart: (DataStreamPartType & { type: 'source' })['value'],\n  ) => Promise<void> | void;\n  onDataPart?: (\n    streamPart: (DataStreamPartType & { type: 'data' })['value'],\n  ) => Promise<void> | void;\n  onErrorPart?: (\n    streamPart: (DataStreamPartType & { type: 'error' })['value'],\n  ) => Promise<void> | void;\n  onToolCallStreamingStartPart?: (\n    streamPart: (DataStreamPartType & {\n      type: 'tool_call_streaming_start';\n    })['value'],\n  ) => Promise<void> | void;\n  onToolCallDeltaPart?: (\n    streamPart: (DataStreamPartType & { type: 'tool_call_delta' })['value'],\n  ) => Promise<void> | void;\n  onToolCallPart?: (\n    streamPart: (DataStreamPartType & { type: 'tool_call' })['value'],\n  ) => Promise<void> | void;\n  onToolResultPart?: (\n    streamPart: (DataStreamPartType & { type: 'tool_result' })['value'],\n  ) => Promise<void> | void;\n  onMessageAnnotationsPart?: (\n    streamPart: (DataStreamPartType & {\n      type: 'message_annotations';\n    })['value'],\n  ) => Promise<void> | void;\n  onFinishMessagePart?: (\n    streamPart: (DataStreamPartType & { type: 'finish_message' })['value'],\n  ) => Promise<void> | void;\n  onFinishStepPart?: (\n    streamPart: (DataStreamPartType & { type: 'finish_step' })['value'],\n  ) => Promise<void> | void;\n  onStartStepPart?: (\n    streamPart: (DataStreamPartType & { type: 'start_step' })['value'],\n  ) => Promise<void> | void;\n}): Promise<void> {\n  // implementation note: this slightly more complex algorithm is required\n  // to pass the tests in the edge environment.\n\n  const reader = stream.getReader();\n  const decoder = new TextDecoder();\n  const chunks: Uint8Array[] = [];\n  let totalLength = 0;\n\n  while (true) {\n    const { value } = await reader.read();\n\n    if (value) {\n      chunks.push(value);\n      totalLength += value.length;\n      if (value[value.length - 1] !== NEWLINE) {\n        // if the last character is not a newline, we have not read the whole JSON value\n        continue;\n      }\n    }\n\n    if (chunks.length === 0) {\n      break; // we have reached the end of the stream\n    }\n\n    const concatenatedChunks = concatChunks(chunks, totalLength);\n    totalLength = 0;\n\n    const streamParts = decoder\n      .decode(concatenatedChunks, { stream: true })\n      .split('\\n')\n      .filter(line => line !== '') // splitting leaves an empty string at the end\n      .map(parseDataStreamPart);\n\n    for (const { type, value } of streamParts) {\n      switch (type) {\n        case 'text':\n          await onTextPart?.(value);\n          break;\n        case 'reasoning':\n          await onReasoningPart?.(value);\n          break;\n        case 'reasoning_signature':\n          await onReasoningSignaturePart?.(valu