How to reuse prompts that requires different variables?

[onhate]

For example, the loadQAStuffChain requires query but the RetrievalQAChain requires question.

import { loadQAStuffChain, RetrievalQAChain } from 'langchain/chains';
import { PromptTemplate } from 'langchain/prompts';

const template =
  'You are an customer support agent working for a company. ' +
  'Use the following pieces of context to answer the question at the end. ' +
  "If you don't know the answer, just say that you don't know, don't try to make up an answer.\n\n" +
  '{context}\n\n' +
  'Question: {question}\n' +
  'Helpful Answer:';

export const qaPrompt = new PromptTemplate({
  template,
  inputVariables: ['context', 'question']
});

export const qaStuffPrompt = new PromptTemplate({
  template: template.replace('{question}', '{query}'),
  inputVariables: ['context', 'query']
});

right now I'm doing manual replace as you can see but I would like to tell the prompt to "replace a variable" or use aliases, for example:

export const qaPrompt = new PromptTemplate({
  template,
  inputVariables: ['context', 'question']
});

const qaStuffPrompt = qaPrompt.replaceVariable('question', 'query');

or

export const qaPrompt = new PromptTemplate({
  template,
  inputVariables: ['context', 'question'],
  aliasesVariables: [['question', 'query']] // this way it would be interchangeable accepting any 
});

[onhate]

posted on langchain-ai/langchainjs#1989