string.ts

// Default generic "any" values are for backwards compatibility.
// Replace with "string" when we are comfortable with a breaking change.

import type { InputValues } from "../utils/types/index.js";
import {
  type StringPromptValueInterface,
  StringPromptValue,
} from "../prompt_values.js";
import { BasePromptTemplate, type TypedPromptInputValues } from "./base.js";

/**
 * Base class for string prompt templates. It extends the
 * BasePromptTemplate class and overrides the formatPromptValue method to
 * return a StringPromptValue.
 */
export abstract class BaseStringPromptTemplate<
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  RunInput extends InputValues = any,
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  PartialVariableName extends string = any
> extends BasePromptTemplate<
  RunInput,
  StringPromptValueInterface,
  PartialVariableName
> {
  /**
   * Formats the prompt given the input values and returns a formatted
   * prompt value.
   * @param values The input values to format the prompt.
   * @returns A Promise that resolves to a formatted prompt value.
   */
  async formatPromptValue(
    values: TypedPromptInputValues<RunInput>
  ): Promise<StringPromptValueInterface> {
    const formattedPrompt = await this.format(values);
    return new StringPromptValue(formattedPrompt);
  }
}