llama.cpp/examples/server/webui/src/utils/misc.ts

// @ts-expect-error this package does not have typing
import TextLineStream from 'textlinestream';
import { APIMessage, Message } from './types';

// ponyfill for missing ReadableStream asyncIterator on Safari
import { asyncIterator } from '@sec-ant/readable-stream/ponyfill/asyncIterator';

// eslint-disable-next-line @typescript-eslint/no-explicit-any
export const isString = (x: any) => !!x.toLowerCase;
// eslint-disable-next-line @typescript-eslint/no-explicit-any
export const isBoolean = (x: any) => x === true || x === false;
// eslint-disable-next-line @typescript-eslint/no-explicit-any
export const isNumeric = (n: any) => !isString(n) && !isNaN(n) && !isBoolean(n);
export const escapeAttr = (str: string) =>
  str.replace(/>/g, '>').replace(/"/g, '"');

// wrapper for SSE
export async function* getSSEStreamAsync(fetchResponse: Response) {
  if (!fetchResponse.body) throw new Error('Response body is empty');
  const lines: ReadableStream<string> = fetchResponse.body
    .pipeThrough(new TextDecoderStream())
    .pipeThrough(new TextLineStream());
  // @ts-expect-error asyncIterator complains about type, but it should work
  for await (const line of asyncIterator(lines)) {
    //if (isDev) console.log({ line });
    if (line.startsWith('data:') && !line.endsWith('[DONE]')) {
      const data = JSON.parse(line.slice(5));
      yield data;
    } else if (line.startsWith('error:')) {
      const data = JSON.parse(line.slice(6));
      throw new Error(data.message || 'Unknown error');
    }
  }
}

// copy text to clipboard
export const copyStr = (textToCopy: string) => {
  // Navigator clipboard api needs a secure context (https)
  if (navigator.clipboard && window.isSecureContext) {
    navigator.clipboard.writeText(textToCopy);
  } else {
    // Use the 'out of viewport hidden text area' trick
    const textArea = document.createElement('textarea');
    textArea.value = textToCopy;
    // Move textarea out of the viewport so it's not visible
    textArea.style.position = 'absolute';
    textArea.style.left = '-999999px';
    document.body.prepend(textArea);
    textArea.select();
    document.execCommand('copy');
  }
};

/**
 * filter out redundant fields upon sending to API
 * also format extra into text
 */
export function normalizeMsgsForAPI(messages: Readonly<Message[]>) {
  return messages.map((msg) => {
    let newContent = '';

    for (const extra of msg.extra ?? []) {
      if (extra.type === 'context') {
        newContent += `${extra.content}\n\n`;
      }
    }

    newContent += msg.content;

    return {
      role: msg.role,
      content: newContent,
    };
  }) as APIMessage[];
}

/**
 * recommended for DeepsSeek-R1, filter out content between <think> and </think> tags
 */
export function filterThoughtFromMsgs(messages: APIMessage[]) {
  return messages.map((msg) => {
    return {
      role: msg.role,
      content:
        msg.role === 'assistant'
          ? msg.content.split('</think>').at(-1)!.trim()
          : msg.content,
    } as APIMessage;
  });
}

export function classNames(classes: Record<string, boolean>): string {
  return Object.entries(classes)
    .filter(([_, value]) => value)
    .map(([key, _]) => key)
    .join(' ');
}

export const delay = (ms: number) =>
  new Promise((resolve) => setTimeout(resolve, ms));

export const throttle = <T extends unknown[]>(
  callback: (...args: T) => void,
  delay: number
) => {
  let isWaiting = false;

  return (...args: T) => {
    if (isWaiting) {
      return;
    }

    callback(...args);
    isWaiting = true;

    setTimeout(() => {
      isWaiting = false;
    }, delay);
  };
};